焊接短筋连接的加固组合梁试验研究

EXPERIMENTAL STUDY ON THE STRENGTHENED COMPOSITE BEAM JOINTED WITH WELDED SHORT REBAR

参照成熟的加大截面加固施工工艺,连接件选用焊接短筋,制作了2根下托槽钢加固组合梁,1根未加固钢筋混凝土梁对比梁进行试验研究和计算分析。试验采用实验室室内模型短期静载试验,主要观测了采用焊接短筋连接的下托型钢加固组合梁的极限承载力、抗弯刚度、裂缝情况、跨中截面荷载-应变分布情况等。从试验结果可以看出:下托型钢与原钢筋混凝土梁协同工作的性能良好;焊接短筋连接的下托型钢加固组合梁极限承载力和抗弯刚度大幅提高,裂缝开展也得到有效控制。

According to the technics of structure member strengthened with R. C, it is designed that two pieces of composite beams by shaped-steel underpinning （CBSSU） jointed with welded short reinforcing steel bars and one R. C beam in order to contrast their experimentation and analysis. The short period loading test by indoor model is used, and it is observed that several parameters of these beam behaviors, such as limit load-bearing capacity, bending stiffness, flaw condition and stress-strain in the middle section of the beam. On the basis of the experimental study, it can be found that the shaped-steel works in coordination with the R. C beam very well. The CBSSU jointed by welded short reinforcing steel bar gains better bending stiffness, higher limit load-beating capacity and flaw of the beam can be controlled effectively.