Performance of Pervious Concrete Pavements Marty Wanielista, Manoj Chopra, Joshua Spence, Craig Ball

1
Performance of Pervious Concrete Pavements Marty
Wanielista, Manoj Chopra, Joshua Spence,Craig
Ballock, Thomas Kunzen and Ben Pernezny

• Stormwater Management Academy
• University of Central Florida
• Orlando, FL 32816
• wanielis_at_mail.ucf.edu

2
Stormwater Management Academy
3
Acknowledgements

• Rick Renna, Florida Department of Transportation
• Eric Livingston, Florida Department of
  Environmental Protection
• Matt Offenberg, Rinker Materials
• Diep Tu, Florida Concrete Products Association

4
Outline of Presentation

• Overview
• Background and Current State
• Objectives of this On-going Project
• Progress to Date
• Construction Specifications
• UCF Test Site
• Field Performance Tests
• Evaporation
• Water Quality Testing
• Discussion

5
Overview

• Pervious or No-fines Concrete mixture of coarse
  aggregate, Portland Cement, admixtures and water
• Increased Porosity due to limited fines and
  15-20 air voids
• Strong need for Current and Updated Assessment of
  Pervious Pavements due to new regulations pending
  for Stormwater Management

6
Background and Current State

• Replacement of Impervious Areas with Properly
  Designed and Constructed Pervious Paving Surfaces
  is Desirable
• Treating pervious concrete as a system with
  pavement and sub soil
• ACI Committee 522 has been formed to develop
  Guidelines for the use of Portland Cement
  Pervious Concrete

7
Historical and Literature Review

• PC Pervious Pavements have been used for past 20
  years in Areas of Lower Traffic Loads (parking
  lots, shoulders, airport taxiways, some state and
  local roads).
• Must have suitable
• Subsoil Conditions
• Groundwater Locations

8
Historical and Literature Review

• Field et al (1982) Water Resources Bulletin
  detailed information on PP.
• Florida Concrete and Products Association (FCPA)
  Portland Cement Pervious Pavement Manual (No.
  605)
• EPA (1999) Stormwater Technology Fact Sheet on
  Porous Pavements
• Several recent articles from USC and Purdue, as
  well as UK, Japan and China.

9
Advantages and Disadvantages(EPA, 1999)

• Advantages -
• Recharge to Local Aquifer
• Water budget retention and pollution removal
• Less need for Storm Sewers
• Disadvantages
• Lack of Construction Experience and Expertise
• Clogging
• Cold Weather Problems

10
FDOT Interests

• Need for a permit, or credit (partial or total)
  for substituting pervious surfaces
• Based on Volume of water that can be Stored and
  allowed to Replenish the Aquifer
• Issues under investigation
• What is design materials, dimensions, GWT?
• What are proper construction methods?
• What is the infiltration rate for the system?
• What is the water quality improvement?
• What is the evaporation through the pavement?

11
Objectives

• Issues being addressed
• Design Section
• Construction Methods
• Acceptance Criteria
• Infiltration Rate Performance
• Credit for Replacement of Impervious Area

12
Construction Specifications

• Specifications for materials and mix design,
  construction practices, and post construction
  care
• Other Sources - EPA, California-Nevada Cement
  Promotions Council PC Specs, and PCI Systems,
  LLC. PC Specs

13
Construction Specifications

• Placement and finishing techniques for pervious
  concrete are different from plain concrete
• Pervious concrete must be placed with specialty
  equipment and the water content of the fresh
  concrete must be carefully controlled
• Rinker Materials has implemented a Contractor
  Certification Program as of September, 2005

14
Construction Specifications

• Appropriate mix proportions
• /- 5 lbs/CF of design unit weight
• Discrepancies are generally related to water
  content
• Too much water reject load

15
Construction Specifications

• Concrete should be stricken off ¼ to ½ of an inch
  about the form boards and compacted to level
• Compaction roll with a 10-inch schedule 40
  steel pipe
• Curing Time pavement should be covered a
  minimum of 7 days
• Curbing should be used to direct infiltrating
  water downward and to prevent erosion at the
  edges of pervious concrete slabs

16
(No Transcript)
17
Proposed Design Section (Preliminary)
COMPACT SUBGRADE TO 92 MODIFIED PROCTOR (ASTM
D-1557)
18
Operational Specifications

• Limit frequency of heavy traffic e.g.
  construction vehicles, garbage trucks, etc.
• Remove or Limit sources of sediment
• Signage such as ADOPT A LOT
• Maintenance specifications forthcoming

19
Damage due to Excessive Load
20
Design and Construction Specifications

• Cities of Stuart, Zephyr Hills, Winter Park, and
  Titusville and the Counties of Citrus, Hernando,
  Pasco, and Hillsborough have adopted
  specifications.
• Credit is being determined for use by other
  Cities and WMDs.
• A goal is to have 24 cities and counties with
  pervious concrete code language for pervious
  concrete.
• Contractor Certification will be an Important
  Factor
• Soil Preparation, Curbing, Field Infiltration
  Tests and Inspections will be Important.

21
Field Testing Objectives

• Develop New Embedded Single Ring Test Method to
  Measure Infiltration rates
• Laboratory Testing Build Two Test Cells at the
  UCF Stormwater Laboratory Site and a Control
  Chamber
• Field Testing Sites
• Four located in Central Florida
• One located in Tallahassee
• One located in Greenville, South Carolina
• One located in Charlotte, North Carolina
• Two located in Georgia

22
Preparation of Test Cells

• Stormwater Laboratory Field Sites
• Two 6 ft.x 6ft. x 4 ft. deep Chambers
• 5 inch thick pervious concrete pavement
• One cell has a reservoir of 3/8 inch coarse
  aggregate to increase storage
• Soils were Sandy (Type A hydrological) compacted
  in 8 inch lifts to 92 Standard Proctor to about
  104 lb/ft3

23
(No Transcript)
24
Strength Tests
25
Development of Embedded Single Ring Infiltrometer

• Double Ring Infiltrometer on the surface of
  Pervious Pavement not Suitable due to Preferred
  Lateral Migration of Water
• Led to Concept of Single Embedded Infiltrometer
• Depth of Embedment is an Important Parameter
  (Initial Assumption 14 inches including the 6
  inches of pavement)
• 12 inch Diameter (11-5/8 ID) with 11-Gauge Steel

26
Embedded Single Ring Infiltrometer

• Advantages
• One dimensional flow (no horizontal flow between
  pavement and soil)
• Representative of site existing conditions
  assuming same soil types,
• and concrete conditions.

27
Results at Test Cells

• Using ASTM D3385-03 (Double Ring) procedure
  adapted to embedded Single Ring
• Initial Double Ring Tests on Bare Subsoil before
  Concrete Placement have yielded infiltration rate
  of 2.6 in/hr
• Without compaction, the rate for the soil was
  12-20 in/hr

28
Results of UCF Embedded Ring Tests


29
Preliminary Observations from UCF Test Chambers

• Pervious Concrete Pavement and Subsoil System
  displays Infiltration Rates nearly equal to
  Subsoil Alone
• Infiltration rates of the system are greater than
  the minimum rates of 1 in/hr used for the design
  of FDOT retention areas.

30
Laboratory Control Chamber

• Better Control
• Address issues such as Clogging and Water Table
  Impact
• The Chamber was Filled with Sandy Soils from UCF
  Stormwater Lab. (Type A Hydrologic Group )
• Filled in 8 lifts to 92 Standard Proctor

31
Laboratory Control Chamber
32
Laboratory Control Chamber
33
Field Site Reconnaissance

• Completed Field Sites
• Vet Office in Sanford
• FCPA Office in Orlando
• Sunray StoreAway Lake Mary
• Strang Communications Lake Mary
• FDEP Office Tallahassee
• Planned Field Sites
• Greenville, South Carolina
• Atlanta, Georgia
• Savannah, Georgia
• Charlotte, North Carolina

34
Strang Communications
35
Sunray StoreAway
Why?
36
Sunray StoreAway
37
Field Testing Progress

• Six cores at Sunray Storaway, Three at Strang
  Communications, Three at FCPA, Six in
  Tallahassee, and Three at Murphy Vet Clinic.
• Field infiltration tests completed at all
  locations
• Laboratory tests using Control Chamber on-going

38
Field Testing Process

• 12-in diameter cores
• Run field tests
• Determination of Field Unit Weight of Compaction
• Embedded Single Ring Infiltrometer
• Collect soil samples
• Lab work on soil samples
• Sieve Analysis
• Liquid Plastic Limits
• Permeability Tests
• Lab test on core infiltration rates

39
(No Transcript)
40
(No Transcript)
41
(No Transcript)
42
(No Transcript)
43
Field Test Results
44
Field Test Results
Age of concrete varies from 10 to 20 years
(except for Site 4 Area 1).
45
Evaporation - Objectives

• Determine the rate of evaporation through
  pervious concrete compared to bare soil
• Mass balance approach
• Multi-purpose experiment setup
• Water quality
• Infiltration rate

46
Evaporation - Setup
47
Evaporation Moisture Probes
48
Evaporation Mass Balance
E S1 P S2
49
Water Quality

• Objectives
• Observe the capability of pervious concrete to
  remove stormwater contaminants
• Verify (or reject) claims by EPA and other
  sources that pervious concrete filters out
  significant quantities of typical stormwater
  contaminants
• Determine if there is a significant difference in
  the pollutant removal capacity between the
  pavement/subgrade system and the subgrade alone

50
Water Quality

• Current Testing
• Three test chambers 2 containing
  pavement/subgrade systems, 1 with subgrade alone
• Samples analyzed for pH, Alk, NH3, NO3-, PO43-
• Sampling began in Mid-September and will continue
  until late November. We anticipate a report will
  be available for FDOT review soon thereafter.

51
Pervious Concrete Mix Design

• Investigating the modification of pervious
  concrete mixes to produce a mix with enhanced
  structural, hydraulic, or environmental
  properties
• Recent completed study determination of optimal
  water/cement and cement/aggregate ratios to
  obtain satisfactory compressive strengths
  (Mulligan, MS Thesis, 2005)

52
Pervious Concrete Mix Design

• Fly Ash as a Supplementary Cementious Material
• Can attain higher ultimate strengths
• Possibility for increased adsorption capacity
• Green building
• Plan of Work
• Structural strength, rate of strength gain
• Hydraulic porosity, permeability
• Environmental water quality, leachability of
  heavy metals present in fly ash

53
Conclusions

• Proper construction is important (water in mix,
  curing)
• Specifications need to be followed for design and
  construction Good design practices (curbing,
  pavement thickness).
• Infiltration rates are comparable to Stormwater
  Retention Ponds.

54
Conclusions

• Pavement and Subsoil must be treated as a SYSTEM.
• Water storage is directly proportional to the
  porosity and the depth to the water table.
  Modeling efforts currently underway.

55
Thank You!For additional informationPlease see
www.stormwater.ucf.eduor call 407.823.4143Quest
ions?