Monitoring the Deformation of Asphalt Concrete under Repeated Tensile and Shear Stresses through Micro Cracks Healing Cycles

摘要

Micro cracks healing property of asphalt concrete is considered as start for understanding its elastic behaviour However, the impact of repeated micro crack healing cycles on deformation has not been investigated thoroughly. An attempt has been taken in this work to investigate the crack healing cycle's phenomena on specimens of 100 mm diameter and 63 mm height, prepared using Marshall Method. Specimens were divided into two sets. The first set was subjected to repeated indirect tensile stresses, while the second set was subjected to the repeated double punch shear stresses (both at 25 °C) to initiate micro cracks within the specimens using controlled stress mode of loading. After controlled number of stress application, Specimens were subjected to external heating in an oven at 60° C and allowed to heal for two hours, conditioned, then subjected to another two courses of repeated stresses and healing. The permanent deformation of the specimens was monitored through continuous video capture in the pneumatic repeated load system (PRLS). The impact of asphalt content, type of test, and healing cycles on the permanent deformation have been analysed.