Influence of active filler, curing time and moisture content on the strength properties of emulsion and foamed bitumen stabilized mix

Abstract

Foamed bitumen and emulsion are common stabilizing agents that are currently used for recycled asphalt pavement construction throughout the world. The strength of stabilized Reclaimed Asphalt Pavement (RAP) is influenced by factors such as filler content, moisture level and curing time. This paper describes the strength impact of ordinary Portland cement as active filler, the length of the curing time and moisture content on the foamed bitumen and emulsion stabilized mix. The basic objective of the paper is to evaluate the effect of active filler (Ordinary Portland Cement), curing time and moisture content on the strength of foamed bitumen and emulsion treated mix. The foamed and emulsion treated samples with various contents of RAP and crushed stone aggregates were tested for their strength properties. The resultant strength increases in terms of resilient modulus, Unconfined Compressive Strength (UCS) and the Indirect Tensile Strength (ITS) values, were correlated with the length of curing time, using various percentages of active filler and proportions of RAP in the pavement mix. It was found that the strength decreased with increased RAP content, however if 100% RAP is to be used then the required pavement strength can be achieved by utilizing a higher active filler ratio. The effect of moisture content variation on foamed bitumen and emulsion treated samples with high percentage of RAP is not significant.