关于水泥胶砂干缩试验方法的探讨性研究

Discussion on Testing Method for Measuring the Drying shrinkage of Cement Mortar

针对当前国内外典型的水泥胶砂干缩标准试验方法存在的问题,提出了一种新的水泥胶砂干缩试验方法。通过实验用新、老两种方法对比研究了五种水泥所配制砂浆的干缩特性,分析了两种方法所得结果之间的相关性;同时研究了用新、老方法测得的水泥砂浆28d干缩率与水泥3d抗压强度间的关系。实验结果表明,新、老方法测得的水泥砂浆干缩率是线性相关的;新方法测得的水泥砂浆的28d干缩率与水泥3d强度之间相关性更明显。这证明用新法进行水泥胶砂干缩试验是可行的,新法不仅可以节省时间和节约原料,还可以减少系统误差和人为误差。

The current standard test methods for drying shrinkage of mortar with Portland cement are commented, and a new test method is proposed. The shrinkage characteristics of five types of cement mortars are studied by using the new method and compared with the old method to study the correlation between this two methods. The relationship between drying shrinkage at 28 days and compressive strength at 3 days is also investigated. The results indicate that the drying shrinkage values of cement mortars tested by the new method keeps a well linear correlation with that of using the old method. There is more clear relationship between drying shrinkage at 28 days tested by the new method and compressive strength at 3 days. All comfirm that the new test method is feasible, and it is not only able to save time and materials, but also to reduce the system errors and manmade errors.