A Deformation Sweep Testing Procedure to Evaluate Damage in Cold Recycled Material Mixtures

This chapter describes a new testing procedure to assess damage in cold recycled material mixtures. Specifically, stiffness modulus tests were performed at increasing deformation levels, with the objective of creating a gradual increase in damage. The succession of tests with increasing deformation was interspersed with tests at small deformation, with the objective of evaluating the damage gradually inflicted on the specimen. In the present research, the resilient stiffness modulus test was carried out in indirect tensile configuration at peak horizontal deformations from 2 μm to 15 μm. Cement–bitumen-treated materials specimens (80% of RAP, 4.0% of bitumen emulsion and 2% of cement) with three level of voids (12%, 14%, and 16%) were tested. The results showed that even small deformation levels lead to a significant reduction in stiffness, which can be interpreted as damage accumulation. Moreover, the dissipated energy approach shows that the damage is probably due to the failure of cementitious bonds.