空心墩墩底实体段混凝土温度裂缝防治措施

Prevention And Control Measure of Temperature Crack in Solid Bottom of Hollow Pier

由于山区高速公路地势陡峻,因此,在桥梁设计中根据线位情况采用空心墩跨越,为满足桥墩的强度、刚度、稳定性等方面的要求,空心墩具有较大的截面尺寸。但是空心墩墩底为实体段,这种大体积混凝土在浇筑过程中产生的水化热与外界环境温度及约束的综合作用会导致混凝土出现温缩裂缝。这种裂缝虽然不会影响桥墩的受力能力,但为空气、水和侵蚀介质提供了通道,加速了混凝土劣化和钢筋锈蚀,严重降低结构的耐久性。因此,加强空心墩墩底实体段混凝土温度裂缝防治尤为重要。

Because the mountain highway is steep,hollow piers are adopted in bridge design according to the line po⁃sition.In order to meet the requirements of the strength,stiffness and stability of the piers,it has a large section size.Since the bottom of the hollow pier is a solid section,the comprehensive action of hydration heat generated in the pouring process of this mass concrete with the external environment temperature and constraints is the main reason for the occurrence of temperature shrinkage cracks in concrete.Although such cracks do not affect the bearing capaci⁃ty of the piers,they provide channels for air,water and erosion media,accelerate the deterioration of concrete and steel corrosion,and seriously reduce the durability of the structure.Therefore,it is particularly important to strength⁃en the prevention and control of concrete temperature cracks at the bottom of hollow pier.