Urban Mining Mechanical Engineering 310 Winter Design Document

Team Volvo Kristine Bunker, Jared Ostdiek, Tom Owlett, Teresa Tombelli

Mechanical Engineering Design Group 416 Escondido Mall Stanford University Stanford, CA 94305-2203 http://me310.stanford.edu c March 17, 2015 1 Executive Summary

Raw materials for construction and industrial use are becoming increasingly expensive and difficult to harvest. There will soon come a time when it is cheaper to recycle and reuse material that has already entered the manufacturing process than to mine new material from the earth. This is already the case in the steel industry, where scrap metal is easily melted down and recast. However, many materials are more challenging and expensive to recycle, even if the waste products themselves are valuable. Urban mining is the practice of reusing these potentially valuable waste materials in their most processed form. It seeks to not only recycle products, but to prevent them from being degraded or downcycled. Investing in urban mining now makes economic sense because the cost of new materials is expected to rise to match the cost of recycled material. Volvo Construction has asked a team of students from Stanford University in the United States of America and the Blekinge Technical University in Sweden to develop a new tech- nology in the field of urban mining that could be added to their product line. Volvo sees great future value in products that expand the field of large-scale recycling. A machine that can repurpose waste from construction or municipal waste sites would fit nicely in Volvo’s existing product line of earthmovers, excavators, and demolition equipment. To better understand the problem, the Stanford and BTH teams conducted interviews and site visits to businesses relevant to the four urban waste streams: construction and demolition (C&D), municipal, electronic and rubber. It was found that designing for the C&D and municipal streams is the most relevant to Vovlo’s product goals, and that the volume of waste in the two streams accounts for the vast majority of all urban waste. It was found that C&D waste has a generally consistent composition with great potential for reuse. C&D waste is made mainly of wood, metal, glass, plastic, concrete and earth, which are all usable as byproducts. After speaking with an urban infill developer in the city of San Francisco, CA, it also became apparent that there was added value in keeping waste materials on a construction site instead of trucking them to a landfill. The cost to off-haul C&D waste from a demolition site often accounts for more than half of the total spent on the demolition phase of a project. This promotes the idea of reuse or recycling in the same area as the materials were used originally. A recycling process that reduces the amount of trucking from a job site would be appealing to a building developer looking to cut costs. After categorizing the types of C&D waste and investigating how often they are recycled, it was found that window glass is almost always disposed of in a landfill. It cannot be easily recycled due to differences in composition from the manufacturing process. To prevent the need for trucking glass away from a job site, it would make sense to incorporate some of the glass into the new building. While reusing full windows may not be plausible, adding crushed class as aggregate in concrete would be an effective way to keep the material on site. To test the viability of this idea, a set of concrete bricks were made using 100% glass aggregate which, when mixed with Portland cement, resulted in 80% glass by weight. This process was found to be a technically feasible way to keep glass from being sent to a landfill. The process of crushing and sifting windows could be easily automated by modifying machines that grind concrete. However, as these bricks were created and more

2 CHAPTER 1. FRONT MATTER 3 interviews with representative from the C&D industry were conducted it became clear that another problem was in play: space. Last quarter it was determined that using material on-site to reduce trucking was an important step in increasing the frequency of urban mining, but what was overlooked was a method to store this material during the course of the project. The real solution to reducing trucking is to keep the material on-site for the duration of the C&D project. To solve this idea multiple iterations were made on an on-site storage device and the system that surrounds it. Through these prototypes and feedback from users, design requirements were developed for further refinement of the idea. First, the system should be modular to ensure that it can accommodate the needs of any job site both in shape and size. Second, the system should be movable. Currently after piles of material are created, they often have to be moved depending on the phase of the project. Allowing the system to be movable eliminates double handing and creates a unique opportunity for sorting and emptying within our storage system. Last, there must be an efficient way to empty the storage device. Based on this feedback the Stanford and BTH teams tested multiple emptying mechanisms for a modular storage device including a trap door, an auger, and a removable flexible bottom. As the prototypes were refined, the system vision was elaborated to ensure that the design direction fit into Volvo’s current product line. Moving forward with the project, further research will be done into the manufacturing of modular panels and the business aspects of the system as well as finalizing a method for emptying the storage containers.

Figure 1.1: Overview of the NIX system Contents

1 Front Matter 2 Glossary ...... 10

2 Context 13 2.1 Need Statement ...... 13 2.2 Problem Statement ...... 14 2.3 Corporate partner: Volvo CE ...... 15 2.4 The Design Team ...... 16

3 Design Requirements 21 3.1 Functional Requirements ...... 21 3.2 Physical requirements ...... 24 3.3 Business requirements ...... 24

4 Design Development 25 4.1 Defining Urban Mining ...... 25 4.2 Benchmarking and Needfinding ...... 27 4.3 Persona ...... 55 4.4 Critical Function Prototype ...... 58 4.5 Critical Experience Prototype ...... 61 4.6 Dark Horse Prototype ...... 64 4.7 Emptying the Storage Containers ...... 83 4.8 System Prototype ...... 93 4.9 Findings ...... 97

5 Design Description 101 5.1 Vision ...... 101 5.2 System Overview ...... 101 5.3 Hardware ...... 102

6 Planning 106 6.1 Deliverables and Milestones ...... 106 6.2 Distributed Team Management ...... 107 6.3 Project Budget ...... 110 6.4 Reflections and Goals ...... 112

7 Resources 117

Bibliography 118

A Site Visits 119

B Municipal Waste Benchmarking and Needfinding 121

4 CONTENTS 5

C Electronic Waste and Tires Benchmarking and Needfinding 126 C.1 Electronic Waste ...... 126 C.2 Tires ...... 127

D More Critical Function Prototypes 129 D.1 Wood De-nailing CFP Description ...... 129 D.2 Density Sorting CFP ...... 130 D.3 Tire Reuse CFP Description ...... 133

E Glass Brick Making Process 134 E.1 Crushing ...... 134 E.2 Sizing ...... 134 E.3 Mixing ...... 135 E.4 Testing ...... 135 List of Figures

1.1 Overview of the NIX system ...... 3

2.1 Volvo’s product line ...... 15

4.1 The design team’s development process from receiving the initial Volvo prompt to creating a functional prototype...... 25 4.2 Graphic depicting the four sectors of urban mining as well as the main benefits it could have on the community [14]...... 26 4.3 Summary of the recycling processes currently in place for materials on a con- struction and demolition site. Percentages based on volume from San Mateo Country, CA [12]...... 28 4.4 A vision of a world perfectly suited to urban mining ...... 29 4.5 Project ideas, ranging from plausible to implausible ...... 29 4.6 The ReUse People retail store, where salvage materials are sold to the public . 31 4.7 A house after the ReUse People have removed the lights and other valuable pieces 32 4.8 A window seat has been removed so that it can be resold as a complete unit . . 32 4.9 Workers pry up wood flooring with very simple tools ...... 33 4.10 After prying up each wooden plank, they stack and bind the reclaimed wood for shipping ...... 34 4.11 Workers remove scrap waste from the jobsite by filling trash cans and carrying them on their backs ...... 35 4.12 They then hand each trash can to another man who stands inside of the truck. He empties the trash cans and roughly sorts material by placing large ans small pieces on the opposite ends of the trailer ...... 35 4.13 The roof has been removed from a house, with studs and frame remaining . . . 36 4.14 Salvaged wood stacked neatly, waiting to be denailed ...... 36 4.15 The ReUse People store sells higher-end cabinets and appliances ...... 37 4.16 The ReUse People salvage kitchen appliances and bathroom fixtures ...... 37 4.17 Salvaged wood packed and ready for sale outside the ReUse store ...... 38 4.18 Building ReSources has a plethora of doors which are not only purchased as doors, but purchased to be used for table tops and other hardwood furniture. . 39 4.19 Levesque outfits about two cafes, two start-ups, and three households each year with the light fixtures he reclaims...... 39 4.20 Scrap metal is a valuable resource and bought up quickly from Building ReSources 40 4.21 Tumbled glass and tile sold to landscapers and artists...... 40 4.22 An excavator with shears that can easily cut through I-beams ...... 42 4.23 A huge, ”portable” concrete crusher ...... 42 4.24 An old Clorox testing facility being demolished by Ferma ...... 43 4.25 Huge, roughly sorted piles filled the jobsite ...... 43 4.26 A shredder sorts materials further and grinds up waste ...... 44 4.27 A worker holds a high pressure hose while spraying the work area to control dust 45 4.28 Ferma’s own water truck for storing the water used for dust control ...... 45

6 List of Figures 7

4.29 Two of the buildings on the current Kirkham Project site...... 46 4.30 The Kirkham Project is located at the top of a road with 17% grade...... 46 4.31 Mind map completed by the Stanford team and Porat while visiting the Trans- form Urban office on the Kirkham Project site...... 47 4.32 There are tall metal retaining walls that will have to be removed and recycled throughout the site...... 48 4.33 The majority of the material used in the units is wood and concrete, typical 1950’s construction...... 48 4.34 The Meyer Library [8]...... 50 4.35 The Meyer Library demolition ...... 52 4.36 The Meyer Library demolition site from above after all metal material was trucked away ...... 52 4.37 Summary of the steps involved during the demolition of a building...... 53 4.38 Summary of the steps involved during the deconstruction of a building. . . . . 53 4.39 Dave the Deconstructor is an idealized C&D worker ...... 55 4.40 Devon the Developer is an idealized building developer ...... 57 4.41 Window glass concrete brick composed of 100% glass aggregate...... 59 4.42 Testing window glass concrete specimen at the Blume Earthquake Center at Stanford University...... 60 4.43 (a) White Mortar Glass Brick (b) Plaster of Paris Glass Brick (c) Ultra Glass Epoxy Gloss Brick...... 61 4.44 Survey set up for feedback on aesthetics of glass bricks. From top left clockwise: control store bought concrete brick, Plaster of Paris glass brick, white mortar glass brick, ultra gloss epoxy glass brick with LEDs, and CFP glass brick. . . . 62 4.45 Schematic proposed design for dirt mushroom v1 in collapsed form...... 64 4.46 Cardboard pieces with electrical wire in collapsed position...... 65 4.47 The remaining crushed glass from the CFP was used to simulate aggregate in the cardboard model of the dirt mushroom storage container...... 66 4.48 After forcing the closure of the rigid sides, the device stayed closed and we could simulate the idea of using the area under the overhang for vehicles...... 66 4.49 The aggregate began to bulge through the gaps in the rigid siding, preventing full closure...... 67 4.50 Cardboard frame with added cardstock pieces to prevent bulging of aggregate. 68 4.51 The cardstock pieces reduced the bulging but did not completely eliminate it and the cardstock jammed against the cardboard when sliding closed...... 68 4.52 The completed dirt mushroom folded up and ready for transport...... 69 4.53 The dirt mushroom easily fit into the back of a standard four door sedan. . . . 69 4.54 The wire frame of the dirt mushroom laid out just before assembly...... 70 4.55 The trunk of the dirt mushroom in upright position...... 70 4.56 With the trunk of the mushroom up and the tarp on we began to fill the dirt mushroom with dirt...... 71 4.57 The dirt mushroom began to tip as soon as the loading of the dirt was not perfectly centered...... 72 4.58 Despite our best efforts, the dirt mushroom ultimately toppled over before it was fully filled...... 72 4.59 Connection point between two of the week panels with steel rod...... 74 List of Figures 8

4.60 Schematic of panels used in the shape shifting storage device...... 75 4.61 Completed wood panels with hardware...... 75 4.62 The shape shifting storage easily fit into the back of a four door sedan for transport. 76 4.63 Assembly was quick and easy due to the simple design of the panels...... 77 4.64 Fully assembled shape shifting storage...... 77 4.65 We filled the storage container until it was over flowing with sand...... 78 4.66 We were able to get all four of our Stanford team members on top of the filled storage container...... 79 4.67 Essentially as soon as the fourth team member stepped onto the top the whole thing collapsed under the added weight...... 79 4.68 (a) Connection between plywood panels before filled with sand (b) Bend in connection at half-filled point (c) Bend and gap in panels once shape shifting device full of sand...... 80 4.69 Hammock prototype and shape sketches...... 81 4.70 Elevated storage for construction and demolition sites...... 82 4.71 Attachments designed to be easy modular, attach- and detachable...... 82 4.72 Workers carry trash cans of deconstruction material from the building...... 84 4.73 Trapdoor prototype base ...... 85 4.74 Testing in the Peterson Building atrium ...... 86 4.75 Testing in the Peterson Building atrium ...... 86 4.76 Illustration of how Archimedes screw principle can be applied to transport water to a higher level ...... 88 4.77 Test of auger dispenser...... 89 4.78 Angled walls in order to make it possible for all the material to fall down into the auger...... 89 4.79 Dispensing test was performed to measure the efficiency of the auger...... 90 4.80 Walls with increased angles and added plastic to make them more slippery (less friction)...... 91 4.81 Auger dispenser with plastic coated walls and test with top soil dirt...... 92 4.82 Auger dispenser with plastic coated walls and sand as a test material...... 92 4.83 A person of average height lifts the panel ...... 94 4.84 Difficulty lifting when panels are laying horizontally ...... 94 4.85 Flexible bottom before attachment to frame ...... 95 4.86 Flexible bottom attached to frame ...... 95 4.87 Setting up the flexible bottom ...... 96 4.88 Complete flexible bottom half scale prototype ...... 96

5.1 Overview of the NIX system ...... 101 5.2 Proposed panel dimensions ...... 102 5.3 Preliminary Panel CAD Model for testing hinge joints ...... 103 5.4 Proposed base dimensions ...... 104 5.5 Prototyped Base Designs ...... 104

6.1 Distribution of focuses for the winter quarter among both the Stanford and BTH teams...... 108 List of Figures 9

B.1 Mix of woods and paper products sorted from collected municipal waste.) . . . 122 B.2 Electronic waste sorted from collected municipal waste ...... 122 B.3 Large waste is packed together into bales and burned for local district heating. 123 B.4 All sorted wood is chipped up and used for heating or mulch...... 123 B.5 The remaining municipal waste is sorted through a machine and chipped up. . 124 B.6 Overview of Affrsverken Recycling and Waste Management Facility ...... 125 B.7 Bins used for sorting different colored bags of municipal waste...... 125

C.1 Big bins full of electronics that arrive at Stena for sorting and recycling . . . . 126 C.2 Sorting based on materials after electronics have been dissembled manually . . 127

D.1 Air Locker AP700 Air Punch De-nailer...... 129 D.2 Dimensional lumber with protruding nail...... 130 D.3 Using a hack-saw to cut the nail flush to the board...... 131 D.4 Trimmed nail...... 131 D.5 Using a hammer and punch to remove a nail...... 132 D.6 CFP exploring separating materials with liquids of different densities...... 132 D.7 Flattened bicycled tire...... 133

E.1 Teresa and Kristine breaking a window pane into smaller pieces...... 134 E.2 Glass blender design. The pink insulation foam was used to shield the user from flying glass...... 135 E.3 Tom operating the glass blender...... 136 E.4 Teresa making the sieves used to size the glass aggregate...... 137 E.5 Teresa sifting the crushed glass particulate...... 137 E.6 Crushed and sized window glass. From right to left: 1/10” diameter, 1/4” diameter, 1/2” diameter...... 138 E.7 Crushed and sized beer-bottle glass. From right to left: 1/10” diameter, 1/4” diameter, 1/2” diameter...... 138 E.8 Concrete mixture components by weight...... 138 E.9 Window glass concrete mixture sans water...... 139 E.10 Jared pouring and smoothing concrete into the wooden brick mold...... 140 E.11 Bricks curing in the ME310 Loft...... 141 E.12 Window glass concrete brick composed of 100% glass aggregate...... 142 E.13 Beer-bottle glass concrete brick composed of 100% glass aggregate...... 142 E.14 Testing window glass concrete specimen at the Blume Earthquake Center at Stanford University...... 143 List of Figures 10

Glossary

Aggregate The filler material in concrete. Usually made of crushed granite or limestone, but replaced with glass in our prototype.

Angle of Repose The steepest angle of descent or dip relative to the horizontal plane to which a granular material can be piled without slumping.

Benchmarking A process of researching and observing to understand the state of the art for a given field or topic.

Brainstorming A process by which groups of people generate ideas.

C&D Construction and demolition encompasses the creation of new structures, renova- tions, destruction or deconstruction and off-hauling of waste materials.

Cement A powdery substance made with calcined lime and clay. It is mixed with water to form mortar or mixed with sand, gravel, and water to make concrete. The process to make cement releases a large volume of CO2.

CEP Critical Experience Prototype. Simulates a function of a product to a user without using fully-functioning technology.

CFP Critical function prototype. A rough prototype created to study the efficacy of a critical system in a design.

Concrete The complete mixture of aggregate, water, and cement.

Controlled empty A function of the storage container prototype that would allow an operator to choose the location and speed at which material is released from the container.

Dark Horse An idea that is unlike the others preceding it, an outlier.

Dimensional Lumber Lumber cut to a standardized height/width. Typically used in the framing of buildings.

DIY Do it yourself. A home improvement project done by a homeowner instead of a hired professional.

Downcycling Recycling a material in a way that degrades its value. An example would be turning dimensional lumber into mulch, rather than reusing it as clean lumber.

Functional Prototype A prototype that shows the key functions of an idea integrated into one system.

Funktional Prototype A prototype that demonstrates the key functionality of an idea, but that is hacked together with cheap materials.

Glass Blender A custom-made hand-held device for crushing broken glass into small pieces. Consists of a PVC tube to hold the glass and an electric drill with a cus- tom tool made from a cross-shaped wall mounting bracket. List of Figures 11

I-Beams I-beams are usually made of structural steel and are used in construction and civil engineering. They take on an ”I” shape due to flanges on the top and bottom of a vertical component.

Jobsite The location where a building is being constructed or demolished.

Knuckles The part of a hinge that holds the pin in place. They are cylindrical in shape and attached to the hinge plate on one side.

LEED Leadership in Energy & Environmental Design, is a green building certification program that recognizes best-in-class building strategies and practices. To receive LEED certification, building projects satisfy prerequisites and earn points to achieve different levels of certification.

Modular Employing a repeated unit as the basis of a design.

On-site Something that occurs on a jobsite that does not need require the transportation of materials to another location.

Mortar A workable paste used to bind building blocks such as stones, bricks, and concrete masonry units together, fill and seal the irregular gaps between them, and sometimes add decorative colors or patterns in masonry walls.

Panels The modular units of the storage system under development. Each ”panel” acts as one wall of the unit.

Plaster of Paris A gypsum building material used for coating walls and ceilings.

Rods The vertical steel rods that hold the plywood storage unit prototype together. These are meant as a rudimentary fastener, and will not be used in the final design.

Salvage The act of preventing an object from going to a landfill, and instead reusing it again for its intended purpose.

Sifters A series of three sieves that were used to separate the differently sized glass pieces after crushing. The mesh size on the sieves was 1/2”, 1/4” and 1/10”.

Urban mining The practice of reusing or recycling potentially valuable waste materials instead of sending them to a landfill.

Jackhammer A pneumatic or electro-mechanical tool that combines a hammer directly with a chisel often used to break up concrete.

Drywall A panel made of gypsum plaster pressed between two thick sheets of paper often used for walls in buildings.

Excavator Heavy construction equipment consisting of a boom, stick, bucket and cab on a rotating platform.

Pile Driver A mechanical device used to drive piles (poles) into soil to provide foundation support for buildings or other structures. List of Figures 12

Rebar Short for reinforcing bar. Used to add structural integrity to concrete.

Ultra Glass Epoxy A liquid epoxy that dries clear giving the effect of glass. 2 Context

2.1 Need Statement

As we continue to deplete our natural resources, there will likely come a time when the traditional, destructive methods of gathering materials are no longer acceptable. The highly efficient practices of strip mining for minerals, fracking, and clear cutting forests will degrade air and water quality until society can no longer afford to allow them to continue. This future will likely become a reality within the next thirty years, and while the supply of fresh resources will drop dramatically, the demand for them will remain as high as ever. The clearest solution to this problem is to reuse the materials that have already entered the manufacturing stream. Currently, resources are harvested, used to manufacture goods, sold, and end their life in a landfill where they sit untouched. If instead the loop could be closed and the waste stream redirected back into manufacturing, a significantly smaller quantity of new materials would be required to satisfy the demand for raw goods. As natural resources become scarcer in the environment, there will be an economic push for reuse and recycling as well. We are beginning to see this already, as in recent years removing gold components from electronic waste has become more lucrative than mining it from the ground. This process of exploiting the waste stream for potentially valuable materials is called urban mining. In some cases, it goes beyond simply recycling to prevent downcycling. Wooden boards ground into mulch are technically recycled, but the material itself has been downgraded to a less valuable form and has lost embodied energy. Urban mining seeks to reuse the material in a way that maintains its value making the boards into furniture or railings, for example. Urban mining places higher value on already processed materials, and is a more effective way of prolonging their useful life than recycling alone. While some urban mining techniques are already being implemented, there is still much work to be done to make the process economically viable. In San Francisco, CA, some of the leading technologies in urban mining are being implemented creating an advantage for research and visiting recycling facilites that are using state of the art equipment and innovation.

13 CHAPTER 2. CONTEXT 14

2.2 Problem Statement

The main focus of urban mining is to supplement the stream of raw materials by reusing waste in its most valuable form. In todays economy, there are four solid waste streams:

• Construction and demolition waste • Municipal waste • Electronic waste • Tires and rubber waste

Each type of waste has a different composition, value and challenges in harvesting. While a solution that could be applied broadly to all of these waste streams would have the greatest benefit, it is likely that a single solution in the sector of urban mining would be applicable to only one type of material in one waste stream. Which material and waste stream to focus on will have to be carefully chosen during the design process. The reason that urban mining is not currently being applied to waste matierials is because new materials are still very cheap, and the recycling process is labor-intensive and expensive. Manufacturing practices are almost entirely driven by cost, and any recycled product or process will have to compete with cheap, imported raw materials. An proposed solutions will have to have clear economic benefits. CHAPTER 2. CONTEXT 15

2.3 Corporate partner: Volvo CE

The corporate partner for this project is Volvo Construction Equipment. Volvo CE man- ufactures and distributes construction equipment worldwide. Their products can be found in quarries, oil and gas fields, road construction projects, recycling plants, waste facilities and demolition sites in as many as 125 countries. Their product range includes excavators, dump trucks, haulers, wheel loaders, pipelayers, demolition equipment, waste handlers, graders, pavers, compactors, milling equipment, and a range of compact equipment such as mini excavators and backhoes.

Figure 2.1: Volvo’s product line

Volvo CE has a strong commitment to ethical business practices, human rights and environmental care. They seek to have a net positive impact on the world, and are interested in the sector of urban mining both because it is likely the future of resource harvesting and because it is the responsible thing to do as stewards of the environment.

2.3.1 Corporate Liaisons Jenny Elfsberg Director of Emerging Technologies, Volvo CE [email protected]

Martin Frank Product Development Engineer, Volvo CE [email protected] CHAPTER 2. CONTEXT 16

2.4 The Design Team

The Stanford Team was assembled from individuals with a creative passion for mechanical engineering. We are excited about the topic of urban mining and the opportunity to develop new technologies for Volvo CE.

The Stanford Team

Kristine Bunker Status: M.E. Master’s Student Contact: [email protected] Skills: CAD modeling, machining, prototyping, woodworking, Matlab, sketching

Born and raised in Falmouth, MA, Kristine attended the Massachusetts Institute of Technology for her undergraduate degree, and majored in mechanical engineering. She focused mainly on design, precision engineering, and manufacturing during her time at MIT, in addition to playing on the varsity volleyball team and running track.

Jared Ostdiek Status: M.E. Master’s Student Contact: [email protected] Skills: Rapid prototyping, CAD modeling, visual media

Jared was born and raised in the great state of Nebraska. He did his undergraduate at the University of Nebraska majoring in Biomedical Engineering. He enjoys taking on multidisciplinary projects and learning about a new topics. Outside of the classroom, Jared likes playing sports, being outside, having fun with friends, and exploring new places. CHAPTER 2. CONTEXT 17

Tom Owlett Status: M.E. Master’s Student Contact: [email protected] Skills: CAD modeling in Pro-Engineer, program- ming in Python, Java, and C++, machining (both manual and CNC), and 3D printing

Tom graduated from Princeton University in 2013 with a Mechanical Engineering degree focusing on mechanical systems and design. He spent the last year in New York and working for a small engineering firm called American Energy Assets, which works with healthcare facilities to reduce energy use. He enjoys traveling, hiking, skiing, and spending time outdoors.

Teresa Tombelli Status: M.E. Master’s Student Contact: [email protected] Skills: Sketching, prototyping, machining, writing, enthusiastically trying new things

Teresa is from Michigan and attended university there. Her undergraduate major was engineering physics, but found mechanical engineering design to be more interesting, as it allows her to be both technical and creative at the same time. Her goal after graduation is to find a job in engineering that lets her continue to be creative in a design role.

Coach Michael Balsamo Hardware Engineer, Momentum Machines Co [email protected] CHAPTER 2. CONTEXT 18

The BTH Team

Niklas Nilsson Education: M. Sc. Industrial Management and Engineering. Innovative and sustainable product development. Contact: [email protected] Skills: I am flexible and purposeful in my work and have the willingness and ability to deliver my work on time. I handle criticism well, am sensitive to other people’s perspectives, and work well with others. I find that I am quickly able to understand my role in a group and I aspire to find the best solutions with available resources. Resources: I am knowledge regarding organization and communication achieved through work and life experience. I have a firm understanding of the product de- velopment process and sustainability as well as the ability to utilize tools related to the process. Basic knowledge regarding business development and related economic calculations.

Karin Dahlqvist Education: M. Sc. Mechanical Engineering. Inno- vative and sustainable product development. Contact: [email protected] Skills: Knowledge of theories, methods and tools for problem solving. Awareness of innovative and sus- tainable ways to create new services and products, and engineering methods to evaluate the outcome. Understanding of the impact a project can have on the environment and surrounding community.

Resources: Practical experience of working in an industry. CHAPTER 2. CONTEXT 19

Oskar Erlingsson Education: M. Sc. Mechanical Engineering. Inno- vative and sustainable product development Contact: [email protected] Skills: Mechanical skills from working with vehicles, including everything from the basics to welding. Skilled in virtual modeling, with knowledge of product development, manufacturing, distribution.

Resources: Practical and theoretical experience from working in industry with submersible water pumps, and from growing up on a farm. I have experience with operating and repairing various machinery, and was involved in the construction of several barns.

Simon Ha Education: M. Sc. Industrial Management and Engineering. Innovative and sustainable product development. Contact: [email protected] Skills: Theoretical and practical knowledge in strategic and project management, sustainability, product development, logistics, HRM and facilita- tion of activities.

Resources: Experience from employment as moderator for conferences, managing and dealing with projects, working within manufacturing industry.

Zainalabidin Tahir Education: M. Sc. Mechanical Engineering. Inno- vative and sustainable product development. Skills: Theoretical knowledge about quality-, service- and product development, strategic man- agement towards sustainability, and have different tools and methods within creativity and innovation. Also has general interest in the topic of renewable energy. CHAPTER 2. CONTEXT 20

Gustav Kagesson Education: M. Sc. Mechanical Engineering. Inno- vative and sustainable product development. Contact: [email protected] Skills: Knowledge about tools for sustainable product development and virtual and physical prototyping. Resources: Experience from working at a company, first as machine operator and recently as product developer, working mainly to transfer ideas from CAD models to drawings.

Victor Sderberg Education: M.Sc. Industrial management and En- gineering, Mechanical Engineering and Sustainable Product Innovation Skills: I am described as careful, analytical, tena- cious, responsive to new ideas, responsible and goal-oriented. I am good at organizing and struc- turing a projects, making it easy to work with all kinds of people. Re- sources: Knowledge of how to structure, plan and apply ideas in organizations, with understanding of how to organize and communicate within organizations. Understand- ing of product and service development processes and how they relate to sustainability. Practical and theoretical knowledge about business-related calculations, both from an efficiency and valuation perspective. 3 Design Requirements

Introduction

Volvo did not want to limit the scope of exploration, so the urban mining project information they provided was intentionally left broad. An open prompt allows for creativity in the ways that problem is approached, but also makes it important to develop design requirements to determine what to design. Through benchmarking and needfinding over the past two quarters, we have decided on designing a material handling system to enable on-site reuse and recycling of material. Based on interviews and feedback from general contractors, project managers on large scale C&D sites, urban developers, and many other professors from the C&D industry we have determined the following design requirements moving into the design refinement stage of the project. The initial requirements are broken up into functional requirements, what the product must be capable of doing, and physical requirements, what it must be physically. The requirements will continue to be updated to make them more specific and quantifiable as the final design in developed.

3.1 Functional Requirements

Requirement Rationale Metric Modular Construction sites vary a Be configurable to at least 3 lot in size and volume different diameters with three of waste material. Many different heights different sizes of storage container will be needed Simple to set up Setup time must be low Can be done with two people and easy to understand, in less than 15 minutes and no or construction workers special tools will not want to spend time on it and abandon use Safe for operators Operators must not be Must prevent bursting and at risk of being crushed pinch points by material or injured by moving parts Collapsible to small vol- It should be easy to Must be collapsible into the ume transport many empty footprint of the base and be storage containers using moveable with a forklift existing equipment

21 CHAPTER 3. DESIGN REQUIREMENTS 22

Requirement Rationale Metric Controlled empty Forming piles of material Removing material must be creates double handling done without forming piles, and should be avoided and should ideally be con- trolled so that the operator can decide where it lands Easy to repair Deconstruction is very Can be repaired with tools on hard on equipment, and the jobsite, with the exception everything breaks even- of material failure tually. Repairs need to be done quickly, and ide- ally in the field Sealed to dust and water The state of California Design should have a lid or mandates that piles of tarp covering and no gaps dirt must be covered to larger than .25 inches prevent runoff and dust Able to store bulky ma- Storage will be required Must handle pieces as large as terial to operate with dirt and 6 inches in diameter crushed concrete, which is a much harder material that can come in larger chunks Must operate without a Having a truck on the Must require no extra equip- truck jobsite would make the ment to operate other than the storage useless, as mate- storage system and a backhoe rial could be stored in the or excavator truck itself Moveable Piles often have to be Must be either self-powered or moved around a jobsite moveable with a forklift, back- to dodge work areas hoe or excavator Few moving parts Simplicity in design Storage should have one door will prevent parts from for emptying material, and breaking should be moveable, but its bulk should be static Few powered parts Powered parts break eas- Goal should be that the stor- ily and are expensive to age device is entirely mechan- repair. Electrical power ical, with all power coming is sometimes limited on from excavators, backhoes or jobsites human power Table 3.1: Functional Requirements CHAPTER 3. DESIGN REQUIREMENTS 23

3.1.1 Functional constraints • Any equipment developed must be in compliance with jobsite safety regulations. • A construction worker should be able to handle the equipment components without injury if provided with proper training. • The cost of construction loans does not include long-term environmental impacts in their financial calculations. • The final design must work within the limited space available on most C&D jobsites.

3.1.2 Opportunities • Currently there is no material handling system widely used in the C&D industry, more often than not material is just piled. • Current solutions are not modular or easily transported. • Lots of double handling of material occurs throughout a project due to changes in logistics due to project phasing. If this double handling could be eliminated, a lot of money could be saved. • Trucking is costly and disruptive to neighborhoods. If the material can remain on-site, the developer can save money and avoid some community opposition.

3.1.3 Assumptions • The importance placed on urban mining is growing and will continue to grow as building materials become scarcer. • Financial incentives for recycling and reuse will increase in the future. • Modern buildings will continue to be made primarily of steel, glass, and concrete. • The product will be used on construction sites and will be operated by workers with a general knowledge of power tools. CHAPTER 3. DESIGN REQUIREMENTS 24

3.2 Physical requirements

Requirement Rationale Metrics Can be filled with a back- It should be possible to Large enough at the top to be hoe fill the container with filled with a 2 excavator bucket machines already onsite Panels small enough to Fast setup is impor- Panels must weigh less than be handled by one person tant to keep projects on 50lbs each schedule, and few people should be required Generic panels Generic panels will make Each side panel is identical and setup and replacing parts ideally symmetric so that they easier, and will enable can be installed in any direc- modularity tion Durable to impact Anything on a construc- Must support repeated side tion site will be backed loads on the top and sides of into and hit by the the container bucket of an excavator Panels small enough to Fast setup is impor- Panels must be maximum 4x4 be handled by one person tant to keep projects on schedule, and few people should be required Table 3.2: Physical requirements for storage device.

3.3 Business requirements

Volvo Construction Equipment is one of the worlds largest designers and manufacturers of heavy equipment in the world. Their product line consists of pavers, milling equipment, skid steer loaders, and several other machines. An urban mining machine should be able to be integrated into their product line. Our solution must fit within the product line of Volvo and follow their core company values or sustainability, quality, and safety. Addition- ally as Volvo’s looks to the future, they plan to be on the forefront of the zero emission and autonomous equipment, so our material handing system must meet and aid in these specifications. 4 Design Development

In this section of the report, we will discuss the process we took to progress from the original Volvo prompt to the functional prototype at the end of the winter quarter. We first explored the four sectors of urban mining through site visits and interviews to get an overview of the current state of urban mining. We spoke to many different contacts in different industries, and continually sought feedback for our prototypes as they were built. This process of investigating and needfinding during the prototyping process gave us a broad view of urban reuse in general, while allowing us to keep our users in mind.

4.1 Defining Urban Mining

A visual representation of our brainstorming process can be seen in figure 4.1 below. We began thinking at a very high level to familiarize ourselves with the scope and definition of urban mining, to ensure that we had a clear understanding of the field before moving forward. Next, we moved to the research phase of needfinding and benchmarking, and finally to prototyping. We continued to interview users throughout the prototyping process however, and let their feedback guide our design decisions. The sections of research and prototyping will be presented separately, but happened concurrently throughout the winter quarter.

Figure 4.1: The design team’s development process from receiving the initial Volvo prompt to creating a functional prototype.

Early on, during our initial research phase, we found that the urban waste stream is split into four main categories, shown in figure 4.2:

25 CHAPTER 4. DESIGN DEVELOPMENT 26

1. Construction and Demolition: Any material from demolishing a building or scrap materials from the construction process

2. Municipal Waste: All the waste that is throw away in households and businesses

3. Electronic Waste: Old computers, phones, and other electronics

4. Tires: mainly car and truck tires but other rubber products as well

Figure 4.2: Graphic depicting the four sectors of urban mining as well as the main benefits it could have on the community [14].

From there both teams spent a week researching in all four sectors. We ultimately decided that based on Volvo’s current product line, core company values, and interest in urban mining to focus on the construction and demolition sector of urban mining. CHAPTER 4. DESIGN DEVELOPMENT 27

4.2 Benchmarking and Needfinding

The benchmarking and needfinding sections will include background research on the con- struction and demolition industry as well as site visits and interviews conducted throughout the last two quarters about urban mining. (A summary of our benchmarking and needfinding the Municipal Waste sector can be found in Appendix B, electronic waste and tires in Appendix C)

4.2.1 Construction and Demolition Construction is defined as building a structure - in this case houses, apartments, commercial buildings and infrastructure. Demolition is the opposite and in most cases means tearing something down. Construction and demolition (C&D) are usually grouped together as a single industry, and can also include renovation and deconstruction. In most construction projects today, one building must be demolished for another to be built. This will become increasingly prevalent as people continue to move into cities, and developments become denser. Urban mining in C&D is the reuse of waste materials from a demolition site in the new building construction. We did some initial research to understand the composition and amount of C&D waste produced so that we could understand how it could be better utilized instead of sent to a landfill. Construction and demolition waste accounts for about 30% of the total waste stream in California. A lot of the material from a demolition site, by weight, is already recycled and reused. About 80% of concrete is crushed up and reused as infill, 90% of steel is recycled and cast into new steel, 90% of asphalt is reused for new roads, and any wood that is sorted out on a large construction site is chipped up and sold as mulch. However, by volume there is still a huge amount of material that goes to landfills. In fact, insulation and asbestos make up the majority of a landfill’s composition [4]. On smaller construction sites dimensional lumber and high quality wood is reclaimed and used to make wood floors, decking, and furniture. Countertops can be made of recycled cardboard, glass, stone, or timber. However these products are significantly more expensive than getting a non-recycled product because of the labor that goes into recycling the material. To get a more detailed idea of how C&D works, we talked to a wide range of people in the construction and demolition industry. Through numerous site visits, we spoke with developers, contractors, non-profit reclamation services and demolition experts. CHAPTER 4. DESIGN DEVELOPMENT 28

Figure 4.3: Summary of the recycling processes currently in place for ma- terials on a construction and demolition site. Percentages based on volume from San Mateo Country, CA [12]. CHAPTER 4. DESIGN DEVELOPMENT 29

4.2.2 Brainstorming After the initial research was finished, the Stanford and BTH teams worked together through three rounds of brainstorming to try to define what urban mining could mean in the future, and what could be done to make it better. Our first exercise was to imagine an ”urban mining utopia” that was perfectly suited to reuse. This could be a future where people were very motivated to reuse materials, as well as a place where the current infrastructure was designed specifically to aid in reuse.

Figure 4.4: A vision of a world perfectly suited to urban mining

Figure 4.5: Project ideas, ranging from plausible to implausible

We identified several key things that would need to happen to make the reuse of materials more efficient and economically viable. Not all of these things, however, were within the CHAPTER 4. DESIGN DEVELOPMENT 30 scope of Volvo’s project. For example, Volvo would not be in the business of re-certifying light fixtures so they could be used in commercial buildings. We then elaborated on the areas that could be addressed by Volvo, and came up with a list of ideas that were either conservative or idealistic. The final solution should be something in between - that is innovative and novel, while making good business sense and is desired by the Volvo’s customers.

4.2.3 Site Visits San Francisco is at the forefront of recycling and reuse in the United States. To get an idea of what this means, the Stanford team started off our site visits by touring two non-profit organizations that specialize in reclamation and salvage. This is the most ideal form of reuse because it leaves materials in their manufactured form, and allows them to retain their value instead of being down cycled. One of these places, the ReUse People, even offers contractor services and can be hired to deconstruct a house. This means that they carefully remove each piece of the house so that it can be resold as reclaimed material. On the other end of the spectrum, we also visited the Ferma demolition company. They are a major contractor in the Bay Area that specializes in very large-scale projects, such as the Meyer Library on Stanford’s campus. Ferma takes the opposite approach to the ReUse People. They tear down a building into pieces that can be reground and sorted either on site or at a separate facility. After seeing contrasting examples of demolition, we next focused on a few demolition case studies. This included two high-profile projects in two different phases. The first focused on a planned development called the Kirkham Project and the developer that is planning the site, Transform Urban LLC. The Kirkham Project will begin to break ground in the next five years, and is still in the planning phase to work out how the site will be managed. It is located on the west side of San Francisco in a dense neighborhood near UCSF. It is an excellent example of a development in an urban environment, and is surrounded by a close-knit community that cares deeply about the environment and the impact the Kirkham Project will have on the neighborhood. The second case study is the closer to home Meyer Library demolition. We have been watching this process closely, and have spoken to the contractor and site manager during different phases of the project. The library is an interesting case because it too is in a very tight location, and also has massive amounts of concrete and re-bar that need to be handled. We have found that Stanford is making a considerable effort to reuse a lot of the waste material on site as infill, meaning that the contractors can give us a firsthand perspective of the process and how it can be improved.

4.2.3.1 Salvage and Deconstruction Salvage and reuse is the most ideal form of urban mining. It allows for manufactured goods to serve their full useful life, even after they have been lightly worn and are out of style. Materials retain the shape and function imparted to them by the manufacturing process instead of being dismantled and turned into less valuable products. In the Bay Area, there are many places to purchase used and salvaged furniture, but a nonprofit called the ReUse People goes a step further. The ReUse People run both a salvage yard and a deconstruction CHAPTER 4. DESIGN DEVELOPMENT 31 contractor, and specialize in the salvage of the material in entire buildings (fig. 4.6). A home owner could hire the ReUse People as an alternative to traditional demolition. The process of deconstruction begins when the ReUse People win a bid to take down a structure. While their operating costs are often significantly higher than a traditional demolition, they make up for the extra cost through tax credits. As a nonprofit, their business model works by crediting the homeowner with a tax exemption based on the value of the materials removed from the deconstructed house. This usually makes the total cost of a deconstruction lower than for traditional demolition, after money savings in tax exemptions are accounted for. The physical deconstruction occurs in three steps:

1. Cherry picking all the valuable and easy to remove material is taken out such as furniture, lighting fixtures, and appliances

2. The interior is gutted for recycling hardwood floors are carefully torn up and any other non-structural materials and taken down and sorted on site

3. Final deconstruction studs are removed and saved, all electrical work is stripped out and finally the excavators come in and grind the concrete up

The Stanford team toured deconstruction sites at each step to understand and document the process. Was there a tool that the deconstruction workers needed to make their jobs easier? Why isn’t deconstruction a widespread practice?

Figure 4.6: The ReUse People retail store, where salvage materials are sold to the public

The cherry picking step of deconstruction is the most labor-intensive, and can be the most lucrative. It takes about a week for a crew of workers to remove all light fixtures, cabinets, doors, mantel pieces and decorations by hand (figs. 4.7 and 4.8). Each piece must CHAPTER 4. DESIGN DEVELOPMENT 32 be handled carefully to avoid damage, and no two houses are the same. Cherry picking requires adaptable, efficient and gentle workers, meaning that complex automated tools are not well-suited to this task. Most of the tools used by workers are simple and mechanical, and can be adapted to many different conditions (fig. 4.9).

Figure 4.7: A house after the ReUse People have removed the lights and other valuable pieces

Figure 4.8: A window seat has been removed so that it can be resold as a complete unit CHAPTER 4. DESIGN DEVELOPMENT 33

Figure 4.9: Workers pry up wood flooring with very simple tools CHAPTER 4. DESIGN DEVELOPMENT 34

After all valuable fixtures are removed, carpet, drywall, windows and wood flooring are taken next, until the building is a shell with the studs exposed (fig. 4.10. Wood flooring is separated and de-nailed outdoors or at a different site, and windows are carefully loaded onto a truck in their frames for resale. Drywall debris, small pieces of wood and carpet is loaded into a separate truck to be recycled. At this point, most of the material that is removed from the property is an odd size that makes packing trucks difficult. To make things worse, there is often not enough room to park multiple trucks or to store material in piles. The site is still very confined because all of the walls are still in place, leading to a material handling issue. At the deconstruction site that we toured, we watched as all of the workers loaded scrap materials into plastic trash cans and carried them on their backs to the waste truck (fig. 4.11). This seemed strenuous and inefficient at first, but as we watched the workers we realized that the process moved very quickly (fig. 4.12). It seemed that the construction workers favored reliable but sometimes inefficient working procedures that could function in almost every condition over specialized processes that would streamline one aspect of the job but be useless in other cases.

Figure 4.10: After prying up each wooden plank, they stack and bind the reclaimed wood for shipping

The last phase of deconstruction is to remove the roof, and allow the building frame to fall to the ground. This part goes very quickly and yields large pieces of dimensional lumber that can be regraded and sold (figs. 4.13 and 4.14). Used dimensional lumber usually cannot be reused as structural components, but the ReUse people can resell two by fours for applications that are not load-bearing. These are often purchased by individuals working on DIY projects or by building contractors looking to save some money. As materials are removed from a jobsite, they can end up in one of two places. Either the material is considered waste and sent to a recycling center, or it is found to be salable and taken to the ReUse People store. Items are cleaned up and displayed in a warehouse, where the public can view and purchase items (figs. 4.15, 4.16, and 4.17). CHAPTER 4. DESIGN DEVELOPMENT 35

Figure 4.11: Workers remove scrap waste from the jobsite by filling trash cans and carrying them on their backs

Figure 4.12: They then hand each trash can to another man who stands inside of the truck. He empties the trash cans and roughly sorts material by placing large ans small pieces on the opposite ends of the trailer CHAPTER 4. DESIGN DEVELOPMENT 36

Figure 4.13: The roof has been removed from a house, with studs and frame remaining

Figure 4.14: Salvaged wood stacked neatly, waiting to be denailed CHAPTER 4. DESIGN DEVELOPMENT 37

Figure 4.15: The ReUse People store sells higher-end cabinets and appliances

Figure 4.16: The ReUse People salvage kitchen appliances and bathroom fixtures CHAPTER 4. DESIGN DEVELOPMENT 38

Figure 4.17: Salvaged wood packed and ready for sale outside the ReUse store

Building ReSources is another non-profit salvage yard that is similar to the ReUse People. Instead of contracting to deconstruct houses however, Building Resources relies on donations that people bring to their store. Homeowners and construction workers bring the material as a donation, and in exchange receive a tax write off. Building Resources stocks smaller items than the ReUse People, but are also more creative about material processing. All the materials brought in are sorted into metals, wood, windows, doors, furniture, and other miscellaneous materials (figs. 4.18, 4.19, and 4.20). Building ReSources is one of only two facilities in the United States that repurposes tile, glass, and old dishware. The owner developed a method to break down and tumble ceramics so they can be repurposed as landscaping material or art installments (fig. 4.21). After touring the store, we asked the owner, Matthew Levesque, about problems that he faces in trying to salvage and reuse material. He spoke at length about issues of storage and material handling for oddly shaped and fragile items. Many items from commercial buildings are not salvaged or reused because stores like Building Resources and the ReUse People cannot accommodate large inventories. Currently, there is no good way to stack, store and catalog so many non-standard pieces. Additionally, due to city ordinances, many materials cannot be reused in commercial settings. For example, the Building Resources owner told a story of a new office building outfitted with all new lighting fixtures only to have the owners decide they didnt like them. Because the lights had already been installed, they no longer could be used in commercial buildings and there were too many for Building ReSources to handle, so they went to the landfill. Cases like this happen all too often due to the frequency of turnover and remodeling in skyscrapers and office buildings today. Another area of interest for the salvage business is the de-nailing of lumber. Timber retains value when stripped from a building for reuse, but a lot manual labor is required not only for removal but for the removal of nails. All the nails have to be removed one by one before the wood can be reused. CHAPTER 4. DESIGN DEVELOPMENT 39

Figure 4.18: Building ReSources has a plethora of doors which are not only purchased as doors, but purchased to be used for table tops and other hard- wood furniture.

Figure 4.19: Levesque outfits about two cafes, two start-ups, and three house- holds each year with the light fixtures he reclaims. CHAPTER 4. DESIGN DEVELOPMENT 40

Figure 4.20: Scrap metal is a valuable resource and bought up quickly from Building ReSources

Figure 4.21: Tumbled glass and tile sold to landscapers and artists. CHAPTER 4. DESIGN DEVELOPMENT 41

4.2.3.2 Ferma Corporation After learning about small-scale salvage and deconstruction, we also wanted to investigate the industry standard for large-scale demolition. For this we contacted the Ferma Corpo- ration, a San Francisco-based company that custom modifies its demolition equipment for each job. The first part of our tour was of their office, machine shop and equipment yard in Newark, CA, and later we continued to an active demolition site. Marc Ferrari, president of Ferma Corp, met us at the Ferma equipment yard to give us a tour and discuss the equipment and processes involved in demolition. He explained that demolition is mostly done with various sizes of excavator, with different tool attachments for each portion of the job. He said that the familiar image of a wrecking ball was now obsolete, and that excavators can be much more precise in bringing material to the ground. The equipment yard held all of Ferma’s machines that were not currently being used on jobsites - half a dozen excavators, pile drivers, water tank trucks, excavator tool attachments and trailers to move each piece of equipment (fig. 4.22). Around the side of the building there were also several shredding, crushing and sorting machines (fig. 4.23). The debris brought down by the excavators could be fed into each of these machines to make a finer mixture, to sort out valuable metals and to crush concrete into pre-determined sizes. These machines were massive, and Ferrari explained that while these machines were considered portable, only the largest sites could accommodate them. They were considered the state of the art, with modifications made by Ferma to make them more reliable. Attached to the equipment yard was also a machine shop, where repairs and extensive modifications could be done. At the time, Ferma was making a custom bucket attachment for a excavator, and replacing the hydraulics on a broken down machine. Marc explained that demolition is very hard on his machinery and always requires different strategies when completing a job. Because of this, his company buys off-the-shelf excavators and modifies their boom arms and hydraulics to make them longer or more powerful. He says this can make the machines less durable, but more effective for his demolition jobs. CHAPTER 4. DESIGN DEVELOPMENT 42

Figure 4.22: An excavator with shears that can easily cut through I-beams

Figure 4.23: A huge, ”portable” concrete crusher CHAPTER 4. DESIGN DEVELOPMENT 43

After seeing the equipment yard, we drove to the site of an old Clorox testing facility that was being demolished (fig. 4.24). Here, we could see the sorting and demolition process first hand. The first thing that we noticed was the sheer amount of material that came from the building. The parking lot and old footprint of the building were covered in ten foot tall piles of rebar, twisted I-beams, drywall, glass and concrete. The piles seemed to be roughly sorted by material (fig. 4.25), and a shredder was grinding waste into smaller pieces while pulling out the metal. We were told that each material had a different value, and would be trucked off site to different places (fig. 4.26). For example, the I-beams would be sold to a local pipe maker to be melted down and recast, while the roofing material and insulation would be sent to the landfill. Any material of potential value was sorted and sold to offset the company’s cost. The most valuable metal - copper - was long gone. It was one of the first things to be removed and sold to prevent theft. Marc told us that the police arrest several people every week on his jobsites for stealing copper and power tools.

Figure 4.24: An old Clorox testing facility being demolished by Ferma

Figure 4.25: Huge, roughly sorted piles filled the jobsite CHAPTER 4. DESIGN DEVELOPMENT 44

Figure 4.26: A shredder sorts materials further and grinds up waste CHAPTER 4. DESIGN DEVELOPMENT 45

We also learned that the demolition process requires a surprising amount of water. Regulations limit the amount of dust that can be released into the air, which means that any time part of a building is being torn down, a person must stand nearby with a high pressure hose to wet down the concrete (fig. 4.27). This makes for a soggy, muddy jobsite and a large expense for the demolition company. To conserve water, Ferma brought in their own water tanker that could be filled from a nearby water reclamation pond (fig. 4.28). The idea was that most of the water pumped out of the pond would be sprayed on the jobsite and would trickle back to where it started.

Figure 4.27: A worker holds a high pressure hose while spraying the work area to control dust

Figure 4.28: Ferma’s own water truck for storing the water used for dust control CHAPTER 4. DESIGN DEVELOPMENT 46

4.2.3.3 Transform Urban and the Kirkham Project Transform Urban LLC just began work on an urban infill development in West San Francisco called the Kirkham Project. We spoke with Naomi Porat, the founder of Transform Urban, who has a background both in urban planning and business and focuses on sustainable design with a net positive impact on the environment and community. The Kirkham Project is currently an 86 unit apartment complex built in the 1950s on six acres of land with two of those acres remaining forest. It us located on a very steep hill, shown in figure 4.29 and 4.30, which poses problems for construction and demolition. The new site will consist of 460 units and leave the two acres of forest untouched.

Figure 4.29: Two of the buildings on the current Kirkham Project site.

Figure 4.30: The Kirkham Project is located at the top of a road with 17% grade. CHAPTER 4. DESIGN DEVELOPMENT 47

The biggest problem currently facing the Kirkham Project, as is the case with many urban infill projects, is what to do with all the demolition waste material. Typically, material is carried away by truck to a different location for processing. For urban infill projects however, trucking is very disruptive to the dense community that surrounds the project. For this reason, Porat is looking not only to recycle as much material as possible, but to reuse or process that material on site to avoid trucking and, in turn, reduce disruption to the neighborhood and the carbon footprint. Reprocessing on site is a admirable goal, but this leads to another problem: how can this material be stored? On the Kirkham Project site there is room for some storage, but many materials such as dirt and concrete piles take up a lot of space due to their low angle of repose. During first visit with to the Kirkham Project, we took a walk around the project site to see what the primary materials and designs were in the buildings (figs. 4.32 and 4.33). This gave us insights into the typical construction materials used in buildings from the 1950’s, as well as some of the challenges that go into demolishing a building. Before we left the site, Porat sat down with us to brainstorm some ideas about the direction of the project (fig. 4.31). We broke it down by the materials that will be coming out of the Kirkham site. The idea that seemed the most compelling was the concept of a mini on-site factory. If it is possible to repurpose material on site, recycling would become much easier while cutting down tremendously on the carbon footprint of the project. Currently, some on-site batch plants do exist, but they are still extremely large. Even if there was room for a batch plant however, the storage of input and output material would still be an issue.

Figure 4.31: Mind map completed by the Stanford team and Porat while visiting the Transform Urban office on the Kirkham Project site. CHAPTER 4. DESIGN DEVELOPMENT 48

Figure 4.32: There are tall metal retaining walls that will have to be removed and recycled throughout the site.

Figure 4.33: The majority of the material used in the units is wood and concrete, typical 1950’s construction. CHAPTER 4. DESIGN DEVELOPMENT 49

In subsequent meetings, we were also able to meet with several members of the Kirkham Project team. Gary Strang, of GLS Landscape Architecture, is the Landscape Architect on the Kirkham Project. He told us that in the landscape architecture, planning to reuse materials and plants is always discussed and often turned down due to cost and storage. Landscaping is the first part of a project to be demolished and the last part to be con- structed, so in terms of timeline and phasing, it is hard to store any materials for the full length of the demolition and construction process. While he may like for the industry to be motivated by environmental concern, he has found that it is much more strongly motivated by cost, meaning that the reuse of landscaping materials rarely happens. However, another angle that Porat and Strang mentioned is that on urban infill projects, one real benefit of using environmentally friendly practices is that the surrounding community is more likely to support the project and therefore the entitlement process time is reduced. Entitlement time can last six or more months so any reduction in time is money saved. In one of the following weeks, we also spoke to Brian Scott, of Bkf Engineers, the civil engineer on the Kirkham Project who calculated the amount of earth that needed to be cut and filled on site. We found that the amount of extra dirt that will be coming from the Kirkham Project site is considerable, and has the potential to require very many trucks to move it all away. This further motivated the need to reuse as much dirt on site as possible, but also to find creative ways to incorporate it into the new buildings. The clearest way to do this is to make bricks, roads and sidewalks with the dirt as a fill material. Currently there are several such products, but none involve a portable factory that can manufacture things on site. At that same meeting, we also spoke to Chuck Paley, President, and Howard Carlson, Field Operations Manager, of Cahill Construction. They shared with us specific numbers about the construction industry, including that 85-90% of material from a site is recycled. The recycling is mostly done at off-site facilities however, since there is no room on site for extra large machinery. Paley and Carlson were the first to mention that crushing concrete on a jobsite can offer significant savings in trucking, though it brings the added complications of dust and noise. Carlson specifically insisted that space on a jobsite was a key resource and that material storage with a smaller footprint would be ideal. He also emphasized that time is money, safety constraints can limit what is feasibly done on a jobsite, reducing the labor force saves money, and that job phasing and timeline are a large part of site management. Our latest interview was with David Mar, of Mar Structural Design, the structural engineer for the project. He also supported the idea of an on-site batch plant or mini factory. When we presented him with a proposal for movable storage containers, he liked the idea that they could be a dynamic way to separate, move and retain different materials. He went as far as to suggest that they could become part of the mini factory as a way to handle input and output materials. He thought it was important that each container be movable and stackable and gave some structural pointers about how to do this. He also encouraged us to focus on material handling instead of storage, which could broaden the scope of our project, and make it easier for people to imagine the impact it could have on a demolition site. CHAPTER 4. DESIGN DEVELOPMENT 50

4.2.3.4 Meyer Library Demolition Our last case study was to follow the demolition of the Meyer Library (fig. 4.34). We began by meeting with Brian Carilli, the Associate Director of Construction and Renovations at Stanford, Kharon Hathaway, the Stanford Construction Project Manager, and Sarah Lar- son, the General Contractor for the Meyer Library demolition from Level 10 Construction. Carilli focuses on the interior construction of labs and classrooms at Stanford but has a lot of experience with demolition in the industry. We learned that on big projects, like those at Stanford, material that comes out of the demolition site involves putting the entire building through a shredder, and sorting the wood chips and metal chips from the rest of the material. On smaller projects, material is sorted by hand before chipping to reduce the amount of equipment needed on site. For large projects, concrete crushing can happen on site using portable (yet still very large) machines that grind the concrete to the desired aggregate size and remove all the rebar. However, most projects cannot bring a concrete crusher on site because it simply takes up too much space. Carilli thinks that the only way recycling and urban mining will become a priority is if there are incentives. For example, if developers or homeowners had to pay a cradle-to-grave tax for choosing less recyclable materials, such as rubber roofing and tile. Another key insight Carilli gave us is that the composition of buildings is changing from wood based to steel based. Most modern buildings today are made solely of steel, concrete, and glass. This is important to note so that any new technology that we develop will be designed to handle the materials that are common in the future.

Figure 4.34: The Meyer Library [8]

We spoke with Hathaway and Larson twice during the Meyer Library demolition. Before the demolition began, we asked to see what measures Stanford was planning to take to reuse and recycle material. They told us that Meyer Library is going to be replaced with a grassy landscape area instead of a new building. The whole project was on a tight schedule, with the demolition done by Ferma Corp in about 30 days, with 10 additional days to crush the concrete. Hathway said the timeline was determined by budget restrictions, which is often CHAPTER 4. DESIGN DEVELOPMENT 51 the reason why innovative reuse methods are not attempted. Stanford’s plan for reuse of material includes cherry picking out all usable furniture, and saving the old ceramic roof tiles for use on another building. Carpet is prohibitively expensive to recycle, and the building needs to be rid of all asbestos before demolition can start. After demolition, all metal that can easily be extracted from the building will be put into a recycling bin, and the rest of the walls and partitioning will be shredded and used as mulch. The concrete will be crushed up on site and reused as infill beneath the new landscaping. Hathaway has said that crushing and reusing the 13,000 cubic yards of concrete on site will save them $1.3M in trucking cost. When asked whether the crushed concrete could be reused on site for new concrete, Larson told us that this is possible in some cases, but not common because of structural concerns. Sometimes crushed concrete is used for roads and sidewalks because they can be less durable, but it is almost never used for load bearing members. From this conversation, we left with the message that everything is driven by labor costs and time, meaning that any newly developed technology would have to show obvious practical and economic benefits. In the following weeks we watched the changes in the Meyer site with interest. The Ferma trucks rolled in after the asbestos was removed, and demolition began shortly. It was amazing how quickly the building was demolished and how simple the demolition tools were. While an ultra high reach excavator may not seem simple, its core function is to be a giant pole with scissors or a hammer on the end to literally smash the building to pieces. Ferma began by gutting the interior of the building and made the shell collapse inward to save space. Pieces of the building were brought down sections at a time by jackhammering on the roof and cutting load bearing walls and I-beams with shears. Meanwhile, a worker with a hose kept the dust down, and smaller excavators sorted material into piles of rebar, larger steel and concrete. The steel was trucked away to be recycled, while the concrete remained on site waiting for the crusher. The site footprint was confined to the library lot size, but continued to expand into nearby bike paths and disrupted traffic. At one point the lot was completely full of two story piles of twisted rebar and concrete, with an almost overwhelming amount of waste material (fig. 4.35). Just about a week later, the site was clear, leaving a big hole in the ground to reuse the concrete onsite as infill (fig. 4.36). We went back to talk to Hathaway and Larson to get feedback about the idea of improv- ing storage and material handling on demolition sites. They believed the concept would be good for bulky materials, especially crushed concrete and soil, and helped us to develop some user requirements. Larson felt that it was very important that the units stack, move and empty in a controlled way. Both Hathaway and Larson emphasized the importance of robust and simple components that were extremely easy and fast to operate. When we suggested some sort of motor-operated release door, Hathaway steered us away from electronic components, saying that they are just one more thing that can break and waste time, and that there may not be a readily available power source. She suggested that we explore latches and other purely mechanical solutions instead. To improve safety, the latches for releasing material could be actuated by an excavator or machine instead of a person standing dangerously close to falling debris. In general, this system should not require any specialty tools to operate and should adapt to the changing needs of different demolition sites. It should be sturdy enough to take heavy abuse from being repeatedly hit with an excavator bucket and from being backed into with various vehicles. Hathaway and Larson also brought up points that we didn’t realize were important. For instance, the CHAPTER 4. DESIGN DEVELOPMENT 52

Figure 4.35: The Meyer Library demolition

Figure 4.36: The Meyer Library demolition site from above after all metal material was trucked away CHAPTER 4. DESIGN DEVELOPMENT 53 state of California requires all dirt piles and containers to be covered and protected from rain and wind to prevent run off and dust. This would certainly be much easier if the dirt was stored in a container, but is something that we have to keep in mind and design for.

4.2.3.5 Summary The site visits we took helped us to understand the deconstruction and demolition processes, the current state of urban mining in construction and demolition for a range of materials, and obstacles that limit the amount of urban mining that takes place. Below is a flow chart of the demolition process (fig. 4.37), the deconstruction process (fig. 4.38), a summary of material recycling (fig. 4.3), and a table summarizing the obstacles prohibiting urban mining.

Figure 4.37: Summary of the steps involved during the demolition of a build- ing.

Figure 4.38: Summary of the steps involved during the deconstruction of a building. CHAPTER 4. DESIGN DEVELOPMENT 54

Table 4.1: Summary of Obstacles Impeding Urban Mining Obstacle Reasons Trucking Most material is shipped off site to be sorted because storage on site takes up too much space. This re- sults in huge disturbances to com- munity, large carbon footprint, and very high costs. Community Support Despite the potential long term benefits to a community a project may have, the disturbance of truck- ing and construction sounds results in a long entitlement time before the project is approved (which is costly). Cost Currently recycled materials and urban mining practicing are much more expensive than buying some- thing new and demolishing a build- ing to the point where the client will not pay the extra cost. Time Urban mining processes require lots of manual labor and in turn lots of time. This is not possible given project timelines enforced by the banks construction loan practices. Space Even if there are options for taking care of material onsite there are no storage solutions for the materials to be stored until they are needed later in the project, and often times the ”portable” equipment is still too large to bring onsite. Table 4.2: Summary of obstacles prohibited urban mining in construction and demolition that we need to consider when moving forward with the project. CHAPTER 4. DESIGN DEVELOPMENT 55

4.3 Persona

A persona is a representation of a critical user. A persona can be modeled on one specific person or an amalgamation of traits from several people. It is helpful to build a persona early in the design phase as it brings the focus of new ideas back to the user.

4.3.1 Dave the Deconstructor After completing benchmarking, needfinding and numerous site visits, it seemed clear that a focus on C&D side of urban mining would be the best fit for Volvo CE. Any technology created for C&D would be used at a C&D site at some point, and if the technology was a piece of hardwear it would likely be used by the construction workers themselves. This led naturally to the idea of the deconstruction worker being the main user, since this was the person who was most likely to interact with our product every day.

Figure 4.39: Dave the Deconstructor is an idealized C&D worker

Dave the Deconstructor is a laborer on a construction and demolition site. He is an hourly worker who is highly skilled and motivated to complete jobs as thoroughly and quickly as possible. He is managed by a foreman who directs each construction worker to a specific job. The pace of work is dictated by the demolition schedule and is often very CHAPTER 4. DESIGN DEVELOPMENT 56 tight, forcing Dave and his coworkers to be very efficient with their time. For this reason, Dave has no time to waste with new equipment that doesn’t function properly. He will improvise with the methods that have been shown to work, even if they were not specified in the building plan.

Traits

• Industrious and resourceful • Job is physically demanding • Places high value on ergonomics • Interested in making money for his family

Likes

• Seeing a job completed • Finding a way to make a few extra dollars • Going home after a long day

Dislikes

• Wasting time • Being injured • Equipment that is difficult to use • Demands from people with no experience in construction

4.3.2 Devon the Developer From the case studies of the Kirkham Project and the Meyer Library, we also identified a second key user. The building developer is the person who hires contractors and ultimately decides how resources are allocated and how work will be done. They have control over what technologies are to be used to handle materials, and where resources are to be allocated. They have the power to alter the flow of materials around a job site, and whether those materials could be reused or sent to a landfill. Devon the Developer is the manager of an urban infill development. She oversees the top level details of the entire development project and works with a building team of engineers, architects, urban planners and contractors to plan and divide labor. She is hired by a client who owns the development site, and it is her job to assemble the building team. Her main motivators are time and cost, though she does have strong personal ideals for what makes a good development. She would like to be as environmentally friendly as possible with the best aesthetics, but is often prevented from doing these things by limitations in budget and customer priorities. She is willing to explore new ways to protect the environment through ethical business practices, as long as they still fit into the bottom line. At the end of the day, it’s measures that save money and time that end up being implemented in the final project. CHAPTER 4. DESIGN DEVELOPMENT 57

Figure 4.40: Devon the Developer is an idealized building developer

Traits

• Concerned about time and money • Environmentally conscious • Ultimately driven by cost and providing competitive bids • Has many responsibilities from varied sources, and needs to pull them all together into a cohesive project

Likes

• Projects that run on time and within budget • Finding new clients by winning a bid • Getting work done quickly

Dislikes

• Unforeseen delays and problems • Conflicting customer and business interests • Pushback and protests from the people who live and work near a jobsite • Unreliable contractors CHAPTER 4. DESIGN DEVELOPMENT 58

4.4 Critical Function Prototype

Needfinding and benchmarking made it clear that trucking waste and recyclable material from a construction site is expensive for the developer, disruptive to the community, and harmful to the environment. One way to reduce the amount of trucking from a jobsite is by reusing demolition waste on site as new construction material. We researched how demolition waste is currently being handled and were pleased to find that urban mining regularly occurs. Concrete is often crushed on site and reused as infill for the new construction. Also, wood, such as dimensional lumber, is chipped up and used as mulch. The advantage of onsite reuse is two-fold. It reduces the amount of trucking from the site, and it supplies the developer with a building material that can be used in new construction. Through talking with developers, we discovered glass is not typically reused or recycled. Unlike glass bottles which are all a similar composition, window glass varies widely from building to building, so a standardize process cannot be used. Also, the developers that we have spoken to do not feel that there is a current reuse for glass that merits the effort it takes to remove each window from a building before it is torn down. This is important because modern buildings are incorporating more and more glass into their design. In the future, having an effective reuse for glass will be imperative. With our critical function prototype (CFP), we tested the feasibility of reusing glass as aggregate in concrete. In the following section, we will focus on the glass concrete prototype as it was a key point of inspiration for our current direction. Details about our other, smaller CFP’s can be found in Appendix D.

4.4.1 Glass Aggregate Concrete Concrete is made up of four main components: course aggregate, fine aggregate, cement (the binding agent), and water. Researchers have explored the idea of reusing glass in concrete [6][10]. However, in most of the studies, only a percentage of the aggregate was replaced by glass. Also, most are aimed at reusing bottle glass from municipalities instead of window glass. The goal of our CFP was to determine if replacing all of the aggregate in concrete with window glass would create a material with similar physical properties to concrete. Scientists have been working to optimize concrete performance for years. Varying the mix ratios and curing conditions can alter concretes properties. Concrete aggregate usually consists of sand and gravel that has been crushed and sized. These course and fine aggre- gates are then mixed in a specific ratio with water and cement, typically Portland cement. The reaction between the water and the cement powder is what binds concrete together. Ling, Poon, and Kou of The Hong Kong Polytechnic University performed an extensive study on replacing the fine aggregate of concrete with crushed glass [7]. We wanted to see the results of not only replacing the fine aggregate, but also the course aggregate in an effort to utilize more of the glass from a construction site. The particulate size and mix ratios for our CFP glass concrete were modeled off of the concrete Ling, Poon, and Kou tested. For the CFP, we decided to minimize the number of steps required to make the product. Concrete strength could be improved by adding fiber or surface treating the glass CHAPTER 4. DESIGN DEVELOPMENT 59 to increase surface area for adhesion. However, we wanted to see if it was possible to create a viable concrete without these added steps.

4.4.2 Glass Aggregate Concrete CFP Description With this CFP we wanted to compare the compressive strength of 100% glass aggregate concrete bricks to standard concrete. Additionally we wanted further explore the process required to create glass concrete to determine if it could be automated. The process for creating concrete with glass aggregate consisted of four steps:

1. Crushing the glass 2. Sizing the particulate 3. Mixing the concrete and setting in a mold 4. Testing the specimens

Two different batches of concrete were made to see if the type of glass used has an effect. One used typical, clear 2’ x 4’x 1/8” window glass panes purchased from Home Depot as aggregate; the other used beer-bottles. The crushing and sizing process was the same for both types of glass. After crushing the glass by hand and sizing the material using sifters of varying size mesh, we mixed the glass aggregate with Portland cement. We let the molds sit for three days and then took out the final specimens for testing (fig. 4.41). (Details of this process can be seen in Appendix E)

Figure 4.41: Window glass concrete brick composed of 100% glass aggregate.

The testing machine at the John A. Blume Earthquake Engineering Center at Stanford University was used to quantitatively measure the strength of the window glass concrete (fig. 4.42). The cylinders tested had a fracture strength 60% that of standard concrete fracturing around 1800 psi. 3000 psi is the low end for concrete used in construction. The CHAPTER 4. DESIGN DEVELOPMENT 60 other beer bottle glass concrete and the Quikrete was not tested because no cylindrical samples (required for the machine) were made in the first CFP exploration.

Figure 4.42: Testing window glass concrete specimen at the Blume Earth- quake Center at Stanford University. CHAPTER 4. DESIGN DEVELOPMENT 61

4.5 Critical Experience Prototype

Our Critical Function Prototype (CFP) and Critical Experience Prototype (CEP) developed a process to reuse glass on-site. In the fall quarter we completed the CFP portion of the module by crushing glass window panes and using that material to make glass bricks with Portland cement as the adhesive. However, we found that although this process could easily be done on site using existing technologies, the final product looked essentially like standard concrete bricks. The glass bricks did not have the visual effect we were hoping for with the opacity and sparkle of glass. We do not think they are appealing enough for a contractor to put in the extra time and effort of window extraction. Therefore, for our CEP, we tried using different adhesives to make the bricks more aesthetically pleasing. For our CEP we considered two main aesthetics for the glass bricks: opaque adhesive and clear adhesive with lighting. Using the remaining glass from the CFP, we were able to make small glass bricks using three different adhesives. To test the potential of making glass bricks of different colors, we used white adhesives, which could be dyed if desired. Ideally this test would have been done using white Portland cement, but due to time constraints, and California state regulations, we were unable to acquire this material in time to complete a prototype. Instead, we simulated white Portland cement using Plaster of Paris and white mortar (fig. 4.43). For the clear brick, we used ultra gloss epoxy as the adhesive and strung an LED light string through the brick (fig. 4.43). Because glass bricks are made using recycled material, under current regulations they cannot be used as structural components of a building. Therefore, given the unique aesthetics of the bricks, they could be used for more decorative purposes such as patios or walkways. The lit bricks in particular could act as lighting for a walkway up to a house at night.

Figure 4.43: (a) White Mortar Glass Brick (b) Plaster of Paris Glass Brick (c) Ultra Glass Epoxy Gloss Brick.

To see how people felt about these bricks we conducted a survey asking participants to rank the bricks in order of visual preference and give a percentage for how much more they CHAPTER 4. DESIGN DEVELOPMENT 62 would be willing to pay for one of our glass bricks versus a standard concrete brick. During the test we compared the three glass bricks from our CEP, a glass brick from the CFP, and a standard concrete brick. We set up the bricks we were testing around a brick paver to simulate them lining a walkway (fig. 4.44).

Figure 4.44: Survey set up for feedback on aesthetics of glass bricks. From top left clockwise: control store bought concrete brick, Plaster of Paris glass brick, white mortar glass brick, ultra gloss epoxy glass brick with LEDs, and CFP glass brick.

Overall the results were not positive for the glass bricks. All the bricks except the ultra gloss epoxy were ranked evenly with or lower than the standard concrete brick (table 4.4). Additionally, we compared the cost to make the bricks to how much people were willing to pay, and no one was willing to pay the price increase (table 4.4). The cost was calculated by comparing the cost of the three adhesives that would have been used in large scale production: gray Portland Cement (CFP glass bricks), white Portland Cement (analogous to white mortar and Plaster of Paris bricks), and ultra gloss epoxy (table 4.3). For the purposes of this analysis we did not include the cost of glass because it would be the same for all the glass bricks. Additionally the cost of the LED strings were not included in the cost for the clear bricks.

Adhesive Cost/cubic yard Gray Portland Cement $19.96 White Portland Cement $40.30. Ultra Gloss Clear Epoxy $1997.16 Table 4.3: Calculated cost of cement/adhesive for one cubic yard of recycled glass concrete. CHAPTER 4. DESIGN DEVELOPMENT 63

Adhesive Rank Willing to Actual Increase Pay Gray Portland Cement 3.5 0.97 1 Plaster of Paris 2.5 1.2025 2 White Mortar 4.5 0.932 2 Ultra Gloss Clear Epoxy 1.7 1.94 100 Bought Concrete 2.8 1 (control) 1 Table 4.4: Survey results comparing five bricks ranking aesthetic preference and perceived value increase.

While making glass bricks would serve as a viable product reuse for glass from C&D waste, this benefit does not offset the extra time and cost to complete the process. While there isn’t a cost increase to make the glass bricks from our CFP, they do not look special enough to warrant the extra time to carefully remove all the windows and all the glass from the windows. In order to make the bricks looks aesthetically pleasing, the same extra time has to be put in to remove the glass, in addition to a 100 fold price increase to use a clear adhesive rather than Portland Cement. CHAPTER 4. DESIGN DEVELOPMENT 64

4.6 Dark Horse Prototype

A dark horse is defined as a little known contender that makes an unexpected entrance. The Dark Horse Prototype is intended to be a radical prototype with a complete change of direction from the CFP and CEP prototypes. For our CFP and CEP we focused on how to reuse glass on-site to reduce both the amount of material that goes to the landfill and trucking. Through both site visits and interviews with professionals from across the construction and demolition industry, we have seen that another reason urban mining does not take place is due to lack of on-site storage solutions. Many aggregates, such as dirt or crushed concrete, are torn up early in the demolition phase of a project, but they are not needed again until the construction phase. Aggregates have a low angle of repose, which means, when piled up, they fall into a cone shape with about a 45◦ slope. This results in a large footprint that could be used for equipment, storage of other material, or trucking. Therefore, rather than keeping the material on-site for later use, the owner pays to truck the material off-site, pays to deposit the material, buys new material, and then pays to truck that material back on-site, increasing not only the cost but the carbon footprint of the project. To eliminate this redundancy and encourage urban mining, we prototyped a collapsible, portable storage container for aggregates that reduces the footprint taken up by the material.

4.6.1 Dark Horse v1 - Dirt Mushroom In the first Dark Horse design we tried to simulate a mushroom shape in our storage container. The mushroom shape decreases the footprint at the base of the mushroom and increases volume in the hat. Additionally, this design requires less height compared to a cylindrical shape. This decreases the risk of tipping and makes filling the container easier. The space below the overhang of the hat of the mushroom can still be used for trucks or storage of other material. The first step to making this prototype was developing a schematic to work out the intricacies of a collapsible design. For our first iteration we decided to try making a rectangular mushroom because components would be easier to manufacture and fold than a spherical top (fig. 4.45).

Figure 4.45: Schematic proposed design for dirt mushroom v1 in collapsed form. CHAPTER 4. DESIGN DEVELOPMENT 65

The main body of the dirt mushroom is made of aluminum wire mesh to keep the weight low and make the whole device fold-able. The steel pipes add support to the trunk of the dirt mushroom, and the metal cables cinch the wire mesh panels together. Inside the wire mesh layer a tarp contains the aggregate in the storage device. This design is collapsible so that the material can be piled on without any machinery, then the whole container is cinched up into the reduced footprint state. The 2’×4’s are used to lift the sides of the dirt mushroom into their upright position. After we had a basic design, we made a cardboard model (fig. 4.46) to determine if the proposed design was feasible. We used leftover crushed glass to act as the stored aggregate (fig. 4.47) and modeled what the saved space under the hat of the mushroom could be used for (fig. 4.48). The materials for the proposed scale model were replaced as follows in the cardboard model:

• Wire Mesh Cardboard

• Steel Pipes Thin wood piece

• Metal Cable Electrical Wire

• 2’×4’s Popsicle sticks

• Cloth Tarp

Figure 4.46: Cardboard pieces with electrical wire in collapsed position. CHAPTER 4. DESIGN DEVELOPMENT 66

Figure 4.47: The remaining crushed glass from the CFP was used to simulate aggregate in the cardboard model of the dirt mushroom storage container.

Figure 4.48: After forcing the closure of the rigid sides, the device stayed closed and we could simulate the idea of using the area under the overhang for vehicles. CHAPTER 4. DESIGN DEVELOPMENT 67

The first problem arose early. Pulling the electric wire to cinch the panels together was tough because of the sharp corners, so we added pieces of straws to run the electrical wire through to reduce some of the friction in the pulling (fig. 4.49).

Figure 4.49: The aggregate began to bulge through the gaps in the rigid siding, preventing full closure.

Additionally, using the Popsicle sticks to lift the sides up did not work due to the weight of the aggregate. Therefore moving forward with the dirt mushroom we decided to have the trunk of the dirt mushroom fully assembled while filling. Once the trunk is full, the hat is assembled and the storage device is filled the rest of the way. Later prototypes could focus on post fill assembly if needed. The biggest problem we saw with our design was that the aggregate fell between the cardboard pieces, which caused bulging and prevented the dirt mushroom from closing into its final shape. To try to remedy this problem, we added cardstock pieces to the cardboard siding. The cardstock was only attached on one side, allowing the second side to slide over the cardboard and fold into the dirt mushroom as it was cinched into the upright position (fig. 4.50). However, even with this added rigidity the aggregate bulged out the sides of the dirt mushroom as it was lifted (fig. 4.51). Although the bulging was reduced, there was still too much to properly close the storage device; additionally the cardstock jammed against the cardboard under the weight of the glass causing the closure to be more difficult. This jamming would have been amplified when using wire mesh instead of cardboard. After this cardboard model, we decided to return to a more mushroom-like shape with the thought that having more panels would reduce the bulging potential at the base, while the spherical top would allow for bulging to take on its shape. For the scale model, we built the dirt mushroom to be 40 tall with a 20 diameter. To begin, we cut six panels of 20x50 aluminum wire mesh and covered all the edges with duct tape to hide the sharp edges. We then drilled holes through six 20 long steel pipes and ran the metal cable through alternating between the steel pipes and weaving through the aluminum wire mesh. To replace the pieces of straws, we cut 200 pieces of PVC piping and zip-tied them to the wire mesh. Last, we zip-tied wood stakes to the steel pipes to hammer into the ground adding support the dirt mushroom to prevent tipping (fig.4.52). CHAPTER 4. DESIGN DEVELOPMENT 68

Figure 4.50: Cardboard frame with added cardstock pieces to prevent bulging of aggregate.

Figure 4.51: The cardstock pieces reduced the bulging but did not completely eliminate it and the cardstock jammed against the cardboard when sliding closed. CHAPTER 4. DESIGN DEVELOPMENT 69

Figure 4.52: The completed dirt mushroom folded up and ready for transport.

To test the dirt mushroom we drove to Redwood City to dig up Kristines backyard and fill the prototype with dirt. The dirt mushroom easily fit into the back of a standard four door sedan with shovels and repair materials (fig. 4.53). To begin we laid the wire mesh frame (fig. 4.54) and cinched the wire cable closed to get the trunk of the dirt mushroom into its upright position (fig. 4.55). We then put the tarp in and began filling the dirt mushroom with dirt (fig. 4.56). Once the trunk of the mushroom was filled, we pulled the top cable shut to form the hat of the mushroom and again began filling with dirt, however problems arose quickly.

Figure 4.53: The dirt mushroom easily fit into the back of a standard four door sedan. CHAPTER 4. DESIGN DEVELOPMENT 70

Figure 4.54: The wire frame of the dirt mushroom laid out just before as- sembly.

Figure 4.55: The trunk of the dirt mushroom in upright position. CHAPTER 4. DESIGN DEVELOPMENT 71

Figure 4.56: With the trunk of the mushroom up and the tarp on we began to fill the dirt mushroom with dirt. CHAPTER 4. DESIGN DEVELOPMENT 72

First, as soon as the dirt began filling the hat of the mushroom slightly off-center, the whole mushroom began to tip (fig. 4.57). We leveled out the dirt and switched to pouring buckets full of dirt into the dirt mushroom, but as soon as the dirt level rose a few inches above the supported trunk the dirt bulged out the sides and the whole thing began to tip. We added more top weaving through the mesh with rope for support to the top half, but it wasnt enough. Ultimately the whole dirt mushroom toppled over (fig. 4.58).

Figure 4.57: The dirt mushroom began to tip as soon as the loading of the dirt was not perfectly centered.

Figure 4.58: Despite our best efforts, the dirt mushroom ultimately toppled over before it was fully filled.

Although the dirt mushroom was not successful as a storage device, we learned a lot CHAPTER 4. DESIGN DEVELOPMENT 73 moving into Dark Horse v2. First, aggregate is too heavy to rely on siding that is not rigid, the final structure will need rigid support up to the full height. Second, closing the device after putting all the dirt on top will require an extreme amount of force which is not plausible to obtain on a C&D site for a lower cost than trucking the material off-site. Third, although the dirt mushroom was easy to transport it was not easy to set up or take down, so a much more simplistic design is required. Last, even though the dirt mushroom design didn’t work, the premise is a viable solution for on-site storage. We ran some numbers on the cost and footprint saving when using a storage device like the dirt mushroom and were excited to see the results. The dirt mushroom was 20 in diameter, but when we opened it up and let the dirt fall naturally, that same volume of dirt had a footprint with a 50 diameter. This reduction in footprint means that users could store approximately five times as much dirt in the footprint of un-contained dirt using dirt mushrooms. We then looked at how a dirt mushroom would be scaled up. For these calculations we chose 25 truckloads of dirt to be stored in a large dirt mushroom. A truckload is equivalent to 11 cubic yards of material ([1]). Typical excavators can reach about 8yds vertically ([3]) so, if we set this as our maximum height, that yields a diameter of 6yds to store 25 truckloads of dirt. On average it costs $25/cubic yard to truck dirt off-site ([13]). Therefore the minimum cost savings of using one dirt mushroom is around $14,000 when including cost to truck the dirt off and back on site. Additionally this saving doesn’t account for the increase in surface area on site that can now be used for other materials or equipment. Based on these numbers we feel that looking into on-site storage is still a viable direction for the remainder of the Dark Horse Prototyping phase. CHAPTER 4. DESIGN DEVELOPMENT 74

4.6.2 Dark Horse v2 - Shape Shifting Storage Moving into the second stage of the Dark Horse Prototyping phase, we reevaluated what we were trying to solve with our storage device. While the dirt mushroom will greatly reduce the required footprint to store material on-site, it would only work on really large scale C&D sites, and the design changes required to make the device feasible eliminated the benefit of the mushroom hat. Therefore we decided to look at a design that would be more modular, to cater to a large range of C&D sites, with rigid sides to add support and facilitate assembly. In order to test just the premise of the idea, we settled on the simplest design we could think of. The design is based on a repeating 2’×2 wood panel. The panels have metal loops on the sides to act as hinges when connected to the neighboring panel (fig. 4.59). Metal rods run through the loops connected the panels. To connect the panels vertically there are metal T’s in the center of the panel to prevent tipping (figs. 4.60 and 4.61). With this simple panel design the user could chose whichever height, width, and shape is needed for the amount of material and available space on the job site. Additionally, this allows for small enough storage devices to be used in residential settings or large enough to be used on large scale commercial projects.

Figure 4.59: Connection point between two of the week panels with steel rod. CHAPTER 4. DESIGN DEVELOPMENT 75

Figure 4.60: Schematic of panels used in the shape shifting storage device.

Figure 4.61: Completed wood panels with hardware. CHAPTER 4. DESIGN DEVELOPMENT 76

The idea behind using these standard panels was that they could be constructed into various sizes. For example, if a home owner was getting mulch for the backyard, they could put together a 2’×2 square to store the small amount needed to cover their yard. On the other hand, a construction worker could make a 12 tall decagon to store all the crushed up concrete from the foundation of the building they are demolishing. Either way, the same panels can be assembled to make these shapes. For our test, we built enough panels to make a 6 tall hexagon storage device. However, we ran out of hardware at the top, so we used zip-ties instead of the metal loops on the top layer. Because of the increase in volume, instead of using dirt, we filled the storage container with sand from Half Moon Bay. Damp sand has the same density as dirt, but it is much easier to dig. The shape shifting storage was easy to transport (fig. 4.62), but unlike the dirt mushroom, it was also easy to set up, only taking about five minutes to get the whole structure standing (figs. 4.63 and 4.64).

Figure 4.62: The shape shifting storage easily fit into the back of a four door sedan for transport. CHAPTER 4. DESIGN DEVELOPMENT 77

Figure 4.63: Assembly was quick and easy due to the simple design of the panels.

Figure 4.64: Fully assembled shape shifting storage. CHAPTER 4. DESIGN DEVELOPMENT 78

After filling the shape shifting storage to the point of overflow, we left it for about an hour to make sure it would hold the weight over time (fig. 4.65). After an hour it was still standing, and we realized we had no way to take it all down. Therefore, we had to test it to failure, so we starting piling people on top. We were able to get all four of our Stanford team members on top of the shape shifting storage device (fig. 4.66) before it failed (fig. 4.67).

Figure 4.65: We filled the storage container until it was over flowing with sand. CHAPTER 4. DESIGN DEVELOPMENT 79

Figure 4.66: We were able to get all four of our Stanford team members on top of the filled storage container.

Figure 4.67: Essentially as soon as the fourth team member stepped onto the top the whole thing collapsed under the added weight. CHAPTER 4. DESIGN DEVELOPMENT 80

This prototype was a huge success. We were able to hold 2.3 cubic yards of sand which is equivalent to three tons. After watching the footage of the collapse in slow motion, we were able to isolate the point of failure to be one of zip-ties on the top layer of the shape shifting storage, so with the proper hardware, our prototype would have held even more weight than the three tons plus four engineers. Additionally, we saw a 5:1 footprint reduction between the un-contained and contained sand. However there are two areas where we can make improvement in future iterations of this prototype. First, the steel rods bent a considerable amount under the weight of the sand (fig. 4.68). To remedy this, we can increase the diameter of the steel rods and increase the number of loops to add more points to distribute the force along the rods.

Figure 4.68: (a) Connection between plywood panels before filled with sand (b) Bend in connection at half-filled point (c) Bend and gap in panels once shape shifting device full of sand.

Second, as mentioned above, there is currently no method to empty the shape shifting storage device. In future prototyping phases, we plan to develop a quick release door or alternative method for removing the material once in the storage device. Given the cost savings discussed in the dirt mushroom section, and the added benefits of modularity and simplicity discussed here, we feel that with an added release mechanism, the modular storage device could be a viable product addition to Volvos current product line. CHAPTER 4. DESIGN DEVELOPMENT 81

4.6.3 BTH Dark Horse - Hammock Storage Machines, materials, waste and transportation all share the space, and due to the nature of the work this issue also have implications on for instance costs, regulations, logistics and safety. We set out to address the primary need of facilitating logistics on site by keeping materials off the ground. The design we choice to implement was that of a hammock-like storage device which reduces the space taken up on the ground by elevating the material (fig. 4.69).

Figure 4.69: Hammock prototype and shape sketches.

The concept is to store materials on a vertical level rather than on the ground. The pillars telescope and are six meters tall, which is within the reach of an excavator (fig. 4.70). The design is modular so that the customer can optimize the system for their needs. The hammock consists of a carbon/Kevlar hybrid fabric, making the system lightweight and foldable, and thereby easy to deploy for transportation (fig. 4.71). One of the ideas for the hammock storage is that trucks, humans, and other machines would be able to pass underneath it. The streets of New York were one of the possible areas of use that was considered for this concept. The pillars would stand on the sides of the roads, allowing some storing place in the air, and still allow traffic to pass underneath it. We used the following numbers for our calculations based as an example configuration for the hammock storage device:

• Height = 6meters

• Triangular Frame = 6meters in length, diameter = 10cm (3cm thickness)

• Hydraulic Cylinders Load Capacity = 36 tons

The yellow shell (fig. 4.70) is a protective barrier for the hydraulic cylinders and are non structural. Through our research we have found hydraulic cylinders with the capability CHAPTER 4. DESIGN DEVELOPMENT 82

Figure 4.70: Elevated storage for construction and demolition sites.

Figure 4.71: Attachments designed to be easy modular, attach- and detach- able. CHAPTER 4. DESIGN DEVELOPMENT 83 of supporting more than 1000tons and carbon Kevlar hybric fabric with a tensile strength of more than 3500MPa. (ref Fibre Glast Development Corporation. Product specification of their kevlar hybrid fabric: http://cdn.fibreglast.com/downloads/00347-A.pdf - accessed 2015-03-03.) We conducted an interview with a manager of product development at BTH with many practical years of experience. He said the concept is possible and the dimensions and choice of materials are the factors that determine feasibility. The triangular and hexagonal shapes could help in saving space when putting multiple hammocks besides each other. Another interview was conducted with a retired construction manager. The safety factor was highlighted during this interview. The C&D sector have strict laws and regulation, since they represent a large number of incidents in Sweden and the sectors requires high safety. This could mean that our idea of having traffic and humans moving underneath the hammock is not possible, if the product is not designed with a high safety factor. A high safety factor would also mean a higher cost for the product. Another big challenge that was identified was how the stored materials would be emptied or removed. The storage is easy to load but can be tricky to be emptied in an efficient way. Due to the high mass of the stored materials, it could be difficult to have a controlled dispensing or an emptying process. Upcoming prototypes attempts to address this issue.

4.7 Emptying the Storage Containers

Conversations with contractors from both small and large deconstruction projects made it clear that storage is certainly a growing need on deconstruction and demolition projects. After showing our dark horse storage solution, both groups of contractors had the same question. Once the containers are filled, how will they be emptied? If contractors take the time to pile deconstruction debris neatly in a container, there should be an elegant solution for emptying the containers to take advantage of the work they have already done. For our FUNKtional prototype, we focused on emptying the container on a small residential scale project, such as the ones we visited with Juan.

4.7.1 Self-Emptying Storage While deconstructing houses, Juan’s teams take countless trips from all over the house to the dumpster or truck parked outside. Often the materials are sorted and piled up in the house, then put into garbage cans and carried out to the dumpster when it arrives as shown in fig. 4.72. This is inefficient because it involves double handling materials inside the house and lifting them above the worker’s heads to empty them into the dumpster. Our aim was to create a solution that eliminates this double handling and reduces the need for workers to lift heavy containers above their heads.

4.7.1.1 Mobile Base To be useful on a small deconstruction site, our solution should be mobile and easily moved from the middle of a house to the dumpster outside in the driveway. A worker should be able to fill the container as he works instead of piling it on the ground. By filling as he goes, the storage container eliminates the double handling that currently occurs. When the CHAPTER 4. DESIGN DEVELOPMENT 84

Figure 4.72: Workers carry trash cans of deconstruction material from the building. dumpster or truck arrives, the worker simply wheels the container out of the building and empties all the material at once. Our system vision involves using different configurations of the same panels for each size job. For consistency and simplicity in prototyping, we continued to use the half scale wood panels from our dark horse prototype. While wood is not the final building material, it was used in our prototypes because it is strong enough for simulated tests and easy to cut to proper lengths. We selected four large caster wheels for our mobile base. They allow the prototype to easily move in any direction. The wheels are also made of solid plastic (fig. 4.73), which allows them to roll over exposed nails without the worry of flat tires.

4.7.1.2 Emptying Mechanism In addition to being mobile, the solution must also be quickly and easily emptied once the mobile container reaches the dumpster or truck. While the current method of carrying garbage cans may be labor intensive, the workers we observed can very quickly transfer the material to the truck. The tools used in deconstruction projects are often very simple. For the workers on the site, complicated tools and electronics are seen a liability which can actually slow down work if they are not robust and easily taught to new workers. For this reason, we chose to construct a completely mechanical latching system. For the prototype, we cut a door out of the wheeled base and put hinges on one side as shown in fig. 4.73. To keep the door closed, we attached gate locks to the other side of the door. When the locks are tripped, the door is able to swing open, allowing the container to empty. Once the container has CHAPTER 4. DESIGN DEVELOPMENT 85

Figure 4.73: Trapdoor prototype base been emptied, the door automatically locks when swung back into place.

4.7.1.3 Dumpster Attachment When loaded with material, these rolling containers will be too heavy to be manually lifted into a dumpster for emptying. They require a system that can be temporarily retrofitted to a dumpster or truck for loading and can be removed when the dumpster is picked up. We couldn’t get a lift, so we chose to build the part that attaches to the dumpster and simulate the lifting mechanism. Our dumpster attachment consists of a track for the wheels with two wedge shaped beams along the edge of the track that trigger the gate locks and allow the door to open (fig 4.74). The rest of the beams are used to securely attach to the dumpster and provide stability for the track.

4.7.1.4 Testing and Results To test the unloading function, we used the balcony in the Peterson Building atrium as our dumpster edge. Because we didn’t have a lifting mechanism, two team members lifted the storage container onto the wooden track and pushed it along the track to trip the gate latches (fig 4.75). Once the container was empty, we manually swung the door back into locked position and lowered it to the ground. With a few small modifications, we were successfully able to dump material into the atrium using our prototype. We discovered that the hardware on the caster wheels was hitting the wooden sides of the track, motivating us to shave down the sides of the track. We also found that the rods on the gate latches needed more clearance to operate properly, so we had to cut notches in the track so that the door could swing open. The latches also couldn’t hold much weight and were very loose, so we would need to redesign the CHAPTER 4. DESIGN DEVELOPMENT 86

Figure 4.74: Testing in the Peterson Building atrium

Figure 4.75: Testing in the Peterson Building atrium CHAPTER 4. DESIGN DEVELOPMENT 87 release mechanism if we use this dumping method. Finally, when we pulled the container backwards along the track, the caster wheels would jam against the sides as they tried to spin in place. This would have to be addressed if we were to continue using caster wheels in a final design. CHAPTER 4. DESIGN DEVELOPMENT 88

4.7.2 BTH: Auger Emptying System This prototype investigated if the use of Archimedes screw principle (fig. 4.76) can be applied to dispense stored and packed materials from storage in a controlled manner. Dis- pensing it in a controlled manner could reduce unnecessary time and effort.

Figure 4.76: Illustration of how Archimedes screw principle can be applied to transport water to a higher level

To build this prototype BTH followed the same design the Stanford team used in their Dark Horse Shape Shifting prototype. At the bottom of the storage container a soil pipe is inserted into a cut-out in one of the panels (fig. 4.77). An auger is then placed in the bottom and used to push the material out the soil pipe. In order to facilitate the material leaving the storage container, we angled the bottom toward the pipe opening. We then put a layer of sand into the storage container (fig. 4.78) to test the dispensing mechanism and rotated the auger by hand to force the material out (fig. 4.79). CHAPTER 4. DESIGN DEVELOPMENT 89

Figure 4.77: Test of auger dispenser.

Figure 4.78: Angled walls in order to make it possible for all the material to fall down into the auger. CHAPTER 4. DESIGN DEVELOPMENT 90

Figure 4.79: Dispensing test was performed to measure the efficiency of the auger. CHAPTER 4. DESIGN DEVELOPMENT 91

In this small test, it took 30 revolutions to dispense 14.3kg of wet sand which equates to 0.48 kg/rev or 0.4L/rev. One large hauler can hold 20 cubic meters (36 tons). This means that will take 50,000 revs to empty one hauler load with this setup. A small com- mercial motor designed for this auger can operate the auger about 250 rev/min, so an entire truckload is emptied in 20 minutes for this size prototype. There were a few issues with the use of an auger. The sand did not slip against the walls, which resulted in clogging and stopped the sand from exiting the storage device. We had to push the sand down or shake the whole system to get the sand to dispense. The weight of the stored mass is not directly related to the auger torque resistance, since the auger was equally heavy to rotate regardless of the amount of materials in the storage. However the auger’s size and radius would affect the torque resistance. There were a couple options available to modify the auger dispensing method in order to address the clogging problem. We could use a larger diameter auger, a higher angle for the bottom walls, or use a slippery material to line the bottom walls. For this prototype we decided to implement the first two options (fig. 4.80). The plastic coated has a lower friction in contact with the stored materials compared to the bare storage walls made out of plywood and the increased angle used gravity to our advantage. We tested this design with top soil (fig. 4.81) and sand (fig. 4.82) to make sure it was versatile. Additionally we continued to shake the prototype when needed to force the material out.

Figure 4.80: Walls with increased angles and added plastic to make them more slippery (less friction).

Top soil dirt reacted similar to the sand, i.e. it also clogged before going into the auger.The changes to the prototype did not solve the problem and the result was more or less the same as before. However, one difference was noticed: when the storage had very little material inside, it worked well with the lower friction walls. But when it was filled, it clogged. The shaking on the other hand did make the material fall down into the dispenser. The only problem was that it had to be shaken a lot. A larger diameter auger and a bigger opening would probably be needed to improve the emptying function. The vibrations caused by the shaking had to be quite intense to make the material move as desired. A device that vibrates the material over the auger would also be needed. CHAPTER 4. DESIGN DEVELOPMENT 92

Figure 4.81: Auger dispenser with plastic coated walls and test with top soil dirt.

Figure 4.82: Auger dispenser with plastic coated walls and sand as a test material. CHAPTER 4. DESIGN DEVELOPMENT 93

4.8 System Prototype

In our next series of prototypes, we focused on refining the storage idea that we began developing in the last two rounds of prototypes. We had to begin to narrow down what features are critical to the user and what features would be less critical for our design. We also began to focus on designing the complete system, addressing the questions: what steps would be required for the transportation, setup, and use of the modular storage system?

4.8.1 Panel Sizing An important design parameter is the size of the panels. If the panels are too small, a jobsite will require too many containers of material and the advantages to the storage will be outweighed by the amount of time it takes to move them. On the other hand, if the panels are too large, they will be hard to set up by hand and the container will be too heavy to be picked up when full. Based on these constraints, we decided on a panel length and width of 48 inches. Standard pallets have a width of 45 inches, so they could be used to handle and transport the disassembled panels. Flatbed trucks are 102 inches wide, so two rows of stacked pallets should easily fit on the trucks. We also looked at a hexagonal base. With a panel size of 48 inches, the base would allow a standard two foot excavator bucket to dump into the container without spilling any material. When full of crushed concrete with a density of 100 lbs per cubic foot, the container would weigh 8.5 tons, which is within the lifting range of most medium-sized excavators.

4.8.2 Full Size Cardboard Panels To get a better sense of the size of the full-sized panels, we created cardboard prototypes. We used pizza boxes to get to get a realistic panel thickness of about 2 inches. We then added handles to the panels based on the biometrics of an average sized person. Based on our model, the handles should be at shoulder width about 16 inches from the top for comfortable lifting (fig. 4.83). When experimenting with lifting, we discovered that we needed handles on the edges of the panel as well as the face. When the panels are flat on the ground, it is difficult to stand them up without handles on the edge(fig. 4.84). We will also need to make the handles over-sized to accommodate work gloves.

4.8.3 Flexible Container Bottom From our meetings with general contractors, we have learned that mobility is important for a storage solution. Additionally, some way to control the release of material from within the container would be a beneficial addition to our storage solution. With these two design goals in mind, we decided to try to prototype a container bottom made from heavy duty tarp fabric. Our design used solid rods that run along the outside of the hexagon shaped fabric (fig. 4.85). The panels slide into a base which has hooks along the outside to hold the fabric to the base (fig. 4.86). When the container is to be emptied, the rods can be released from the hooks and the container can be lifted. We again tested our prototype by filling it with sand. In our tests the fabric bottom held the weight that we put on it, though we did not fill it up completely (fig. 4.87 and CHAPTER 4. DESIGN DEVELOPMENT 94

Figure 4.83: A person of average height lifts the panel

Figure 4.84: Difficulty lifting when panels are laying horizontally CHAPTER 4. DESIGN DEVELOPMENT 95

Figure 4.85: Flexible bottom before attachment to frame

Figure 4.86: Flexible bottom attached to frame CHAPTER 4. DESIGN DEVELOPMENT 96

4.88). It seemed like the fabric was close to ripping in the spots where we had cut it to make room for the hooks. If we are to use a fabric bottom for the final design we will have to come up with a better way to attach it without making cuts that compromise the strength of the weave. The dumping function worked well in this prototype, however. If fabric can withstand the high stresses, this flexible bottom could be the final design direction.

Figure 4.87: Setting up the flexible bottom

Figure 4.88: Complete flexible bottom half scale prototype CHAPTER 4. DESIGN DEVELOPMENT 97

4.9 Findings

4.9.1 General Findings Many modern developers are motivated to be environmentally conscious on projects. This motivation may come from a client pursuing LEED certification, a local government policy, an economic reason, or even a personal conviction to improve our earth. However, good in- tentions may not be realized due to the cost, schedule, or inconvenience of reuse or recycling. Therefore, developers need ways to make reuse and recycling C&D waste economically and logistically feasible. Over the past two quarters, our team has performed benchmarking and needfinding to understand the current state of the construction and demolition industry, and where it will be heading in the future. Talking with a general contractor, developer, civil engineer, deconstruction manager, demolition company owner, and other professionals in the industry has provided us with a well-rounded view of what is currently being done to reduce waste from C&D projects. Each project is unique. Most C&D equipment is designed to be capable of performing several functions. For example, Volvo CE provides versatility by offering different attach- ments for their demolition excavators such as grapples, hammers, shears and pulverizers. Along with adaptability, robustness is another key trait required of demolition equipment. Most demolition projects require the tear down and removal of large volumes of heavy materials such as concrete, dirt, and steel. Equipment must be able to handle large, dynamic forces without breaking. In talking with construction workers and construction managers, we found that workers value simplicity over complexity in their tools. A complex electro- mechanical tool or attachment is viewed by workers as a potential point of failure with no easy, on-site fix. A replacement for a specific part may not be immediately available, which could mean schedule delays and require more manual labor to complete a job. One issue brought up by many industry professionals in our discussions was the off-haul of material. Whether the material is being hauled to a landfill or a recycling center, large amounts of trucking is required. Trucking is disruptive to the community surrounding the construction site, produces CO2 emissions, and is costly for the building developer. Also, off-haul costs often can account for more than half of the total demolition cost. Finding a way to reduce the amount of trucking from a job-site would offer several benefits to a developer. The prompt given by Volvo CE focuses on projects in urban areas as the populations of cities continues to increase worldwide. Urban job-sites bring about challenges not experi- enced on more rural projects. One of the most glaring issues is the lack of space on the site. Developers must create a plan to effectively use the limited space and often times there simply is not room to store large volumes of materials on-site. To address this problem, there are portable, on-site material handling systems already on the market that are ca- pable of sorting and crushing materials such as concrete. However, there is no widespread solution for storing the resulting material in a small footprint after it has been separated and crushed. Our work this quarter has primarily focused on providing a solution to in- crease the amount of on-site reuse by providing a place to store material that is not being processed. CHAPTER 4. DESIGN DEVELOPMENT 98

4.9.2 CEP: Aesthetic Glass Brick Findings Last quarter, we explored a way to reuse glass on a jobsite by using it as aggregate in concrete. Though we were not able to achieve the full strength of industry standard concrete in our first prototype, we think that with modifications to the mixture ratios and molding process that glass bricks could be a viable building material. The first glass bricks made utilized gray Portland cement as a binder, which caused them to look similar to standard concrete. The effort and time put in to separate, crush, size, and mix glass concrete would be much greater than buying new concrete. We expect that in order for glass concrete to be used by our user, it needs to be more visually appealing. Therefore, more aesthetically pleasing glass concrete was simulated and showed to users. We found that users preferred the visual effect of the new bricks over the old, but that they would be prohibitively expensive for most projects.

4.9.3 Dark Horse v1: Dirt Mushroom Findings With the Dark Horse prototype, we shifted our attention from finding new ways to reuse jobsite materials and focused on a way to enable more reuse through effective storage. Knowing that space is a constraint on urban projects, the goal was to create a storage container that could hold a large volume in a small footprint. The choice of mesh for the supporting walls was made with portability in mind, but ended up creating problems. The mesh walls of the prototype were unable to support the weight of the dirt. However, we were surprised to find the amount of footprint space it could save our user, Devon the Developer.

4.9.4 Dark Horse v2: Shape Shifting Storage Findings Moving forward, we addressed the Dirt Mushroom’s shortcomings by creating a more rigid design. The Shape Shifting Storage device was designed based on our general findings to be modular, robust, and capable of holding many different materials. It was promising to learn that we were able to make a container that could hold 3 tons of material with only plywood and simple hardware.

4.9.5 BTH Dark Horse: Hammock Storage Findings BTH also looked at a way to store materials on-site. They designed a Hammock system that lifted the material off the ground so the workspace underneath could still be used. It was determined that the hydraulics for the system would likely be very expensive, and it would be hard to find a suitable fabric material for large sizes.

4.9.6 FUNKtional Prototype: Self-Emptying Storage Findings When talking to Kharon,the Associate Director of Construction and Renovations at Stan- ford; Jaun, a deconstruction site manager for The ReUse People; and from seeing jobsites firsthand, it became clear that any storage unit we develop must be able to be moved and emptied. The potential energy stored in the container should be utilized and not wasted. In CHAPTER 4. DESIGN DEVELOPMENT 99 the FUNKtional prototype, we set out to provide this functionality in a self-emptying stor- age container aimed for smaller deconstruction projects. The idea was to provide another use for the modular Shape-Shifting Storage panels we developed. On a visit to a single- family home deconstruction site, we were surprised to learn how quickly our user, Dave the Deconstructor, was able to haul recyclables to the dumpster. If we expect Dave to use this product, it would need to be equally as quick (or substantially less physically staining). Some design modifications need to be made to meet this specification. We decided not to pursue this idea because of the small size of the current deconstruction market, but think it could still be a viable use for the panels. This prototype allowed us to test one emptying design idea and elucidated several complications we previously had not considered during material emptying.

4.9.7 BTH Prototype: Auger Emptying System Findings BTH also prototyped and tested an emptying mechanism for a modular storage container. They made use of an auger system to dispense material from the bottom of a container. They found success in emptying sand, but encountered clogging problems in their testing caused by the damp sand sticking together. Understanding and designing for the different interactions between grains that occur in damp and dry soils will be critical to creating a reliable emptying mechanism.

4.9.8 Functional System Prototype: On-site Storage Solution Findings The goal of the Functional System Prototype was to flesh out the process of an on-site material handling system. The needs of both Dave the Deconstructor and Devon the Developer were considered during the system design. We began by selecting a container volume using the process discussed in the Design Description. The storage solution is meant to replace the need for Devon to off-haul material with trucks. Therefore, we used a standard 12 cubic yard truck as a volume comparison when sizing the container. The containers were designed to hold the weight slightly less than the lifting strength of an average sized excavator, which ended up being half of the capacity of a truck. Once the panel size was calculated, we created full-scale cardboard prototypes to gain an understanding of the maneuverability of the panels. Handles were added to help Dave the Deconstructor assemble the storage container. However, we learned that when the panels were laid flat, as they will be when they arrive on the project site, the handles were ineffective. This finding will be incorporated into our next design to improve ergonomics. The Functional System Prototype also incorporated a new emptying mechanism design. Currently, there are heavy duty fabric bags that can be used to haul small volumes of debris. We were able to purchase a bag capable of holding 3300 pounds on Amazon.com called the Bagster. The bag was cut to fit the bottom of the hexagonal storage container. With this design, we found that the lightweight, flexible bottom made transportation easier. Also, the strong fabric was relatively cheap to purchase. One of our most important goals is to make attachment and detachment of the bottom quick and simple for Dave. The hook and bar design we tested was difficult to detach after lifting due to the sagging of the flexible bottom, which caused material to mound between the base and the bottom. The prototype showed promise, and with improvements, could be the direction of the final product. CHAPTER 4. DESIGN DEVELOPMENT 100

Another consideration of the Functional System was designing for use with autonomous machines. Volvo is currently designing autonomous construction equipment, and we want our system to work on the jobsites of the future as well as ones today. Making the setup and tear-down process simple would allow a machine to use the containers. Simplicity also improves Dave’s experience. After another quarter of needfinding and prototyping, we have developed a system that we believe addresses a critical need in the Construction and Demolition industry. We have received positive feedback from professionals within the industry including two people who expressed interest in purchasing the idea. This feedback has made it clear that our storage solution is addressing a need, and we are looking forward to developing it into a finished product next quarter. 5 Design Description

5.1 Vision

The volvo Nix is the solution to jobsite logistics and material handling on construction and demolition jobs with tight space constraints. In the future, we foresee a higher percentage of on site reuse and recycling. By reducing the footprint of a material by up to 600 percent, it enables more material to remain on site for reuse, decreasing the disruptive trucking through the surrounding neighborhoods. This trucking is both a substantial cost for the developer and can be used by the community to deny the permits necessary to undergo the development project. The Nix consists of modular panels that are lightweight and easy to set up. The panels can be combined in a wide variety of configurations to create a stationary silo or they can be attached to a base that allows them to be picked up and moved by an excavator. The base includes a dumping mechanism that allows the material to be released where needed in a controlled manner. The entire system is reusable, so after the project is complete, the contractor can set up the same panels in another configuration on another job site.

5.2 System Overview

The overall system can be decomposed into 6 simple steps, as shown in fig 5.1.

Figure 5.1: Overview of the NIX system

101 CHAPTER 5. DESIGN DESCRIPTION 102

1. The panels are either purchased from Volvo or picked up from the contractor’s yard where they are neatly stacked on pallets. The pallets allow large numbers of the panels to be moved efficiently using a forklift. They are loaded in large numbers onto a flatbed truck and transported to the jobsite.

2. The panels are removed from the truck on the jobsite where the storage is needed. A worker attaches the panels in the desired configuration.

3. Once the panels are connected, an excavator can fill multiple containers with material.

4. When the containers are full, the excavator lifts and moves the containers to an unused portion of the jobsite. The containers are stackable for maximum area savings.

5. The containers remain stacked on site for months until they are needed again.

6. When the material is needed again, the containers are brought back by the excavator. The opening mechanism is activated and the material is emptied.

5.3 Hardware

5.3.1 Panel Size Panel size is a very important design consideration. If the panels are too small, the com- pleted container will not hold enough volume. If the panels are too large, they will be too hard to put together and the container will be too heavy to be moved around the jobsite. We selected the panel size based on an excavator lifting weight of 10 tons and a hexagonal base for close packing. The panel dimensions are shown in figure 5.2.

Figure 5.2: Proposed panel dimensions

The panels are sized to fit on a standard pallet, which are 45 inches by 45 inches. This allows stacks of panels to be easily moved around a warehouse, storage yard, or construction site. An outer edge of 50 inches means that the panels will be able to be loaded onto a 102 inch wide flatbed truck in rows of two, reducing the number of trucks required to transport the panels to the jobsite. Once on site, the panels have inset handles so they are able to be lifted and put in place by one person. CHAPTER 5. DESIGN DESCRIPTION 103

5.3.2 Connection Hardware Another important design consideration is the type of hardware used to connect the panels to each other and the base. In the prototypes, we have been using a hinge style rod that slides into knuckles that are affixed to the panels to pin the joints together (fig. 5.3). On the base we have used simple slots to keep the panels in place. The hinge style joints are ideal as they are strong and they allow the panels to be attached at any angle. The slots are excellent for simplicity, although the final design may require a more substantial connection between the panels and the base.

Figure 5.3: Preliminary Panel CAD Model for testing hinge joints

5.3.3 Lifting Base One of the most important features of our panel design is modularity. The panels can be combined in any shape that is desired by the contractor. A base would restrict this, but when interviewing users, they indicated that mobility was very important. Therefore we added a base at the expense of modularity. Multiple size bases are possible, but we have focused on a hexagonal base. Hexagons naturally allow for close packing, as seen in the honeycombs built by bees. Furthermore, when speaking to users, we found that a two foot excavator bucket is one standard that we should think about designing for. As shown in figure 5.4 one of these buckets has a sweep of about 64 inches. A hexagonal design allows this standard bucket to fill our container without any spilled material. These two foot buckets have a volume of 0.47 cubic yards, so a hexagonal storage container will hold about 13 buckets. This is equivalent to half a truck load of material. This gives a good ratio between filling the containers and moving them. Another important design consideration is weight capacity. Ultimately we are limited by excavator lifting capacity. These vary, but we have designed for a mid-sized excavator with a lifting capacity of 10 tons. If we use a crushed concrete density of 100 pounds per cubic foot, the weight of a full container will be 8.5 tons, well below the 10 ton lifting limit. Crushed concrete is a worst case scenario, and many materials have densities below this. CHAPTER 5. DESIGN DESCRIPTION 104

Figure 5.4: Proposed base dimensions

5.3.4 Emptying Mechanism After speaking to our users, we have concluded that an emptying mechanism for the base is a crucial feature for these storage containers. The contractors have spent time to pile material in the containers, so they should have an easy way to remove the material from the container in a controlled manner. Emptying is something that we have looked into extensively in our prototypes and while we don’t have a complete solution, we have gained insight from our prototypes that we will be able to utilize in the final design (fig. 5.5).

Figure 5.5: Prototyped Base Designs

Each of the emptying mechanisms that we have prototyped have positives and negatives associated with their design. These details are discussed in more detail in the findings section. Our final design will undoubtedly take positive aspects from the three designs that we have prototyped so far. The emptying mechanism should be simple and purely mechanical if possible. It should be capable of controlled empty, so that contractors can control exactly where the material is deposited. Finally it should be robust and capable of holding the large forces exerted by the weight of the material. CHAPTER 5. DESIGN DESCRIPTION 105

5.3.5 Final Design Challenges Based on the design requirements from our user interviews, the final container design will have significant mechanical design challenges. Many of these are due to the modular options that makes our design so attractive and versatile. The mobile containers with bases must be stackable to maximize the amount of site space savings. This requirement brings several design challenges with it. For jobsite safety, the containers must have some way to securely lock together in the stack so that the containers cannot slide off and spill material or injure workers. Stacking will also significantly alter the stresses on the containers. In a simple silo configuration without any bases, the only significant stress will be the hoop stress from the outward force of the material on the container. With stacking, each layer of panels must support the entire weight of the material in the container above it. In this configuration, vertical forces and buckling become a significant issue. Going back to the weight capacity numbers above, for a three layer container configuration the bottom container must vertically support the two containers above it, which will amount to 17 tons if we continue to assume a container capacity of 8.5 tons. The containers with bases must also be liftable to move material around the jobsite. The bottom must be able to fully support the weight of the materials in the container. Our prototypes have used cables attached to the base for lifting, and this has shown to be a viable option for the final design. The cables come together above the panels, so the panels will require eyelets to guide the cable over the top of the container. The containers must be strong, but they also must be lightweight so that they can be lifted and assembled by on site workers. Material selection will be very important to maximize panel strength while minimizing weight. The most likely design will probably consist of a strong metal frame where the connection hardware is mounted with a sheet of metal or plastic over much of the panel area to reduce overall panel weight and cost. 6 Planning

6.1 Deliverables and Milestones

As we move into the Spring Quarter we have the following deliverables and milestones to structure our work.

Table 6.1: Spring Quarter Milestones and Deliverables Mission # Mission Title Dates Mission 19 Spring Hunting Plan Mar 31 - Apr 2 Mission 20 Part X is Finished Apr 2 - Apr 16 Mission 21 Manufacturing Plans Apr 9 - Apr 21 Mission 22 Penultimate Review Apr 23 - May 21 Mission 23 EXPE Brochure and Poster May 21 - May 29 Mission 24 EXPE Presentations May 26 - June 4 Mission 25 Final Documentation June 2 - June 9 Mission 26 End-of-Year Checkoff June 9 - June 12 Table 6.2: Basic deliverables and milestones set for the spring quarter with approximate dates they will be worked on.

6.1.1 Project Time Line Over spring break, the Stanford team will visit Volvo in Germany and Sweden as well as BTH. The feedback received during the trip will be used to help finalize the product design. In addition to the deliverables for prototyping next quarter, we will continue to meet with Naomi on the Transform Urban Project. Also, we have contacting a former IDEO employee to be our manufacturing consultant. The plan is to hire a structural engineering consultant as well. Our weekly meetings with our corporate liaison and BTH team members.

106 CHAPTER 6. PLANNING 107

6.2 Distributed Team Management

For collaboration over the course of the year the Stanford and BTH teams are taking every effort possible to act as one unit. To do so the following communication platforms are being utilized:

• Dropbox: File Sharing

• Facebook Group: Quick Communication

• E-mail Lists: Long Updates

• Weebly Team Blog: Quick Summary of Work

• Google Hangout: Weekly Video Meetings

• Google Hangout: Bi-Weekly Video Meetings with Volvo CHAPTER 6. PLANNING 108

Figure 6.1: Distribution of focuses for the winter quarter among both the Stanford and BTH teams. CHAPTER 6. PLANNING 109

Table 6.3: Planning for Spring Quarter Deliverables Mission Title Plans People Spring Hunting Plan Develop a comprehensive Both Stanford and BTH will quarter-long plan for how need to be involved in the to complete the project creation of this time-line. by EXPE. This will re- Tasks will be divided be- quire us to think about tween the two teams. long lead time items and finalize the functions of the storage containers. Part X is Finished Finalize the emptying and Stanford and BTH will both bottom attachment mech- work on ideation, design cal- anism for the storage con- culations, and prototyping tainers. to decide on a final design. Kharon, from the Meyer Li- brary Project, will be con- sulted throughout the de- sign process to get user in- put. Manufacturing Plans Plan for building a final, The Stanford team has functional prototype. contacted a manufacturing coach to help in the pro- cess. Also, our team coach, Michael Balsamo, has man- ufacturing and design expe- rience. BTH will work on developing the business plan for the storage solution. Penultimate Review Finalize the storage solu- Stanford team will build and tion design and continue assemble. BTH will work manufacturing the final on an integration plan for product. Volvo. Functional System Based on the above find- Stanford and BTH will work ings we will pick which more closely at this point one we feel will have the and begin to converge on a greatest impact, is the single solution and process most plausible, and best fits into Volvo product line Table 6.4: Planned work for deliverables over the spring quarter with assign- ments for Stanford and BTH teams. CHAPTER 6. PLANNING 110

6.3 Project Budget

Table 6.5: Fall Spending Vendor Name Description Amount Radioshack Sensors for paper robot $16.61 JoAnn Fabircs Fabric for paper robot $20.95 Fry’s Electronics Sensors and LEDs for paper $40.74 robot toolmarts.com handheld denailer $78.11 Home Depot bricks, cement, glass $128.87 Mileage Benchmarking, needfinding, $113.12 team building Total $601.60 Table 6.6: Summary of spending during Fall quarter given $1,000 budget.

Table 6.7: Winter Spending Mission Description Amount CFP/CEP Epoxy, cement, and plaster $64.26 Dark Horse: Dirt Mush- Aluminum mesh, steel rope, pipe $508.79 room Dark Horse: Shape- Lumber, shovels, truck rental $97.26 Shifting Storage FUNK-tional: Self- Lumber, latching hardware, U- $262.88 Emptying haul rental Functional System 3D scale model print, cardboard $217.58 boxes, Bagster dumpster, hard- ware, straps Mileage Visiting Transform Urban and $253.12 other site visits Extras Bride-tolls, overnight shipping, $250.64 working lunches Domino’s SUDS Personalized Domino’s medium $404.51 pizzas Total $2059.04 Table 6.8: Summary of spending during Winter quarter given $3,000 budget. CHAPTER 6. PLANNING 111

Table 6.9: Expected Spring Spending Mission Description Amount Spring Hunting Plan Design development will primar- $100 ily be completed with calculations and small prototypes. Part X is Finished Container base and attachment $500 hardware. Manufacturing Plans Production of full scale panels $3000 Penultimate Review Prototyping materials. $500 Mileage Visiting Transform Urban and $350 other site visits Extras Mistakes, overnight shipping, etc. $200 SUDS Great food for everyone. $450 Total $5100 Table 6.10: Prediction for spending during Spring quarter given $4,000 bud- get (plus $1500 roll-over from previous quarters). CHAPTER 6. PLANNING 112

6.4 Reflections and Goals

Niklas Nilsson In general I really enjoy working with the project. All the prototypes we have been doing have provided us with several important insights regarding feasibility and suitability for our intended customer. Being able to have all these hindsight but still be given the opportunity to go back and rework it have been giving. But before prototyping, we have always made sure that our creations as based on actual customer needs and wants. Which meant that we actually go into the prototyping phase with an idea. The idea then of course varied depending on what type of prototype we aimed to create. Regarding the needfinding I feel like we really benefited from keeping our scope wide, meaning that we did research on several different areas including C&D, Municipal solid waste, electronic waste and appliances, rubber waste and water waste. This, I feel, provided us with a wider span of knowledge going into each prototype. And we were able to combine features and technology from a wide range of fields. I feel like there have been two different coaching approaches, one that have been applied to the students at Stanford and one that has been applied to the students at BTH. This has caused several issues for the team and the project as a whole. It has made communication increasingly more difficult and as far as general direction for the project we just recently discovered that we have been working in two separate directions. However, this new found insight of course provides us with the opportunity to fix the problem. Adding to this, I feel like we have two different visions regarding what is expected from Volvo CE as the owner and customer of this project. However, these two visions might be merged and something awesome might be the outcome. Given the circumstances I really do feel like we are doing what we can to maintain a beneficial group dynamic. And I am impressed with how everybody on the team have been able to handle the obstacles that have come up during the project. I am very much looking forward to meet the Stanford part of the team when they travel to Germany and the later on to Sweden to meet us. I both hope and believe that it will be really fun and strengthen the group as a whole. And it will increase the chance of a successful project which have created a kickass product incorporated in a kickass system!

Simon Ha From last fall reflection a common goal from many of us was to establish better team- work and collaboration. This winter I think we have made good progress in this aspect. Everybody seem to encourage and work for it. We had open discussions, giving each other critique and feedback which I believe have helped the project a lot. I wish us to keep trying to be open with critique and feedback, and to not hesitate or hold back in communicating these. In the end I think it will help the project a lot. There may be some mismatch between us in the team on the coach’s and Volvo’s expectations. I think it will be better as long as we are keeping our communication going and keep struggling with the less comfortable matter. These past weeks we’ve been working a bit separated. Stanford with the prototype and BTH with the vision part. I hope that we can unite our brains eventually in both of these, even if course expectations or planning is not directly supporting it. I think that restricting CHAPTER 6. PLANNING 113 ourselves to the planning set by the ME310 course too much might have a bad effect on the project. I wish we could be more flexible in this aspect even though it may bunch up a lot of work in the end. Late evenings with pizzas and coffee will always solve whatever is left to do, in my opinion. Not to mention the great experiences and memories it will give us. I’m looking forward to when our Stanford colleagues come to Sweden mid Mars. It will be one out of few occasions we will be working together in the same place. I wish that the team will come out even more motivated and more united towards the last efforts before the expo in June.

Gustav Kgesson First of all I really enjoy working in this project, it is very interesting and I get questions about it from friends and family all the time. Early this year we started to focus more on prototyping and building stuff. These were made in cad, random junk and some real materials to get different aspects out of it. I feel that this was both good and bad. It was good because it is fun to build stuff and it is easy to learn from it. It is much easier for me to take something useful with me from something I was a part of building and tried out then just to read about it. However I feel that the general creativity and innovation decreased when the focus was too heavily on building stuff. I feel that we lost our big visionary thinking and started thinking more on what we could build to the very short weekly deadlines. It might have been better to do one prototype every other week or so just to decrease the stress of just building something. I think this would have led to fewer but better prototypes in the end if there was more thought put into it before we started building. But I think we realized that and tried to take a step back too look at what was good, what was bad and what can be improved. Another bump in the road has been the different coaching methods the team has re- ceived. To me it feels like the Stanford coaches have been pushing towards a solution that can be build and be more or less ready for production at the end of the project. The BTH coaches on the other hand have been pushing for larger picture ideas and to have the goal of changing the world with less focus on a ”perfect” prototype and more focus on conceptual prototype with a good story around it. This lead to a disruption in the group for a while that we are now trying to mend and I think we are on the right track again or at least heading towards it. I think that this disruption might be help to build a stronger group in the end where the visions and goals for the project is more clear and agreed upon by everyone in the group. I look forward to meeting the Stanford students when they get here to just start to build the team dynamic with the help of Sebastian and get to know the students a bit more on a personal level.

Karin Dahlqvist I really enjoy working in this project since its both fun and educational. I feel that the results we have reached so far in the project are good and interesting. We have learned a lot from the process, especially from the prototyping where we got a chance to try out our ideas. It has not only been fun, but it has also given us some important insights and eye-openers. The detailed needfinding that we performed earlier in the project has been of CHAPTER 6. PLANNING 114 great use for us with the ongoing work, especially when we narrowed down and decided in which direction we wanted to continue our work. Since the BTH part of the team doesnt have a specific course plan to follow anymore, unlike the Stanford part of the team, we are freer to put extra time on things if we find something we want to investigate further, which I think can be really useful for us. Every now and then it has felt like the BTH part of the team and the Stanford part of the team has had different perceptions of what Volvo CE wants from us, and also that we have had a different view on how the vision for the future could look like. This can for example be due to differing views from our coaches, which may have led us on slightly different paths. Despite this minor setback, I believe that our common vision of the project became clearer after some discussion and reflection about this. I do think that we all want the same thing in the end; that we can arrive at a solution that everyone is happy with and can be proud of. Regarding the corporation in general I feel that it gets better and better every week, and Im really looking forward to when the whole group will meet in March. I think that we can work on a better group dynamics and together reach a common vision. I do think that the group dynamics have been good so far, but it is essential to keep working on it so that we understand each other and are working to achieve the same goals so that we in the end can reach a really cool result!

Zainalabidin Tahir I think the collaboration between the two parts of the team is working well thus far and keeps improving. It feels that all group members are working hard and showing great ambition to achieve something amazing that we can be proud of. This quarter has been both fun and challenging; we focused mainly on the C&D field within urban mining, taking with us a lot of knowledge and understanding from the past of the overall definition of what urban mining is. This was of great help regarding the creation and evaluation of our prototypes. What has worked less good between the two parts of the team is that we had differ- ent understanding of Volvo CE expectations and vision regarding the urban mining topic. Besides that we received different feedback from our coaches. This misunderstanding has been clarified and now we are working our way through it together as a team. Otherwise, I think the group dynamic has been good. The communication and exchange of ideas and knowledge has been great! Now am really looking forward to finally meet the rest of the group to get a chance to know them better and work closer together towards a shared vision and goals to make our way through and come up with something really awesome.

Oskar Erlingsson I think this quarter has been great, and I am really enjoying the work and the progress that we are doing in the project. We have for instance done some real functional prototyping that has led to important insights. This suits me very well since Im a very practically oriented person. Our broad and thorough needfinding that was performed in the fall quarter has by now helped us a lot with ideas for further work. We at BTH has also been working with our vision of Urban Mining for the future and how the market will look then, to be CHAPTER 6. PLANNING 115 able to implement this into the final product/service. Although the work has been going on well I think that in somehow BTH and Stanford has got a bit different coaching the last part of this quarter, mainly regarding the wideness of the design scope of the project. I can totally understand the arguments from both sides, but I actually feel that this has caused a bit of a misalignment between us. But further on I think this will turn into a good thing because we are investigating different areas that can contribute to the same outcome in separate ways. After some discussions in the group and with Volvo coach about the vision and so on, I think that we are aiming more against the same goal now and that we are able to converge more and more to the same result especially when we meet again in March. Even though we have been working in slightly different fields sometimes, I feel that the dynamics in the whole group are good and I think that also this will be even better when we meet. Thus, this ensures that we can create a totally awesome final result together.

Victor Sderberg I think the results in the project have been good so far, where there have been fun to see how the prototypes have evolved and given us some good insights. I think that these have given us some good experiences in relation to the need finding, but also to make the project feel more real and concrete. During this last winter period there have been some differences of opinions between the two parts of the team. This is much due to the different coaching strategies that have been given to the team regarding the vision for the project and the interpretation of what Volvo CE expects to get delivered. It led to a ”small bump in the road”, where we did not really understood the different directions of the project or desire to deliver. However, I feel like this has given more clarity in the project and to each team members thoughts, which is what I think and hope makes the team stronger in the end. To develop and maintain good group dynamics is something I think is important, due it is something that Volvo CE is also keen to see happen and want to learn from. I also look forward to meet the remaining part of the team from Stanford in reality in order to build an even stronger team. My expectations from this meeting is to share a clear shared vision of the project and agree on the final parts of the project to reach an awesome result.

Tom Owlett About halfway through the winter quarter, it was great to finally find and prototype the ”nugget” that we will likely pursue through EXPE. We have a lot of contacts who work in the field and it has been great to get their input on the important features for our design. In fact, two people have told us jokingly (I think) that they are going to steal this idea. It’s been awesome to have people with 30 years of industry experience say this and it has really given us faith that this is something that could gain traction on tightly constrained jobsites in the future. Moving forward, I’m excited to start moving from prototyping to the design phase. At this point we have a good feel for the essential features for our modular storage container, but we still have a good bit of work to do to finalize the design and manufacture some of CHAPTER 6. PLANNING 116 these panels for EXPE. I’m looking forward to traveling to Sweden to both present our idea to Volvo and work in person with BTH. I think that the trip will help with some of the communication issues we’ve been seeing from working apart. I’m confident that in June we will have a very solid, finished prototype.

Teresa Tombelli This project has continued to build momentum through the winter quarter, and has been largely supported by detailed needfinding and benchmarking that has extended far past the fall quarter and well into the winter. The Stanford team has found some fantastic contacts in the C&D industry through working with Naomi Porat of Transform Urban. Through extended site visits and small group meetings, we have gotten a very thorough idea of the state and needs of the industry. Everyone on the Stanford side of the team is excited about how things are turning out, though it seems that the students at BTH do not agree. I am hoping that this is just a communication issue, and that it will be resolved when we meet in Sweden and can tour the Volvo facilities together.

Jared Ostdiek The Winter quarter was incredibly exciting. We were able to meet with many industry professionals, which helped us to gain a deeper understanding of the design space. I feel like our team has a solid grasp on the current state of urban mining in the C&D industry, and I believe that our current direction fills a need that will enable more material reuse. There was some disagreement on the project direction between the BTH and Stanford team. I am looking forward to visiting BTH in Sweden over break and working face-to-face as one team. It is important that we are all on the same page as we move into the Spring quarter. It will be exciting to work on finalizing a design and manufacturing a final product to present at EXPE in June!

Kristine Bunker This winter quarter I feel that we were able to really key in on a huge need that we can fill during the spring quarter. We talked to so many people throughout the C&D industry which was awesome just from a learning stand point and seeing so many cool things, but we also were able to get tons of feedback and see how our solution would work on a jobsite today. Noami has been instrumental in setting us up with contacts that have been invaluable for our research. On the Stanford site we are still working amazing as a team, we honestly have had no conflicts and are always very efficient. So far there have not been any late nights or last minute scrambles which is awesome for balancing other classes. Additionally we all share the same vision of the future of urban mining and the impact Nix could have on the C&D industry. We have had conflicts with the Swedish team throughout the Winter quarter and we hope to work them these out when we visit next week. Additionally I am excited to talk to Volvo and get some more in depth feedback about our project and start moving forward with a manufacturing plan and creating our beta prototype. 7 Resources

Amazon.com Purchased items and shipped to Stanford

Home Depot Ravenswood Shopping Center, 1781 E Bayshore Rd, East Palo Alto, CA 94303

John A. Blume Earthquake Engineering Center 439 Panama St, Stanford, CA 94305 Gregory Deierlein, [email protected]

McMaster.com Purchased items and shipped to Stanford

Mid-State Engineering & Testing 11 E 11th St, Kearney, NE 68847 Simon Schacher, [email protected]

Stanford Product Realization Lab 475 Via Ortega, Stanford, CA 94305

117 Bibliography

[1] Howard Carlson. In person discussion, Dec 2014.

[2] DoSomething.org. 11 facts about e-waste, June 2014. https://www.dosomething.org/ facts/11-facts-about-e-waste.

[3] Marc Ferrari. In person discussion, Jan 2015.

[4] Cascadia Consulting Group. 2008 california state wide waste categorization study, Au- gust 2009. http://www.calrecycle.ca.gov/Publications/Documents/General/2009023. pdf.

[5] Daniel Hoornweg and Perinaz Bhada-Tata. What a waste : A global review of solid waste management, March 2012. https://openknowledge.worldbank.org/handle/ 10986/17388.

[6] W Jin, C Meyer, and S Baxter. Glasscrete: Concrete with glass aggregate. ACI Materials Journal, 97(2), 2000.

[7] Tung-Chai Ling, Chi-Sun Poon, and Shi-Cong Kou. Influence of recycled glass content and curing conditions on the properties of self-compacting concrete after exposure to elevated temperatures. Cement and Concrete Composites, 34(2):265–272, 2012.

[8] Terence Luk. Stanford university: Meyer library, 2009. https://www.flickr.com/ photos/terenceluk/3911933501/.

[9] Krause Manufacturing. Construction waste recycling, December 2012. http://www.krausemanufacturing.com/material-recovery-facility/ construction-and-demolition-recycling/construction-waste-recycling/.

[10] Roz-Ud-Din Nassar and Parviz Soroushian. Strength and durability of recycled aggre- gate concrete containing milled glass as partial replacement for cement. Construction and Building Materials, 29:368–377, 2012.

[11] Nebraska Department of Transportation. Materials and research, 2014. http://www. transportation.nebraska.gov/mat-n-tests/.

[12] RecycleWorks. Construction and demolition recycling introduction, August 2008. http: //www.recycleworks.org/con dem/.

[13] Brian Scott. In person discussion, Dec 2014.

[14] Chuck Vollmer. Urban mining, July 2014. jobenomics.com/urban-mining/.

118 A Site Visits

Transform Urban LLC. Kirkham Project Office 1585 5th Avenue, San Francisco, CA Naomi Porat, Transform Urban Co-Founder

Kirkham Project Associates Landscape Engineer: Gary Strang, GLS Landscape Architecture Civil Engineer: Brian Scott, Bkf Engineers Structural Engineer: David Mar, Mar Structural Design General Contractor: Howard Carlson, Cahill Construction General Contractor: Chuck Palley, Cahill Construction

Meyer Library Demolition Brian Carilli, Associate Director of Construction and Renovations Kharon Hathaway, Stanford Construction Project Management Sarah Larson, Meyer Library General Contractor, Level 10 Construction

The ReUse People The ReUse People Warehouse 9235 San Leandro St, Oakland, CA Ted Reiff, The ReUse People Founder Juan Gomez, Deconstruction Project Site Manager 2133 Webster Street, Palo Alto, CA 410 Cervantes in Portola Valley, San Francisco, CA

Ferma Corporation 6655 Smith Ave A, Newark, CA Marc Ferrari, President

Building ReSources 701 Amador Street, San Francisco, CA Matthew Levesque, Founder

Bredemads Recycling and Waste Management Facility Bredemadsvgen 2, 341 34 Ljungby, Sweden Roland Lennartsson, Chief Section Manager

119 APPENDIX A. SITE VISITS 120

Anders, Line Manager

Affrsverken Recycling and Waste Management Facility Tippvgen, 370 30 Rdeby, Sweden Hkan Sandegrd, Chief Section Manager

Stena Technoworld Recycle Facility Kistingevgen 15, 302 62 Halmstad, Sweden Rickard Knutsson, Chief Section Manager

Dckia Gullbernavgen 19, 371 47 Karlskrona, Sweden Magnus Andreasson, Section Manager B Municipal Waste Benchmarking and Needfinding

Municipal waste covers waste from households, office buildings, institutions, small, busi- nesses and street sweepings. The levels of municipal waste are expected to double by 2025, so it is going to be key to have reliable recycling processes in place to avoid the negative impacts on health, environment, and economy that poorly managed waste can result in. The process of collection for municipal waste can be done in a number of ways [5]

1. House-to-house: company collects garbage from each house individually. Usually, the user pays for this service.

2. Community Bins: Users throw their garbage in fixed bins that are placed in a neigh- borhood or locality. MSW is picked up by the municipality, according to a set schedule.

3. Curbside Pick-Up: Users leave their garbage directly outside their homes. And local authorities collect the garbage according to a set schedule. Self-Delivered: individuals deliver the waste directly to disposal locations or transfer stations.

4. Contracted or Delegated Services: Businesses hire firm (or municipality with munici- pal facilities) who arrange collection schedules and charges with customers.

Once the waste is collected is it sent to a municipal waste sorting facility. In some cases there are portable sorting machines, but in most cases this equipment is too big to fit on the construction site so it is shipped off to be shorted. Kraus Manufacturing is one sorting facility on the west coast in the United States. Their machines use magnets to sort out ferrous materials, sifters to sort by size and weight, then manual sorting to check for any recyclable materials that may have slipped through the sorting process [9]. BTH visited two of these facilities in Sweden. At Bredemads Recycling and Waste Management Facility the BTH team was guided through the tour by Anders, a manager at the facility. Right off the bat they learned that most waste can generate value on some level, but often it does not due to lack of recycling processes being in place. The first step, and most labor intensive, is pre-treating and sorting all the material that comes in. The material is sorted into different categories, as shown in figures B.1 and B.2, such as e-waste, wood, metals, and plastics; some of these are shipped off to be handled elsewhere. Large waste which cannot be recycled is then packed into bales of waste shown in figure B.3, and shipped out to be used for local district heating. Pure wood waste is chipped into flakes, shown in figure B.4, and put through a magnet to remove any metals that may be mixed in. The majority of this is also used for district heating. The rest of the mixed waste is processed by a machine, shown in figure B.5, to sort out metals and heavy stones. Whatever is leftover is used as the final covering on landfills on top of more hazardous waste such as insulation, ashes, and asbestos. BTH also visited Affrsverken Recycling and Waste Management Facility, shown in fig- ure B.6, where they were given a tour by Hkan Sandegrd the Section Manager. Affrsverken

121 APPENDIX B. MUNICIPAL WASTE BENCHMARKING AND NEEDFINDING 122

Figure B.1: Mix of woods and paper products sorted from collected municipal waste.)

Figure B.2: Electronic waste sorted from collected municipal waste APPENDIX B. MUNICIPAL WASTE BENCHMARKING AND NEEDFINDING 123

Figure B.3: Large waste is packed together into bales and burned for local district heating.

Figure B.4: All sorted wood is chipped up and used for heating or mulch. APPENDIX B. MUNICIPAL WASTE BENCHMARKING AND NEEDFINDING 124

Figure B.5: The remaining municipal waste is sorted through a machine and chipped up. collects waste from three main areas: organizations and businesses, recycling facilities, and household collection. They offer sorting and recycling of waste, immediate storage, composting, waste containers, and landfill shipping. To facilitate the sorting process, orga- nizations and households that use Affrsverken for their municipal waste collection are given 2 - 8 different colored bags for the different categories of waste. When waste is dropped off, the user sorts it into the appropriate bags on site as shown in figure B.7. Finding a way to make this on location sorting wide spread is one potential direction for the project. If the sorting is done immediately upon disposal, the manual sorting of truck loads of waste on site will be reduced. Requiring that individual responsibility is taken to sort waste could reduce the amount of material that goes to landfill by making people think about what they are throwing away. APPENDIX B. MUNICIPAL WASTE BENCHMARKING AND NEEDFINDING 125

Figure B.6: Overview of Affrsverken Recycling and Waste Management Fa- cility

Figure B.7: Bins used for sorting different colored bags of municipal waste. C Electronic Waste and Tires Benchmarking and Needfinding

C.1 Electronic Waste

Electronic-waste represents about 2% of Americas trash in landfills, however that is equiv- alent to 70% of the overall toxic waste in America. Worldwide 20-50 million metric tons of e-waste is disposed of each year, but only 12.5% of that is currently recycled [2]. BTH visited an e-Waste recycling facility in Sweden called Stena, which focuses on IT-equipment and small appliances, to learn about how e-waste is handled. They were given a walk-through of recycling facility by Rickard Knutsson, section manager for Stena Technoworld. The e-waste arrives in huge bins with unsorted electronics along with organic material that ended up in the wrong bins during sorting at another facility (see figure C.1). The first step is to manually remove hazardous materials such as mercury, batteries, PCB, lead and asbestos which go into the deep layers of landfills. When this is done the rest of the products head down a moving belt to be dissembled manually and sorting into five different categories, as shown in figure C.2. Stena is currently working towards making this process automated.

Figure C.1: Big bins full of electronics that arrive at Stena for sorting and recycling

Next they use a combustion process to extract precious metals such as gold, silver, palladium as well as common metals such as iron, aluminum and copper. Plastics, circuit boards, and other materials are also sorted out to be recycled. Stena collects many different raw materials during their recycling of e-waste. Much of this sorting is done using liquid separation with varying densities along with some sorting by hand to extract valuable materials. They sell and distribute materials, such as glass, plastic, non-ferrous metals, and steel, to chosen customers around the world. It is common for all flat screens that use fluorescent lamps or LED lamps, which contain hazardous materials, like mercury, to be taken care of in a specific way based on national and industrial standards. Stena can recycle 90% of a flat screen as either raw material or

126 APPENDIX C. ELECTRONIC WASTE AND TIRES BENCHMARKING AND NEEDFINDING 127

Figure C.2: Sorting based on materials after electronics have been dissembled manually energy. Old ”glass TVs” are not produced anymore, but they are still in the system because they have a long life length. These TVs use a technology called CRT (cathode ray tube) and need to be handled with care to avoid the glass being crushed during the transport. There are several hazardous substances in these monitors and need a special pre-treatment facility. The CRT-glass is separated from the cover, cables, speakers and circuit boards to go through a mechanical treatment which cleanses it from all hazardous materials. Around 90-95% of the glass is converted into raw material that can be used to produce new TV glass and lead products. Disposing of cooling appliances is a major responsibility since they are classified as hazardous materials and need to be taken care of by a certified recycler. Stena picks up the appliances from the customer to transport them to one of their plants where the appliances is identified and registered. The hazardous materials, oil and cooling agents, are removed in a closed system. The rest is then separated in metals, plastic and PU insulation. The cooling and blowing agents are neutralized while the rest of of the material is recycled. Stena can recycle 99% of all these appliances. The different metals, plastics, oil and insulation become new raw materials or energy. At the end of the whole process about 90% of what comes in is recycled and reused while 10% goes to landfill. One area for potential growth in the e-waste field is to implement an automated sorting system. Currently all steps in the process are manual including the handling of hazardous substances.

C.2 Tires

Because it is hard to incinerate them and extract energy without affecting the environment badly, there are a lot of areas of use for recycled tires once chipped up. A very small percentage of recycled tires actually become new tires, most are made into rubber roofing, or chipped up and used for turf infill, indoor horse riding arena, or playground infill, among others. BTH visited Dckia, a company that sells/handles tires and rims in Sweden. Dckia han- dles all types of tires, from the smallest wheelbarrow to the largest construction equipment APPENDIX C. ELECTRONIC WASTE AND TIRES BENCHMARKING AND NEEDFINDING 128 tire. All these tires then get thrown into a big container which then gets picked up by Ragn-Sells when it is full with more than 300 tires. Ragn-Sells is hired to do the job by another company, Svensk Dcktervinning AB, who actually recycles the tires. Ragn-Sells is the entrepreneur for all tire retrieval and recycling in Sweden. About 95% of all the tires get collected and are thereby recycled or reused in someway. In Europe, when a new tire is bought, the cost includes an environmental fee in the price. This fee pays for all the environmental affects the tire has during its lifecycle and also for the retrieval of tires by Ragn-Sells. The fees vary depending on what kind of tire it is, a larger tire with a higher environmental effect, has a higher fee. This is an example of how the United States is far behind Europe in enforcing environmentally friendly practices. A potential area for urban mining technology in this field is to develop a process to retread tires to avoid the environmental damage that occurs when manufacturing tires. D More Critical Function Prototypes

D.1 Wood De-nailing CFP Description

In our interview with Mathew Levesque, he told us that hard wood and even dimensional lumber could be reused as is instead of chipping up into mulch. Avoiding chipping maintains the embodied energy stored in the wood. One issue with recycling wood from buildings is that it often contains nails, which are labor intensive to remove. There are several types of hammers that are specially designed to make the removal of nails easier. There are also de-nailing guns (D.1) that use compressed air to drive a piston that punches out a nail from a board. Even with the de-nailer gun, a person still needs to remove each nail one by one from each board. A machine that can automatically remove nails from a board would streamline the lumber reuse process. With our 10 minute CFP, we looked at the steps that would be required for an automatic nail removal machine.

Figure D.1: Air Locker AP700 Air Punch De-nailer.

The process used to remove a nail consisted of three steps: cut the nail flush to the board, locate the nail, and punch the nail out of the wood. The goal was to keep each step as simple as possible and use only linear motions that could be achieved with 1 degree of freedom movements. Dimensional lumber removed from a building usually has bent nails protruding from it (fig. D.2). If the nails are cut flush to the board in the first step, it eliminates variability for the removal step of the process (figs. D.3 and D.4). Next, the

129 APPENDIX D. MORE CRITICAL FUNCTION PROTOTYPES 130 nail needs to be located. An automated machine would need to use computer vision, metal detection, or some other technology to locate the nail and position the removal device. Lastly, the nail needs to be punched out of the board. In our CFP demonstration, a hammer and a punch were used in place of a pneumatic de-nailing gun, which would likely be implemented in an automated machine ((fig. D.5). We were able to successfully remove a nail from a board using only linear motions.

Figure D.2: Dimensional lumber with protruding nail.

D.2 Density Sorting CFP

Our team members at BTH in Sweden have been exploring how waste is handled at munici- pal waste treatment facilities. Some facilities accept mixed-load dumpsters from companies and then sort out the recyclables at the waste plant. The sorting process is done by hand at some facilities and is a tedious task. Automated sorting systems are currently being developed and are already implemented at some waste management plants. Sorting with a density-controlled liquid is one step these machines use to separate different materials. BTH worked on a CFP to test if materials can be sorted on a more granular level through of the use of multiple liquids with different densities. Water and rapeseed oil were mixed together in a container. Materials were then introduced into the mixture. It was found that pure wood and styrofoamfloated in the oil, some plastics, masonite, and glass fiber insulation did not float in oil but did in water, and, as expected, concrete, asphalt, stone, glass, and ceramics all sank to the bottom (fig. D.6). APPENDIX D. MORE CRITICAL FUNCTION PROTOTYPES 131

Figure D.3: Using a hack-saw to cut the nail flush to the board.

Figure D.4: Trimmed nail. APPENDIX D. MORE CRITICAL FUNCTION PROTOTYPES 132

Figure D.5: Using a hammer and punch to remove a nail.

Figure D.6: CFP exploring separating materials with liquids of different den- sities. APPENDIX D. MORE CRITICAL FUNCTION PROTOTYPES 133

D.3 Tire Reuse CFP Description

BTH also looked at a way to reuse tires. Currently, old tires and other rubber products are chipped up and reused on roofs, playgrounds, indoor horse riding arenas, and turf fields. The team explored new reuses for worn-out rubber tires. A bicycle tire was successfully flattened using heat (fig. D.7). The team is still exploring potential reuses for such a product.

Figure D.7: Flattened bicycled tire. E Glass Brick Making Process

E.1 Crushing

First, the glass was broken into smaller, more manageable pieces using a hammer and plenty of safety protection (fig. E.1).

Figure E.1: Teresa and Kristine breaking a window pane into smaller pieces.

To crush the glass further, a “glass blender” was created. A cross-shaped, metal bracket was affixed to a large bolt with the head cut off to create a custom made cordless drill attachment (fig. E.2). A six-inch diameter PVC tube was used as the container for the glass blender. The tube was partially filled with glass pieces and an assortment of nuts and bolts to help aid in the grinding (fig. E.3).

E.2 Sizing

After grinding for approximately one minute, the glass particulate was sifted using sieves created out of large cardboard tubing and different sized mesh cloth (figs. E.4 and E.5). The sieve sizes were chosen to match typical aggregate sizes used in concrete. The glass was ground, sifted, and then reground until the required amount of each of the three sized of aggregate was created. The course aggregate sizes were 1/2 and 1/4 inch diameter. The fine aggregate was 1/10 inch diameter(figs. E.6 and E.7) .

134 APPENDIX E. GLASS BRICK MAKING PROCESS 135

Figure E.2: Glass blender design. The pink insulation foam was used to shield the user from flying glass.

E.3 Mixing

The ratios used for our CFP are in Table E.8. These values were calculated using the experimental values from Ling et al. and the Nebraska Department of Roads concrete mixture specifications [11]. Along with the two types of glass concrete, we made bricks out of pre-mixed Quikcrete as a control. The components were mixed in five-gallon buckets, poured into a wooden molds, and left to cure in the ME310 Loft (figs. E.9, E.10, E.11)). The bricks were left to cure for three days before they were removed from the molds (figs. E.12 and E.13). It takes seven days for concrete to reach functional strength. However, concrete continues to hardness long after it is poured. Some concrete takes years to reach full strength.

E.4 Testing

Because of the tight timeline, the bricks were not fully cured at the time of our CFP Small Group Meeting, but all three types, the window glass, the beer bottle glass, and the Quikcrete bricks, were at the same point. We decided to drop test the different types of bricks to provide qualitative comparison of strength and brittleness. The bricks were dropped from a height of six feet onto a metal plate. None of the bricks fractured from a drop at this height. The testing machine at the John A. Blume Earthquake Engineering Center at Stanford University was used to quantitatively measure the strength of the window glass concrete (fig. E.14). The cylinders tested had a fracture strength 60% that of standard concrete fracturing around 1800 psi. 3000 psi is the low end for concrete used in construction. The APPENDIX E. GLASS BRICK MAKING PROCESS 136

Figure E.3: Tom operating the glass blender. APPENDIX E. GLASS BRICK MAKING PROCESS 137

Figure E.4: Teresa making the sieves used to size the glass aggregate.

Figure E.5: Teresa sifting the crushed glass particulate. APPENDIX E. GLASS BRICK MAKING PROCESS 138

Figure E.6: Crushed and sized window glass. From right to left: 1/10” diameter, 1/4” diameter, 1/2” diameter.

Figure E.7: Crushed and sized beer-bottle glass. From right to left: 1/10” diameter, 1/4” diameter, 1/2” diameter.

Figure E.8: Concrete mixture components by weight. APPENDIX E. GLASS BRICK MAKING PROCESS 139

Figure E.9: Window glass concrete mixture sans water. other beer bottle glass concrete and the Quikrete was not tested because no cylindrical samples (required for the machine) were made in the first CFP exploration. APPENDIX E. GLASS BRICK MAKING PROCESS 140

Figure E.10: Jared pouring and smoothing concrete into the wooden brick mold. APPENDIX E. GLASS BRICK MAKING PROCESS 141

Figure E.11: Bricks curing in the ME310 Loft. APPENDIX E. GLASS BRICK MAKING PROCESS 142

Figure E.12: Window glass concrete brick composed of 100% glass aggregate.

Figure E.13: Beer-bottle glass concrete brick composed of 100% glass aggre- gate. APPENDIX E. GLASS BRICK MAKING PROCESS 143

Figure E.14: Testing window glass concrete specimen at the Blume Earth- quake Center at Stanford University.