不同细度水泥的水化特性及其对水泥砂浆自愈合性能的影响

Influence of Different Fineness of Cement on the Hydration Characteristics and the Self-healing Properties of Cement Mortar

研究了不同细度水泥的水化热、水化产物和力学性能,以及水泥细度和养护条件对预制裂缝的水泥砂浆强度恢复率和裂缝愈合的影响。结果表明:随着水泥比表面积增大,水泥水化放热量峰值越高,相同龄期下的水化程度越高;预制裂缝试块在自然养护、标准养护和水中养护90 d后的强度恢复率呈现出来相似的规律,均随着细度增加而逐渐减小;比表面积为254 m2/kg和407 m2/kg的水泥制成的砂浆试块,预制裂缝的初始最大宽度都为0.070mm,前者水中养护90 d后裂缝基本愈合;而后者的裂缝愈合率只有57.1%。

The hydration heat, hydration products and mechanical properties of cement with different fineness were studied, Effect of cement fineness and curing condition on strength restoration ratio and the change of crack width of cement mortar cracks was analyzed. The results show that with the increase of cement specific surface area, the peak value of hydration heat of cement is higher, and the degree of hydration is higher at the same age. The strength restoration ratio of pre-craeked specimens in natural curing, standard curing and water conservation showed a similar regularity decreasing with the increase of the fineness. With specific surface area of 254 m^2/kg and 407 m^2/kg of cement mortar block precast cracks, the initial maximum width of the crack is 0.070 mm, After curing in water for 90 d, the former cracks were healed. However, the latter fracture healing rate was 57.1%.