大体积混凝土底板温度裂缝控制技术研究

Research on Temperature Crack Control Technology of Mass Concrete Bottom Slab

裂缝是土建工程中混凝土结构面临的最大问题。通过在大体积底板混凝土中掺入水化热抑制剂,调控水泥水化历程,减小混凝土温度收缩,进而减小混凝土温度裂缝出现概率。本文以武汉某地下室的大体积混凝土底板为例,应用温度裂缝控制技术,将混凝土温峰保持在40℃以下,经过后期观测,混凝土未出现贯穿性有害裂缝。为进一步验证大体积混凝土底板温度裂缝控制技术的应用效果,根据实测数据,采用Midas civil软件中的水化热分析模块,对混凝土底板进行有限元分析,温度云图显示,降温过程中结构内部没有产生较大的温度梯度,混凝土温度收缩小;温度裂缝系数显示,混凝土升温、降温阶段开裂风险均很低,说明大体积混凝土底板温度裂缝控制技术可调控混凝土温度收缩,降低混凝土开裂风险。

Crack is the biggest problem of concrete structure in civil engineering.By addinghydration heat inhibitor into mass concrete,the hydration process of cement is regulated,and the temperature shrinkage of concrete is reduced,thus reducing the probability of temperature cracks in concrete.The temperature crack control technology was applied to the mass concrete bottom plate of a basement in Wuhan,and the temperature peak of the concrete was below 40℃.After observation,no harmful cracks were found in the concrete.In order to further verify the application effect of temperature crack control technology of mass concrete floor,according to the measured data,the hydration thermal analysis module of Midas civil software is used to carry out finite element analysis of concrete floor.The temperature cloud map shows that there is no large temperature gradient inside the structure during the cooling process,and the temperature of concrete shrinks.The temperature crack coefficient shows that the cracking risk of concrete is very low at both temperature rise and temperature drop stages,indicating that the temperature crack control technology of mass concrete floor can regulate the temperature shrinkage of concrete and reduce the cracking risk of concrete.