Pervious Finished Product

Pervious concrete is a mixture of coarse aggregate, Portland cement, water and little to no sand. A typical pervious concrete pavement has a 15-25% void structure and allows 3-8 gallons of water per minute to pass through each square foot.

Carefully controlled amounts of water and cementitious materials are used to create a paste that forms a thick coating around aggregate particles without flowing off during mixing and placing. Using just enough paste to coat the particles maintains a system of interconnected voids. The result is a very high permeability concrete that drains quickly.

Due to the high void content, pervious concrete is also lightweight, 1600 to 1900 kg/m3 (100 to 120 lb/ft3). After placement, pervious concrete resembles popcorn. Its low paste content and low fine aggregate content make the mixture harsh, with a very low slump.

The compressive strength of pervious concrete is limited since the void content is so high. However, compressive strengths of 3.5 to 27.5 MPa (500 psi to 4000 psi) are typical and sufficient for many applications.