UC Pavement Research Center
Available online at: https://trid.trb.org/view/1572852
Zhang, Hengji, Hui Li, Ahmed Abdelhady, John T. Harvey (2019) Laboratory Investigation on Self-Healing Properties of Asphalt Mortar with Different Types of Filler. Transportation Research Board 98th Annual Meeting
The self-healing of asphalt materials has been a hot topic recently. Most of the previous studies have focused on the healing modifier, mechanism and modeling. Limited work has been accomplished to fully understand the healing performance of asphalt mortar with different filler types and ratios. Nowadays, plenty of fine solid wastes with extremely different physical and chemical properties have been used as alternative fillers to limestone powder. This study aims to analyze the effects of different filler types and varied ratios on self-healing capability of the asphalt mortar. Firstly, seven types of filler (limestone, fly ash, diatomite and four types of red mud) were mixed to prepare thirty-five groups of asphalt mortar with different filler-bitumen ratios by volume. Secondly, the rheological properties of asphalt mortar were investigated through Brookfield Viscosity and Multiple Stress Creep Recovery. Thirdly, this study examined the effect of each filler type and its ratio on the adhesion and self-healing performance. Lastly, Hamburg Wheel Tracking Test (HWTT) was performed to evaluate the moisture damage and rutting resistance of asphalt mixture with different types of filler. The results indicate that pull-off tensile strength after the first failure-healing cycle in water condition has a good linear relationship with the dynamic stability of asphalt mixture in HWTT. Moreover, chemical components of filler play a crucial role in the performance of asphalt mortar and mixture. Finally, red mud can be used as a promising alternative filler to limestone powder, while its chemical components need to be carefully selected.
Key words: Asphalt mixtures, fillers (materials), fly ash, laboratory tests, limestone, moisture damage, rheological properties, rutting, tensile strength