An analytical model for predication of crack spacing due to shrinkage in concrete pavements

This paper investigates the minimum and maximum crack spacings in concrete pavements from the energy viewpoint and explores mechanisms that control spacing. An analytical model, which is composed of two cohesive cracks and an elastic bar restrained by distributed elastic springs, is proposed as an idealization of the cracking pattern in the concrete. By varying the length of the elastic bar of the analytical model, the tensile forces acting on the cohesive cracks and the energy profiles are investigated. It is demonstrated that the cracking pattern varies with the length of the elastic bar (i.e., the spacing between the two possible cracks), from which the minimum and maximum crack spacings are obtained. Numerical analyses are made of a model pavement and the results indicate that it is the energy minimization principle that governs the cracking pattern. The practical spacings evaluated by numerical analyses fall within the minimum and maximum crack spacings given by the practical observation