Evaluation of low temperature properties of rubberized asphalt mixtures

Abstract

The paper presents low-temperature test results of asphalt mixtures designed with use of bitumen modified by crumb rubber and also SBS polymer. Laboratory tests were conducted on two types of asphalt mixtures for wearing course – stone matrix asphalt (SMA 8) and porous asphalt (PA 8). This paper presents results of the following laboratory tests at low temperatures: TSRST test, three point bending creep test, fracture toughness test and assessment of physical hardening. It was found that test results of asphalt mixtures with use of polymer-rubber modified bitumen showed high resistance to low temperature cracking in all tests conducted. In some cases use of polymer-rubber modified bitumen even increased resistance to low temperature cracking in comparison with standard SBS polymer modified bitumen. The additional advantage is that usage of crumb rubber allows to reduce the amount of added polymers with respect to the standard SBS polymer modified bitumen.