连续刚构桥0号块水化热温控技术研究

Research on Temperature Control Technology of Hydration Heat of Zero Block of Continuous Rigid Frame Bridge

连续刚构桥0号块的体积较大,在混凝土浇筑过程中水化热较难控制。为避免温度裂缝的产生,确保0号块施工质量,有必要针对0号块混凝土浇筑期间的温度场进行研究。本研究采用有限元方法建立1/4的0号块有限元模型,基于实测数据对有限元模型的精度及适用性进行了验证,并对比分析了不同冷凝参数、分层浇筑高度以及不同等效放热系数下模板的散热效率。结果表明,在冷凝效果方面,改变冷凝管管径和冷凝水温度对于水化热温度控制效果明显;在施工措施方面,从顶板与腹板交界处进行分层浇筑施工能够有效降低高水化热区域在0号块中的比例;同时采用等效放热系数较大的模板材料能够有效提高0号块内部混凝土表面的放热效率。本研究成果可为0号块混凝土浇筑温控方案制订及同类工程提供技术参考。

Due to the large volume of block 0# of continuous rigid frame bridge,it is difficult to control the hydration heat during the concrete pouring process.In order to avoid the occurrence of temperature cracks and ensure the construction quality of block 0#,it is necessary to study the temperature field during the concrete pouring of block 0#.In this paper,the finite element model of 1/4 block 0# is established by the finite element method,and the accuracy and applicability of the finite element model are verified based on the measured data.The heat dissipation efficiency of the formwork under different condensation parameters,layered casting height and different equivalent heat release coefficient is compared and analyzed.The results show that in terms of the condensation effect,changing the diameter of the condensing pipe and the temperature of the condensing water have obvious effects on the temperature control of the hydration heat.In terms of construction measures,layered casting construction from the junction of roof and web can effectively reduce the proportion of high hydration heat area in block 0#.At the same time,the use of formwork materials with larger equivalent heat release coefficient can effectively improve the heat release efficiency of the concrete surface inside block 0#.The research results of this paper can provide technical reference for the formulation of temperature control scheme for block 0#concrete pouring and similar projects.