Curling effects on concrete slab-on-grade fracture

This paper discusses the effects of temperature curling on post-crack responses of concrete slabs-on-grade. The fracture process is idealized using traction–separation cohesive elements recently incorporated in ABAQUS based on the Fictitious Crack Model. Effects of curling alone as well as curling-plus-wheel load are investigated; the latter is carried out by considering two loading scenario: fixed temperature followed by increasing wheel load, and fixed wheel load followed by increasing temperature. In both loading cases, the effects of parameters, such as concrete age, notch size, slab size, slab self-weight, day time and night time temperature variation, concrete tensile strength and fracture energy have been conducted. When the slab is under curling-plus-load, it is observed that daytime curling significantly reduces the peak load capacity results in sudden failure of the slab whereas nighttime curling causes stable cracks and increases the peak load resisted by the slab. It is hoped that the application of fracture mechanics outlined in this study through a step-by-step approach may be extended to in situ pavement systems, thereby addressing the limitations in current pavement design procedures that exclusively rely on statistical algorithms for the prediction of pavement distresses.