Study on temperature field and temperature stress of single-cell box girder cured with electric heater
Yao Gang1,2 Yu Zhiji1,2 Yang Yang1,2 Jia Wei3
1. School of Civil Engineering, Chongqing University, Chongqing 400045, China;
2. Key Laboratory of New Technology for Construction of Cities in Mountain Area of the Ministry of Education, Chongqing University, Chongqing 400045, China;
3. China Railway 12th Bureau Group Co., Ltd., Taiyuan 030024, China
Abstract：Considering the factors of construction period and site, in order to improve the precast efficiency of box girders with heavy weight, the electric heater was installed in the cell of the box girders to heat, and at the same time the surface of single-cell box girder was covered with insulating layer to cure the concrete. Based on the theory of heat transfer, a finite element analysis model was built with Abaqus to simulate the working conditions of construction site. The temperature field and the temperature stress field were numerically analyzed and compared with the actual measurement datum. The results showed that the hydration process developed fast. The temperatures of the box girders experienced a phase of rapid rise and then the temperatures of the single-cell box girder reached the peak. Finally, a slow cooling phase was observed in the temperature field. It was proved that the numerical analysis can describe the actual concrete hydration heat temperature field of the box girders under the curing accurately by comparing with the measurement datum. Temperature stress of single-cell box girders decreased after the peak value, which was less than the tensile strength of concrete. The results of concrete specimens test show that the requirements of prestressing on compressive strength and elastic modulus of single-cell box girders can be met by the proposed curing method. It can be concluded that security and efficiency of precasting single-cell box girder can be guaranteed by this curing method.
姚刚 余志给 杨阳 贾玮 . 单室箱梁电热器养护温度场及温度应力分析[J]. 土木工程学报, 2018, 51(3): 109-114.
Yao Gang Yu Zhiji Yang Yang Jia Wei. Study on temperature field and temperature stress of single-cell box girder cured with electric heater. 土木工程学报, 2018, 51(3): 109-114.
