反拱法加固混凝土受弯构件理论及试验研究

对采用反向起拱粘贴碳纤维布加固混凝土梁构件的基本原理和设计方法进行了初步研究,提出了基于预应力原理的反拱法碳纤维布材加固梁构件的施工工艺。在此基础上,进行了3根试件的试验。通过试验结果对比了不同加固工艺的受弯构件的开裂荷载、极限荷载、抗弯刚度等工作性能,分析了反拱加固的预应力效应。试验发现,反拱加固试件的开裂荷载较普通粘贴加固试件的开裂荷载提高了36.2%,屈服条件下的变形减小了24.2%。试验结果表明,采用反拱加固可方便有效地卸除加固构件的残余应力,并产生预应力效应,可充分发挥碳纤维布材料高强度的特性,提高构件刚度和承载能力。

Study of strengthened reinforced concrete beams with additional reversed deflection

The mechanism of using carbon fiber reinforced plastics(CFRP) sheet to strengthen reinforced concrete beams with additional reversed deflection operation was proposed.Three specimens were tested to investigate the working performance of these beams.The strengthening effects,such as cracking load,ultimate load and flexural stiffness between non-strengthened beams and strengthened beams with either reversed deflection method or traditional method were compared.The effect of pre-stressing caused by reversed deflection was verified through theoretical derivation and experimental results.Compared with the beam strengthened with traditional method,strengthened beam with reversed deflection can enhance the crack load by 36.2%,and the deformation of the beam under yield load can decrease by 24.2%,which means strengthened beam with reversed deflection can unload the residual stress of the beam effectively and cause pre-stress effects,which will utilize more tensile strength of the CFRP and largely improve the performance of the beams.