Temperature and shrinkage cracking in reinforced concrete walls

Concrete cracking due to restrained thermal and shrinkage strain is a widespread problem that could happen to any structural element including base restrained walls. This type of crack usually occurs in structures with rigidly interconnected parts cast after their adjacent parts are hardened. As concrete undergoes volumetric deformations right after casting, the developing strains due to temperature drop and moisture loss get restrained by neighboring parts which causes stress development and could lead to formation of cracks. Cracking could reduce the structure’s integrity and serviceability, cause deterioration which could also lead to esthetical concerns. Therefore, structures should be designed to limit cracks to an acceptable level depending on the functionality requirements of the structure and its exposure conditions. Although it has been proven that it is almost impossible to completely eliminate cracking, providing an adequate amount of appropriately positioned reinforcement can reduce the width of cracks significantly. This study aims to investigate the behavior of base restrained reinforced concrete (RC) walls under volumetric changes due to thermal and shrinkage strains and providing a procedure to determine the amount of reinforcement needed to control the width of cracks. The ABAQUS finite element (FE) program is used to simulate the structures used in this study. The models are verified by comparing the results with previous experimental studies. Based on the performed parametric study, a procedure is suggested to determine the amount of steel reinforcement required to satisfy the cracking limitations based on major parameters that affect the crack width.