超效缓凝砂浆可塑性能试验研究

Experimental study on the plasticity of the super-retarding mortar

超缓凝砂浆是由水泥、复合缓凝剂、水和砂经适当配比而形成的,该种砂浆可塑性能的研究是其在工程上应用的重要依据。试验测定了A,B,C三种不同配比的缓凝砂浆静态塑性指数,分析了温度、龄期、复合缓凝剂的掺量及不同水泥品种对缓凝砂浆的缓凝时间的影响。结果表明:(1)三种缓凝砂浆各温度下的静态塑性指数都随龄期的增长而增大,说明缓凝砂浆在缓凝早期塑性指数小,触变性能好;(2)缓凝时间随复合缓凝剂的增加增长,随温度的升高缓凝时间会延长。(3)缓凝砂浆的凝结时间与水泥品种也有较大关系,同配比下早强型水泥凝结时间短,抗硫酸盐水泥凝结时间长。

Super-retarding mortar is composed of cement, water, retarding admix and sand in appropriate rate, and study on its plasticity is a very important evidence for application in projects. The static plasticity coefficient of retarding mortar of three different proportions(A,B,C) are tested in this paper, and the effect of temperature, age, addition of compound retardant and different cement type on retarding setting time of retarding mortar.The result shows:(1)the static plasticity of all the three kinds of retarding mortar increased with the age, it indicated that in the early set age, the plasticity coefficient of retarding mortar was low and the rheopexy was good; (2)retarding set time increased with the increase addition of compound retardant and the temperature. (3)And in addition, the setting time of retarding mortar had something to do with the cement type, if given the same proportion, the setting time of early strength cement is short and that of sulphate cement is long.