Fire resistance of prestressed continuous steelconcrete composite beams(PDF)
长安大学学报（自然科学版）[ISSN:1006-6977/CN:61-1281/TN]
- Issue:
- 2018年06期
- Page:
- 40-48
- Research Field:
- 桥梁与隧道工程
- Publishing date:
Info
- Title:
- Fire resistance of prestressed continuous steelconcrete composite beams
- Author(s):
- ZHOU Huanting; ZHENG Zhiyuan; HAO Conglong; LI Hui
- (1. School of Civil Engineering and Architecture, Wuhan University of Technology, Wuhan 430070, Hubei, China;〖JP〗2. China Railway Bridge Science Research Institute Ltd., Wuhan 430034, Hubei, China)
- Keywords:
- bridge engineering; fire resistance; finite element method; prestressed continuous steelconcrete composite beam; parameter analysis
- PACS:
- -
- DOI:
- -
- Abstract:
- To study the fire resistance of prestressed continuous composite beams (PCCBs) under fire, a finite element model for simulating the nonlinear performance of PCCBs during fire exposure was investigated by numerical simulation using the ABAQUS software. The Fire resistance effects of the load ratio, prestress ratio, ratio of crosssectional area of the external tendons, and ratio of span to height on the deflection of the beams were studied, by analyzing deflection at midspan and the tension in the external tendons and the moment with temperature at the midspan and middle support of the PCCBs. The results show that the load ratio has a negative impact on the fire resistance of the PCCBs. The greater is the load ratio, the slower the tension in the external tendons decreases with increasing temperature, the lower is the critical temperature, and the smaller is the deflection at the critical state of PCCBs. The effect of the prestress ratio on the composite beam is mainly in the initial stages of the fire exposure. At the early stage, the larger is the prestress ratio, the slower is the rate at which the deflection increases. The deflection temperature curves under different prestress ratios tend to coincide at the critical stage. For PCCBs with different ratios of crosssectional areas of the external tendons, the moment at the midspan of PCCBs gradually decreases with an elevated temperature. After reaching the minimum at 150 ℃, the moment increases with the increase of temperature. Relatively, the moments at middle support increase with an elevated temperature at the initial stage. After reaching the maximum value, they gradually decrease with increasing temperature. In the critical state, the moment of middle support of the PCCBs is very small. Critical temperatures for PCCBs with different span and high ratio have a small difference in critical temperature when the load ratio is the same, and their deflection values are very close. When the span high ratios are greater than 10, the effect on performance of PCCBs can be ignored.
Last Update: 2018-12-18