大体积混凝土在施工中,往往会发生裂缝,而裂缝有多种原因,主要是温度和湿度的变化,混凝土的脆性和不均匀性,以及结构不合理,原材料不合格(如碱骨料反应),模板变形,基础不均匀沉降等。混凝土硬化期间水泥放出大量水化热,内部温度不断上升,在表面引起拉应力。后期在降温过程中,由于受到基础或老混凝上的约束,又会在混凝土内部出现拉应力。气温的降低也会在混凝土表面引起很大的拉应力 Massive concrete often cracks during construction, but there are many reasons for cracks, mainly the changes of temperature and humidity, the brittleness and inhomogeneity of concrete, unreasonable structure and unqualified raw materials (such as alkali-aggregate reaction) , Template deformation, uneven foundation settlement and so on. During the hardening of concrete, a large amount of hydration heat is released from the cement, and the internal temperature is constantly rising, causing tensile stress on the surface. Late cooling process, due to the basic or old coagulation constraints, will appear in the concrete tensile stress. A decrease in temperature can also cause a significant tensile stress on the concrete surface