The
ASTM International recently released C1781 Standard Test
Method for Surface Infiltration Rate of Permeable Unit Pavement Systems.
This test method is specifically designed for assessing the surface
infiltration rate of new and in-service permeable interlocking concrete
pavements and permeable clay brick pavements. The test method involves timing a
slow pour of a known weight of water into a 12 inch diameter pipe fastened to
the permeable pavement surface with plumber’s putty. The infiltration rate is
easily calculated using a formula in the test method. The test method also
provides guidance on how to locate the 12 in. diameter pipe on the unit paving
surface to measure infiltration that represents the pattern on the larger
pavement area. The test uses similar equipment and methods in ASTM C1701 Standard Test Method for Infiltration Rate of in Place Pervious
Concrete. The similarities between C1701 and C1781 make the test
results comparable.
“We
are seeing more provincial, state and local permeable pavement specifications
require surface infiltration tests
to accept new permeable pavements and to evaluate their in-service infiltration
for determining surface cleaning,” says Craig Walloch, chair of ASTM
Subcommittee C15.04 on Research who helped develop the standard. “Now they have
a method with specific guidance for testing unit paving with results that can
be compared to that from pervious concrete and porous asphalt.” Mr. Walloch
further noted that existing guidelines published by stormwater agencies have
used C1701 to test surface infiltration of permeable unit paving. While the
results from that test method applied to permeable unit pavement are useful,
C1781 provides clear guidance on executing the test on these pavements.
To
purchase and download C1781 from ASTM, visit www.astm.org/Standards/C1781.htm. The
standard retails for $42 and ASTM members receive a 10% discount. For further
information on permeable interlocking concrete pavement design, construction
and maintenance visit the Interlocking Concrete Pavement Institute at www.icpi.org.
