Numerical analysis of longitudinal cracking in widened jointed plain concrete pavement systems

Abstract

While widened slabs have been used to mitigate transverse cracking in jointed plain concrete pavements (JPCP), it is well-known that use of such slabs increases longitudinal cracking potential in JPCP. Field investigations have been conducted in Iowa widened JPCP and it was found that: (1) all longitudinal cracks are top-down cracks; (2) longitudinal cracks start mostly from transverse joints about 0.6–1.2 m (2–4 ft) away from widened slab edges (3) sites with a tied PCC shoulder exhibited fewer longitudinal cracks than sites constructed with hot mix asphalt (HMA) shoulders. In this paper, the longitudinal cracking mechanism of widened JPCP was demonstrated and longitudinal cracking potential was evaluated using numerical analysis. The critical load configuration with the highest longitudinal cracking potential for widened JPCP was identified. Three shoulder design alternatives were also compared in terms of their contributions to mitigation of longitudinal cracking potential. Compared to the use of a widened slab, the use of a regular size slab was found to be beneficial in mitigating longitudinal cracking at the cost of increasing transverse cracking potential. The findings of this study provide explanations as to where and how longitudinal cracking is likely to be initiated as well as recommendations as to how longitudinal cracking potential could be mitigated.