Influence of Self-Healing Behavior on the Viscoelastic Properties of Asphalt Concrete

Abstract

The environmental impact and vehicular load repetitions on asphalt concrete pavement exhibits negative influence on its service life. It is known that the asphalt concrete exhibit Self-healing behavior when practicing hot environment or rest period. In the present work, the influence of self-healing behavior on viscoelastic properties of asphalt concrete in terms of the variations in the cumulative dissipated energy and the phase angle after practicing the self-healing process was assessed. Asphalt concrete slab sample of (40 x 30 x 6) cm was prepared in the laboratory with optimum binder requirement and compacted with the aid of laboratory roller compactor. Beam specimens of 50±2 mm high, 63±2 mm wide and 400 mm length were obtained and tested for fatigue under dynamic flexural stresses at 20 °C and constant strain level of 400 micro strains. The test was terminated when the flexural stiffness declined to 50 % of its original value. The specimens were then stored inside an oven at 85 ° C for two hours to allow for the self-healing of micro cracks. Beam specimens of asphalt concrete were allowed to cool at room temperature for two hours, then transferred to the testing chamber and subjected to dynamic flexural fatigue test to determine the impact of healing on its viscoelastic properties. It was concluded that at failure, the cumulative dissipated energy increases by 100 % after practicing micro crack self-healing process while the fatigue life increases by 53.8 % as compared with the case before healing process. At failure, the phase angle declined by 6 % after self -healing process.