Field and Laboratory Evaluation of Pervious Concrete Pavements

Portland cement pervious concrete (PCPC) is a material of increasing interest for parking lots and other applications. PCPC typically consists of coarse aggregates, portland cement, water, and various admixtures. Similar materials are used for cement-stabilized drainage layers in highway and airport pavements. In this research, in-service PCPC pavements were inspected in the field, and cores were removed in order to investigate properties in the laboratory. Field evaluation methods included visual inspection, two surface drainage measurements, and an indirect-transmission ultrasonic pulse velocity (1UPV) test. Laboratory testing methods included void ratio, unit weight, compressive strength, splitting tensile strength, hydraulic conductivity, and direct-transmission UPV. Because it is compacted on the surface with screeds or rollers, PCPC generally has higher strength, lower void ratio, and lower permeability at the surface than at the bottom. Therefore, the properties of the tops and bottoms of core samples were compared. Generally, the PCPC installations evaluated under this research project have performed well in freeze-thaw environments with little maintenance required. No visual indicators of freeze-thaw damage were observed. With the exception of some installations in which the pore structure was sealed during construction with wet mixtures or overcompaction, nearly all sites showed fair to good infiltration capability on the basis of drain-time measurements.