Abstract:

In order to obtain the low-temperature relaxed modulus of elasticity for bitumen by tests with easy manipu-lation, the blending beam rheometer (BBR) was used to measure the creep compliance. The experimental data of BBR were then discretized in time domain. According to the constitutive relationship between the creep and the re-laxation, a numerical iteration expression was thus proposed to describe the relationship between the relaxed modu-lus of elasticity and the creep compliance. By the proposed expression , the relaxed modulus of elasticity for bitumen at the fiducial temperature was further calculated. Moreover , the main curves of the relaxed modulus of elasticity at different temperatures were drawn via the time-temperature equivalent principle. The characteristics of the main curve were finally analyzed and were used to evaluate the low-temperature performance of bitumen , thus providing some references for making the right choice of bitumen in practical engineering.

Key words: bitumen, creep compliance, relaxed modulus of elasticity, bending beam rheometer