Measurement of Infiltration Rates and the Rejuvenation of Pervious Concrete Pavements

Measurement of Infiltration Rates and the Rejuvenation of Pervious

Concrete Pavements

Manoj Chopra, Ph.D., P.E.Professor of Civil EngineeringUniversity of Central Florida

[email protected]

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


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


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


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


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.


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


Embedded Single Ring Infiltrometer

11-5/8”

11-Gauge Steel

Subsoil

Pervious ConcreteCore

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


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

University of Central Florida 10

Coring Operation at Existing PC Site




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 ConcreteSite 1 – Area 2 3.6 (2.8 – 4.5) 14.8 ConcreteSite 2 5.9 (5.3 – 6.6) 5.4 SoilSite 3 14.4 (2.1 – 22.5) 21.5 ConcreteSite 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).


Control Tanks for Evaporation and Water Quality Testing


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


INSTALLATION OF PERVIOUS CONCRETE TEST SECTION


Forming

Florida Concrete Products AssociationOffice in Orlando

SWMA Test Facility


Placement and Screeding



Screeding and Rolling


Scoring and Curing


Finished Installation


SWMA Test Facility



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.

http://dx.doi.org/10.1061/(ASCE)IR.1943-4774.0000757


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)


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


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


Typical View of Embedded ERIK Device


Plan View of Embedded ERIK Device


Views of Embedded Ring of the ERIK Device

Embedded ring

Ring-shaped gap for testing collar


Schematics of Measuring ERIK Device


Views of Measuring Unit of the ERIK Device

Graduated cylinder

Testing collar

Control valve


ERIK Device Test ResultsReproducibility 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%


INFILTRATION RATES AND REJUVENATION TESTING


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


New Pavement Surface


Adding Sediment


Spreading of Sediment


Washing In of Sediment

Washed into the pavement pores


Infiltration Rate Testing of Clogged Pavement Surfaces


Rejuvenation (using Dry Vacuum)


Rejuvenation (using Wet Vacuum)

Vacuum sweeping of pavement surface


Rejuvenation (Pre-Saturation and Vacuum)


Pre and Post Rejuvenation - ERIK Testing


RESULTS: INFILTRATION RATES


Pervious Concrete Pavements: Long-Ring ERIK North Infiltrometer


Pervious Concrete Pavements: Long-Ring ERIK

South Infiltrometer


Pervious Pavements: Long-Ring ERIK

New Install Average In-filtration Rate [in/hr]

Clogged Average Infil-tration Rate [in/hr]

Rejuvenated Average Infiltration Rate [in/hr]

0

5

10

15

20

25

3026

13

17

Long-Ring ERIK Results for Pervious Pavements

Infil

trat

ion

Rat

e [in

/hr]


Pervious Concrete Pavements: Short-Ring ERIK

East Infiltrometer


Pervious Concrete Pavements: Short-Ring ERIK West Infiltrometer


Pervious Pavements: Short-Ring ERIK

100

1000

10000

1,432410 475

Short-Ring ERIK Results for Pervious Pavements

Infil

trat

ion

rate

[in/

hr]


Pervious Pavements: Long-Ring ERIK

0

5

10

15

20

25

30

PerviousConcrete

RecycledRubber

Pavement

Recycled GlassPavement

Perm

eabi

lity

[in/h

r]

Long-Ring ERIK Results for Pervious Pavements

New Average InfiltrationRate [in/hr]

Clogged AverageInfiltration Rate [in/hr]

Rejuvenated AverageInfiltration Rate [in/hr]


Pervious Pavements: Short-Ring ERIK

1

10

100

1000

10000

PerviousConcrete

RecycledRubber

Pavement

RecycledGlass

Pavement

Perm

eabi

lity

[in/h

r]

Short-Ring ERIK Results for Pervious Pavements

New Average InfiltrationRate [in/hr]

Clogged AverageInfiltration Rate [in/hr]

Rejuvenated AverageInfiltration Rate [in/hr]


SUSTAINABLE VOID SPACE(POROSITY)


Laboratory Testing for Porosity


Barrel Testing for Porosity


ResultsEFFECTIVE POROSITY

S/NO. MATERIAL Pre-Loading Post-Loading1 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


Recommended Effective Porosity Values

Type Sub-TypeSustainable Void

Space (%)Pervious Concrete 20Flexi-pave™ 20

Pervious PaversOld Castle 10Hanson 10

#4 RockLimestone 30Granite 30

#57 Recycled Crushed Concrete 25#89 Pea Rock 25


DESIGN AID SOFTWARE

Available for Download atwww.stormwater.ucf.edu



Slide #60

Example Problem #1For six (6) inches of pervious concrete * placed directly on top of the parent soil

Pull down menu for the type of pervious pavement


Slide #61

Example Problem #1For 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)


Slide #62

Example Problem #1For 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 = 92Rational

“C” = 0.85


Slide #63

Example Problem #1Six (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 = 0.831.1 x 0.95 = 1.05 (use 1.0)

Similar results for sandy soils


CONCLUSIONS


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


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


PC Pavements - PorosityPorosity 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

Thank you!

Questions?