大体积混凝土中功能轻集料的应用与控温技术

Functional Lightweight Aggregates in Mass Concrete:Application and Temperature Control Technology

研究了2种功能轻集料(保温细集料和储热粗集料)在C55和C30大体积混凝土中的应用技术及其对水泥水化过程的影响,并测试了功能轻集料掺量对混凝土新拌性能、力学性能和峰值温度、升降温速率等的影响规律;提出了功能轻集料使用时宜采用半饱和状态、通过适当降低用水量来控制工作性能相近的应用技术.结果表明:保温细集料和储热粗集料均具有一定的早强作用和控温功能,且储热粗集料的效果更优;保温细集料对于混凝土凝结硬化速率影响不大,但储热粗集料因其相变储能作用,在早期可以起到原位自热养护的作用,明显加快凝结硬化速率.

Application techniques of two functional light aggregates(thermal insulation fine aggregate and thermal storage coarse aggregate)in C55 and C30 mass concrete and their effects on the hydration process of cement were investigated.The influence of functional light aggregate admixture on the fresh concrete properties,mechanical properties,peak temperature,and rate of temperature rise was measured.An application technique under semi‑saturated conditions and controled comparable working performance by decreasing water content was proposed.The results indicate that both thermal insulation fine aggregate and thermal storage coarse aggregate have certain early strength and temperature control functions,in which the thermal storage coarse aggregate is better.The thermal insulation fine aggregate has little effect on the setting and hardening rate of concrete,whereas the thermal storage coarse aggregate can play the role of in‑situ self‑heating curing in the early stage due to its phase change energy storage,which obviously speeds up the setting and hardening rate.