Mechanistic-Empirical Characterization of Bonding Between Ultra-Thin White-Topping and Asphalt Pavement

Abstract

Abstract This paper presents a mechanistic-empirical methodology to evaluate the effect of partial bonding on ultra-thin white-topping (UTW) pavement structure. Based on the analytical work conducted for unbonded and fully-bonded interfaces, this paper displays the intrinsic relation between interface bonding and structural capacity, and provides a practical approach torelate interface bonding condition to UTW pavement structure. Information presented herein will help pavement engineers understand the composite behavior of the interface, and improve the current procedures for designing UTW pavement. Also, this paper provides fundamentals for pavement engineers to estimate UTW interface bonding using Falling Weight Deflectometer (FWD) testing. It is concluded that the asphalt layer's Poisson ratio has only a minor effect on the stresses in UTW pavement. Bonding affects the stresses under edge and center loading more significantly than under corner loading. The effect of bonding on the curling stress depends on UTW panel size. If the panel size is very large (3 m × 3 m) or very small (0.6 m × 0.6 m), the effect of bonding is negligible. The curling stress decreases significantly as the bonding condition improves if the panel size is 1.8 m × 1.8 m or 1.2 m × 1.2 m. It is also demonstrated by employing the FWD deflection measurements that as the UTW pavement age increases, its interface bonding may deteriorate.