CONCRETE ENGINEERING August 2020 International Volume 24 Number 2

Sustainability and the circular economy

Formwork and Falsework Historic Concrete

Contents

2 Editor’s Desk 4 Data Download 6 Gallery Architectural Precast 8 Precast stars in prominent residential build Iain MacIntyre Cover The GCCA’s Dinah McLeod and Andrew Minson address the topic of 12 UHPC shading elements create an iconic building in Qatar sustainability in the concrete sector. Bernhard Sagmeister

Sustainable 16 Sustainability will help guide the future of the cement and concrete industry Dinah McLeod

18 Circular economy Andrew Minson UHPC was used to create the iconic 22 Is it possible to recycle concrete? 12 Manateq HQ building, which was Eduardo Souza designed to reflect traditional Qatari architecture. Historic Concrete 24 Michelin House, London Edwin Trout

Floors and Screeds 28 Overcoming challenges faced by the global Covid-19 pandemic Ruth Waugh The Bandra Kurla Complex Formwork and Falsework 30 underground station on the Mumbai Metro required comprehensive 30 Bandra Kurla Complex, Mumbai, India formwork and scaffolding solutions. CEI report

34 Barntrup bypass, Germany Katja Münch

Repair and Strengthening 36 Not out of reach CEI report

Sprayed Concrete The sprayed concrete form of the 40 Ayla Golf Club, Aqaba, Jordan 40 clubhouse of the Ayla golf academy CEI report in Jordan captures the vibrant beauty of rolling desert landscapes. Editor’s Desk

The Covid-19 pandemic has certainly made the world’s population stop and think a little more about the precious planet they call home. After weeks of lockdown measures, the majority of nations reduced their emission levels, with almost no international flights and next to no traffic on the roads in many parts of the world. There have been indications that such measures, despite turning major world economies Editor: upside down, have reaped benefits to the natural Helen Marney Tel: +44 (0)1276 607159 environment. [email protected] A recent suggestion that a large hole in the ozone layer Associate Editor: has closed and in cities around the globe many citizens James Luckey have noticed bluer skies and less smog on the skyline Technical Advisor: is certainly a positive at a time when there are so many Richard Day negatives to deal with. But, as we breathe in this cleaner air, some experts Sales Representative: Fred Combe have said that unless there are technologies, policies and Tel: +44 (0)20 3859 7097 investments to replace fossil fuels with energy efficiency, [email protected] cleaner air and a stable climate can’t be achieved long term. James Pembroke Media Ltd is The Concrete Society’s In this issue, Dinah McLeod, the Global Cement and appointed advertising sales agency. Concrete Association’s (GCCA) new chief executive Subscriptions Manager: explores the benefits of sustainability within the concrete Val Goddard industry, an industry that is set to grow substantially over Tel: +44 (0)1276 607149 the coming decades (see page 16), while Andrew Minson, [email protected] also of the GCCA, considers the benefits of a circular Concrete Engineering International is published twice economy (see page 18) within the concrete industry to yearly and sent free to all Concrete Society members deliver the future built environment in an environmentally and Concrete magazine subscribers. Single copies and responsible manner. back issues are available at a cost of £15 per issue. Elsewhere in the issue, Ruth Waugh of Twintec explains The Concrete Society how Twintec moved quickly to adopt and implement virus- President: Deiniol Williams related work-safe practices as a result of the Covid-19 Managing Director: Kathy Calverley ೷೬೯ pandemic in the UAE (see page 28). The concrete industry has shown that it can adapt to The Concrete Society, Riverside House, accept change and move forward in these unprecedented 4 Meadows Business Park, Station Approach, Blackwater, Camberley, Surrey GU17 9AB, UK times, just as we are all coming to terms with the ‘new normal’ in the post-pandemic world. Tel: +44 (0)1276 607140 Fax: +44 (0)1276 607141 Helen Marney, Editor e-mail: [email protected] Concrete Engineering International www.concrete.org.uk Tel: +44 (0)1276 607159, E-mail: [email protected] Printed by Bishops Printers, Portsmouth, Hampshire

© The Concrete Society, 2020 ISSN 1460-5856 Neither Concrete Engineering International nor The Concrete Society are responsible for the statements made or the opinions expressed in this journal by third parties and organisations.

2 Concrete Engineering International August 2020 THE CONCRETE SOCIETY is an independent membership organisation dedicated to supporting the use of concrete – the most widely used in the world.

Established in 1966, The Society encourages innovation and the exchange of knowledge and experience across all disciplines. The Society works through the co-operation of our members, who come from all sectors of the industry to exchange information and experience, and to enhance the performance, productivity and quality of concrete as a construction medium. Supported by the technical and administrative staff of The Society, our members collaborate to produce and disseminate state-of-the-art reports, recommendations and practical guidance.

The Society receives special support from the following:

Special Category Members

www.breedongroup.com www.laingorourke.com www.tarmac.com

www.cemex.co.uk www.sir-robert-mcalpine.com www.hanson.co.uk

www.concrete.org.uk

The Society is supported by a global community of 250+ Corporate and 500 individual members. Data Download CEI takes a look at recent media coverage to give readers a snapshot of global concrete industry facts and figures, events and projects.

A proposed ASTM International Standard will be used to evaluate A consortium of Bouygues the tensile performance of Construction, Saipem and Boskalis fibre-reinforced concrete (FRC) has won a contract for design work, using cylindrical specimens with construction and installation of 71 double-punch loading. concrete gravity-based structures According to ASTM International as foundations for the Fécamp member Shih-ho Chao, professor windfarm off the French coast. of at the The contract was awarded by EDF University of Texas at Arlington, Renewables, Enbridge and WPD. a double-punch test is an indirect The 500MW windfarm will be tensile test method that shows located between 13 and 22km from The Statue of Liberty Museum much less variability and is more the coast of north-west France. and Visitor Center, which was time efficient than typical beam- Project commissioning is scheduled completed last year, has been type testing. ”It only requires a in 2023. awarded the 2020 PCI Design very simple and small capacity Award for Best Sustainable compression testing equipment Design. The iconic 50,000ft2 to perform the test,” said Chao. (4645m2) facility is durable – to Ready-mixed concrete, aggregate “This method can be used for withstand the millions of annual and asphalt producer, Sunrock investigating various properties visitors and the increasingly Group has acquired a quarry of FRCs such as strength, destructive storms and waves from Votorantim Cimentos’ St stiffness, ductility and mix that periodically batter the east Marys Cement/Canada Building quality.” The proposed Standard coast. Precast concrete was Materials. The Burnt River site (WK73384) will be useful to selected to provide a resilient, encompasses 1400 acres (567 contractors, testing agencies and flexible material to accommodate hectares) of high-quality aggregate researchers. complex designs, while delivering reserves and will operate under a sustainable, low-maintenance Sunrock Canada Construction structure. The high thermal Materials. “The group is looking mass of the precast concrete The Concrete Sawing & Drilling forward to building a strong panels helps maintain interior Association has released a new Canadian company in the Greater temperatures and minimises the best practice to help anyone Toronto Area that is poised to effects of outdoor temperature involved with the specifying supply high-quality aggregates to swings. The precast sandwich of concrete cutting, polishing, construction projects throughout panels feature an irregular ground penetrating radar (GPR) the market,” said chair Bryan Pfohl. imaging and selective vertical design that reflects the work. The new best practice, dramatic setting of the island. CSDA-BP-026 Operating in GPR Scanned Slabs, was developed Ventures has invested in Arqlite SPC, a US firm that with input from GPR contractors, GS Engineering and Construction processes unrecyclable plastic manufacturers, concrete cutting has entered into an agreement waste into artificial gravel, contractors and specifiers. The with North Chungcheong to avoiding the use of natural quarry document provides an overview build a precast concrete factory aggregates and boulders in the and methodology for core in North Chungcheong Province production of lightweight concrete drilling, sawing or hand breaking in South Korea. The factory will with a low CO footprint. Arqlite in concrete when GPR scanning 2 be capable of producing up to SPC light aggregates multiply has been used, as it applies to 100,000m3 of precast annually thermal and acoustic insulation by the sawing, drilling and selective and is expected to be completed ten times compared with mineral demolition industry. It covers in June 2021, with investment aggregates and offer better practical applications, limitations reaching US$82.8 million. The construction quality and greater and liability issues. Visit: https:// company is seeking to reinforce its energy conservation. csda.org/specifications. portfolio of prefabricated modular business and has already acquired two modular companies in England and Poland recently.

4 Concrete Engineering International August 2020 Data Download

A UCLA research team has Construction has begun on a received US$2 million grant concrete tower factory, which from the US Department of will employ up to 300 people Energy to support development in Castilla-La Mancha, Spain. of a process that can convert German OEM Nordex’s new carbon dioxide emissions into factory will produce concrete construction materials. The towers suitable for Nordex’s grant and additional funding AW3000 turbine. The tower- will advance research led by manufacturing plant will be the Gaurav Sant, a professor of civil 12th facility owned by Nordex. and environmental engineering The construction will allow some and of materials science and manufacturing activities, such as engineering at the UCLA producing concrete, to take place GE Renewable Energy, COBOD Samueli School of Engineering. closer to the windfarms under and LafargeHolcim have A team headed by Sant invented construction, resulting in better announced a partnership to CO Concrete, a form of concrete logistics and lower costs. Each co-develop wind turbines with 2 that is made in part from carbon week, the plant will be capable of optimised 3D-printed concrete dioxide emissions, which are manufacturing enough segments bases, reaching record heights an underlying cause of climate for two 120m concrete towers. up to 200m. The three partners change. The technology they will undertake a multi-year devised captures CO from collaboration, which will increase 2 raw flue gas as it exits power renewable energy production plants, cement plants and A house constructed with the while lowering the levelised other producers of carbon largest 3D concrete printer in cost of energy and optimising dioxide, reducing emissions to Europe has been built at Kamp construction costs. The partners the atmosphere. The process C, the provincial Center for will produce a wind turbine also cuts down on the use of Sustainability and Innovation prototype with a printed pedestal traditional cement, the binding in Construction in Westerlo, and a production-ready printer agent in concrete. Since the Belgium. The two-floor, 90m2 and materials range to scale up system developed by Sant’s team house is 8m high and was printed production. The first prototype, captures CO directly from raw in one piece with a fixed printer a 10m-high tower pedestal, 2 flue gas, it eliminates the high as part of project C3PO with was successfully printed in cost of carbon dioxide capture. the support of the European October 2019 in Copenhagen. Sant said the product will have a Regional Development Fund. GE Renewable Energy will carbon footprint 50–70% lower The house is three times stronger provide expertise related to than that of regular concrete than a house built with bricks. the design, manufacture and used in construction. “The compressive strength of the commercialisation of wind material is three times higher turbines, COBOD will focus on than the classic fast construction the robotics automation and 3D with brick,” explained Marijke printing, and LafargeHolcim will JCB has been awarded a contract to supply the US military with a Aerts, at Kamp design the bespoke concrete, its C. This house is a test building processing and application. fleet of high-speed excavators in a deal worth up to US$269m and research will take place as to (£217m). The deal centres on whether its strength is maintained the supply of high-mobility over time. The technique makes engineer excavators (HMEEs) for formwork unnecessary, which the US Army and Marine Corps. saves an estimated 60% of the Prototypes of the machine – material, time and money. Kamp capable of speeds up to 55mph C was printed in only three weeks. (88kph) – were first developed in 2002 specifically for the US Army to meet its demand for a high- speed backhoe loader capable of undertaking military engineering The editor welcomes tasks. The new contract is for contributions from readers. the supply of up to 400 HMEEs. Contact: cei_editorial@concrete. JCB will also provide armoured org.uk if you have material variants, as well as attachments suitable for future issues. and service support.

August 2020 Concrete Engineering International 5 CEI gives power to pictures, showcasing projects Gallery where creative use of concrete is centre stage.

Incorporating in-situ and precast GRC concrete, the iconic new flagship store for fashion house The Webster is situated adjacent to the historic Los Angeles Beverly Center in California. With its cantilevered concrete façade, it reimagines the Brutalist shell of the original existing building and is injected with a pink dye — an ode to the luminosity of California, where the Pacific light naturally amplifies saturated colours. (Photo: Laurian Ghinitoiu.) (Photo: Dror Baldinger.)

Pink felt like fashion, but I wanted to make something that was tough and (Photo: Laurian Ghinitoiu.) “ gentle at the same time. Sir David Adjaye OBE ” Gallery (Photo: Dror Baldinger.)

Sir David Adjaye OBE, a Ghanaian-British born in Tanzania to Ghanaian parents. His influences range from contemporary art, music and science to African art forms. He founded Adjaye Associates in 2000, which now operates

globally. (Photo: Laurian Ghinitoiu.) (Photo: Dror Baldinger.) E Please contact: E-mail: [email protected] Web: www.adjaye.com Twitter: @AdjayeAssoc Facebook: @adjayeassociates Instagram: @adjayeassociates LinkedIn: @adjayeassociates

August 2020 Concrete Engineering International 7 Architectural Precast Precast stars in prominent residential build Precast concrete is playing a prominent role in a unique Cosgrove Goodwin -designed home built recently in Kaiwharawhara (Wellington) by Homestead Construction.

Iain MacIntyre, MacIntyre PR, Wellington, New Zealand

Providing a stunning 180° view of Wellington Harbour, the “The smart systems in the home are impressive. You can Satchell Way new build has been enriched with an array pretty much control the entire house from Canada if you of architectural features, including an overall precast look needed to.” complemented by stained plywood. Among the project challenges was operating on a completely undeveloped site, which drops away from the Challenging build roadside. “Access proved difficult. Getting the precast Delighted with the outcome, Homestead Construction panels in place was problematic with the site being so project manager Darcy Currie describes the 14-month steep. However, these challenges were overcome as project as, “definitely one of the most challenging Homestead is well equipped to deal with these constraints. residential builds we’ve been involved with. “We needed to cut into the hillside. It was all covered “It is very architecturally focused. There are so many in scrub, gorse and blackberries – you would have hardly bespoke elements involved in the build; a huge amount is known a section was there before we started. In fact, it was going on.” one of the last houses to be built in that subdivision.” (Photos: Homestead Construction.)

8 Concrete Engineering International August 2020 Architectural Precast

Consisting of two concrete floors and a lower service which is the first of those I have encountered.” area, the home’s 140m2 ground floor is a combination of While Currie notes that speed of construction is often slab-on-grade and a suspended concrete tray floor system, a key driver in the decision to use precast concrete with the 80m2 top floor being entirely suspended. construction, in this case it also delivered on the client’s “One of the key benefits of using concrete is we have the vision of a ‘natural’ and ‘honest’ look, particularly for the hydronic underfloor heating in both levels (hot water piped main entrance. through the slab). The top floor is also polished concrete.” “It has some rain wash stain and general character, Another notable design feature is a unique ‘linear crank’, making it perfect for the type of finish the client was after. I meaning the whole house is on a 13° twist that runs am really impressed with the way it has turned out.” through the centre of the dwelling, “so there were some interesting angles to work with.” Design inspiration “We had to construct the precast panels with integrated Paul McCardle of Cosgrove Goodwin Architects says the utility points, such as the wall lights up the stairs, which design was informed by a number of considerations, needed to be set out perfectly. including the desire to create functional yet artistic “The internal stairs are also precast concrete and are architecture and by the constraints of the south-east facing polished. They look fantastic and seem to almost float.” site. In addition to the steep fall of the section, Currie says the “The concept was to create two contrasting forms – a street itself slopes in another direction. “The garage door is solid core structure, anchored to the hill, that is sheltered not even a square and the garage floor is actually sloping, by a floating protective shell,” says McCardle.

Reprinted from Concrete, Volume 60 issue 4, with kind permission of Concrete NZ. Visit: http://concretenz.org.nz. Architectural Precast

Above: Set among timber-framed houses, the new residential build on Above: The interior precast concrete is complemented by stained Satchell Way is unique in its use of precast concrete. plywood to create an inviting feel.

“The result was a south-east facing precast concrete we looked into both options – precast concrete vs timber building, inspired by the early 1940s bunkers in the framed. Wellington hills, that is enveloped by a modern angular “At the end of this process the decision was made to metal roof.” move forward with precast concrete due to its honesty, Both protect the warm interior spaces, provide sculptural structure and cladding durability, acoustic performance and yet practical spaces, and frame the stunning views of alignment with the design concept.” Wellington Harbour. “The roof and the concrete are the main elements of the 3UHFDVWEHQHÀWV building’s exterior form,” adds McCardle. While precast residential concrete construction has carved “The concrete is also a main feature of the interior, with out a niche over the past two decades, Currie notes that polished concrete floors and walls in the lower service level, there are many who are still unaware of its benefits. and a concrete floor and balustrade to the top floor. “As this project demonstrates, it is ideal for discrete “The other focal point of the interior is the angled timber homes, but it is also perfect for multi-unit residential ceiling, which works together with the concrete to create a developments as it offers excellent quality control off-site, cosy environment.” repeatability of design/rapid construction, not to mention McCardle emphasises that concrete was a calculated inter-tenancy fire separation and acoustic insulation. choice for the build. “Awareness of what precast concrete construction “Concrete speaks of permeance and reflects the concept has to offer is definitely growing among developers and of contrast (solid vs open and fixed vs floating), as well as their clients, as evidenced by Homestead Construction’s fitting within the Wellington context of a concrete fort in involvement in a 56-unit development at Paetutu in Petone the hills. and an 80-unit development at Erskine in Island Bay. “Like most homes in New Zealand, the early thinking on “Precast concrete also offers a great range of the project was to go with a timber-framed house with a architectural options in terms of surface finish, whether plaster finish to give a solid look.” it’s wood grain or other treatment – the possibilities are “When the house was put out for preliminary pricing limitless.” „

Below: Precast concrete allowed for uninterrupted views – here Below: The site, located in the hilly Wellington suburb of looking northeast towards the Hutt Valley and Eastbourne. Kaiwharawhara, posed a number of construction challenges.

10 Concrete Engineering International August 2020 August 2020 Concrete Engineering International 11 Architectural Precast UHPC shading elements create an iconic building in Qatar The Emir of Qatar has placed emphasis on the creation of a solid infrastructure in the country; one in which medium-sized enterprises of non-oil-related industries can prosper. Adjacent to the international airport of Doha, a complex of four office buildings was planned as a new headquarters for Manateq, a developer within Qatar. Laceco Architects and Engineers from Lebanon won the international design competition.

Bernhard Sagmeister, Durcrete, Limburg, Germany

The design of the Manateq HQ was conceived as a The contractor for the shading elements was Doha composition of four inverted cubes sheltering an internal Cladding Solution (DCS). In 2015, the owner of the oasis. The outside of the iconic building should reflect prefabrication plant decided to move into the business of the brand of Manateq and reinterpret traditional Qatari UHPC façade elements. The management refused to buy architecture using a modern language. The headquarters’ ready-dry mixes of mortar or concrete, without knowing parametric façade was inspired by Manateq’s logo and the ingredients and details of the mixture, as they preferred optimised daylighting in offices. To achieve a long-lasting, solutions where the formulation can be adjusted during high-quality and low-maintenance performance, an the production process. With the high-performance binder ultra-high-performance concrete (UHPC) was selected as Nanodur, DCS was able to batch a UHPC mix within short material for the permanent shading construction. notice and to adapt this recipe to the varying requirements of the mould, mixer configuration, ambient temperature, Requirements change of raw materials, strength, flowability and ductility. The façade elements were produced within Doha; the The subcontractor carried out a tough prequalification and material is highly adapted to local climatic conditions the client had to be convinced by the testing of specimens, (corrosion, dust, etc). that all the requirements of the tender could be fulfilled. The single panels have a length of approximately 9m and a width of approximately 3.3m. All panels are visible Structural design from the outside as well as from the inside (offices), so The structural analyses for the UHPC elements, as well that all sides should be as-struck concrete. As there is a as for the fixing to the steel construction, were the groove on both sides of the curved panels, the production responsibility of the subcontractor. It was performed was done in vertical glass-fibre-reinforced plastic (GFRP) by a local engineering office in Doha, following British moulds using self-compacting concrete. Standards. (Photos: DCS, Ayman Badr.) Architectural Precast

Each panel is connected as simply supported directly on the steel back frame. The fixing is strain free to avoid stresses due to temperature, elongation and warping in the concrete element, as well as strain due to different deformations between steel frame and elements. A maximum permanent deflection a value of span/35000 was calculated; similarly, a maximum wind-load deflection a value of span/15000 was calculated, which means nearly no deformation occurs. The elements are calculated with Above: Pouring of panel. a linear elastic calculation in an uncracked state. The maximum tensile stresses due to dead weight and wind are tensile strength of the uncracked concrete (modulus of compared with an admissible strength of 5MPa. rupture) of a minimum of 12MPa. The Young’s modulus As the chosen Nanodur UHPC has a minimum flexural had to exceed 55,000MPa. Deviations, bowing and tensile strength of the uncracked concrete of 15–20MPa, warpage due to production and shrinkage were restricted. there is a safety factor of 3.0. Experience over the past ten The subcontractor used Nanodur Compound 5941 as years with this material, suggests this should be enough to a UHPC-binder premix of Portland and slag cements, avoid uncertainties of the load, material, decrease of tensile admixtures and quartz flour. Instead of silica fume or strength due to temperature and humidity, fatigue and metakaolin, very fine cement particles as well as synthetic other influences. Fibres and reinforcement within the UHPC oxides were used to fill the gaps between the cement may increase ductility, tensile and compressive strength. particles and to influence the hardening process. This However, all these positive effects were not considered; the results in very smooth, flowable and self-compacting design was carried out with the pure flexural strength of UHPC mixes without the need for further post-processing. the UHPC. Doing so, the concrete remains uncracked and Common UHPC formulations with silica fume often need the visual characteristics remain perfect. The given wind thermal curing between 60° and 80°C over a one- to two- load onto the UHPC elements was accounted for in X and Y day period, or even a treatment in an autoclave to reach directions, and dimensioning was done with unsymmetrical the required strength. The binder and admixtures were bending. imported from Germany, aggregates from India, steel The connection between the UHPC elements and the fibres from China. The final mix design is shown in Table 1. steel support should allow movements up to 5mm in order to avoid thermal strain. Due to the tolerance compensation Production during the erection, it was decided to avoid embedded All particles finer than 0.63mm were combined within the threaded sleeves. The stainless steel M12-size bolts are cement plant using a high-intensity mixer. To batch the undercut anchors with a length of 120mm. The anchors concrete, a simple pan mixer in the prefabrication plant are drilled and installed at the site. Intensive testing was was sufficient and no special equipment was necessary. required to get the ultimate loads of the fixing in various The mixing time depended on the polycarboxylate directions. The panel thickness of the in-plane shear superplasticiser (PCE) used and was normally between 8 connection was only 130mm. and 10 minutes per charge. At temperatures of more than 30°C, most PCEs lose their effectiveness, so the material Mix design was stored inside and not in the sunlight. The use of The tender documents required an UHPC with a strength high-intensive shear mixers was found not to shorten of 150-200MPa in accordance with ASTM and a flexural the required mixing time and did not improve the result;

Table 1 – UHPC mix design and test results Nanodur Compound 5941 1320g/m³ Special aggregates size 3–5mm 312kg/m³ Special aggregates size 1–3mm 864kg/m³ Quartz sand from India 160kg/m³ Superplasticiser – PCE 26kg/m³ Shrinkage reducer 16kg/m³ Steel fibres 70kg/m³ Water 160kg/m³ Mean 100mm cube compressive strength at 56 days >180MPa Architectural Precast

Above: The front of the building. very often they cause problems because they bring in too much energy and increase the temperature of the mix. The Nanodur binder was delivered in large bags and dosage of all ingredients was done by hand. Pouring of concrete was possible with buckets or with a wheelbarrow; no special equipment was required. The greater the flow of concrete, the better the loss of entrapped air and the surface quality of the element. The challenge in production was not the recipe or the mixer but the crucial task of constructing the mould. The self-compacting concrete with a lot of fine particles gives an exact mirrored impression of the mould. Every small error and uncleanliness marked on the mould surface is reflected in the element. The air bubbles rise to the top and get trapped at corners or edges within the mould. The shrinkage of the concrete of millimetres over the whole length leads to deviations in dimensions, which should be defined within given tolerances. All inner formwork and preformed voids are restrained within the concrete due to shrinkage. These should be constructed in a ‘soft and weak’ material construction in order to facilitate the demoulding and to avoid cracking of the concrete. However, the formwork should be not too weak, so that the given tolerances are not exceeded. DCS used GFRP for the construction of the mould. This material also has the advantage of being lightweight, so that moulding and demoulding procedure are possible to do by hand, without using a crane. „

Below: Building site at night.

Corners and edges.

Sustainable Construction

Sustainability will help guide the future of the cement and concrete industry

In recent years, more and more progressive companies have put sustainability at the heart of their business. The climate crisis, of course, has lent urgency to the trend – but this is not the only reason for change. Sustainability also makes sound business sense – it offers brand and reputational returns, improves talent retention and attraction, and leads to productivity gains. More generally, sustainability allows companies a ‘social licence to operate’.

Dinah McLeod, Global Cement and Concrete Association (GCCA), London, UK

With the Covid-19 pandemic taking its toll on lives, jobs responsible leadership in the manufacture and use and economies, a moment of greater change is upon us. of this fundamental building block. Even before the What we do now – at this most critical time – will impact Covid-19 crisis, demand for our product was set to grow our planet for generations to come. From the economic significantly – the world’s population is expected to reach and health catastrophe now engulfing the world, we must 9.8 billion people by 2050, more than two-thirds of whom build back better and more sustainably. Concrete and are expected to live in cities. This significant growth will cement will play an outsize role in this work. It is more necessitate infrastructure that supports crucial amenities than a building material – it provides homes, it connects such as clean water, sanitation and dwellings. Resilient communities and encourages trade. Our industry, construction is needed that simultaneously protects therefore, will be at the forefront of the world’s economic our natural environment from changing climates. Our and social recovery. sustainability ambitions must match the growing demand This offers a significant opportunity to drive for our products.

16 Concrete Engineering International August 2020 Sustainable Construction

So why did I, a sustainability professional, seize the members recognise that there is much more to do. Over opportunity to join this industry at such a crucial point? the next five years, our aim is to enhance the ecosystem Because in doing so, I have an unparalleled chance for delivering sustainable construction with concrete, by to achieve impact. By way of introduction, I’ve spent providing a platform for our members, affiliates, industrial much of my career focusing on support for businesses partners and other stakeholders to align and act on. We as they embark on their own sustainability journeys. want to work with all players in the construction sector This was at the heart of my most recent role with to ensure we are maximising the innumerable benefits of ‘The B Team,’ a group of some of the world’s leading concrete, while minimising its environmental footprint. CEOs seeking to improve business practices while This will be guided by our approach to continuously enhancing the well-being of people and the planet. improve the sustainability performance of our industry Sustainability was also interwoven into my work with through innovation and best practice, supporting the Business and Sustainable Development Commission members as they address the challenges and meet the as well as in positions with some of the world’s largest opportunities ahead of us. telecommunications, healthcare and financial services The GCCA is a CEO-led initiative, which means the companies. leaders of our member companies set the strategy and Each of these roles provided me with a solid oversee our work. This is important as it means buy- understanding of the vital role that infrastructure plays in, support and involvement at the most senior levels in creating a more sustainable world. This guided my of our industry. As the new GCCA CEO, I am excited to decision to take up the position of chief executive with use my background and expertise to collaborate with the GCCA. I believe that this organisation is instrumental our board and our member companies and affiliates, to to promote innovation and collaboration among industry set ambitious goals and develop tangible ways we can that will only accelerate the progress that has already further reduce the impacts of cement production and been made towards a more sustainable future within the promote concrete’s unique properties as a sustainable, built environment. durable and resilient building material of choice, now and I was immediately attracted to the vision and mission in the future. of the GCCA because its work, and the ambitions of its As the world begins to reawaken and redefine our ‘new members, align strongly with my own core sustainability normal’ following the Covid-19 pandemic, I believe we values. The GCCA envisions a world in which concrete must take full advantage of the opportunity this presents is seen as an essential material that supports global to build a more sustainable and resilient society that sustainable economic, social and environmental will create a more prosperous world. The cement and development. It is this opportunity – to show that concrete industry can play a fundamental role in this and concrete can help meet the world’s needs to support it’s great to be a part of this crucial journey. „ growing, modern, sustainable and resilient communities – that excites me the most. Dinah McLeod has recently taken up the post as chief executive with the Global Cement and Concrete Association. Our aim is to enhance the ecosystem for delivering sustainable “construction with concrete, by providing a platform for our members, affiliates, industrial partners and other stakeholders to align and act on.

As the respected and trusted ’’voice of the sector, the GCCA represents a broad, global footprint of cement and concrete producers, as well as an important platform for

national and regional cement and concrete associations. (Photo: DANIEL LEWIS/Vismedia.) The industry has a long-held commitment to taking climate action. This hard work has resulted in a more than

19% reduction in CO2 emissions per tonne of cementitious material since 1990, as well as an 18% improvement in energy efficiency. This is while the percentage of alternative fuels across the industry has increased by more than nine times in the same timeframe. This is important progress, but the GCCA and our

August 2020 Concrete Engineering International 17 Sustainable Construction

Circular economy

Circular economy brings together concepts such as reducing resource depletion, recycling, waste reduction and reduction in landfill. It is an umbrella term and at times is a means to an end, unlike reduction in greenhouse gases and reversing biodiversity losses which are ends in themselves. The Organisation for Economic Co-operation and Development (OECD) published a report on circular economy as recently as April 2019.

Andrew Minson, Global Cement and Concrete Association, London, UK

While currently, climate change, biodiversity and the products, and their constituent materials, in the economy UN Sustainability Development Goals are perhaps pre- for longer periods). eminent, we do need to continue using the language of Ƌ narrowing resource flows (generating additional circular economy. And through this lens we, as a cement economic value from a fixed amount of natural and concrete industry, have a great story to tell. But first, resources)”. more from the OECD report in 2019(1). The OECD returns to these three mechanisms at key OECD business models points in the report, which explores five business models: Business Models for the Circular Economy: Opportunities Ƌ Circular Supply – close material loops and Challenges for Policy states “there is no single Ƌ Resource Recovery – close material loops definition of the circular economy,” but does offer, Ƌ Product Life Extension – slow material loops “Previous OECD work in this area highlights three main Ƌ Sharing – narrow resource flows mechanisms [to ultimately lower rates of natural resource Ƌ Product Services System – narrow resource flows. extraction]: Ƌ closing resource loops (the diversion of waste from In terms of material production, Circular Supply – disposal and subsequent transformation into secondary recycle concrete aggregates to replace virgin aggregates raw materials). thereby, “replacing traditional material inputs”; and Ƌ slowing resource loops or flows (the retention of Resource Recovery – use of fly ash and GGBS as secondary

18 Concrete Engineering International August 2020 Sustainable Construction cementitious materials, “to produce secondary raw must be considered in order to determine the optimum materials from waste”. environmental outcome: the choice of when and where In terms of design, Product Life Extension – increasing to use recycled aggregates and by whom, and the choice design life through specification of concrete, cover and/or of building design strategy between demountable and non-ferrous reinforcement, “to extend product lives”. durable. In terms of asset management, the OECD highlights the First, aggregates. Academia and industry have done, Airbnb business model as an example of Sharing, which and continue to do, an excellent job of establishing results in “increased utilisation of assets”. An example of a concrete technology understanding behind use of recycled Product Services System business model is harder to come aggregates in concrete, ensuring standards are in place by in the cement and concrete industry, but these models that permit use of recycled aggregates and equipping are characterised by the application of new technology, the clients, consultants, supply industry and contractors retention of ownership and narrowing resource flows. to accept, specify, manufacture and build with them. This These three characteristics are seen in the ready-mixed work is ongoing and addresses potential impediments to concrete industry where in-transit management through the use of recycled aggregates in concrete. It enables the internet-connected sensors provide real-time monitoring use of recycled aggregates when it will deliver an improved and control, and “product ownership remains with the environmental outcome. supplier” – in this case the technology is the product, However, sometimes it gives a better environmental the supplier might be the admixture company and the outcome for available recycled aggregates not to be used narrowing of resource flow arises from avoidance of over in concrete and for virgin aggregates to be used instead. specification. The italicised quotes above are the key Additional transportation, additional resources to ensure characteristics in the OECD report for each of its business quality and additional cementitious content in the concrete models. are all reasons why use of recycled aggregates in concrete The OECD report recognises that its five business models may not be the optimum choice. If all potentially recycled are already being applied and explores how they can aggregates are being recycled and used in construction, become more widespread. It also considers when their then the aggregates/concrete industry itself is best application may not deliver an improved environmental placed to determine where the recycled aggregates are outcome and what the potential downside might be deployed. The system boundary in LCA terms for concrete of rebound effects. Finally, it recognises that society’s and recycled concrete aggregates should be the whole demands cannot be met by reuse and recycling alone, and aggregates industry and not the subset of concrete, to that virgin materials are still needed. avoid adverse outcomes. The main ambition of the broader aggregates sector in each geographic area should be Considering all impacts to use all potentially available recycled and secondary The OECD report provides a useful overview of the “vast aggregates in place of virgin aggregates. number of life-cycle assessments (LCAs) that assess Second, and more briefly, building design strategy. Two recycling relative to other end of life options”. It identifies competing approaches to building design in response how few consider all impacts, stresses the importance of to the circular economy are demountable structures and LCAs comparing “apples with apples” and highlights the long-life loose-fit structures. The first is self-explanatory. difficulty in doing this. The second is about both engineering the structure for It is worth considering two examples where all impacts longevity and designing for architectural flexibility (loose (Photo: CC-BY-2.0/Peter Craven.)

AugustAugAAuugugustusustst 202020202020 ConcreteCoConnccreretete EEngineeringnngginineeeerriingng IInternationalntnterernnaattiiononaall 1919 Sustainable Construction fit) so that future modifications, refurbishments and even it is versatile (in constituents, production, how/where it repurposing can be done with the minimum of work, to is cast, design, finish and texture) – narrowing resource ensure the asset does not become obsolete. The first loop. maximises closed loop; the latter slows the loop. Whichever Ƌ Concrete can be used for design for disassembly (DfD) – one is most appropriate depends on the project. closed resource loop. Both require some anticipation of what the future holds Going further, it is useful to also communicate: and it is this anticipation, or assumption about the future, Ƌ Society’s demand for building materials outstrips what is that makes a whole-life-cycle assessment comparison available from demolition, so virgin materials are needed. For these virgin materials, responsible sourcing should between the options difficult and perhaps even subjective. be specified. Housing, education and medical facilities are typically Ƌ The demolition industry should be encouraged to known needs that will last for many decades and into the maximise recovery of hard demolition waste. next century, and a long-life loose-fit will enable the most Ƌ The system boundary for recycled concrete aggregates efficient use of resources. A can design should be the whole aggregates industry and not the this more resource efficiently than a demountable structure. subset of concrete, to avoid the perverse outcome of But for a project that is only needed for a short period, a virgin aggregates being transported from A to B and less structurally efficient design may be the answer in order recycled concrete aggregates transported from B to A. that whole elements – columns, beams and floor units – can be dismantled, transported and erected elsewhere. All Conclusion the impacts must be considered on a project-by-project Circular economy is a term widely used and encompasses basis to determine the optimum solution. many different aspects of sustainable production, sustainable use and responsible end-of-life redeployment GCCA circular economy activity of resources. There is a strong story to communicate on The GCCA has a spectrum of activity that can be described the circular approaches embedded in the production under the umbrella of circular economy, relating to side of the cement and concrete industry, especially with both production and how concrete is used. More detail use of by-products from other industries. And there is a about the Association’s work can be found at: https:// strong story for subsequent life stages through to end gccassociation.org. of life when concrete can be crushed and reused. Further Our industry messages in terms of circular economy research to improve technical understanding and practical can be summarised as follows (with the specific circular implementation of using demolition waste and by-products economy outcome in italics): from other sectors and industries into the cement and Ƌ Concrete is durable – slow resource loop. concrete industries, will enable our industry to continue Ƌ Concrete is fully recyclable – closed resource loop. and, increasingly, to play its part in delivering society’s Ƌ Concrete uses secondary aggregates from other need for infrastructure and buildings in an environmentally industries – closing resource loops for other industries. responsible way. „ Ƌ Cement/concrete uses by-products from other industries to replace cement clinker – closing resource loops for Reference other industries. 1. ORGANISATION FOR ECONOMIC CO-OPERATION AND DEVELOPMENT. Ƌ Clinker manufacture uses waste as fuel and raw material Business Models for the Circular Economy: Opportunities and Challenges for (co-processing) – closing resource loops for other Policy. OECD Publishing, Paris, 2019, https://doi.org/10.1787/g2g9dd62-en. industries. A version of this article first appeared in The Indian Concrete Journal, Ƌ Concrete can enable optimised design solutions because January 2020.

20 Concrete Engineering International August 2020 August 2020 Concrete Engineering International 21 Sustainable Construction Is it possible to recycle concrete?

Having been used as early as the Roman era in buildings of almost every scale, it is almost impossible to think of a structure that does not have at least one concrete element. In fact, it is the most widely used construction material in the world, due to its versatility, resistance, ease of handling, accessibility, aesthetics and other factors. At the same time, its manufacture is also one of the main polluters to the atmosphere, mainly due to the fact that the cement industry emits approximately 8% of all global CO2 emissions.

Eduardo Souza, ArchDaily

22 Concrete Engineering International August 2020 Sustainable Construction

In addition to its intensive production, concrete is an contaminated with substances, such as pigments, calcium extremely robust material, heavy and composed of cement, sulfate, chlorides, and oils can cause damage and therefore water and coarse and fine (sand) aggregate. Thus, would should not be used as raw material. Whenever possible, it be possible to continue to use concrete sustainably after the most effective method of recycling would be to carry demolition, eliminating its disposal as mere waste and out the crushing on the construction site itself, which overloading landfills? reduces construction costs and the pollution that would The quick answer is yes – even if it isn’t exactly simple, otherwise be generated when transporting material to and it is possible to use concrete waste to manufacture from a quarry. new structural parts, maintaining concrete’s essential Approximately 60% of what is crushed can be used qualities of strength and resilience. First, it is important for downcycling processes (recovery of materials with a to understand that the extraction of aggregates effects more limited range of uses than the original material). a huge environmental impact, even if they are exploited These fragments can be used as base materials for locally. Although cement releases the largest amount of structures such as roads. It is also possible that the carbon dioxide during production compared with similar crushed concrete can partially replace the aggregate in the materials, conserving natural resources by reducing structural concrete, respecting the specified limitations to extraction would already be a huge environmental gain, properties detailed in Standards. The German Committee especially if we consider the amount of concrete produced for Structural Concrete (DAfStb) guideline(1), for example, daily around the world. prescribes a limit on the proportion of recycled aggregate In practice, after the demolition of structural elements, at 45%. “In 2006, material tests in Switzerland showed, it is possible to crush the concrete so that the fragments however, that high-quality concrete can be produced are later classified by size. Metals such as reinforcement even with the use of more than 90% of aggregates made bars are also accepted, as they can be separated by from scrap”(2). The resulting concrete maintains structural large magnets and eventually recycled. Only concrete characteristics very similar to the traditional one. Although the reuse of aggregates for the production of new concrete structures is commendable, it is important to mention that this does not represent a closed cycle for recycling the material, since the new structure cannot be made of crushed concrete without adding more cement, sand and water. In fact, studies carried out in Switzerland have shown that the use of recycled aggregates might save non-organic raw materials (gravel sand), but can increase energy consumption and greenhouse gas emissions if, due to a higher void content and water demand, more cement is used to manufacture the concrete. When we approach the subject of sustainability, the most important thing is to understand most of the variables and the factors that impact the final result. There are many researchers focused on making concrete a more sustainable material and every day new studies on the subject appear, whether through recycling, more sustainable mixtures of recycled aggregates and even through processes that make the production of this material less harmful to the environment. „

References 1. DEUTSCHER AUSSCHUSS FÜR STAHLBETON, DAfStb. Richtlinie Beton mit rezykliertem zuschlag, German Committee for Reinforced Concrete, DAfStb. Guideline Concrete with Recycled Aggregates, Germany, Entwurf Stand, 1998. 2. HILLEBRANDT, A., RIEGLER-FLOORS, P., ROSEN, A. and SEGGEWIES, J-K. Manual of Recycling: Building as Sources of Materials. Edition Detail, Germany, 2019, 224pp.

A version of this article first appeared on the ArchDaily website on 17 February 2020. Visit: www.archdaily.com

August 2020 Concrete Engineering International 23 Historic Concrete Michelin House, London

Michelin House at 81 Fulham Road, Kensington & Chelsea (London SW3) is an extraordinary building by any measure. Architecturally it is a one-off, an exuberant fantasy of commercial self- aggrandisement, designed to project the identity of a new company operating in an emerging market sector. Though now a combination of shop, restaurant and office, it was originally the Michelin Tyre Company’s first permanent HQ and tyre depot in Britain.

Edwin Trout, The Concrete Society, Camberley, UK

The French Michelin enterprise had established its constraints of its first headquarters in Sussex Place and presence in Britain to exploit the market opportunities the directors started to look for a site for new purpose- opened by the lapse of the Dunlop patents in 1904 built premises. The Fulham Road site became available in and in June 1905 the Michelin Tyre Co Ltd was formally 1909, an island location with a footprint of approximately incorporated. The new business soon exceeded the 30,000ft2 (2787m2) and bounded on all sides by roads:

24 Concrete Engineering International August 2020 Historic Concrete

Fulham Road, Leader Street, Sloane Avenue and Lucan Place. It was a prime location on one of the main routes into and out of the capital, and so the freehold was purchased. Designs for a customised building were already being prepared in anticipation and by 4 April 1910 they were ready.

Design The overall architectural design was by the in-house engineer François Espinasse (1880–1925), a long-serving Michelin employee who worked in the construction department of the company’s headquarters in Paris – which indeed is the only other building in whose design he is known to have been involved. And the design is like nothing else. Built at the tail-end of the Art Nouveau period, it includes some elements that hark back to that taste, with decorative metalwork at the front, plants incorporated around tyre motifs and a mosaic in the entrance. Likewise, its use of decorative wall tiles and pictorial elements, which also foreshadow the Art Above: Bibendum in stained glass. Deco aesthetic of the post-war years, an impression strengthened by overt advertising iconography and “During the two months that elapsed after the first date, roadside location so typical of the new age. the ferro-concrete skeleton had been completed to roof However, behind the distinctive decoration lies an level, all the floors had been finished and considerable early reinforced concrete structure. It was built using progress had been made with the terrace roof. Three Hennebique’s proprietary ferro-concrete system with months later, on 15 December, the building was ready in hollow pot floors, the detailing of which was undertaken by every way for occupation”.(1) Completed, furnished and the specialist LG & Partners. Reinforced concrete, occupied by the company within five months from the increasingly used for industrial buildings at this time, was commencement of operations, the project programme chosen for several reasons. Perhaps most obvious to the was claimed by Mouchel & Partners to be a record time modern mind was its ability to provide open, unrestricted and, it was added on their behalf, “speaks well of the spaces, suitable for vehicular access and storing the organising power of the engineers and their contractors”. large number of tyres required by the client. At this time, The contractor in question was Messrs WJ Fryer & Co of fire resistance was a greatly valued (and energetically Bravington Works, Paddington, a firm that specialised in promoted) characteristic of concrete – an important factory work. In addition to the construction staff, Fryer consideration for those engaged in the motor business, employed electrical and mechanical engineers to equip the where the stock in trade is highly inflammable. But what plants being built, an advantage that it was said “enables really caught the imagination of industry in 1910 was them to bring the different sections of the work much concrete’s facility for rapid construction. more rapidly to completion.” So, after just five months of building work, the new headquarters opened on 20 Rapid construction January 1911. And rapid it certainly was in the case of Michelin House. Work commenced on 7 July and progressed at pace: The building Michelin House offered the latest in motoring convenience Below: Motoring motifs. with a drive-through tyre-fitting bay at the front, complete with automatic doors and a weighbridge used to assess the optimum tyre pressure. It held a stock of up to 30,000 tyres in the basement, raised to ground level by lift and rolled to the front on a sloping floor. The building overall consisted of three floors with a flat roof. Below ground, besides tyre storage, the basement held machinery. Alongside the tyre-fitting bay, the ground floor included a saleroom, the touring office, more tyre storage and eight loading stages. At the back, there was a garage for up to 40 cars. The upper floor comprised office accommodation for a staff of 300, with a boardroom and the director’s office. All this, while largely unfamiliar to a public just getting used to motoring, might reasonably have been expected for the purpose intended. What was unique was the

August 2020 Concrete Engineering International 25 Historic Concrete

Left: Ceramic tiles celebrate success. Below: ‘M’ for Michelin.

idiosyncratic ornamentation that proclaimed the place The refurbished building, now extended again, opened as Michelin’s own. Two glass cupolas designed to look to the public in 1987. The restaurant continues to be a like piles of tyres surmounted the corner turrets of the popular attraction. „ façade. There were three large stained-glass windows based on adverts of the time, each featuring ‘Bibendum’ Reference (the Michelin Man), and etchings of the streets of Paris 1. LG MOUCHEL AND PARTNERS. Mouchel-Hennebique ferro-concrete: theory embellished the first-floor windows. At street level were and practice. 4th Edition, London, 1921. decorative tiles, featuring examples of famous racing cars that used Michelin tyres. Other tiles inside the tyre-fitting Below: Advertising in architecture. bay at the front included a floor mosaic of Bibendum raising a glass of nuts and bolts, while declaring “Nunc est bibendum” (now is the time to drink). Not surprisingly, such a characterful building featured in Mouchel’s publicity as well as in Michelin’s.

Later extensions Later in that first year of operation, an extension was undertaken on the second floor to provide extra office space on the Lucan Place side. A second extension of three floors was built in 1922. However, with the production of British-made tyres in Stoke-on-Trent starting in 1927, the firm moved its headquarters north in 1930 and retained only a limited presence in Fulham Road. Apart from a continuing business in the basement and ground floor, much of the remaining space was let to tenants. After World War Two, further work added a third floor along the Lucan Place elevation in 1952. Thereafter the building faded, although the original front section was Grade II listed on 15 April 1969. Michelin eventually left in 1985 and the building was bought by Paul Hamlyn and Sir Terrance Conran, who between them redeveloped it with offices for Octopus Publishing, a Conran Shop and the new Bibendum Restaurant & Oyster Bar. Sixty steel columns were inserted through the existing floors to support a fourth above without obstructing the ground-floor shop (the detailing of which required an astounding 1300 drawings by the structural engineer YRM Anthony Hunt Associates) and a glass curtain was added to enclose what had been a loading bay on Sloane Avenue.

26 Concrete Engineering International August 2020

Floors and Screeds Overcoming challenges faced by the global Covid-19 pandemic

In these extraordinary times, we have faced a pandemic situation for the first time in our lives, all construction businesses have had to look closely at how to work within WHO, government and site-specific guidelines, with the safety and well-being of employees and our communities being paramount. Not just site-based activities but everything was questioned – from how and where employees worked to how they engaged with customers. Twintec was no different and moved quickly to adopt and implement virus-related work-safe practices across the group.

Ruth Waugh, Twintec Middle East Industrial Flooring, Dubai, UAE

On 19 March 2020, Twintec Middle East, with its regional headquarters in Dubai, was faced with a new unprecedented challenge as the UAE introduced strict lockdown measures to combat the coronavirus outbreak – including the closing of borders to residents and visitors alike – leaving some staff unable to return from overseas trips, delays on import of materials, restrictions on office capacity and public transport. Unlike many countries in Europe, the United Arab Emirates defined construction activities as a key economic sector permitted to continue working within clearly defined guidelines relating to movement of personnel and equipment, personal hygiene and social distancing measures. While this meant that site operations could continue, it required a rapid adjustment of some on-site working practices and a review and implementation of additional health and safety measures, to ensure continued protection of all operatives and preparation of clear documentation for the authorities and general contractors on-site. Mandatory home working was introduced for all office staff and, as for millions of others around the world and (Photo: Mark Alexander.) widely documented and discussed, this meant a severe readjustment to daily work routines. To address these challenges, the following actions were taken: Ƌ a thorough risk and continuity-of-work assessment, considering international and local guidelines on health, safety and best practice

Above: Successful site execution is built around robust processes and Ƌ briefing of all staff on mandatory preventative measures practices, maintaining PPE use and social distancing measures. and conduct weekly review meetings to assess the rapidly changing situation Ƌ introduction of a rigid equipment and warehouse/office Working in the construction industry, everyone is cold fogging disinfection regime, appointing authority- familiar with the challenges that present themselves on approved providers a daily basis and contractors, subcontractors, materials Ƌ providing all staff (on- and off-site) with PPE (face suppliers, developers, consulting engineers and all related masks, gloves and sanitiser) stakeholders adapt to each scenario as it presents itself on- Ƌ appointment of key personnel to monitor and ensure and off-site. compliance.

28 Concrete Engineering International August 2020 Floors and Screeds

Work together, stay apart the contractor to keep the project moving forward. COSCO, the Chinese government-owned shipping and logistics company, appointed Twintec to design and Critical success factors construct a 50,360m2 Freeplan ‘jointless’ SFRC concrete floor slab for its new development in the UAE. People In light of the pandemic situation, the Chinese The most valuable resource in any organisation. A contractor, together with the Twintec team, introduced willingness of employees to adapt – in addition to stringent measures to ensure personnel safety, alongside knowledge, skill and experience – is key, combined with a commitment to complete the construction of the an informed, proactive management able to support staff concrete floor slab. and maintain operatives’ motivation under extremely The Twintec area of work was off limits to all other demanding circumstances. contractors during concrete pours and operatives were provided with self-contained rest areas. Operatives Process were also accommodated in hotels that demonstrated Successful site execution is built around robust processes measures over and above the minimum recommended and practices. Fast-paced decision making and execution guidelines, including guest-only policies, strict regular to adapt those processes proved key to maintaining work disinfection regimes and restaurant social-distancing output and customer satisfaction in a safe manner. measures. The self-contained Twintec team maintained a Partners ‘lockdown’ regime for the duration of works, consisting of: Communication and commitment of all stakeholders Twice-daily temperature checks and coronavirus Ƌ within the business working together as partners to symptom checks implemented and recorded in addition to regular toolbox talks. achieve a common goal. Ƌ Face masks and gloves mandatory on-site, in addition to usual PPE requirements. The next normal Ƌ Strict social distancing and personal hygiene observed We all need to stop assuming that the old ways will come during all interactions with the contractor or other back. As the construction industry worldwide takes the trades on-site. first steps to rebuild, businesses need to find a balance between what worked before and what needs to happen In its drive to combat the spread of coronavirus, the in the next normal. The past few months have revealed UAE government introduced a national decontamination how agile the industry can be and where we can perform programme and restrictions on people’s movements even better. Remote working may not be ideal for all but (including concrete deliveries) from 8pm to 6am. These can work. Experience has shown that clients are willing to presented further challenges, especially when normal chat on a video call for more time than they were willing contracting operations continue around the clock. It to spend in a meeting at their offices. was an additional issue during May and June, as daily Digital tools have enabled us to increase productivity temperatures rise to in excess of 40°C and concreting in some areas of the business. In our industry, the daily works would generally take place at night. business is on-site and for companies such as Twintec, A collaborative approach between all parties agreed as a specialist on-site subcontractor, this doesn’t change. programme and output modifications, with a clear focus But it is clear that we must continuously adapt and closely on maintaining safety and quality of work under the monitor conditions for our people, projects and clients, conditions of operation. while maintaining proven and successful practices that The result was a high-quality ‘jointless’ slab that allowed continue to produce positive outcomes. „

Application of dry-shake topping to industrial floor. Note the use of face masks by operatives.

August 2020 Concrete Engineering International 29 Bandra Kurla Complex, Mumbai, India

Above: The columns were formed in a straightforward manner without any special-purpose components thanks to the integrated perforated strips on the LIWA panel formwork. The Bandra Kurla Complex (BKC) is an underground station on the Mumbai Metro, a rapid transit system that is currently under construction. The rapid transit system in the Indian metropolis will serve the city of Mumbai itself, as well as its entire metropolitan area in the federal state of Maharashtra. Comprehensive formwork and scaffolding solutions, provided since construction began on the major project in April 2019, should allow BKC to be completed within the demanding construction time- scale of only 14 months.

CEI report The Bandra Kurla Complex (BKC) is located on the section pressure on the wall formwork using ties, on account of of the 33.5km-long Colaba-Bandra-SEEPZ line (also known the subterranean position up against the ground earth. as line 3) that connects the Cuffe Parade business district in What was required was a single-sided formwork solution the extreme south of Mumbai to the Santacruz Electronics that could also cover the surface of the 24m-long and Export Processing Zone (SEEPZ) and the Aarey in the 4.5m-high concreting sections at a single pour. north. Upon completion, the BKC will act as an extremely important hub for passengers looking to change swiftly Below: On account of the subterranean position up against the ground to line 2. When completed, the BKC will be the largest earth, it was not possible to use end-to-end formwork ties when concreting the retaining walls. For this reason, a single-sided formwork underground station on the Asian continent. solution was required.

Complex The 475m-long and 30m-wide underground station consists of two subterranean levels. The first level is 8.4m high, ending with a 750mm-thick slab. The second level is 5.5m high and ends with a 1200mm-thick floor. Since all loads acting on the slabs are transferred directly into the columns, approximately 1450mm-thick drop panels were used between the columns and the slabs. Concreting the retaining walls was the first challenge that the construction team faced due to the fact that it was impossible to absorb the horizontal fresh concrete

30 Concrete Engineering International August 2020 Formwork and Falsework

non-tied wall formwork, it was possible to transfer the loads resulting from the fresh concrete pressure through climbing ties and into the previous concreting section via the brackets. In this way, it was possible to stick to the demanding concreting cycle of only 25–30 days that had been stipulated. The LIWA panel formwork was also used at the construction site in Mumbai for the construction of the 8.40m-high columns. This system formwork stands out not only due to its low weight but also on account of its integrated perforated strip. This allowed the construction site team to use the elements in a multi-purpose manner. For example, it was possible to form the columns in a Above: The 750mm- and 1200mm-thick slabs with drop panels were single operation and without the use of any special- cast effortlessly with the aid of the PERI UP Flex shoring tower plus purpose components. Opting for the LIWA instead of a and Table Module VT slab table. conventional formwork system resulted in valuable time savings and a significant reduction in personnel costs. Constructing retaining walls PERI came up with a special-purpose solution that ensured Modular scaffold system that the retaining walls could be constructed in only a The construction site team came up against another single cast and in the sectional dimensions required: the challenge when it came to constructing the 750mm-thick single-sided SCS climbing system in combination with slab area and the 1200mm-thick roof floor covering a 24 × the LIWA panel formwork. With the aid of the SCS for 32m single-pour plan area. The solution came in the form

Below: PERI has delivered approximately 480 tonnes of formwork and scaffolding material to the client’s construction site in addition to providing comprehensive on-site support.

August 2020 Concrete Engineering International 31 Formwork and Falsework

Above: With the aid of the SCS climbing system for non-tied wall formwork, it was possible to transfer the loads resulting from the fresh Above: On the Indian construction site, the LIWA panel concrete pressure of the second concreting section through climbing formwork was effective, especially due to its low weight. ties and into the previous concreting section via the brackets.

of the height-adaptable table support PERI UP Flex shoring time at all, thus contributing to the smooth execution of the tower plus. With the aid of standards and horizontal ledgers time-critical construction schedule. of the modular scaffold UP Flex and a few additional components, it was possible to erect shoring that was On-site support ideally suited to slab tables. It was also possible to adjust Thus far, approximately 480 tonnes of formwork and the positions of the standards so that they were perfectly scaffolding material has been delivered to the client’s equipped to deal with the loads to be transferred, with each construction site. The formwork planning and construction standard being able to absorb a maximum load of 40kN. engineers have also been on hand to support and train the To form the slabs, Table Module VT slab table was used in construction site team throughout the entire process, in combination with VT 20K formwork girders. The large-scale an effort to ensure that the major construction project is formwork areas of the slab tables were moved quickly and completed within the scheduled period of 14 months. easily by crane and movable trolley. The slab tables were The Bandra Kurla Complex is scheduled for completion preassembled at site, meaning they were ready for use in no in 2020. „

Below: VT 20K Formwork Girders were used to support the slab formwork. (Photos: PERI GmbH.)

32 Concrete Engineering International August 2020 This qualification can be carried out whilst on furlough!

University Certificate in Concrete Technology

“Having completed the Derby course , I can now interact with others on a technical level that wasn’t possible for me before”

Why choose Who’s it this course? for?

• Conveniently delivered, on-line and at the University This course is open to all with an interest in concrete of Derby Enterprise Centre* over one year, this course particularly; is the ideal launch pad for further study in Concrete • anyone within the industry wishing to gain formal Technology. recognition of their experience. • This on-line course has been developed by University • supervisors, managers and support personnel wishing of Derby with The Concrete Society and the Institute of to gain wider knowledge of the science of concrete Quarrying - so you can be sure you’re learning relevant and its properties. and up to date information. • On successful completion you’ll gain a nationally *The optional tutorial sessions may be delivered online due to Covid 19. recognised qualification, a Level 4 University Certificate in Concrete Technology, which will help your career development. How to apply For more information: • Graduates of this course will be eligible to apply for Membership of the Institute of Concrete Technology Email: [email protected] at Associate level. Tel: 01276 607140 ZZZFRQFUHWHTXDOL¿FDWLRQVRUJTXDOL¿FDWLRQVDVS The course starts in September so apply early to ensure all course )RUIXUWKHUDGYDQFHGFRQFUHWHUHODWHGTXDOL¿FDWLRQVDW materials are received WKH8QLYHUVLW\RI'HUE\SOHDVHYLVLWWKH8QLYHUVLW\RI www.derby.ac.uk in good time. 'HUE\ZHEVLWH

The Institute of Quarrying Formwork and Falsework Barntrup bypass, Germany (Image: PASCHAL-Werk G. Maier GmbH.)

Reinforced concrete work for two new bridges for the Barntrup bypass in the state of North Rhine-Westphalia, Germany is complete, allowing road and rail traffic to flow smoothly from March 2020.

Katja Münch, PASCHAL-Werk G Maier, Steinach, Germany

The construction work for bridge structure nine began in May 2019. Using approximately 770m² of Logo.3 for one abutment, the entire inner formwork was ready after only six weeks of construction.

The construction company Wilhelm Becker worked on and inexpensive rental offer, the entire formwork plan behalf of the Ostwestfalen-Lippe regional branch of the was developed and calculated at the Gifhorn branch using NRW provincial road authority to build bridge structures Paschal Plan Pro (PPP) software, based on the construction four and nine concurrently for the Barntrup bypass, which and design drawings from the company eberhardt - die is part of the Lippe general transport concept. ingenieure. The , foreman and formwork consultants Railway bridge were involved from the beginning in order to ensure that Bridge structure four is located immediately to the west any and all opportunities to improve the efficiency of the of Barntrup and serves the future B66n now that the formwork and concrete work could be implemented in underpass is completed. Since it is a railway bridge, this accordance with company policy. structure has been built as a single-span composite structure using the ‘rolled steel girders in concrete’ (WiB) Vertical formwork tasks construction method in accordance with DB-Ril 804.9010(1) It became clear during the preparatory meetings for the and has a span of 21.86m. best formwork plan that the LOGO.3 formwork system Following completion of the overpass, bridge structure would be most suitable for shuttering of the four bridge nine serves the B66n, taking it over the Alverdissen- abutments of building structures four and nine. In addition, Barntrup railway line. Since this bridge structure is the construction company Wilhelm Becker has its own designed without any abutments on the parallel wings, formwork systems, the Modular/GE universal formwork the structural plan stipulated that it should be built as a system and the Athlete steel frame formwork from Paschal single-span structure with integral framework and a span that had already been used to form and concrete the load- of 14.2m. bearing foundation plates up to 1.6m thick. As a regular client of Paschal, the construction During an on-site interview, site manager Stephan company requested the formwork and shoring systems Hirschmann mentioned that one of the many advantages from the formwork company’s trade partner Heinrich of Logo.3 is that it allows both of the chamber walls of Grotemeier in Bünde. In order for the Wilhelm Becker building structure four to be formed together using the construction company to be able to establish a coherent system.

34 Concrete Engineering International August 2020 Formwork and Falsework (Images: PASCHAL-Werk G. Maier GmbH.)

Left and far left: 3D views for the abutments for bridge structure nine created using Paschal Plan Pro.

This is another advantage of particular importance for Logo.3 formwork panels, for the reinforced concrete the construction company, since each of the four bridge surfaces of both structures that were not covered in abutments was entirely formed and concreted in one pour. earth, were mounted on-site using saw rough-cut boards. In the formwork plan, engineers combined Logo.3 with The construction company also relied on its permanent the hinged corner posts at the full height of the formwork employees, who had been trained as reinforced concrete in order to be able to use the system to form all the acute, experts. obtuse and right-angled corners accurately. The diversity of the Logo.3 system was also seen in The sloping formwork inserts to align each inclination combination with the security equipment. Every concrete were prepared on-site by the construction company’s section was therefore prepared using the Multip multi- reinforced concrete operatives using wooden structures. functional working platform for safe ascent and descent. The same applied to certain fillers that were deliberately The Multip and Logo.3 formwork panels were, again, made of timber since the asymmetrical corners were combined with the Logo.3 platform brackets and offer the cross-braced due to the enormous pressure of the fresh important workplace safety required for formwork, bracing concrete. and concreting. These measures also helped to simplify the Approximately 290m³ of C30/37 strength-class concrete operatives’ jobs and, consequently, increased efficiency as was laid in one pour, up to a height of approximately 9m a whole. This was all prepared in advance according to the for each abutment in bridge structure four. respective formwork plan. Approximately 350m³ of concrete was laid in one pour Successful completion of the entire project was reached up to a height of over 9m for each of the large abutments earlier this year in March. „ of bridge structure nine. Reference In order to meet the visual quality stipulated by Wilhelm 1. DEUTSCHE BAHN, Richtlinie 804 – Modul 804.9010. Richtzeichnungen “Stählerne Eisenbahnbrücken”. DB Netz AG, Frankfurt am Main, Germany, Becker in accordance with the tender specifications, the 2012. (Image: Stephan Hirschmann.)

Completed concreting work.

August 2020 Concrete Engineering International 35 Not out of reach

The Port of Pittsburgh’s Inland Waterways Navigation System consists of 17 locks and dams on the three major rivers that connect in Pittsburgh – the Allegheny, Monongahela and Ohio. Much of the infrastructure in the waterway system is 70–80 years old and desperately in need of repair. Due to its age and lack of consistent maintenance and upgrades, this lock and dam system, essential to shipping and recreation in the area, has deteriorated to the point that watercraft lockages have become severely impeded.

CEI report

Operatives used a JLG lift to perform the vertical wall saw cuts. Repair and Strengthening

holes enabled the excavator mill head to know its depth when milling the face wall of the chamber. During the first shutdown, work on the ladder and line hook area commenced. The area to be demolished was 13.5ft long, 22ft tall and 2.5ft thick (4.1 × 6.7m, 760mm) and could not be reached by the mill. CCS used a Hilti DSW 3018E wire saw to cut the ladder and line hook area into four 28,000lb (12.7 tonnes) pieces. Wire sawing the ladder and line hook section into pieces was the only way to remove this concrete. First, two 2-inch-diameter (50mm) vertical holes were drilled 22ft (6.7m) deep, followed by 12 number

Above: Vertical cuts were made 12-inches (305mm) deep along the 6.5-inch-diameter (170mm) horizontal holes. The wire lock chamber wall with a Hilti DSW 3018E wire saw. cuts consisted of four 13.5ft by 2.5ft-deep (4.1 × 760mm) horizontal push wire saw cuts, two 22- by 2.5ft-deep (6.7m The lock facility is more than 80 years old and only has one × 760mm) vertical pull wire saw cuts, finishing with a 22- chamber, measuring 56 × 360ft (17.1 × 110m). The lock is by 13.5ft-deep (6.7 × 4.1m) vertical pull wire saw cut. open to commercial navigation and recreational boating The mill also could not reach the face wall in front of the 24 hours a day, seven days a week. metal pump house building, which was 23ft long, 22ft tall The US Army Corps of Engineers (USACE) was tasked and 12-inches thick (7m, 6.7m, 305mm). This concrete was with resurfacing the deteriorated vertical land wall concrete substantially deteriorated and wasn’t strong enough to be within the lock chamber at lock number two on the lifted out in pieces with a crane. CCS determined the safest Allegheny River near Pittsburgh. It hired general contractor way to remove the face wall was to cut it into one piece (GC) CJ Mahan Construction Company for this demolition with the Hilti DSW 3018E wire saw and then hammer it with and restoration job. a Husqvarna DXR demolition robot from a barge as the The GC’s contract was to resurface an area measuring back cut was pulled up. To make this cut, two 22ft (6.7m) 360 × 22ft (110 × 6.7m), with 22ft (6.7m) being roughly vertical wall saw cuts 12-inches (305mm) deep were made, the minimum normal water level measured from the followed by a 23ft (7m) horizontal cut. Then, a 23 × 22ft (7 top of the wall downward. The scope of the work × 6.7m) vertical pull wire saw cut was made to finish. was to include concrete removal, concrete placement Elsewhere, wall saw cuts were needed on the face wall (including fabrication and placement of precast panels), at the limits of work to provide a neat line and clear limit reinforcement bar and anchor installation. of demolition for all work. CCS used Husqvarna HF482 Concrete Sawing and Drilling Association member wall saws to saw a 360ft (110m) horizontal cut for a neat Concrete Cutting Systems of Pittsburgh (CCS) was line at the bottom of the chamber wall removal limits and contracted to remove: two 22ft (6.7m) vertical cuts for a neat line at the limits of Ƌ a vertical concrete wall inside the lock chamber work. At the top of the wall, CCS slab-sawed 700ft (213m) measuring 360ft long by 22ft tall and 12-inches thick of 15-inches (380mm) thick concrete for the work limits. (110 × 6.7m, 305mm) Slab sawing was the only logical solution to make this cut, vertical concrete walls 330ft long, 6ft tall and 12-inches Ƌ providing the limits of work on the top of the wall. thick (100m, 1.8m, 305mm) to make way for new steel grating above mechanical access points Below: In total, 1460 linear feet (445m) of wall saw cuts were made. Ƌ ladder and line hooks along a vertical concrete wall inside the lock chamber measuring 13.5ft long by 22ft tall and 2.5ft thick (4.1 × 6.7m, 760mm).

A challenging work schedule The USACE allowed work within the lock chamber on a 3-2-5-2 schedule: three weeks full chamber closure, two weeks restricted chamber width to pass navigation, five weeks full chamber closure and two weeks restricted chamber width. CCS was to complete all face wall demolition during the first three-week shutdown so the GC could install new precast panels during the five-week full chamber closure. Only having three weeks to complete the demolition posed a big challenge. Before the first shutdown, CCS spent 30 days line-drilling 130 number, 2-inch-diameter (50mm) vertical holes to a depth of 22ft (6.7m). CCS used three Hilti DD350 core drills for this phase of the job, drilling an average of six holes per ten-hour shift, 22 shifts total. Core drilling vertical line

August 2020 Concrete Engineering International 37 Repair and Strengthening

At the gate recess area, the mill and crane couldn’t reach the vertical concrete wall, which was 34ft long, 22ft tall and 12-inches thick (10.4m, 6.7m, 305mm). In order to demolish this area, CCS used a Husqvarna HF482 wall saw to cut 22ft (6.7m) vertical cuts 12 inches (305mm) deep every 13 inches (330mm). Then they used a Husqvarna DXR secured to a barge to hammer the sections into manageable pieces. A JLG lift was used to perform the wall sawing. Two concrete walls between steel wall armour posed a unique challenge. The USACE wanted to save and protect the armour, so a big excavator was not an option. Time was short and hand tools could not complete the demolition on time. The only option was to use a Husqvarna DXR chained to a barge to hammer the sections, which were 15 × 22ft (4.6 × 6.7m) tall and up to 12-inches (305mm) deep. The mill head also could not reach the bottom 2ft (610mm) Above: Part of the 360 × 22ft (110 × 6.7m) deteriorated chamber lock wall section is removed via crane. of a 360 × 22ft × 12-inches deep (110 × 6.7m × 305mm) section of vertical wall where the neat cut line could not be disturbed in any way. Again, a DXR chained to a barge was Overcoming hazards and challenges the only option for the demolition. Even though the start date for the job was delayed one During the final 30-day phase of the post chamber month while the GC was waiting on USACE to approve the shutdown, CCS removed vertical concrete walls 330ft long work plans, CCS finished its pre-lock chamber shutdown by 6ft tall by 12-inches thick (100m, 1.8m, 305mm) for new vertical line drilling a few days ahead of schedule. During grating for mechanical access, and core-drilled to prepare the lock chamber shutdown phase, CCS employees worked for installation of new precast ladder and line hooks. To two 12-hour shifts, seven days a week. Complicating the job remove the walls, CCS core drilled 58 number 6.5-inch- was that most of the work was performed over water, as the diameter (170mm) vertical holes to 6ft (1.8m) in depth, chamber could not be drained. CCS used a swing scaffold, plunge wire sawed 58 6ft-deep vertical cuts and wall sawed barges with JLG lifts and floating steel and wood platforms 58 horizontal cuts 12 inches (305mm) in depth. The lengths to work in areas that couldn’t be reached by the mill. of each cut varied, but totalled 330ft (100m). To ensure safety, CCS operatives always wore life vests, Saw cutting was the only way to demolish these walls were tied off with 3ft (910mm) lanyards when working off because hammering this concrete would have sent debris lifts, wore safety harnesses when working near fall hazards into the mechanical controls for the lock and dam. The and completed rigorous safety inspections on each shift preparation for the installation of the precast ladder and when working with electric tools. Despite these challenges, line hooks required core drilling 14 number 1.125-inch- CCS completed its shutdown work one week ahead of diameter (30mm) horizontal holes to 2.33ft in depth schedule. Rather than sit idle, the GC asked CCS to take on (710mm), four 1.75-inch-diameter (45mm) horizontal holes more work to help complete the demolition on time. to 2.33-inches depth (60mm) and four 1.75-inch-diameter CCS finished all its post lock chamber shutdown work horizontal holes to 8.5ft deep (2.6m). Coring holes for the several weeks in advance of its deadline. The GC has since new precast and existing concrete was the only way to awarded CCS a sawing and drilling project in Kentucky anchor the concrete together correctly. scheduled for early 2020 because of its professionalism, project management, ability to meet deadlines and Below: Core drilling sawing tolerances and the fact that the company provides allowed for the wire saw runs, with 3028ft2 its operators with the latest in sawing and drilling (280m2) of total wire Below: In total, 1460 linear feet (445m) of technologies. sawing. wall saw cuts were made. Jon Wilson of CCS remarks, “Our original contract was to line drill and wall saw the bottom horizontal limit of work. By the time we completed the work, our contract tripled in size because of our efficiency in concrete sawing, drilling and demolition. Overall, the project was a huge success for Concrete Cutting Systems and we look forward to future work on the river wherever that may be.” Wilson believes CCS was selected for the project because it has a comfortable relationship with the GC. It previously worked with the company on three other USACE projects in Pennsylvania, Ohio and Indiana. „

This article first appeared in the December 2019 issue of Concrete Openings, the official magazine of the Concrete Sawing & Drilling Association; reproduced with kind permission.

38 Concrete Engineering International August 2020 BNMBQDSD OGNSNFQ@OGX

• BNMBQDSDmagazine prides itself on giving concrete a It’s all about the angles • The people behind the bold, vibrant image. Our front covers are an important buildings aspect of that goal... • First light on-site • Sunset and evening. WE invite all budding amateur photographers among our readership The best photos will be used in to submit suitable images for use on the front cover of BNMBQDSD or future editions of the magazine and Concrete Engineering International .magazine the photographer provided with a framed high-quality print of the cover featuring their submitted image. Photos must be sized at a minimum To get you started here are some possible categories: of 185mm (width) × 235mm (height) at 300dpi resolution (or 2200 × • Breathtaking buildings 2800px). • Work in progress A list of full terms and conditions can be requested from the Editor. • From the ground up E-mail: [email protected]

TCS Photo.indd 1 17/08/2018 11:27:10 Sprayed Concrete Ayla Golf Club, Aqaba, Jordan

The Ayla Golf Club takes inspiration from the natural dunescapes and mountains of the Jordanian desert, as well as the architectural heritage of the ancient Bedouin. The design of the building forms the core of the Ayla Oasis mixed-use resort development in Aqaba city.

CEI report

The 1200m2 building is part of the first phase of a 17 then applied to both the interior and exterior walls to serve square mile (4400 hectare) leisure development currently as the final shell finish, achieving the raw, unadorned look under construction in Aqaba, Jordan. The development that stays true to its context and inspiration. encompasses residential apartments, hotel and commercial Sunlight is filtered through perforated Corten steel space, all centred on an 18-hole signature golf course screens, similar to the traditional Arabic ‘Mashrabiya’ that designed by Greg Norman. were used to allow natural light without compromising The clubhouse features retail, dining, lounge, banquet, the privacy of spaces. Jordanian patterns inspired the spa and wellness components, while the golf academy triangular openings of the screens, while the tones of the includes retail, dining, and indoor/outdoor swing analysis surrounding mountains are echoed in the colours of the studio components. sprayed concrete and the rustic metals. The distinct architectural form of the 3700m2 Ayla golf The construction of the project is the result of a academy and clubhouse establishes a connection with knowledge exchange programme between the European nature by capturing the elemental, vibrant beauty of the office of Oppenheim Architecture and the local workforce. rolling desert landscape. A massive concrete shell drapes Sprayed concrete techniques were taught to operatives over the programme areas, enveloping the interior and in the first phases so that they could take ownership of exterior walls of each volume under one continuous the construction and obtain specialised skills. A local artist surface that emerges from the sand. also helped shape the building by applying a traditional Instead of having conventional walls and ceilings, the pigmentation technique to the interior surfaces, granting curved, sprayed concrete shell blends with the sand, a raw, unadorned look that stays true to its context and mimicking the dunes. The curved openings frame the views inspiration. of the golf course and the colourful Aqaba Mountains in All parties on the project showed a commitment to the the background. use of local resources in creating the golf club structures. Programmatic elements were modelled spatially, based Native raw materials such as non-metallic minerals – such on specific client requirements. Bringing the shells from as phosphate, limestone, silica sand, granite and feldspar – Oppenheim’s computer-generated model to the built and basalt and metallic minerals such as: copper, iron and environment was achieved through a process of individual gold – were incorporated wherever possible, particularly to sectional cuts, which were first built on-site with flexible achieve the desired appearance and texture of the façade. thin-gauge steel ribbons, then adding reinforcing bars and Additionally, the sprayed concrete consultant, Switzerland- an outer steel fabric. An adjustable ‘blanket’ fabric was based Greuter, recruited and trained local Bedouin laid over the top, enveloping each independent volume, operatives on-site, with the objective of employing them followed by a layer of insulation. Sprayed concrete was through completion of the academy and clubhouse. „

(Photo: Rory Gardiner.) Ayla Golf Club, Aqaba, Jordan Architect/ Oppenheim Architecture Landscape Form Landscape Architects Structure consultant WMM Engineers Sprayed concrete consultant Greuter Local architect Darb Architects and Engineers General contractor Modern Tech Construction Sprayed concrete contractor Nino Construction Engineers

40 Concrete Engineering International August 2020