Influence of reinforcement configuration on the shrinkage and cracking potential of high-performance concrete

This study experimentally investigated the effects of the reinforcing bar configuration on the shrinkage behavior of high-performance concrete (HPC), including the restrained shrinkage strain, shrinkage gradient, restrained stress, and cracking potential. The deformation in high-performance concrete specimens was measured with four different reinforcement ratios, two different reinforcement configurations, and two different curing conditions. The results demonstrated that the restraining effect of the reinforcement on concrete shrinkage decreased with the distance from the reinforcing bar. For the same reinforcement ratio, the four reinforcing bars placed at the corners of a concrete member better restrained the shrinkage all throughout the concrete cross-section and decreased the concrete cracking risk better than a single reinforcing bar placed at the center. A formula was put forward to predict the restrained shrinkage strain distribution in the concrete cross-section. In addition, the restrained specimens under the dry curing condition have higher decrease rate of restraining effect, shrinkage gradient, restrained stress, and cracking potential than those under the sealed condition.