Low-temperature performance grading of asphalt binder through dynamic shear rheometer (DSR) testing: a case study in China

Asphalt binder performance grading (PG) is key for selecting suitable pavement materials. Currently, standard test methods to determine the high and low-temperature PG values of asphalt binder are the dynamic shear rheometer (DSR) test and the Bending Beam Rheometer (BBR) test. However, in China, BBR is rarely used due to high costs and complexity, hindering widespread PG adoption. Instead, penetration, softening point and ductility prevail, but their test temperatures misalign with in-service low conditions, failing to accurately reflect true low-temperature performance. This study developed a method to predict low-temperature PG of typical Chinese asphalt binders via DSR: using the 8-mm parallel geometry for low and intermediate temperature data, fitting with the 2S2P1D model, converting frequency to the time domain and calibrating creep stiffness at selected key time points to determine BBR parameters and low-temperature PG. It can effectively address BBR limitations, aiding binder selection and quality assurance in China.