长大0#段混凝土水化热分析与控制

Hydration Heat Analysis and Control of Long 0# Segment Concrete

以巴河特大桥主桥(44.5+108+2×200+108+44.5)m预应力矮塔斜拉桥为例,对0#段大体积混凝土水化热进行分析。采用MIDAS FEA建立0#段实体有限元模型,研究有无冷却管、是否分次浇筑等不同混凝土浇筑施工方案下长大0#段温度场和应力场变化规律。结果表明,二次浇筑成型、铺设冷却管的施工方案对降低水化热影响效果显著,可有效降低构件温度裂缝出现几率,验证了浇筑方案的可行性,保障了0#段施工质量,同时对大体积混凝土温控技术措施提出建议,可为类似施工项目提供借鉴。

Taking the main bridge of Bahe Bridge(44.5 m+108 m+2×200 m+108 m+44.5 m) prestressed extradosed cable-stayed bridge as an example, the hydration heat of large volume 0 # section concrete is analyzed. MIDAS FEA was used to establish the solid finite element model of 0# block, and the variation laws of temperature field and stress field of long and large 0# block under different concrete pouring construction schemes were studied, namely, whether there was a cooling pipe or not, whether there was graded pouring or not. The results show that the construction scheme of secondary pouring molding and laying cooling pipes can effectively affect the hydration heat, also can effectively reduce the probability of temperature cracks in components. The feasibility of this pouring scheme is verified, the construction quality of 0# section is guaranteed, and the suggestions are put forward for the temperature control measures of mass concrete. It can provide reference for such construction projects.