Technology used to develop a new kind of concrete as an alternative to help manage runoff problems. by Matthew Petillo, photos by Steven Hertzog
Concrete has been with humans for as long as people can remember. The first instance of it being used in a building dates back to the Greeks between 1400 and 1200 B.C. Fast-forward to 2021, and concrete is used in everything from roads and buildings to benches and sidewalks. These days, environmental issues are also a concern, and activists have levied their eyes on concrete. During rainstorms, runoff from the grass, trash and concrete travels into storm drains, which lead, at least in Lawrence, to the Wakarusa and Kansas Rivers. There’s a new type of concrete being used to try and alleviate this runoff problem: pervious concrete. Instead of allowing water to pool and take dirt and trash into the stormwater, pervious concrete allows the water drain directly into the storm system by absorbing into the concrete (which is a bunch of rocks compressed together and glued with paste) and either evaporating directly from the concrete or pooling into an underground storage place. Trade industry websites note it can be used for a variety of applications and can replace traditional concrete. The Kansas Department of Transportation (KDOT), one of the biggest users of concrete and asphalt that could be replaced with pervious concrete, does not use this type of concrete. Rick Barezinsky, KDOT assistant bureau chief of materials, says this type is much better suited for urban areas. “Urban areas benefit the most from pervious concrete. Constructing sidewalks and parking lots with pervious concrete provides a path for the rainwater to percolate into the groundwater, often eliminating the need for retention ponds where real estate is expensive,” Barezinsky explains. “This also helps property owners comply with the EPA stormwater regulations. “Using pervious concrete as the surface on highways is typically not done across the U.S. because the concrete is so porous, it is not as durable as traditional concrete pavement,” he continues. “Raveling of the surface is a common distress associated with pervious concrete. There is also concern that it does not provide the same structural support as 62
