冻融环境钢筋混凝土梁抗弯承载力研究

发布时间：2018-04-04 12:30

本文选题：气冻气融　切入点：损伤变量　出处：《铁道学报》2017年11期

【摘要】：为更好地研究冻融环境下混凝土结构承载性能退化规律,采用与大气环境冻融作用方式相同的气冻气融试验方法,对足尺150mm×300mm×2 700mm钢筋混凝土梁冻融后的承载性能进行系统研究,建立冻融后整体承载力计算模型及考虑损伤层的分层承载力计算模型。研究结果表明:气冻气融作用后试验梁正截面应变仍符合平截面假定;其正截面抗弯承载力随着冻融次数的增加而降低,且下降速度随冻融次数的增大而增大;梁的跨中挠度随冻融次数的增加逐渐降低,且两者之间呈明显的线性响应关系;与试验结果及规范计算模型对比,整体承载力计算模型及分层承载力计算模型均具有合理的适用性,且分层计算模型更能充分发挥截面在不同状态下的承载能力。基于承载力计算模型对某实际工程中的混凝土结构进行冻融环境下耐久性寿命预测,并与其他预测方法进行比较,表明计算模型的工程适用性。
[Abstract]:In order to better study the degradation law of bearing capacity of concrete structure under freeze-thaw environment, the load-bearing performance of full-scale 150mm 脳 300mm 脳 2 700mm reinforced concrete beams after freezing and thawing was studied systematically by adopting the same air-freezing and gas-thawing test method as that of atmospheric freezing and thawing.The calculation model of whole bearing capacity after freezing and thawing and the calculation model of delamination bearing capacity considering damage layer are established.The results show that the normal cross section strain of the test beam still accords with the assumption of plane section after the action of air freezing and air thawing, and the flexural capacity of the normal section decreases with the increase of freezing and thawing times, and the decreasing speed increases with the increase of freezing and thawing times.The mid-span deflection of the beam decreases gradually with the increase of freeze-thaw times, and there is an obvious linear response relationship between the two, which is compared with the test results and the calculation model.Both the overall bearing capacity calculation model and the layered bearing capacity calculation model have reasonable applicability, and the layered calculation model can give full play to the bearing capacity of the section under different conditions.Based on the calculation model of bearing capacity, the durability life of concrete structure in freeze-thaw environment is predicted and compared with other prediction methods, which shows the applicability of the model.
【作者单位】：西安科技大学建筑与土木工程学院;西安建筑科技大学土木工程学院;
【基金】：国家自然科学基金(51278403) 教育部创新团队发展计划(IRT13089)
【分类号】：TU375.1

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