Cooler than the Conventional
An estimated 3 to 4 million square feet of concrete grid paving units pave intermittently used parking lots, fire lanes, ditches, slopes, and boat ramps each year in the U.S. and Canada.
ICPI publishes a Tech Spec technical bulletin (No. 8, see www.icpi.org) on this product typically used to help reduce stormwater runoff while accommodating vehicles by reinforcing grass with concrete. Unlike plastic grids, concrete grids have an ASTM product standard, C1319-17 Standard Specification for Concrete Grid Paving Units. This standard defines a concrete grid and provides requirements for compressive strength, absorption and freeze-thaw durability.
Grids have maximum dimensions of 24 x 24 in. and a minimum thickness of 3 1/8 in. The percent solid recently has been updated in C1319 to range from 45% to 75%. This enables grids to conform to the minimum 50% unbound (non-solid) requirement in LEED version 4, Sustainable Sites. An Urban Heat Island Reduction credit is earned when an open-grid pavement system is used. This credit is included in LEED because grids can reduce microclimate temperatures by as much as 4° C compared to conventional pavements.