锈蚀钢筋混凝土梁的抗剪承载力分析模型
2018-01-08余波陈冰刘阳
余波 陈冰 刘阳



摘 要:锈蚀钢筋混凝土梁的传统抗剪承载力模型大多属于经验模型,考虑的影响因素不全面且缺乏严密的理论推导,导致计算精度有限。基于修正压力场理论,建立了可以综合考虑钢筋锈蚀对临界斜裂缝倾角、梁有效抗剪截面积、配筋率、配箍率等关键因素影响的锈蚀钢筋混凝土梁的抗剪承载力模型,通过与85组试验数据和现有模型的对比分析,验证了模型的适用性和计算精度。结果表明,该模型具有严密的理论基础,考虑的影响因素全面,计算精度较高、离散性较小。
关键词: 钢筋混凝土梁;锈蚀;抗剪承载力;临界斜裂缝倾角;剪跨比;修正压力场理论
中图分类号:TU375.1
文献标志码:A 文章编号:1674-4764(2018)06-0131-08
Shear strength model of corroded reinforced concrete beams
Yu Bo, Chen Bing, Liu Yang
(School of Civil Engineering and Architecture; Key Laboratory of Disaster Prevention and
Structural Safety of Ministry of Education; Guangxi Key Laboratory of Disaster Prevention
and Engineering Safety, Guangxi University, Nanning 530004, P. R. China)
Abstract:The accuracy of traditional shear strength models for corroded reinforced concrete (RC)beam are far from satisfactory, since these models generally belong to the empirical methods which are lack of theoretical basis and do not take into account the various influential factors comprehensively. Hence, a shear strength model of corroded RC beam which takes into account the influences of corrosion on key factors including the critical diagonal crack angle, the effective shear cross-sectional area, the reinforcement ratio and the stirrup ratio was established based on the modified compression field theory (MCFT). The accuracy of the proposed model was validated by comparing with 85 sets of experimental data and several existing models. Analysis results show that the proposed model is of good accuracy and small discreteness.
Keywords:reinforced concrete beam; corrosion; shear strength; critical crack angle; shear span ratio; modified compression field theory
受混凝土碳化和氯鹽侵蚀等腐蚀环境作用的影响,在役钢筋混凝土(RC)结构的梁往往发生钢筋锈蚀。董卫等[1] 通过锈蚀RC梁的四点受弯加载试验,分析了钢筋锈蚀对RC梁承载机理的影响,发现锈蚀RC梁的承载机理为梁效应和拱效应的复合体,钢筋锈损率越高,梁效应向拱效应转化的程度越高;张梦光等[2] 通过外加电流加速箍筋锈蚀,开展了4根锈蚀箍筋RC梁的抗剪性能试验,发现箍筋锈蚀会降低RC梁的抗剪性能和变形能力。由于影响锈蚀RC梁抗剪性能的因素较多,导致其抗剪承载力分析较为困难。霍艳华[3] 在未锈蚀RC梁的抗剪承载力模型基础上,分别引入经验影响系数φ和γ′来考虑钢筋锈蚀对混凝土和箍筋的抗剪承载力贡献的影响,建立……
