UHPC加固混凝土梁的抗弯承载力计算  

Calculation of flexural capacity of reinforced concrete beams with UHPC

作　　者：李雪峰 孟帅[2] 杜晓庆 Li Xue-feng;Meng Shuai;Du Xiao-qing(Shanghai Urban Construction Design&Research InstituteCo.Ltd,Shanghai 200125,China;School of Mechanics and Engineering Science,Shanghai University,Shanghai 200444,China)

机构地区：[1]上海市城市建设设计研究总院(集团)有限公司,上海200125 [2]上海大学力学与工程科学学院,上海200444

出　　处：《工程抗震与加固改造》2022年第2期151-157,171,共8页Earthquake Resistant Engineering and Retrofitting

基　　金：2017年度上海市自然科学基金项目(17ZR1421000);上海市建筑建材业科研项目计划(住建管2021-001-009)。

摘　　要：以团体标准《超高性能混凝土加固桥梁技术指南》的编制为依托,将使用超高性能混凝土(UHPC)加固既有混凝土结构,探究加固后组合截面的抗弯承载力计算方法以及超高性能混凝土的加固效率。拟采用在混凝土梁受拉区增设配筋超高性能混凝土层的加固方式以提高混凝土梁的抗弯承载力,并提出了加固后组合截面的抗弯承载力计算方法及基本假定。将试验参数引入计算公式,计算结果表明试验值均大于理论值,且计算值平均为试验值的0.86倍,表明所提出的计算公式可以较好地预测在矩形截面混凝土梁受拉区增设配筋超高性能混凝土层的抗弯承载力。试验表明加固后截面抗弯承载力较原混凝土梁提高了近1倍,使用超高性能混凝土加固混凝土梁能够有效提高混凝土梁的抗弯承载能力。加固实例中,采用在受拉区增设配筋超高性能混凝土层的加固方式,组合截面的理论抗弯承载力提高了128.17%,理论加固效率非常高。验证了超高性能混凝土可以作为一种加固材料,研究成果可为超高性能混凝土加固其他截面形式的混凝土梁在计算抗弯承载力时提供参考。Relying on the compilation of the group standard " Technical Specification for Strengthening Bridge with Ultra-High Performance Concrete", the method of calculating the flexural capacity of the reinforced composite section and the efficiency of the reinforced UHPC are studied by strengthening the existing concrete structure with UHPC. The reinforcement method is proposed by adding a reinforced UHPC layer in the tension zone of the concrete beam to improve the flexural capacity of concrete beams. The method of calculating the flexural capacity of the reinforced composite section and the basic assumption are proposed. By introducing the test parameters into the calculation formula, the results show that the test values are all larger than the theoretical values, the average calculated values are 0.86 times of the experimental values, indicating that the proposed formula can better predict the flexural capacity of the reinforced UHPC layer in the tensile zone of the rectangular section concrete beam. The test results show that the flexural capacity of the reinforced section is nearly one time higher than that of the original concrete beam, and the flexural capacity of the reinforced concrete beam can be effectively improved by using UHPC. In the reinforcement example, the theoretical flexural capacity of the composite section is increased by 128.17% by adding a UHPC layer with reinforcement in the tensile zone. The theoretical reinforcement efficiency is very high. It verifies that UHPC can be used as a reinforcement material, and the research results can provide a reference for calculating the flexural capacity of other concrete beams strengthened by UHPC.

关 键 词：桥梁加固 抗弯承载力 理论分析 超高性能混凝土 组合截面 

分 类 号：U445.72[建筑科学—桥梁与隧道工程]