掺抗裂硅质防水剂对水泥水化的影响研究

Influence of silicon crack waterproof agent on hydration of cement

通过CCD相机搭建试验的数据采集系统,以数字散斑相关方法对试验中采集的散斑图像数据进行分析,研究混凝土试件硬化过程中试件表面变形场演化特征及其对后期受载破坏规律的影响。试验结果表明:混凝土硬化变形时空演化表现为变形缓慢增加、变形快速增加、变形稳定3个阶段特征;混凝土硬化变形时空演化过程是一个从拉、压区域不断调整到最终稳定的动态过程,调整过程中在受拉区形成损伤集中区;混凝土硬化变形场空间演化特征表现为由不均匀分布演化为拉、压应变区域呈条状相间的分布状态。受载过程中裂纹在硬化变形受拉较大的区域开始发育,随着荷载的增加裂纹沿着硬化过程中形成的条状受拉区域扩展成宏观裂纹且试件表面裂纹具有等距分布特征。

The mixture of silicon crack waterproof agent （ SC ）, fly ash and slag power was used to replace part of cement, in order to reduce the cement hydration heat,adjust the setting time and enhance the strength.By measuring cement hydration heat,setting time, cement paste fluidity and mortar strength and doing SEM analysis,the influence of SC on cement hydration was analyzed.The results showed that adding SC had little effect on the fluidity loss of cement paste and could prolong the cement setting time.With the increase of SC content and water-cement ratio, the mortar specimen strength decreased.However, the strength of mortar specimen mixing with 10% SC, fly ash and slag power has no significant decline and the induction period of hydration exothermic was evidently prolonged. Meanwhile, the peak of hydration exothermic was reduced by 46% and the hardened hydration products of cement increased, the material structure was denser and the strength was higher.