高温-水冷循环作用下的水泥石劣化分析

通过失重率与表层损伤评价高温-水冷循环作用对水泥石的劣化方式,利用X射线衍射(XRD)、热分析技术(TG/DTA)对不同循环条件下的水泥石进行物相组成分析.结果表明:高温-水冷循环作用实质是高温损伤、水化以及碳化的耦合作用,水泥石中氢氧化钙(CH)碳化严重,水化硅酸钙(C-S-H)大多脱水分解;不同温度下的循环破坏中,各个作用所占的比重不同;随着循环次数增加,水泥石的破坏历程相近;长时间后,水泥石的脆硬性大大增加,表层出现网状裂纹,破坏样中留有大量碳酸钙(CaCO3).

Deterioration Analysis of Cement Paste under Heat-Water Circulation

The deterioration mode of heat-water circulation was evaluated by weightlessness rate and surface damage,cement paste composition of different circulation condition was analyzed by using X-ray diffraction(XRD)and thermoanalysis technology(TG/DTA).Results show that the heat-water circulation effect is high temperature damage, hydration and carbonization coupling effect in essence, calcium silicate(C-S-H)is mostly dehydrated, and calcium hydroxide(CH)is carbonized in cement paste.Different temperatures circulation effect, different proportion of each role.As the cycle number increases,the damage course of cement paste is similar.After a long time, brittleness and hardness of cement paste are greatly increased, meanwhile, multiple cracks formed as net are appeared on the surface,and a lot of CaCO3left in damage samples.