INVESTIGATING RUTTING PERFORMANCE OF FOAMED COLD-MIX ASPHALT UNDER SIMULATED TRAFFICKING

Abstract

A trial section of a foamed cold mix asphalt (FCMA) pavement was constructed and investigated under simulated trafficking in the Pavement Test Facility (PTF). A combination of crushed limestone and reclaimed asphalt pavement (RAP) aggregates with selected binder was used to simulate recycled construction. Trafficking was carried out at an approximate velocity of 3 km/hr for various applied single wheel load applications. The results have provided preliminary indication of rutting resistance characteristics of foamed asphalt material. The rutting performance depends on the mixture proportion, binder type and the presence of cement. It was found that foamed bitumen bound mixtures that contained a higher proportion of RAP and a softer binder exhibited greater deformation. The effect of mix proportions and penetration grade of the binder on rutting was more pronounced during early life and at low loads, but when the mixture was subjected to higher loads, this effect was less significant. It was also well observed that the use of small amount of cement can accelerate the curing process and significantly reduced the measured rutting.