“九三一”温度控制模式的研究与实践

Research and practice of Nine-Three-One temperature control mode

防裂是混凝土坝建设中的一个重要课题。绝大多数混凝土裂缝都与温度应力有关,因此温度控制是防裂的主要手段。本文的研究团队,总结长期的研究成果与实践经验教训,总结出了‘九字方针、三期冷却、一个监控’的温度控制模式,简称‘九三一模式’,‘九’是‘九字方针’,是指‘早保护、小温差、慢冷却’;‘三’是‘三期冷却’,是指‘一期、中期、二期’冷却;‘一’是‘一个监控’,是指‘智能监控’。研究和实践表明,按照‘九三一’温控模式进行温度控制,可以很好地控制温差和温度梯度在空间和时间上的分布、充分发挥混凝土材料的徐变和抗裂能力,对可能出现的开裂风险进行及时预警,从而有效地防止温度裂缝。

Crack control is an important issue in construction of concrete dams. The vast majority of concrete cracks are related to temperature stress and hence temperature control becomes a primary method of crack control. This paper overviews the experiences of long-term research and practice, summarizes Nine-Three-One temperature control mode developed by the research team of the paper. ＂Nine＂ refers to a guiding principle form nine words （in Chinese） which means ＂earlier defense and cooling by smaller temperature difference with longer time＂; ＂Three＂ refers to three-stages cooling at ＂first stage, middle stage and second stage＂; ＂One＂ refers to one monitor or ＂intelligent monitoring＂. Research and practice show that if this Nine-Three-One mode is adopted to control temperature, its difference and gradient distribution over space and time can be better controlled, the creep and crack resistance of concrete can be taken full advantage, cracking risk can be warned timely, and thus temperature cracks can be prevented effectively.