高性能复合砂浆钢筋网加固高温作用后RC梁二次受力刚度研究

发布时间：2018-04-09 23:36

本文选题：钢筋混凝土梁　切入点：复合砂浆钢筋网　出处：《建筑结构学报》2016年03期

【摘要】：选取适当的混凝土和钢筋的热工参数及其高温后的力学性能,采用有限元分析软件ANSYS对标准升温条件下RC梁的截面温度场分布进行瞬态热分析,利用高度不变、宽度折减的方式得到受火后的等效截面,并在规范给出的短期刚度计算公式的基础上进行了修正。采用刚度解析法推导了高性能复合砂浆钢筋网加固高温作用后RC梁的刚度计算式,计算时考虑了加固时因未完全卸载和重力引起的应力-应变滞后现象,最后结合现场试验来验证所推导计算式的合理性。试验结果表明,高性能复合砂浆钢筋网可以有效提高构件的抗弯刚度。通过挠度理论计算值与试验值的对比可知,理论值均大于现场试验值,且相差在10%以内,高性能复合砂浆钢筋网加固高温作用后RC梁短期刚度的计算式在实际工程应用中偏于安全。
[Abstract]:Selecting appropriate thermal parameters of concrete and steel bar and their mechanical properties after high temperature, the temperature field distribution of RC beam under standard heating condition is analyzed by using finite element analysis software ANSYS, and the height of RC beam is not changed.The equivalent section after fire is obtained by the width reduction method, and modified on the basis of the calculation formula of short-term stiffness given in the code.The stiffness calculation formula of RC beam strengthened by high performance composite mortar mesh at high temperature is derived by means of stiffness analysis method. The stress-strain hysteresis caused by incomplete unloading and gravity is taken into account in the calculation.Finally, the rationality of the deduced formula is verified by field test.The experimental results show that high performance composite mortar steel mesh can effectively improve the flexural stiffness of members.By comparing the calculated values of deflection theory with the experimental values, it can be seen that the theoretical values are all larger than the field test values, and the difference is less than 10%.The calculation formula of the short-term stiffness of RC beam strengthened by high performance composite mortar reinforcement mesh at high temperature is relatively safe in practical engineering application.
【作者单位】：湖南大学土木工程学院;
【基金】：国家自然科学基金青年基金项目(51108173)
【分类号】：TU375.1

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