Laboratory evaluation of clogging potential of porous asphalt mixtures

Abstract

A laboratory test to assess the clogging potential of porous asphalt mixtures is useful as part of a rational design procedure of using these mixtures for construction of pavement surface friction courses. Two prerequisites for the laboratory assessment are (a) the ability to measure an engineering parameter indicative of the mixture's drainage capacity, and (b) the availability of a repeatable procedure of introducing materials into the mixture to create clogging. A laboratory clogging test to cause deterioration in the drainage capacity of typical porous mixtures is described here. Monitoring of the changes in drainage capacity during the test is made possible by the use of recently developed equipment to measure permeability. The proposed clogging test procedure was applied to evaluate four porous asphalt mixtures. Test results suggest that the procedure was able to (a) produce significant degrees of deterioration in the drainage capacities of the mixtures, and (b) differentiate the different behaviors of the four mixes under the clogging treatment of the test.