Modeling of Restrained Shrinkage Cracking in Concrete Materials

Synopsis: An experimental study was conducted to evaluate the restrained shrinkage cracking in plain and fiber reinforced concrete. The experiment utilizes a constant humidity chamber holding the restrained shrinkage specimens. The chamber is subjected to constant flow of air around the specimens. The strain in the restraining steel and the crack width in the concrete samples were monitored continuously. The experimentally obtained results are affected by geometry of the specimen, the humidity and shrinkage conditions, and the restraint offered by stiffness of the steel ring. In addition, concrete properties such as the stiffness, shrinkage and creep affect the response. In order to better understand the restrained shrinkage of concrete under the proposed test method and eliminate the influence of test conditions, an analytical approach was developed. The model incorporates key influential parameters of shrinkage, creep, aging, and microcracking, in the stress analysis of a restrained concrete section. The theoretical model was used to calibrate and interpret the experimental test results