Assessment of the low-temperature performance of asphalt mixtures for bridge pavement

The alternative Stone Mastic Asphalt containing an increased amount of bituminous mastic bituminous mixtures (SMA-MA) have been successfully used for additional protective layers on steel and concrete deck bridges. In this application, the mixtures must feature the desired behaviour at both high and low (i.e. below freezing) temperatures. The SMA-MA mixtures owe their improved low-temperature resistance to the bituminous binder used in them, softer than the binders used in mastic asphalts (MA). This article reports a study comparing the selected low-temperature parameters of the SMA-MA and MA mixtures to the parameters of the bituminous binders used in them. The performance of HMA was evaluated by subjecting the specimens to UTST (Uniaxial Tension Stress Test) and TSRST (Thermal Stress Restrained Specimen Test) tests at the test temperatures from -25 degrees C to -10 degrees C. The low-temperature performance of bituminous binders was, in turn, assessed with the BBR test.