Development of Methods for Investigating Pervious Concrete Resistance to Calcium and Magnesium Chloride Deicers

PROJECT PI

Dr. Liv Haselbach, Chair and Professor, Department of Civil and Environmental Engineering

SHORT DESCRIPTION

Pervious concrete pavement is a highly permeable form of concrete which allows stormwater to permeate through the surface layer to an underground aggregate storage bed and be detained and/or infiltrated into the soil beneath. Benefits include reduced flooding and ponding, stormwater quality improvements, etc. Some deicing salts can have negative impacts on the pervious concrete layer. The objectives of these studies are the initial development of simple testing methods that others can use to compare various mix designs or treatments to pervious concrete to determine which options might be more resistant to deicer deterioration.

water poured onto pervious concrete
pervious concrete

FULL DESCRIPTION

Laboratory tests mimicking field conditions were developed. Once weekly applications of 3% by mass deicer solutions were poured onto pervious concrete column specimens in the laboratory and allowed to permeate through over a 16-week period. Influent and effluent samples were collected. Parallel testing was performed on other specimens in a cold room (4°C). The specimens in the laboratory receiving the calcium chloride had noticeable debris breaking from the columns, indicating that a simple protocol without extensive chemical or physical testing might be appropriate for calcium chloride comparison testing. The specimens in the cold room that received the magnesium chloride treatment appear to have increased calcium concentrations in the effluent. Further testing on the mechanical properties for these specimens are planned to see if this possible ion exchange reaction may be a cause for degradation. Preliminary work was performed at Washington State University and additional research is ongoing at the Lamar University campus in Beaumont, Texas.

FUNDING

  • The Ready Mixed Concrete (RMC) Research & Education Foundation, and
  • The USDOT Tier I University Transportation Center: The Center for Environmentally Sustainable Transportation in Cold Climates (CESTiCC)