THE PROPERTIES AND ADVANTAGES OF POROUS

CONCRETEBy: Aaron Slevin

WHAT IS POROUS

CONCRETE?

What is Porous Concrete? As described by the E.P.A. “Pervious

concrete, also known as porous, gap-graded, or enhanced porosity concrete, is concrete with reduced sand or fines and allows water to drain through it.”

Simply stated porous concrete is just like concrete but with bigger void ratios, usually around 20%

WHY IS THIS IMPORTANT?

WHAT IS CURRENTLY USED

Can you see the problem here…

WHAT IS CURRENTLY USED SOCIOECONOMIC DATA AND APPLICATIONS

CENTER (SEDAC)

Global Rural-Urban Mapping Project (GRUMP), v1

“GRUMP's latest estimates indicate that ~3% of global land surface area is covered by urban areas.  As 29.2% of the planet's surface area is covered by land, this means that 3% x 29.2% = 0.9% of the total planetary surface area (incl. oceans) is covered by urban areas.”

WHAT IS CURENTLY USED

Total surface area of earth = 57,268,988.768 mi2

57,268,988.768 mi2 * .09 = 5,154,208.98912 mi2

Produces Massive Runoff

PROBLEMS WITH

IMPERVIOUS CONCRETE

Increased Soil ErosionEPA-“Impervious surfaces in the watershed may increase the magnitude and frequency of high flow events, thereby increasing resuspension and bed and bank erosion (Figure 9).”

Increased Concentrations of Pollution

Increased Sediment load

Habitat Loss

Impacts of Urban Runoff on Native Woody Vegetation at Clark Reservation State Park, Jamesville, NYby Carol Franco1, Allan P. Drew1, and Gordon Heisler2

“The construction of the Doubletree residential project on the watershed of Clark Reservation State Park has had a variety of effects on the park's ecosystem; thus far, effects are evident primarily in the Dry Lake basin. Late winter and spring flooding in certain areas caused the death of hemlocks present there. Hemlocks did not appear to suffer from ice damage, but trees of other species were killed in the flooded zone, with ice damage appearing to be a primary cause of mortality.”

Figure 4: Flooding effects at Dry Lake basin. Photo taken from the non-flooded area (April 8, 2001). The hemlock trees in the foreground and on the right have been killed by high water

SO HOW CAN POROUS

CONCRETE HELP?

Porous Concrete Benefits Recharge Groundwater Minimize Flood Risk Minimize Soil Erosion Reduce the Spread of

Pollutants Noise Reduction

How is it Made Porous concrete is made following the

same procedure as traditional impermeable concrete except the fine aggregates are removed.

Either rounded or angular aggregates can be used successfully.

The correct ratio of water to aggregates is very important to consider.

How is it Made Below most installments of porous concrete are

additional layers of compacted large aggregates to improve water percolation. “Choke course - This permeable layer is typically 1 -

2 inches thick and provides a level bed for the pervious concrete. It consists of small-sized, open-graded aggregate.”

“Open-graded base reservoir - This aggregate layer is immediately beneath the choke layer. The base is typically 3 - 4 inches thick and consists of crushed stones typically 3/4 to 3/16 inch. Besides storing water, this high infiltration rate layer provides a transition between the bedding and subbase layers.”

How is it Made Open-graded subbase reservoir - The stone

sizes are larger than the base, typically 2½ to ¾ inch stone. Like the base layer, water is stored in the spaces among the stones. The subbase layer thickness depends on water storage requirements and traffic loads. A subbase layer may not be required in pedestrian or residential driveway applications. In such instances, the base layer is increased to provide water storage and support.

How is it Made “Subgrade - The layer of soil immediately

beneath the aggregate base or subbase. The infiltration capacity of the subgrade determines how much water can exfiltrate from the aggregate into the surrounding soils. The subgrade soil is generally not compacted.”

How is it Made Porous concrete mixtures may also

contain a variety of products in order to increase pollution uptake, or help promote self healing with the addition of a biologic component.

FINAL REPORT ON A COLD CLIMATE PERMEABLE INTERLOCKING

CONCRETE PAVEMENT TEST FACILITY AT THE UNIVERSITY OF NEW

HAMPSHIRE STORMWATER CENTER May 2013

Prepared and Conducted by: Robert M. Roseen, D.WRE, PE., PhD.

Associate, Geosyntec Consultants Principal Investigator, Adjunct Professor, UNHSC Phone: 617-992-9067 rroseen@geosyntec.com

Timothy A. Puls, EIT Site Facility Manager Phone: 603-343-6672 timothy.puls@unh.edu

James J. Houle, CPSWQ Program Manager, Outreach Coordinator Phone: 603-767-7091 james.houle@unh.edu

Thomas P. Ballestero, PE, PhD Director Phone: 603-862-1405 tom.ballestero@unh.edu

INSTALLATION

PERVIOUS PAVEMENT SET-UP

THE PATTERN CONTINUES Total Petroleum Hydrocarbons- Over 99%

Mass Reduction Total Zinc- Over 99% Mass Reduction Total Nitrogen- Over 99% Mass Reduction Dissolved Inorganic Nitrogen- Over 99%

Mass Reduction Total Phosphorus- Over 99% Mass

Reduction Ortho-Phosphate- Over 99% Mass

Reduction

SO WHERE CAN POROUS

CONCRETE BE USED?

Where Can it be Used

Parking Lots

Sidewalks

Parks

References http://www3.epa.gov/caddis/ssr_sed_wtl.html https://dpw.lacounty.gov/landing/wr/stormwatermgmt/stormwaterRunoff.cfm https://www.youtube.com/watch?v=06CBL-jGguM http://klorotechpavers.com/water-pollution-can-help/ http://www.montgomerycountymd.gov/dep/community/sediment.html https://www.youtube.com/watch?v=BQrJyw1-vKg http://www.urbanhabitats.org/v05n01/runoff_fig4.html http://sedac.ciesin.columbia.edu/data/set/grump-v1-urban-extents/data-

download https://www.quora.com/What-percentage-of-Earths-land-is-used-for-

infrastructure-like-roads-buildings-all-pavement-etc http://www.unh.edu/unhsc/sites/unh.edu.unhsc/files/UNHSC_ICPI_Final

%20Report_7-8-13_0.pdf http://www.perviouspavement.org/materials.html http://water.epa.gov/polwaste/npdes/swbmp/Pervious-Concrete-

Pavement.cfm http://calstarproducts.com/how-to-incorporate-stormwater-friendly-pavers/

ANY QUESTIONS?