Evaluation of Transverse Cracks for Semi-Rigid Asphalt Pavements using Deflection Basin Parameters

Abstract

To evaluate transverse cracks on a semi-rigid asphalt pavement by falling weight deflectometer (FWD), a three-dimensional (3D) dynamic finite-element (FE) model to calculate the deflections of transverse-cracked semi-rigid asphalt pavements under FWD loading was developed and validated by in-situ FWD tests. Then, the effect of crack types and crack width on the deflection basin was investigated for semi-rigid asphalt pavements under different interlayer contact conditions. The relationship between transverse cracks and deflection basin parameters (DBPs) was also analyzed. Finally, the slope ratio to evaluate transverse cracks was proposed and validated by field application. Results show that cracks on pavements will make the deflection basin steeper and the crack width slightly affects the deflections for the same type of crack without interaction between adjacent cracking surfaces. Results also indicate that deflection values increase obviously when the surface-base interaction changes from “Full bonded” to “Full slip.” In addition, results indicate that the slope index ( S1), the shape index ( F2), and the area index (AREA) correlate well with transverse cracks, and the surface cracking, “Reflective cracking 1” (surface and base cracking simultaneously), “Reflective cracking 2” (surface, base, and subbase cracking simultaneously) and the hidden cracking (base cracking, or base and subbase cracking simultaneously) can be identified by the slope ratio. Field application also indicates that the slope ratio can be applied to evaluate the types of transverse cracks on semi-rigid asphalt pavements.