Installing Pervious Concrete
Installing Pervious Concrete
Presented By: National Ready Mixed Concrete Association National Ready Mixed Concrete Association
• National Trade Association – Established in 1930 • HQ in Alexandria, VA • 1,400+ Member Companies • NRMCA Represents ~75% of North American Ready Mixed Production • Mission - Serve Industry and Partners Through: • Compliance and Operations • Engineering Interested in becoming a member? • Government Affairs Visit: www.nrmca.org/membership/ • Local Paving: Pave Ahead™ Initiative • Structures and Sustainability: Build With Strength™ Initiative 2 Thank you to the NRMCA 2020 Super Sponsors
3 NRMCA Disclaimer
• This presentation has been prepared solely for information purposes. It is intended solely for the use of professional personnel, competent to evaluate the significance and limitations of its content, and who will accept full responsibility for the application of the material it contains. The National Ready Mixed Concrete Association and any other organizations cooperating in the preparation of this presentation strive for accuracy but disclaim any and all responsibility for application of the stated principles or for the accuracy of the content or sources and shall not be liable for any loss or damage arising from reliance on or use of any content or principles contained in this presentation. • Unless otherwise indicated, all materials in this presentation are copyrighted to the National Ready Mixed Concrete Association. All rights reserved. Therefore reproduction, modification or retransmission in any form is strictly prohibited without the prior written permission of the National Ready Mixed Concrete Association. • ©2015 National Ready Mixed Concrete Association.
4 Instructions
• Webinar is being recorded and posted at paveahead.com/education/. • Everyone is muted. • Type questions in the question box. • Download the handouts in the GoToWebinar control panel. • Credit for course: – Based on attendance.
– Survey (Quiz) – In follow-up e-mail, not required, but encouraged.
– Attendance Certificate – In follow-up e-mail 1 hour after webinar. – AIA members – Attendance registered with AIA-CES if AIA number provided. 5 About the Course
Learning Units (LU) or Professional Development Hours (PDH)
• AIA-CES DSP102: 1.0 LU/Elective (1.0 Hour) or 1.0 PDH for Engineers
• Learning Objectives:
– Introduction to the various NRMCA certifications – Understand the different tools required for pervious concrete installation – Understand the steps to proper pervious concrete installation – Introduction to alternate installation machines/techniques used for pervious concrete
6 Your Instructors Today…
• Ken Justice, P.E. –NRMCA Local Paving, Midwest Region –31 Years in Practice –Civil Design & Pavement –Certified Pervious Concrete Craftsman –Contractor trainer –Over 200 pervious concrete projects
7 More information at paveahead.com/experts/ Personal Protective Equipment As We Review Pervious Construction Practices, Please Remember That Appropriate PPE Should Be Worn Based on the Activity!
8 NRMCA Contractor Certifications Pervious Concrete Contractor Training & NRMCA Certification
Over 400 contractors and 120 RMC producers in data base
10 NRMCA Pervious Concrete Contractor Certification Program
• Certification Levels: – Technician – Installer – Craftsman
NRMCA Pervious Concrete Contractor Certifications shall be valid for a period of five [5] years based on the date of completion of the written examination.
11 Written Exam
• The two-hour written examination is “closed book”
• Consists of approximately sixty (60) multiple-choice questions
• The passing grade for the written examination is 75%.
12 Performance Exam
• During the performance examination each examinee must demonstrate procedures for placing, consolidation, finishing, edging, jointing, and beginning curing a pervious concrete slab.
• The examiner will observe and evaluate the techniques used and record passing or failing grades on the various individual procedures.
• A passing grade is defined as “no significant variation from proper procedure and no more than two variations from proper technique in the use of the tools.”
13 Work Experience
• The work experience must include placing, consolidation, finishing, edging, jointing, and curing of pervious concrete.
• Verification of the amount and range of work experience by the applicant's employer(s) is required.
– Documentation of work experience should be reported on Craftsman Applicant Affidavit (NRMCA Form PCC9).
14 15 Tools & Equipment
Chapter 4 Equipment Overview
Winner Farm Moorestown, NJ 17 Notice equipment to clean and oil tools is staged too Placed October 2006 Equipment List
• Safety Equipment • Screed • Hand Tools • Compaction Rollers • String Line • Jointing Tools • Chalk Line • Hand Tamper • Forms and tools and equipment to set forms • Edgers • Riser Strips (optional) • 6 mil plastic • Concrete Rakes • Spray Can with Oil or Water Bucket & • Square Nose Shovels Brush • Hammer and nails, rebar or wood to hold down plastic
18 Safety Equipment
• Hard Hat • Goggles • Gloves • Boots • Long Sleeves • Long Pants
19 Forms – Wood or Steel
20 String lines or lasers may be used to set grades 2-Step Method - Truss Screed and Riser Strips
21 2-Step Method - Truss Screed and Riser Strips
• Place 3/8” riser strip on top of forms when not using a roller screed
22 The Roller – Static or Hydraulic
• 10” Diameter Steel Pipe • 40 lb/ft, 10’ Long = 400 lbs OR • 10 psi down pressure
Static Roller
23 Lawn rollers – NO GOOD!
Excessive compaction may collapse the void structure on a pervious concrete pavement
24 1-Step Method - Roller Screed
NO RISER STRIPS NEEDED!
25 Hand Tamper
$25 at Home Depot or Lowes
26 Edging Tool (1/2” or 3/8” radius)
27 Cross Roller – the “pervious bull float”
28 Pan Float
29 Jointing Tool
Fillet or Radius
30 Concrete Saw
Fillet or Radius
31 Chalk Line for Jointing
32 Proctor Hammer for Testing Density
33 Curing
6 MIL PLASTIC
34 Spray can for oil OR water bucket & brush
35 Lifting Equipment
36 Pervious Concrete Construction
Chapter 5 The Goal
38 Pre-Construction Planning
• Plans and Specifications
• Crew Size
• Ready Mix Supplier
• Tools & Equipment
• Weather
39 Plans and Specs
• Subgrade requirements • Pavement layout • Cross-section
• Does it all make sense?
40 Crew Size
5 1 2 4 6 3 7
8
Crew size = 6 - 12 PEOPLE
41 McCullough Alley, West Cape May, NJ Placed June 2007 Crew Duties
• 1 & 2 strike-off and compact (run screed)
1 5 2 4 6 • 3, 4, 5 & 6 handles 3 chute, keeps stone 7 wet, rakes and levels, tamps edges
8 • 7 & 8 finish (side roller), joint, edge and cure (plastic)
42 Crew Size
9 1 5 2 4 6 3 7
8
Ken’s tip: Have a 9th man!
43 Ready Mix Supplier
• Experience with Pervious
• Within Haul Time/Distance
• Make Sure They Understand Pervious
Estimating quantity for 10 ft x 20 ft x 6 in slab = (10’ x 20’ x 0.5’) / 27 = 3.7 cubic yards (about 4 cubic yards)
44 What Will the Weather Be?
• Sunny
• Cloudy
• Rainy
• Snowy
• Hot
• Cold
45 Tools and Equipment
• Equipment matched to size of the job
• Sufficient tools to do the work
• Curing materials (6 mil plastic) delivered before concrete placement
46 Site Preparation – Survey and Grades
• Plans and Specifications
– Material Type
– Elevation and Slope
– Moisture Content
– Compaction
• Typically grade to 1/10th of one foot (approx. 1-1/8th inches)
• Typically finish pavement to 1/4 inch of spec.
47 Site Preparation – Cut and Fill
48 Site Preparation - Compaction
Compact subgrade to 92% of modified proctor Compact aggregate base to 95% of modified proctor Don’t over compact, subgrade must remain permeable
49 Geotextile Fabric
Non-woven geotextile fabric SHOULD ALWAYS be specified unless on sandy soils
50 Recharge Bed Preparation
• Place and compact stone to desired depth • Keep stone clean
–Remove all dirt and debris that may clog recharge bed
51 Setting Forms
Wood or steel forms can be used
Use string lines to set form elevation
52 Placing Riser Strips – if needed
53 Thinking Ahead
• Crew size / duties
• Construction sequence
• Lane lengths / widths
• Equipment moves
• Delivery scheduling
54 Construction Sequence
55 Construction Sequence
56 Planning Equipment Moves
57 Equipment Moves
58 Concrete Delivery Scheduling
• Unloading time per truck
– Usually longer than conventional concrete
• Paving lanes
• Local Traffic
• Weather
59 Finishing: The Typical Process
• Spreading 1
• Strike-off 2
• Compacting & Finishing 3
• Jointing/Edging 4
5 • Curing
60 Spreading 1 Moistened Base 1
62 Recharge Bed Preparation
• Rake out tire tracks (and recompact)
63 Proper Water Content 1
64 Pervious Concrete Placement 1
• When concrete arrives on site, check for quality
• “Squeeze test”
– Grab a handful, squeeze for 5 seconds, release
– Half of your hand should be coated with paste
65 How Do You Know Its Right? 1
Look for ‘wet metallic sheen’
66 Gauging Water Content 1
67 Pervious Concrete Placement 1
• For fixed-form placement, place and level forms to desired grade • Dump directly and spread • Smaller work crews and less equipment needed save time and money
Crew sizes vary from 6 to 12
68 Mixer Discharge 1
69 Use onlyHang one no chute chutes section Edges 1
Place the edges first, then work toward the middle
70 Mixer Discharge 1
Maintain “horseshoe shape” placement
71 Hang no chutes Edges 1
Place the edges in lifts, tamp, and continue to top of form
72 Edges 1
• Tamp the edges (approx 3”-6”) for durability
73 Compacting the Edges 1
74 End of the Load 1
75 Square off slab at the end of a load Strike-off 2 Raking Concrete 2
Rake the concrete off a little high so it can be screeded.
77 2-Step Method - Vibratory Screed 2
78 2-Step Method - Riser Strips 2
3/8” Riser Strips
79 2-Step Method - Riser Strips 2
80 1-Step Method - Strike-Off 2
Strike-off high so that later you can come back and compact
81 Hydraulic Roller Screed 2
• Smooth and compact pervious concrete ½” +/- to desired final grade
• Roller steel screed recommended – 10 psi down pressure recommended
82 Small Jobs - Sidewalks 2
83 Placing Colored Concrete
84 Compacting & Finishing 3 Compaction 3
• Delaying compaction may cause raveling on a pervious concrete pavement
• Compaction takes place in top ½ inch of surface
• Compaction sets aggregate and smooths the surface
86 Static Roller Compaction 3
87 Roller Screed 3
88 Cross Rolling 3
• The pervious concrete version of the bull float • Removes roller marks and fills “misses”
89 Pan Finish 3
• The OTHER pervious concrete version of the bull float • Removes roller marks and fills “misses”
90 Edges 3
• Use an edging tool to round-off edges • Tamp the tool as shown – DO NOT SLIDE
91 Water Clean/Oil the Roller 3
92 Surface Texture 3
• Important to keep the voids open • Do NOT use trowels • Do NOT seal the surface • No roller marks
93 Pervious Concrete Finishing 3
• DO NOT use trowels or bull floats to finish pervious concrete
• Trowels and bull floats will seal off the surface!!!
• Mag floats only for small imperfections
94 Jointing 4 Why Joint? 4
96 Joints 4
Sawcut Joint Tooled Joint
97 Joints 4
• Cut control joints with a special “jointing” tool with a radius machined at the flange • Joints should be cut at least ¼ the thickness of the slab • Joint spacing between 15’ to 20’
98 Joints 4
• Cut control joints with a special “jointing” tool with a radius machined at the flange • Joints should be cut at least ¼ the thickness of the slab • Joint spacing between 15’ to 20’
99 Concrete Saw Cut Joints
• Tighter, neater joints
• Less prone to damage/raveling
• MUST WAIT 36-72 HOURS BEFORE SAWCUTTING JOINTS!
• Joints should be cut at least ¼ the thickness of the slab
100 Chalk Line for Jointing 4
101 Pervious Concrete Finishing 4
102 Jointing Rules 4
• 10’ - 15’ on centers typical
• 20’ on centers max.
• Square panels
• Cut in perpendicular to the curb
• Cut 1/4 the thickness, 1/3 preferred
103 Jointing Details 4
104 Match Existing Joints 4
105 Utilities 4
Align the joint with utilities to prevent random cracking from coming off the utility.
106 Jointing Into Inlets 4
107 Formed Joint 4
108 Isolation Joints 4
Isolation joints are used when you are adjacent to any fixed structures or anything that might settle and crack.
109 Curing 5 Curing 5
• Cure with 6 mil plastic for at least 7 days
• Cover within 20 minutes
• Plastic should extend 18” on each side to secure
111 Properly Secured Curing 5
Hold plastic down by nailing to forms or placing wood or rebar over plastic – do not use dirt
112 Properly Secured Curing 5
113 Cold Joint Preparation 5
• Square off all cold joints – whenever concrete cannot be delivered timely or at the start of a new day • Whenever plastic is pulled back, keep the exposed concrete wet until plastic can be replaced
114 Discoloration
115 Curing Compounds
• Soy bean oil • Boiled linseed oil • Help retain moisture prior to installation of plastic • Improves quality of paste • Secondary curing if the plastic should be removed • May also reduce surface discoloration • Not recommended as the only means of curing
• Sprayed-on film-forming curing compounds should be avoided • Temporarily clog voids but will likely break down
116 Improperly Secured Curing 5
If plastic is not secured, concrete may prematurely dry out
117 Improperly Secured Curing 5
118 What if it Rains? 5
119 Between Loads
Cover open end if the gap between trucks is more than 20 minutes
120 Preventing Evaporation
121 Cover with Visqueen within 20 Minutes OTHER PLACEMENT METHODS & MACHINES Conveyor
Moves concrete to inaccessible areas
123 Laser Guided Screed
124 Buggie
Hogan’s Park, Northvale, NJ Placed October 2008
Moves concrete to inaccessible areas 125 Straight Edge for Some Small Jobs
126 Other compaction method
Hand placement with tamper compaction – For small placements – Very slow
127 Other compaction method
Hand placement with tamper compaction – For small placements – Very slow
128 Power Screed
129 Slip-form
130 Spreader Box
131 NRMCA Resources
How Can We Assist You for Free? www.paveahead.com
133 134 Must read: PCA/NRMCA – Pervious Concrete Pavements (PCA Publication - EB302) (NRMCA Publication - #2PCP)
NRMCA – Pervious Concrete Contractor Certification (NRMCA Publication - #2PPCRT)
135 136 Pave Ahead™ Concrete Pavement Design Center
paveahead.com/register/ paveahead.com/register/
Pave Ahead™ Design Center • Design and Jointing recommendations and reviews for FREE • Cost comparisons including life cycle costs • Specification review • Ready mixed products: – Conventional concrete (full depth and overlays) – Pervious concrete – Roller compacted concrete – Cement slurry for full depth reclamation (FDR)
138 Local Paving Division: State and Regional Assignments
139 Local Paving Division: State and Regional Assignments
140 www.paveahead.com/education
• More NRMCA Concrete Pavement professional development: – Each Thursday beginning at 2:00 pm EDT Pervious Concrete Webinar Series! – June 11 Installing Pervious Concrete – June 18 Maintenance Guidelines for Pervious Concrete
• Portland Cement Association Webinar Series: www.cement.org/events/pca-infrastructure-webinar-series – Full-Depth Reclamation with Cement – Lightweight Cellular Concrete for Geotechnical Applications – Roller-Compacted Concrete Pavements – Cement Stabilized Subgrade Soils Recordings available for previous webinars! – Cement-Based Water Resource Applications
141 www.paveahead.com/education
• More NRMCA Concrete Pavement professional development: – Designing Concrete Parking Lots and Streets Recordings available for these previous webinars! – Designing Concrete Industrial Pavements – Soils 101: What to Know for a Successful Paving Project – Concrete Pavement Jointing and Details – Materials and Construction Specifications for Concrete Pavement Projects – Concrete Street and Parking Lot Maintenance and Repair – Concrete Overlays of Existing Asphalt Surfaced Streets and Parking Lots – Concrete Trail Design – Designing Pervious Concrete – Specifying Pervious Concrete
• NRMCA Concrete Buildings Webinar Series: buildwithstrength.com/education/
142 www.paveahead.com/education
143 144 Questions?