Laboratory measurements and analysis of clogging mechanism of porous asphalt mixes

A laboratory test to assess the clogging potentials of porous asphalt mixes is useful as part of a rational design procedure of these mixes for the construction of pavement surface friction courses. Following an earlier successful attempt in inducing clogging in porous specimens in the laboratory, this paper describes a project studying the clogging potentials for porous asphalt pavements of different thicknesses under simulated field conditions. The clogging potentials were studied through the monitoring of the deterioration of the permeabilities of the laboratory specimens, made possible by a new falling-head permeameter that measures three-dimensional flow. An attempt was also made to relate the results thus obtained to a simple theoretical model suggested by Giroud for geotextiles. It was found that there was a fairly good comparison between experimental results and theory.