Influence of mineral filler on the low-temperature cohesive strength of asphalt mortar

Abstract

The effects and influence mechanisms of different filler-to-bitumen ratios on the low-temperature cohesive strength of asphalt mortar were studied using quantitative testing technology. Two control variables, namely filler-to-bitumen ratio (the quality of the mineral filler/quality of asphalt) and temperature, were selected for this experiment. The first variable was divided into six groups. The cohesive strength of each group was then measured under different low-temperature conditions. Results show that the optimization of filler-to-bitumen ratio was related to the cohesive strength of the asphalt matrix, which was in turn associated with the change on the surface between the asphalt matrix and the strength of the mineral power fillers generated from asphalt embrittlement. Therefore, the optimal filler-to-bitumen ratio should be determined by the local low-temperature conditions. Moreover, the cohesive strength of the asphalt matrix, its embrittlement state and the contact surface strength effect of asphalt filler should be comprehensively considered in determining the optimal filler-to-bitumen ratio.