Characterization of zirconium tungstate filler and performance investigation on asphalt mastic made with zirconium tungstate filler.

Thermal cracking is a widespread distress for asphalt pavement in cold regions. The main reason causing thermal cracking is due to the contraction of asphalt concrete. Once thermally induced contraction stress exceeds the fracture resistance of the asphalt concrete, cracks start to develop. Comparing to aggregate, asphalt mastic is believed to have much larger thermal coefficient of contraction, therefore play a more significant role in determining the thermal cracking resistance of asphalt pavement. To modify the inherent thermal property of asphalt mastic, a new-developed material, zirconium tungstate (ZT), was utilized in this study. Different from normal material’s heated expansion and cooled contraction properties, ZT has a negative thermal expansion property of heated contraction and cooled expansion. Being as a substitute for mineral filler, the physical properties of ZT fillers and performances of asphalt mastics made with ZT fillers were investigated. Results show that ZT can better absorb and adhere asphalt binder when comparing with mineral filler. The addition of ZT is able to decrease the thermal coefficients of volume contraction and creep stiffness, improve the adhesive bond between filler and asphalt binder and reduce the complex modulus of asphalt mastic. [ABSTRACT FROM AUTHOR]