Presented to: Pervious in Paradise - San Diego Presented by: Manoj Chopra, Ph.D., P.E., University of Central Florida

1. Measurement of Infiltration Rates
and the Rejuvenation of Pervious
Concrete Pavements
Manoj Chopra, Ph.D., P.E.
Professor of Civil Engineering
University of Central Florida
chopra@ucf.edu

2. University of Central Florida
Outline
 Introduction
 Installation of Pervious Concrete Pavement
 Embedded Ring Infiltrometer (ERIK)
 Infiltration Testing – Pre and Post Rejuvenation
 Sustainable Porosity (System and Component)
 Infiltration Results
 Rejuvenation Results
 Conclusions

3. University of Central Florida
Background
 Increased impervious surfaces linked to decline in
surface water quality
 Nutrients
 Heavy metals
 Hydrocarbons
 Using pervious/permeable pavements in low traffic load
areas can help with
 Groundwater recharge
 Pollutant reduction
 Land-use reduction
 Water harvesting

4. University of Central Florida
Overview
 US EPA Recognizes Pervious Concrete as a BMP for
Stormwater Runoff
 Are being Considered as a part of the State Unified
Stormwater Rule in Florida to provide Potential Credit
 Open structure of PC may get clogged due to
entrapment of sediment
 Initial Scope of UCF Research
 Pervious Concrete Pavement
 Expanded Scope
 Pervious Concrete Pavement (continued)
 Pervious Pavers – 2 Types
 Flexipave® - Recycled Rubber Tires
 Pervious Asphalt
 Recycled Glass Pavers
 Permeable Grout Paving Systems – 9 Types
4

5. University of Central Florida
Research Need
 To collect data on long term hydraulic performance of
pervious/permeable systems
 To develop a reliable, non-destructive infiltration
monitoring method
 To determine effective porosity
 To determine in-situ infiltration data for clogged and
rejuvenated systems
 To determine strength data for several systems on the
market
 To determine impact on water quality

6. University of Central Florida
EVALUATION OF EXISTING
PERVIOUS CONCRETE
INSTALLATIONS
Chopra, M, Kakuturu, S., Ballock, C, Spence, J and Wanielista, M. “Determination of the
Infiltration Rates and the Effect of Rejuvenation Methods for Pervious Concrete Pavements, J.
of Hydrologic Engineering, ASCE (Special Issue on LID), Volume 15, No. 6, pp. 426-433, 2010.

7. University of Central Florida
Initial Concept Embedded Single
Ring Infiltrometer
 Double Ring Infiltrometer on the surface of
Pervious Pavement was found to Over-predict
Rates due to Preferred Lateral Migration of
Water
 Led to Concept of Single Embedded Infiltrometer
 For Study of Existing Installations, Coring would
be required followed by installing a strong ring
 12 inch Diameter (11-5/8” ID) with 11-Gauge
Steel Ring was Used

8. University of Central Florida
Embedded Single Ring Infiltrometer
11-5/8”
11-Gauge
Steel
Subsoil
Pervious
Concrete
Core
20”
6”
Advantages
1. One dimensional flow (no horizontal flow between pavement and soil)
2. Representative of site existing conditions assuming same soil types,
and concrete conditions.
Version 1.0 Late 2003

9. University of Central Florida
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
 Other Regional Field Sites
 Greenville, South Carolina
 Atlanta, Georgia
 Savannah, Georgia
 Charlotte, North Carolina

10. University of Central Florida
Coring Operation at Existing PC Site
10

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13. University of Central Florida
Field Test Results
Test Location
Avg. Concrete
Rate [in/hr]
(Range)
Avg. Soil
Rate [in/hr]
Limiting
Factor
Site 1 – Area 1 25.7 (19 – 32.4) 34.5 Concrete
Site 1 – Area 2 3.6 (2.8 – 4.5) 14.8 Concrete
Site 2 5.9 (5.3 – 6.6) 5.4 Soil
Site 3 14.4 (2.1 – 22.5) 21.5 Concrete
Site 4 – Area 1 2.1 (0.7 – 4.5) 15.6 Concrete
Site 4 – Area 2 2.9 (0.9 – 4.9) 15.6 Concrete
Site 5 3.7 (1.7 – 5.4) 8.8 Concrete
*Age of concrete varies from 10 to 20 years (except for Site 4 – Area 1).

14. University of Central Florida
Control Tanks for Evaporation and
Water Quality Testing

15. University of Central Florida
Establishing a Pervious Pavement
Test Site at Stormwater Academy
 Pervious Pavements
 Pervious Concrete
 Recycled Rubber
 Recycled Glass
 Porous Aggregates
 Permeable Paver
Pavements
 Removable Filler
 No Filler
 Permanent Permeable
Grout Joints

16. University of Central Florida
INSTALLATION OF PERVIOUS
CONCRETE TEST SECTION

17. University of Central Florida
Forming
Florida Concrete Products Association
Office in Orlando
SWMA Test Facility

18. University of Central Florida
Placement and Screeding
Florida Concrete Products
Association
Office in Orlando

19. University of Central Florida
Screeding and Rolling

20. University of Central Florida
Scoring and Curing

21. University of Central Florida
Finished Installation
Florida Concrete Products Association
Office in Orlando
SWMA Test Facility

22. University of Central Florida

23. University of Central Florida
IN SITU PERMEABILITY
MEASURING DEVICE
Gogo-Abite, I, Chopra, M., Hardin, M., Wanielista, M. and Stuart, E., “In situ
Permeability Determination Device for Porous Pavement Systems”, J. Irrigation
and Drainage Engineering, ASCE, http://dx.doi.org/10.1061/(ASCE)IR.1943-
4774.0000757. May 2014.

24. University of Central Florida
ERIK Device – Version 2.0
 In-Situ, Nondestructive,
Replicable
 Constant Head Test
 Measures Pavement Infiltration
Rates
 Two types
 System Recovery Type (4-inch
embedment into parent soils)
 Maintenance Indicator Type (2-inch
embedment into sub-base layer)

25. University of Central Florida
Two Types of ERIK Device
 Long-Ring ERIK
 How fast water enters
parent soils
 Evaluates system recovery
 Florida Water Management
Districts require a minimum
of 2 in/hr
 Short-Ring ERIK
 How fast water enters
pavement system
 Evaluates degree of surface
layer clogging

26. University of Central Florida
Typical Cross Sectional View of
Embedded ERIK Device
(a)
(b)
152.4 mm pervious concrete
254 mm coarse sand (or Bold & Gold)
Filter fabric
Compacted subgrade
(90–95% compaction effort)
20.7 MPa concrete curb
(0–152 mm above pavement)
0% slope
Adjacent
landscaping
Long-ERIK terminated 100
mm into subgrade
152.4 mm pervious concrete
254 mm coarse sand (or Bold & Gold)
Filter fabric
Compacted subgrade
(90–95% compaction effort)
20.7 MPa concrete curb
(0–152 mm above pavement)
0% slope
Adjacent
landscaping
Short-ERIK terminated
25 mm into subbase

27. University of Central Florida
Typical View of Embedded ERIK
Device

28. University of Central Florida
Plan View of Embedded ERIK
Device

29. University of Central Florida
Views of Embedded Ring of the ERIK
Device
Embedded ring
Ring-shaped
gap for
testing collar

30. University of Central Florida
Schematics of Measuring ERIK
Device

31. University of Central Florida
Views of Measuring Unit of the ERIK
Device
Graduated
cylinder
Testing collar
Control valve

32. University of Central Florida
ERIK Device Test Results
Reproducibility and
Repeatability
 Both Short-ring and Long-
ring ERIK devices
 Coefficient of variation
(COV) of test results
 96% of COV were less
than 7%
 100% of COV were less
than 10%

33. University of Central Florida
INFILTRATION RATES AND
REJUVENATION TESTING

34. University of Central Florida
Testing Procedure
 Measure infiltration rate of newly installed
pavement
 Clog pavement test section with 2 soil types
 Sandy soil
 Limestone fines
 Measure infiltration rate of clogged pavement
 Rejuvenate pavement with vacuum truck
 Measure infiltration rate of rejuvenated
pavement

35. University of Central Florida
New Pavement Surface

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Adding Sediment

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Spreading of Sediment

38. University of Central Florida
Washing In of Sediment
Washed into the pavement pores

39. University of Central Florida
Infiltration Rate Testing of Clogged
Pavement Surfaces

40. University of Central Florida
Rejuvenation (using Dry Vacuum)

41. University of Central Florida
Rejuvenation (using Wet Vacuum)
Vacuum sweeping of pavement surface

42. University of Central Florida
Rejuvenation (Pre-Saturation and
Vacuum)

43. University of Central Florida
Pre and Post Rejuvenation - ERIK
Testing

44. University of Central Florida
RESULTS: INFILTRATION
RATES

45. University of Central Florida
Pervious Concrete Pavements:
Long-Ring ERIK North Infiltrometer

46. University of Central Florida
Pervious Concrete Pavements:
Long-Ring ERIK South Infiltrometer

47. University of Central Florida
Pervious Pavements: Long-Ring
ERIK
26
13
17
0
5
10
15
20
25
30
New Install Average
Infiltration Rate [in/hr]
Clogged Average
Infiltration Rate [in/hr]
Rejuvenated Average
Infiltration Rate [in/hr]
InfiltrationRate[in/hr]
Long-Ring ERIK Results for Pervious Pavements

48. University of Central Florida
Pervious Concrete Pavements:
Short-Ring ERIK East Infiltrometer

49. University of Central Florida
Pervious Concrete Pavements:
Short-Ring ERIK West Infiltrometer

50. University of Central Florida
Pervious Pavements: Short-Ring
ERIK
1,432
410 475
1
10
100
1000
10000
New Install Average
Infiltration Rate [in/hr]
Clogged Average
Infiltration Rate [in/hr]
Rejuvenated Average
Infiltration Rate [in/hr]
Infiltrationrate[in/hr]
Short-Ring ERIK Results for Pervious Pavements

51. University of Central Florida
Pervious Pavements: Long-Ring
ERIK
0
5
10
15
20
25
30
Pervious
Concrete
Recycled
Rubber
Pavement
Recycled Glass
Pavement
Permeability[in/hr]
Long-Ring ERIK Results for Pervious
Pavements
New Average Infiltration
Rate [in/hr]
Clogged Average
Infiltration Rate [in/hr]
Rejuvenated Average
Infiltration Rate [in/hr]

52. University of Central Florida
Pervious Pavements: Short-Ring
ERIK
1
10
100
1000
10000
Pervious
Concrete
Recycled
Rubber
Pavement
Recycled
Glass
Pavement
Permeability[in/hr]
Short-Ring ERIK Results for Pervious
Pavements
New Average Infiltration
Rate [in/hr]
Clogged Average
Infiltration Rate [in/hr]
Rejuvenated Average
Infiltration Rate [in/hr]

53. University of Central Florida
SUSTAINABLE VOID SPACE
(POROSITY)

54. University of Central Florida
Laboratory Testing for Porosity

55. University of Central Florida
Barrel Testing for Porosity

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Results
EFFECTIVE POROSITY
S/NO. MATERIAL Pre-Loading Post-Loading
1 Pervious concrete 27.2 23.4
2 Flexi-pave 31.1 10.4
3 Permeable Pavers PP 9.1 19.6
4 Pea rock (#89) 36.5 12.5
5 HPF 39.0 15.0
6 Crushed concrete (#57) 41.4 1.4
7 Limestone (#4) 45.2 3.0
8 Granite (#4) 43.6 3.0

57. University of Central Florida
Recommended Effective Porosity
Values
Type Sub-Type
Sustainable Void
Space (%)
Pervious Concrete 20
Flexi-pave™ 20
Pervious Pavers
Old Castle 10
Hanson 10
#4 Rock
Limestone 30
Granite 30
#57 Recycled Crushed Concrete 25
#89 Pea Rock 25

58. University of Central Florida
DESIGN AID SOFTWARE
Available for Download at
www.stormwater.ucf.edu

59. University of Central Florida

60. University of Central Florida
Slide #60
Example Problem #1
For six (6) inches of pervious concrete * placed directly on top of the parent soil
Pull down menu for the type
of pervious pavement

61. University of Central Florida
Slide #61
Example Problem #1
For six (6) inches of pervious concrete * placed directly on top of the parent soil
If a storage reservoir is
proposed, enter the
appropriate thickness of the
material(s)

62. University of Central Florida
Slide #62
Example Problem #1
For six (6) inches of
pervious concrete *
placed directly on
top of the parent
soil, with a 7.5 inch
rainfall depth:
System
Storage (S’)
= 0.9”
CN = 92
Rational
“C” = 0.85

63. University of Central Florida
Slide #63
Example Problem #1
Six (6) inches of pervious concrete * placed directly on top of the parent soil.
The FDOT Drainage Hydrology Handbook is available at:
http://www.dot.state.fl.us/rddesign/dr/Manualsandhandbooks.htm
From the previous
slide, the
Rational “C” = 0.85
For a 25 year design storm,
the FDOT range for Rational
“C” values are:
1.1 x 0.75 = 0.83
1.1 x 0.95 = 1.05 (use 1.0)
Similar results for
sandy soils

64. University of Central Florida
CONCLUSIONS

65. University of Central Florida
Pervious Pavements (PC) –
Infiltration Rates
 Long-Ring ERIK – infiltration rate for the
pervious pavement systems ≥ 2.0 in/hr.
 Short-Ring ERIK
 All pervious pavement systems showed reduction
after clogging
 All pervious pavement systems showed increase after
rejuvenation to varying degrees
 Pervious Concrete showed a 67% reduction in
infiltration rate

66. University of Central Florida
PC Pavements – Infiltration Rate
 Vacuum sweeping was shown to be an effective
way to rejuvenate porous pavement systems
 Pavement surface moisture condition had
significant effect on the performance at
vacuuming
 Dry soil – Vacuum worked well
 Damp soil – Vacuum not effective
 Saturated soil – Vacuum most effective

67. University of Central Florida
PC Pavements - Porosity
Porosity plays an important role in designing porous
pavement systems
 Total porosity not appropriate to use for design purposes
 Subbase aggregates will rarely have no moisture present
 As systems age, sediment will begin to accumulate and
decrease void space
 Sustainable porosity values are recommended for design
 Average of effective porosity for clean sample and effective
porosity for a sediment loaded sample
 Closer to operating conditions while providing safety factor

68. Thank you!
Questions?