Sedimentation of Pervious Concrete Pavement Systems

Abstract

MATA, LUIS ALEXANDER. Sedimentation of Pervious Concrete Pavement Systems. (Under the direction of Michael L. Leming).

Pervious concrete pavement systems (PCPS) are a unique and effective means to address important environmental issues and support green, sustainable growth, by capturing stormwater and allowing it to infiltrate into the underlying soil. Sedimentation leading to clogging is a potential problem in serviceability of PCPS. The sedimentation rates of pervious concrete with 20% porosity were examined with three different soil types: sand, clayey silt, and clayey silty sand. Pervious concrete beam and cylinder specimens were exposed to sediments mixed in water to simulate runoff with heavy and typical load of soil sediments. Falling head permeability tests were performed in the specimens before and after exposure. Results show that storage capacity will be minimally affected by sediment. Exfiltration rate, however, can be affected by sediment characteristics in some situations. A simple, economical test for estimating exfiltration rates of the system in these situations was also developed. The results of this study were used to develop design guidelines that complement the hydrological design of PCPS considering the effects of sedimentation of the system at end of service.

The effects of realistic freezing rates on frost resistance of pervious concrete, including the effects of sedimentation were also examined. Pervious concrete disk specimens were subjected to freezing and thawing cycles using a unique and innovative test that considers realistic, slow freezing rates of partially saturated, pervious concrete disk specimens. Results confirmed previously published reports that sand must be included in the mixture to be frost resistant when saturated or normally saturated, regardless of the addition of air entraining admixture (AEA).