Pervious Concrete

In Pervious Concrete, you'll learn ...

• The benefits and limitations of using pervious concrete for pavement projects
• The merits of pervious concrete relative to traditional concrete with regards to surface runoff volume and contaminant levels
• Hydrological and structural design considerations for pervious concrete
• Pervious concrete construction considerations that are distinctly different from conventional concrete

Overview

Credit: 2 PDH

Length: 36 pages

Urbanization is an increasingly pervasive land cover transformation that significantly alters the physical, chemical and biological environment within surface waters. It results in the prevalence of impervious surfaces including roads, parking lots, driveways, and sidewalks. Impervious surfaces reduce stormwater infiltration and increase surface runoff, altering the pathways by which water (and any associated contaminants) reach urban streams. Such runoff can lead to changes in water quality, water temperature, and habitat for flora and fauna.

Pervious concrete offers an alternative to conventional impervious pavement. A pervious concrete mixture contains little or no fine aggregate (sand) and carefully controlled amounts of water and cementitious materials. The paste coats and binds the coarse aggregates together to render an extensive matrix of interconnected voids; this allows water to easily penetrate the surface and to percolate downward through the voids. Pervious concrete is placed on a subbase of open-graded aggregate. The subbase stores water and allows it to infiltrate into the soil subgrade. Optional components, like underdrains and liners, are applied to the subgrade depending on hydrologic design objectives.

Pervious concrete promotes water infiltration instead of runoff, as well as filtration of contaminants. This combined action of infiltration and filtration can reduce surface runoff volume and reduce contaminant levels, thereby improving compliance with state and local discharge permits.

This course is intended for civil engineers who manage pavement projects for low-speed roads, parking lots, and walkways; especially in areas with high precipitation or poor drainage. The student should be familiar with typical Portland cement concrete.