Effect of Tension at Early Age on Bearing Capacity of PC Continuous Girder Bridge

2019 5th International Conference on Energy Materials and Environment Engineering

能源学;生态环境科学

Zou, Lanlin^1 ; Xue, Bohuang^1

School of Transportation Engineering, Wuhan University of Science and Technology, Wuhan, Hubei

430065, China^1

关键词: Bending capacity;    Continuous box girders;    Continuous girder bridge;    Different ages;    Pre-stressed steel;    Precast box girders;    Prestress loss;    Simulation analysis;   

Others  :  https://iopscience.iop.org/article/10.1088/1755-1315/295/3/032044/pdf
DOI  :  10.1088/1755-1315/295/3/032044

学科分类：环境科学（综合）

来源: IOP

【 摘 要 】

In order to study the influence of prestressed steel bundles on the bearing capacity of bridges in the early age of concrete, a new 5×20 m prefabricated continuous box girder bridge is used as the engineering background, and MIDAS/CIVIL simulation is used. When the age of precast box girder concrete is 3d (working condition 1), 5d (working condition 2), 7d (working condition 3), the steel bundle is tensioned. The ultimate state check and prestress loss analysis of the mid-span middle beam after tensioning at different ages are analyzed. The results show that the positive section bending capacity of working condition 1 and working condition 2 decreased by 13.15% and 6.51% respectively and the earlier the tensile age, the greater the prestress loss value of the steel bundle. Combined with the simulation analysis, the load test is carried out on the bridge (the actual construction is tensioning at 5d): the strain check coefficient is between 0.599 and 0.753, and the deflection check coefficient is between 0.596 and 0.705. The results show that when the concrete age is 5d, the steel bundle is tensioned, and its bearing capacity can still meet Highway Class I requirements.