CFL增强RC梁挠度分析

碳纤维薄板(CFL)加固RC梁技术已成功地应用于桥梁工程.该方法的关键科学问题之一是疲劳荷载下增强梁的变形规律.结合一系列疲劳试验,给出了挠度的发展规律,提出界面疲劳裂缝扩展寿命的预测方法.分析结果表明:构件挠度扩展主要分为三个阶段:快速增加、稳定扩展、失稳扩展,其中第二阶段是构件疲劳寿命的主要阶段,在此阶段挠度缓慢增加,增加量与加载次数成线性关系.采用理论与实验相结合的方法给出了疲劳荷载下挠度的计算公式和疲劳寿命的预测公式,可以较好地符合试验结果.

Analysis of Deflection of RC Beams Strengthened with CFL under Cyclic Bending Loads

The technique of strengthening reinforced concrete beams with carbon fiber laminates(CFL)has been widely used in bridge repairing engineering.One of the key questions of this technique is to analyses the deformation rule of strengthened beams under cyclic bending loads.Based on a series of fatigue tests,the developing rule of deflection is analyzed.The analysis results as following:the deflection of strengthened members is mainly divided into 3 stages:rapid increase,stable expansion and uncontrollable propagation.The stable expansion stage is the main phase of fatigue life,with deflection slightly linearly increasing through fatigue cycles.The deflection of the RC beams strengthened with CFL under cyclic bending loads is predicted well by using the experiential formulas proposed.