水泥水化放热与电阻率变化

EXOTHERMICITY AND ELECTRICAL RESISTIVITY DURING CEMENT HYDRATION

测定了不同水泥的水化放热和电阻率变化,并做了电阻率变化率和放热速率的对比分析。研究发现:水泥水化1d的电阻率随累计放热量的增加而增加;电阻率与放热速率随水化时间的变化均能独立地反映水泥水化进程;且水泥水化放热速率曲线的一些特征峰,如:溶解热峰、主放热峰、钙钒石转化峰等,在一定时间偏差范围内,均可在电阻率变化曲线上找到与之对应的突变点。水泥水化放热速率在诱导期达到极小值后先快速增长,再慢速增长,存在转折点,且电阻率变化率有相应峰值与其对应。

The changes of hydration heat and resistivity of pastes during cement hydration were tested, and their hydration and resistivity rates were also compared. The results show that the resistivity at 1 d increases with accumulative hydration heat, and the alterations of resistivity and hydration rate with time can reflect the hydration process independently. Moreover, some remarkable peaks like the dissolution heat peak, the primary hydration heat peak and the peak of ettringite （AFt） transformation to monosulfoaluminate （AFm）, have corresponding mutations on the resistivity rate curve in a certain period of time. The hydration rate increases rapidly after having reached its minimum in the induction period, and then it increases slowly. There is a turning point, and a corresponding peak exists on the resistivity rate curve.