Dr. M. R. Hansen, a professor of civil and environmental engineering at the South Dakota School of Mines and Technology, has recently completed a project from the South Dakota Army National Guard for "Pervious Concrete Development, Phase I." Pervious concrete, when used for paving a parking lot for example, allows water from a thunderstorm to pass through the concrete into the soil and ground water instead of running off and carrying sediment and pollutants into rivers and streams. The development and use of pervious concrete is encouraged by the United States Clean Water Act, is beneficial to the environment and is another form of "green concrete."
According to Hansen, pervious concrete is made by leaving out most of the sand in the concrete, allowing the formation of interconnected voids. The engineering and research challenge is to obtain sufficient strength to carry vehicular traffic, maintain permeability over the lifetime of the paving and be durable in the freezing environment in South Dakota. Craig Phillips, a civil engineering master's student from North Fairfield, Ohio, did the experimental work.
The first test slab of pervious concrete ever in South Dakota was recently placed at the National Guard Camp in Rapid City. When tested, the slab absorbed 800 gallons of water over a 100-square-foot area in two minutes. This project is a good example of the School of Mines working with a local entity to develop a practical solution to an immediate problem. The project was spearheaded by Dale Ludens, engineering supervisor, at the South Dakota Army National Guard.
