Porous asphalt and pervious concrete are supplied in a ‘plastic’ state and formed on the job site. This makes them subject to weather. PICP can be installed in freezing weather, however, porous asphalt and pervious concrete cannot. In above-freezing temperatures, plastic asphalt and concrete mixes must be regularly checked by the contractor for consistency and conformance to specifications. These materials impose time limits within which the contractor must work before asphalt cools and concrete cures and stiffens. These time and temperature constrained materials rely on a high degree of site control in order to achieve a successful installation.
PICP units are manufactured in a factory and delivered to the site. They are not subject to time and temperature limitations in installation. PICP paving units should comply with national product standards (ASTM C 936 or CSA A231.2). These product standards require manufacture of high compressive strength concrete averaging 8,000 psi (55 MPa). Pervious concrete has a typical compressive strength of about 2,500 to 4,000 psi (17 to 28 MPa). Unlike pervious concrete and porous asphalt, concrete pavers have freeze-thaw durability test methods and requirements within their product standards to help assure adequate field performance in winter conditions. Freeze-thaw durability and higher strength PICP offers a more durable surface under wheel loads, snow plow abrasion and deicing materials.