超载下预应力CFRP布加固腐蚀钢梁抗弯性能试验

Flexural Behavior of Corroded Steel Beams Strengthened with Prestressed CFRP Sheets Under Overloading

为研究预应力CFRP布加固腐蚀钢梁静载、超载的抗弯性能,进行了7根钢梁的抗弯试验,研究了加固梁在静载及超载下的破坏形态、承载力和刚度.结果表明,加固钢梁可以提高钢梁的承载力与刚度,预应力的存在,可以显著提高CFRP布的利用率;腐蚀程度影响钢梁的刚度与极限承载力,腐蚀程度增加1倍,钢梁的承载力降低50%左右.超载次数增加,钢材发生时效硬化,钢梁刚度可提高13%左右,但承载力有所降低;超载下,预应力的施加可提高钢梁的延性.建立了预应力CFRP布加固腐蚀钢梁的承载力计算公式,理论计算结果与试验结果吻合良好.

In order to investigate the flexural behavior of corroded steel beams strengthened with prestressed CFRP sheets under static loading or overloading,the bending tests of seven steel beams were carried out to study the failure mode,bearing capacity and stiffness of the corroded steel beams.The results showed that the CFRP sheets could improve the stiffness and bearing capacity,and adding prestress to the steel beam could remarkably improve the use of CFRP sheets.The corrosion could influence both the stiffness and bearing capacity.The bearing capacity decreased by about 50%when the corrosion degree increased by 1 times.The improvement of the overloading numbers can improve the stiffness by 13%because of the steel’s age hardening,but the bearing capacity can reduce.And the prestress can improve the ductility of the steel beam.The formula of ultimate bearing capacity was established,and the calculated results agreed well with the experimental results.