水泥砂浆塑性抗拉强度与收缩开裂的关系

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

研究了水泥砂浆塑性抗拉强度的实验测试方法及部分基体参数(水泥品种、水泥强度等级、外加剂种类、混合材品种及掺量)、纤维参数(纤维掺量、纤维直径、纤维长度)和实验条件(塑性失水条件、失水时间)对水泥砂浆塑性抗拉强度的影响规律,并分析了其与砂浆塑性收缩开裂总权重值的关系.结果表明:水泥砂浆的塑性收缩开裂性能主要与砂浆的塑性抗拉强度和砂浆中的毛细管收缩应力有关,且取决于该2因素的相对大小.另外,对砂浆塑性收缩开裂机理进行了探讨.

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.