凝结时间调控对大体积混凝土温度历程的影响试验研究

Test Study of Condensing Time Control on Influence of Mass Conerete Temperature Course

大体积混凝土的温度裂缝控制是保障工程质量的重要环节。采用水泥水化热测定直接法与混凝土绝热温升法,试验研究了掺用葡萄糖酸钠和柠檬酸钠调控凝结时间对水泥和混凝土水化温度历程的影响。试验结果表明,缓凝剂主要延长了水泥的水化诱导期,而对随后的水泥和混凝土水化温度上升速率和温度峰值影响十分有限。因此,采用缓凝剂抑制大体积混凝土温度裂缝的效果很小,主要用于控制施工冷缝。

Temperature crack control is an important part in mass concrete construction. Two test methods for heat of hydration of cement and concrete adiabatic temperature rise were adopted to research the influences of sodium gluconate and sodium citrate on the temperature procedures of cement and concrete. The experimental results indicated that the two retards mainly extended cement induction period, but poorly influenced the following hydration temperature rise rate and temperature peak. Therefore, the application of retards to restrain temperature crack usually has little to no effect, while they are mainly used to control construction cold joints.