Investigating the effect of filler Waste wollastonite on the performance of hot mix asphalt

Given the wide range of applications of asphalt Pavement in the world, significant investments are dedicated annually to maintenance and repair of these Pavements. Improving the asphalt mixture's performance can increase the Pavement life and reduce the maintenance and repair costs. In this respect, fillers can significantly influence the properties of asphalt mixtures. Waste wollastonite is a neutral mineral composed of two silica and lime Parts with nearly the same proportions. In this research, Waste wollastonite mineral, a neutral mineral with high elasticity modulus, was utilized as filler and the impact of which on the asphalt mixture's properties was investigated on micro-scale-asphalt mixture performance tests including Marshal Stability, resistance modulus, indirect tensile and moisture sensitivity were performed on the produced samples containing Waste wollastonite filler. The results showed that the use of Waste wollastonite improves the performance of asphalt mixture, so that as the lime filler is entirely replaced by Waste wollastonite filler, the Marshal Stability, Marshal Quotient and resistance modulus were increased by 30%, 28%, and 26%, respectively. However, by 70% replacement of Waste wollastonite filler, the tensile strength ratio (TSR) was increased about 9%, as well as a significant decrease in Indirect Tensile Strength (ITS) compared to the control sample.