Evaluation of experimental testing methods for the design of permeable friction course mixtures

Abstract

Since the first mix design of the permeable friction course (PFC), there are currently more than 20 methods used to design PFC mixtures, and thus it is important to evaluate these methods for optimum design. This paper compares the differences of several critical procedures specified in the main design methods of PFCs and their effects on performances, specifically the procedures of specimen compaction (Marshall compaction and Superpave Gyratory Compaction), the draindown test (beaker method, test pan method, and wire basket method), the theoretical maximum specific gravity assessment (vacuum saturation, solvent immersion, and asphalt immersion), and the bulk specific gravity assessment (dimension analysis and corelok method). The effects of different types of aggregates and test methods on properties of PFC mixes were investigated, and it was found that the testing results acquired by different test methods were clearly different. The wire basket, asphalt immersion, and corelok methods all showed better performances for PFC mixes than the others.