尤作凯1,赵东拂2

(1 中铁建工集团东非有限公司， 北京 100160； 2 北京建筑大学， 北京 100044)

［摘要］在利用扫描电镜检测、XRD射线衍射以及超声波检测等微观手段获得钢筋混凝土简支梁截面温度场分布的前提下，通过高温后钢筋的弹性模量与常温下钢筋的弹性模量的比值计算钢筋的弹性模量折减系数。根据梁截面温度场分布确定钢筋混凝土简支梁截面折减系数。依据平截面假定，建立高温后钢筋混凝土受弯构件短期刚度计算模型。通过与试验所得数据的比较，结果吻合较好，说明了该计算方法的有效性，从而为高温后混凝土简支梁的结构安全评估以及修复加固提供了必要的理论依据。

［关键词］混凝土； 高温； 刚度； 计算模型

中图分类号： TU318，TU375    文献标识码： A    文章编号： 1002-848X(2015)S2-0390-03

Investigation on the calculation of stiffen of simply supported reinforced

concrete beams after high temperature

You Zuokai1, Zhao Dongfu2

(1 China Railway Construction Group, Beijing 100160, China;

2 Beijing University of Civil Engineering and Architecture, Beijing 100044, China )

Abstract: The premise is that the temperature field distribution of reinforced concrete beams is acquired by microstructure method, such as scanning electron microscope, X ray diffraction and ultrasonic test result. The reduction coefficient of elastic modulus of steel bar was calculated by the ratio of elastic modulus of steel bar after high temperature and elastic modulus of steel bar in ordinary temperature. Section reduction coefficient of reinforced simple-supported concrete beams was confirmed by the temperature field distribution of beams. In accordance with the plane-section assumption, calculation model of short-term stiffness for reinforced concrete beam was established. The comparison of calculation results and experimental results was good agreement, which illustrates the calculation method was effective, and what was more, this calculation model can supply necessary theory support to the structural safety assessment and reinforcement of reinforced concrete simple-supported beams.

Keywords: concrete; high temperature; stiffness; model of calculation

作者简介:尤作凯,硕士,助理工程师,Email:yzk0816@163.com。