Plastic Tensile Strength and Mechanism of Plastic Shrinkage Cracking for Cement Mortars

The test method for the plastic tensile strength of cement mortar was studied.Some factors such as cement strength grade, additives, fiber content, fiber diameter, fiber length, waterlosing condition, waterlosing time, were investigated. The total weighted cracking values at different experimental conditions were analyzed accordingly. The analyzing results show that the plastic shrinkage cracking is mainly related to the two factors, plastic tensile strength of cement mortar and the shrinkage stress of capillary,and depends on the relative values of this two factors. In addition, the mechanism of the plastic shrinkage cracking was also discussed in the paper.