CFRP片材加固混凝土梁收缩徐变效应研究

按换算截面法推导了FRP片材加固混凝土梁的短期与长期挠曲变形计算公式,在此基础上编制了相应的分析计算程序,该分析方法能较准确预测开裂混凝土梁的长期挠曲变形。制作了10根钢筋混凝土梁,其中6根为普通钢筋混凝土梁,另外4根为CFRP片材加固梁,并对试件的短期与长期受力性能进行了试验观测,持续荷载作用下对试件进行了近700d的收缩徐变试验。运用本文计算方法预测了试件的长期挠曲变形,理论计算值与本文试验结果吻合较好。研究表明:碳纤维片材对混凝土梁的长期挠曲变形影响很小,但碳纤维片材能有效地控制持续荷载作用下裂缝的进一步开展。研究结果可为CFRP加固混凝土结构工程设计与理论分析提供参考。

Shrinkage and creep effect on concrete beams strengthened with CFRP laminates

Equations and relative analytical procedure were developed to predict short and long-term deflection of cracked concrete beams strengthened with FRP laminates based on transformed section method.The analytical method predicts long-term deflection of cracked concrete beams accurately.The short and long-term behavior of 10 RC beams including 6 ordinary reinforced concrete beams and 4 beams strengthened with CFRP laminates,were tested.The sustained load period was about 700 days for those long-term test beams.Predicting values are in a good agreement with experimental results.It is found that the existing of CFRP laminates is insignificant to the long-term deflection of concrete beams,though CFRP laminates can control the further development of crack effectively under sustained load.The research provides reference for engineering design and theoretical analysis of structures strengthened with CFRP Laminates.