Effect of thermal stresses on mid-slab cracking in dowel jointed concrete pavements

Abstract

Mid-slab cracking is considered to be one of the main causes of pavement deterioration and enormous funds are spent each year on repairing and maintaining cracked pavements. In this study, a nonlinear three-dimensional finite element (3DFE) analysis, which includes detailed consideration of slab constraints by dowel bars, is used to analyse the problem of premature transverse cracking in jointed concrete pavements. The 3DFE model response to ambient temperature variations is validated versus field-measured data obtained from instrumented concrete slabs constructed in Goshen Road near Morgantown, West Virginia, USA. The modelling results indicate that the combination of ambient temperature drop and slab curling induces slab constraints that lead to the development of mid-slab transverse cracks. The slab length is shown to be a critical parameter that governs the magnitude of the maximum thermal stress induced at maximum mid-slab. It is shown in this paper that 4.57 m is the optimal slab length to avoid mid-slab cracking, a conclusion that agrees with recent observations obtained from the analysis of LTPP (Long Term Pavement Performance).

Keywords:

• Concrete pavements
• Dowel bars
• Thermal stresses
• Mid-slab cracking
• Pavement instrumentation

Acknowledgements

West Virginia Department of Transportation entirely sponsored the work presented in this study. The authors gratefully acknowledge fruitful discussions with Mr Norman Roush, WVDOH (West Virginia Division of Highways) Deputy Commissioner, and the participation and advice of WVDOH engineers from District 4, and WVDOH Materials Division.