Influence of specimen size/geometry on shrinkage cracking of rings

This paper presents experimental evidence to show that a size/geometry depe ndence is observed in the shrinkage cracking behavior of restrained concret e structures. A theoretical model is developed to explain this behavior. Fi rst, a solution is presented to compute the stress and displacement fields of an aging, linear, viscoelastic cylinder by assuming that a uniformly dis tributed shrinkage strain is perfectly restrained in the radial direction a t the internal surface of the cylinder. Second, a fracture mechanics failur e criterion is implemented to develop time and geometry-dependent tensile s tress resistance (strength) curves. Third, this model is used to illustrate the role of specimen size/geometry and material composition on the failure response. Finally, experimentally measured ages of cracking are compared w ith the theoretical modeling predictions.