FRP布加固钢筋混凝土梁挠度计算

Calculation Method of Deflection for RC Beams Strengthened by FRP Sheets

鉴于可能较低的弹性模量和2次加载等因素产生的不利影响,对纤维增强聚合物(FRP)布材料加固混凝土梁的抗弯变形能力进行了研究,结合美国混凝土规范和FRP筋混凝土设计和施工指南中建议的关于钢筋混凝土和FRP混凝土梁的挠度计算方法,提出了FRP布粘贴于钢筋混凝土底部梁的挠度计算公式。该公式经与多种形式的梁的抗弯试验结果进行了比较验证,大多符合较好,能够用于受弯构件在开裂后至屈服前的正常使用范围内,短期荷载作用条件下的挠度计算。

Considering lower elastic modular of FRP sheets and effects of the secondary loading, it is necessary to investigate the flexural properties of RC beams strengthened by FRP sheets. In this paper, based on calculating methods of deflections of reinforced steel bars and FRP bars concrete beams which are from ACI318 and ACI440 respectively, a new method dealing with computing deflections of RC beams strengthened by FRP sheets is put forward. Comparing with existing experimental beams, it shows that calculation results by the method are in good agreement with those experimental ones. The method can be applied to the computation of deflections for beams subjected by short-term load during the period from theirs cracking to yielding.