Hydration Heat Evolution and Setting Performances of Alkali-Activated Slag Cement

• 出 处: 2012 Postdoctoral Symposium of China on Materials Science &
• 发表日期: 2012年8期
• 关键词: Alkali-activated slag cement activator water glass hydration heat setting time m

　　The effect of activator and its dosage on the early hydration and setting performances of alkali-activated slag cement (AASC) is very important.The effects of activator type, modulus of water glass (Ms) and Na2O equivalent on setting time and compressive strength were studied by analyzing the heat of hydration.The results show that the heat evolution curve of the slag activated with water glass (WG) belongs to the third type Ⅲ.For the heat evolution curve of the slag activated by NaOH (NH), only initial peak appears before the induction period and one accelerated hydration peak appears after the induction period, which belongs to Type Ⅱ.With the increase of WG modulus, the first combined peak of slag activated with water glass grows lower and bigger diffusion, accelerated hydration peak appears later, induction period prolongs, cumulative hydration heat reduces, setting time extends gradually and the compressive strength increases first, then decreases.When Na2O equivalent increases, for WG-activated slag cement, the first peak appears earlier, higher and narrower, and accelerated hydration peak also earlier and higher, while induction period becomes shorter and cumulative hydration heat increases.Setting time of paste is somewhat longer and strength increases.Besides, for the heat evolution curve of the slag activated by NH, initial peak and accelerated hydration peak appear earlier and higher, cumulative hydration heat also increases.Setting time of paste is shorter and strength increases slightly.