Performance characterization and microscopic properties of asphalt modified with rapeseed heavy oil-activated waste rubber powder

Abstract

To improve the waste rubber powder modified asphalt viscosity is high, poor storage stability, and other shortcomings, 40 mesh, 60 mesh, and 80 mesh are three kinds of mesh rubber powder using rapeseed heavy oil pre-swelling activation way to prepare modified asphalt, improve the waste rubber powder modified asphalt storage stability and reduce the viscosity. The optimum blending amount of rapeseed heavy oil-activated waste rubber powder was determined by setting three oil-rubber ratios, and the unactivated waste gum powder modified asphalt was set as a control group, and the physical, rheological, and microscopic properties of the asphalt were evaluated accordingly. The optimum preparation parameters under the premise of setting the total dosage of modifier as 20% were: the mass ratio of rubber powder to rapeseed oil was 2:1, and the mesh size of rubber powder was 80 mesh. Rapeseed heavy oil-activated waste rubber powder modified asphalt storage stability and low-temperature performance improved, viscosity decreased, but high-temperature performance decreased at the same time. Compared with the unactivated waste rubber powder modified asphalt, the softening point decreased by an average of 16%, the needle penetration increased by an average of 19%, the ductility increased by an average of 44%, the viscosity decreased by an average of 22%, and the softening point difference decreased by an average of 44%. In the high-temperature rheological performance test set temperature interval, the rutting coefficient G*/sinδ decline, creep stiffness Ѕ, and creep rate m have increased. Therefore, rapeseed heavy oil activation can effectively improve the overall stability of waste rubber powder-modified asphalt and can reduce the overall viscosity, which is conducive to the uniform dispersion of rubber powder in asphalt.