Evaluation of the effects of transverse cracking on the falling weight deflectometer data of asphalt pavements

This study aims to investigate the effects of transverse cracking on the deflections of asphalt pavements. 3D finite element models were developed to simulate various intact and cracked asphalt pavements. The deflections of intact and cracked pavements under falling weight deflectometer (FWD) loading were computed and compared. In most cases analyzed, the deflections of cracked pavements are greater than those of intact pavements. For pavements with thermal cracking, the deflections can be 12% and 25% greater than those of intact pavements for cement treated base (CTB) and granular base (GB), respectively. For pavements with reflective cracking, the deflections of cracked pavements can be 98% greater than those of intact pavements, and the deflection decreases sharply across the reflective crack and in some cases it can even increase with increasing distance from the loading center. Crack location and width mainly affect the deflections on the loaded side of crack. Both thermal and reflective cracking have greater influences on the deflections of pavement with a thicker AC layer and a weaker subgrade. The effects of reflective cracking on the deflections are significantly greater than thermal cracking. LTE30-60cm is recommended as a deflection index to distinguish reflective cracking from thermal cracking.