Laboratory Freezing-and-Thawing Durability of Fly Ash Pervious Concrete in a Simulated Field Environment

This laboratory study investigated the durability of pervious concrete containing fly ash to freezing and thawing and salt exposure in a field-representative environment. Pervious concrete was prepared, by replacing cement with 0, 10, 20, and 30% fly ash. The specimens were subjected to one slow freezing-and-thawing cycle per day up to 100 days in a drained condition with sodium chloride solution with concentrations of 0, 2, 4, 8, and 12%. The void content, compressive strength, and hydraulic conductivity of the mixtures were all within the range of typical pervious concrete applications. Freezing-and-thawing testing suggested that for all concentrations of salt solution, 10% and 20% fly ash replacement improved freezing-and-thawing durability. Specimens with 30% fly ash showed more damage than that of the 0% control. The greatest damage from salt solutions was seen in 8%, 4%, and 2% concentrations, respectively. Water and 12% salt solution showed little damage across all mixture designs.