Review

The low-temperature testing of bitumen was performed in accordance with the Canadian LS-308 method - Test method for the determination of performance grade for physically aged asphalt cement using the extended beam rheometer (BBR) method”. The LS-308 method defines the degree of physical hardening occurring in bituminous binders. The bitumen’s physical hardening occurs during prolonged exposure to low temperature. The main result of physical hardening is an increase in the material's stiffness, during which stresses arise inside the binder, which can lead to the formation of cracks.