Modeling the influence of healing on the flexural strain parameters of asphalt concrete under dynamic flexure

Abstract

Utilization of the self-healing behavior of cracked asphalt concrete pavement is a sustainable approach for extending the fatigue life and reserving its mechanical properties. In the current study, the ideal amount of binder was used to manufacture beam specimens of asphalt concrete mixture. The beam specimens were subjected to dynamic flexural stresses at a constant stress level of 138 kPa. The dynamic testing was conducted using 0.1 seconds of loading and 0.9 seconds of rest period at 20°C environment with the aid of pneumatic repeated load system PRLS. The load application was terminated after 650 load repetitions. The specimens were stored in an oven for 60 minutes at 120°C to allow the generated microcracks in the mixture to heal, then the specimens were subjected to another round of dynamic stresses. The flexural strain in terms of (total, permanent, and resilient) were monitored by LVDT which was positioned on the specimens. The influence of the healing process on the strain was modelled. It was concluded that the microcracks healing process exhibits significant influence on the flexural strain parameters of asphalt concrete under the applied dynamic flexural stresses. After 650 load repetitions, the flexural strain declined by (83.3, 84.2, and 55.9) % for (total, permanent, and resilient) flexural strain respectively after practicing microcrack healing process. Mathematical models of the flexural strain parameters before and after the healing process exhibited high coefficients of determination and may be adopted in the design of sustainable asphalt concrete mixture.