Modified asphalt properties by blending petroleum asphalt and coal tar pitch

Abstract

Modified asphalt was prepared by mixing coal tar pitch (CTP) and petroleum asphalt (PA), and the effects of blending conditions on the properties of softening point, ductility, penetration, and elastic modulus of CTP-modified asphalt (CTPMA) were discussed. The group compositions of PA and CTPMA were analyzed by Fourier transform infrared spectroscopy (FTIR). Results show that PA properties (i.e., softening point, ductility, and penetration) can be improved by CTP addition because of the formation of large-molecule compounds as polycondensation reaction products from small-molecule materials in the blending process. CTP is compatible to PA, and CTP percent of 15% is proper under the blending conditions. CTP addition can also improve the anti-aging effect and decrease the elastic deformation of asphalt mixture. Experiments verify that the modification of PA by CTP addition is technologically feasible, and modified PA can be used to pave asphalt.