Presented By:National Ready Mixed Concrete Association

Specifying Pervious Concrete

2

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• Government Affairs• Local Paving: Pave Ahead™ Initiative

• Structures and Sustainability: Build With Strength™ Initiative

Interested in becoming a member?Visit: www.nrmca.org/membership/

3

Thank you to the NRMCA 2020 Super Sponsors

4

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.

5

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.

6

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:

– Understand principles behind proper pervious concrete mix design

– Familiarity with ACI 522R-10: Report on Pervious Concrete and ACI 522.1-13: Specification for Pervious Concrete Pavements

– Understand necessity for pervious concrete contractor certification

– Understand appropriate acceptance testing procedures for pervious concrete

7

Today’s Presenter

• Phil Kresge–Senior Vice President – East Central–Ready Mix Producer–PA Concrete Promotion Council – Exec. Director–NRMCA since 2004

More information at paveahead.com/experts/

Pervious Concrete Design

Pervious Concrete Mix

9

Properties of Portland Cement Pervious Concrete

• 15% to 25% air void content

• 120 to 135 lbs/ft3 unit weight

• 500 to 3,000 psi strength– Introduction of small amount of fine aggregate (sand) can increase strength

– BUT compressive strength typically NOT USED as acceptance criteria.

– Air void structure and unit weight are used for acceptance instead.

10

Mix Design – The Old Way

• 550 - 650 lbs. Portland Cement

• 27 ft3 Coarse Aggregate

• 0.25 – 0.30 W/C Ratio

• Admixtures

– High Range Water Reducer

– Viscosity Modifier

– Hydration Stabilizer

11

12

13

Mix Design – What We’ve Learned

• Maximum 500-550 lbs. cementitious– 5% Silica Fume optional

• 27 ft3 Coarse Aggregate• 0.32 – 0.37 W/C Ratio

– Sufficient water to display a wet, metallic sheen on the aggregate

• Admixtures– Specifically for Pervious Concrete– Mix Water Conditioner

• 550-650 lbs. Portland Cement

• 27 ft3 Coarse Aggregate• 0.25 – 0.30 W/C Ratio

• Admixtures– High Range Water Reducer – Viscosity Modifier– Hydration Stabilizer

14

Typical Portland Cement Pervious Concrete Mix Design

• ADMIXTURES

–Hydration Stabilizer• 10 to 16 ounces per 100 weight

• Ounces depend on temperature – add more on hotter days

–Viscosity Modifier• Ounces depend on % passing the 30 & 50 sieve

• 2 to 6 ounces per 100 wt – add VMA for more fines

15

Permeability and Porosity

• Permeability – rate at which water can flow

• Function of interconnected voids

• Porosity – the amount of voids

• Increase in porosity increases permeability

• Some voids are entrapped during the placement and compaction process

16

Aggregate

• Texture and Porosity Affected by:

–Aggregate Size

–Aggregate Grading

–Aggregate Angularity

–Paving Equipment

17

Strength

• Add sand into mix• 5% up to 25%• Adds up to 1,000 psi• Sacrifice porosity for strength

• Synthetic Fibers• Larger Aggregate Size

• For areas where high heels & wheelchairs are not a concern

• VAE Polymers• Increase density• Increased resistance to de-icing chemicals

• Thicker sections

Pervious Concrete Specification

19

ACI 522 – Pervious Concrete

• ACI 522R – 10– Provides technical information on

pervious concrete’s application, properties, and construction methods

• ACI 522.1 – 13 – Specification for Pervious

Concrete Pavements

20

ACI 522.1 - 13: Specification for Pervious Concrete Pavements

• Provides Guidelines for

– Quality Assurance

• Materials

• Testing - Acceptance

– Placement

• Does not provide recipe for pervious concrete mix design

21

Density

• Two types of density– Fresh Density

– Hardened Density

• Density increases as Void decreases

• Measured to determine acceptability– Fresh density for concrete mixture

– Hardened density for installation

• Assess whether void content is achieved

22

Density of Fresh Concrete

• Measured in accordance with ASTM C1688

• Varies with:– type/quantity of materials– void content

• Void calculated from measured density

• Fresh density used for acceptance at delivery– +/- 5 lb/ft3 of approved mix design

23

Density of Hardened Concrete

• Measured in accordance with ASTM C1754

• +/- 5% of hardened density results from test panels

• Differs from density of the fresh concrete

– Vary with compaction process

– Change in moisture content

24

Acceptance Criteria – ACI 522

• ACI 522 recognizes difference between– Density of fresh mixture

– Density of compacted pavement

• Neither fresh nor hardened density should be specified

• Void content specified by designer– Applies to fresh concrete

– Typically 15% to 25%

– Acceptance range typically +/- 5%

25

Specification Recommendations

“Target void content of 15% to 25% as measured by ASTM C1688*”

Suggested text - Not taken from ACI 522.1-13

•

26

Section 2.2 - Products

• 2.2.2 Aggregates - Nominal maximum aggregate size shall not exceed 1”, unless otherwise specified.

• 2.2.4 Admixtures - Chemical admixtures shall comply with ASTM C260/C260M, ASTM C494/C494M, or ASTM C1017/C1017M unless otherwise specified.

• 2.2.5 Fibers - Fibers shall comply with ASTM C1116/C1116M, 4.1.3 or 4.1.4. Fibers may be used in pervious concrete mixtures when permitted by the Architect/Engineer.

27

Section 1.5: Quality Control

•

•1.5.1.1 Contractor qualification - Unless otherwise approved by Architect/Engineer, Contractor shall provide evidence of employment of one (1) NRMCA certified Pervious Concrete Craftsman who must be on site, overseeing each placement crew, during all concrete placement, or the contractor shall provide evidence of employment of three (3) NRMCA certified Pervious Concrete Installers who have received hands-on training in the construction of pervious concrete pavements, and who must be on site, working as members of each placement crew, during all concrete placement, or, with the approval of Architect/Engineer, contractor may provide written evidence of project experience and proficiency in successfully completing pervious concrete pavement construction, and submit evidence of completion of a pervious concrete craftsman certification program.

28

Certification Levels

• Pervious Concrete Technician– Complete written exam

• Pervious Concrete Installer– Performance Exam– Minimum 3 projects @ 10,000 Sq. Ft.

• Pervious Concrete Craftsman– Prerequisite – ACI Flatwork Certification– 1500 hours work experience + performance exam

or– 3000 hours of work experience

•

29

www.nrmca.org/education/certifications

•

30

1.5.2.2 Test panels - Place two test panels on the project site, on a subgrade and subbase prepared as specified, using the material and construction requirements for pavement in this Specification. Each panel must have an area of at least 225 ft2, and a width and thickness as specified for the pavement in the Contract Documents.

•

Section 1.5; Quality Control

31

•Pre-Placement Conference – A mandatory pre-placement conference will take place including at a minimum, the architect, engineer, general contractor, pervious concrete contractor, concrete supplier, site contractor, landscape contractor and field testing agency. As a guide for the meeting, a copy of the document Checklists for Pervious Concrete Contractors and Suppliers (available from the National Ready Mixed Concrete Association, 900 Spring Street, Silver Spring, MD, 301-587-1400) will be used to review all materials and personnel qualifications, concrete production, preparation, placing, curing, and testing procedures.

•Suggested text - Not taken from ACI 522.1-13

Specification Recommendations

32

Section 3.10 - Curing

•

•3.10.2 - Completely cover the pavement surface and allexposed edges with a polyethylene sheet, unless otherwise permitted.

•3.10.1 - Begin curing within 20 minutes of concretedischarge, unless otherwise specified or permitted.

33

Curing and Protection

•

34

Internal Curing

• Cellulose Fiber

• Expanded Shale Lightweight Aggregate

• Admixtures

– Super Absorbent Polymers

35

Internal Curing

• Cellulose Fiber

• Expanded Shale Lightweight Aggregate

• Admixtures

– Super Absorbent Polymers

36

Internal Curing

• Helps retain moisture prior to installation of plastic

• Improves quality of paste

• Secondary curing if the plastic should be removed

• Not recommended as the only means of curing

37

Section 3.12 - Jointing

• Roughly ½ the shrinkage of normal concrete

• Joints are typically placed every 15 - 20’

• May be sawed or tooled

Sawed Joint

Tooled Joint

38

Tooled Joints

Jointing Roller

Butterfly Groover

Joint Knife

39

Saw-Cut Joints

• Within 24 hours of placement

• Remove dust/wet slurry by vacuum

• Remove plastic only in portions where sawing occurs

• Keep slabs moist

• Replace plastic ASAP

Pervious Concrete Acceptance Testing

41

Acceptance Testing

• Considered zero-slump

• Compressive strength not used as acceptance criteria.

• Air void structure and density are used instead.

42

• Fresh Concrete Density and Voids Content

– ASTM C1688-12: Standard Test Method for Density and Void Content of Freshly Mixed Pervious Concrete

• Field Permeability (Infiltration Rate)

– ASTM C1701-09: Standard Test Method for Infiltration Rate of In-Place Pervious Concrete

• Hardened Concrete Density and Porosity

– ASTM C1754-12: Density and Void Content of Hardened Pervious Concrete

• Surface Durability (Impact and Abrasion)

– ASTM C1747-11: Determining Potential Resistance to Degradation of Pervious Concrete by Impact and Abrasion

ASTM Test Procedures

43

• ASTM C1688-12: Standard Test Method for Density & Void Content of Freshly Mixed Pervious Concrete

44

Section 1.5.5: Acceptance

1.5.5.1 The fresh density from a lot must be within 5 lb/ft3 of the accepted fresh density from the submitted mixture proportion in Section 1.4.1.2.

45

• ASTM C1701-09: Standard Test Method for Infiltration Rate of In-Place Pervious Concrete

46

Testing Permeability

• Perform ASTM C1701 once curing is completed

• Establish baseline/benchmark

• Map/diagram test locations

• Future tests should be evaluated based on initial test results

47

48

Pervious Concrete Cores• ASTM C42

• Measure thickness

– ASTM C174

• Compressive strength test not recommended for acceptance

• Dry Density/Void

– ASTM C140 replaced by ASTM C1754

49

• ASTM C1747-11: Determining Potential Resistance to Degradation of Pervious Concrete by Impact and Abrasion

How Can We Assist You for Free?

NRMCA Resources

51•

www.paveahead.com

52

53

ACI 522-R & 522.1Available through

American Concrete Institutewww.concrete.org

ACI 522.1-13

54

55

paveahead.com/register/

57

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)

58

Local Paving Division: State and Regional Assignments

59

Local Paving Division: State and Regional Assignments

60

www.paveahead.com/education• More NRMCA Concrete Pavement professional development:

– Each Thursday beginning at 2:00 pm EDT

– 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

– Cement-Based Water Resource Applications

Pervious Concrete Webinar Series!

Recordings available for previous webinars!

61

www.paveahead.com/education• More NRMCA Concrete Pavement professional development:

– Designing Concrete Parking Lots and Streets– 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/

Recordings available for these previous webinars!

62•

www.paveahead.com/education

63•