Integrated Experimental–Numerical Approach for Estimating Material-Specific Moisture Damage Characteristics of Binder–Aggregate Interface

An integrated experimental–numerical approach is presented for estimating the material-specific moisture damage characteristics of binder–aggregate interfaces. A pull-off test is conducted with a pneumatic adhesion tensile testing instrument to determine the bond strength between asphalt film and the aggregate surface to which various types of antistripping additives are applied with various levels of moisture conditioning. A sequentially coupled moisture diffusion–mechanical analysis is implemented with a finite element technique to model the bond strength and progressive interfacial degradation caused by moisture diffusion, followed by mechanical pulling pressure. To simulate the adhesive fracture at the binder–aggregate interface, a cohesive zone model is incorporated into the approach. The integrated approach results in a degradation function that characterizes interfacial damage caused by moisture uptake with two model parameters representing the remaining bond strength and the degradation trend. With the two model parameters, moisture damage mechanisms and damage resistance potential, both of which are material specific, can be estimated.