钢板-混凝土组合加固钢筋混凝土简支梁试验研究

钢板-混凝土组合加固钢筋混凝土梁技术,是建立在钢板-混凝土组合梁基础上的一种加固方法。为了研究其受弯性能,对1根钢筋混凝土对比梁和10根钢板-混凝土组合加固简支梁进行了试验研究。加固试件包括直接加固、损伤后加固及持载加固试件。量测分析了试件的荷载、挠度、应变、裂缝宽度及其发展等。试件的破坏形态包括弯曲破坏和新老混凝土剥离破坏。试验表明,组合加固可以大大提高钢筋混凝土梁的承载力和刚度,试件具有良好的延性。采用弹性方法和塑性方法分析了试件的开裂荷载和极限受弯承载力,计算结果与试验吻合良好;用现有规范方法对试件刚度进行估算存在一定误差。

Experimental study on simply supported RC beams strengthened by steel plate-concrete composite technique

Steel plate-concrete composite (SPCC) technique can be applied to the strengthening of reinforced concrete beams. This technique was developed based on the research of SPCC beams. In order to study the structural behavior of RC beams strengthened by SPCC technique, one as-built RC beam model and ten RC beams strengthened by SPCC technique were tested. Three of the beams were strengthened directly; four beams were first loaded and then unloaded, and strengthened in the unloaded state; the other three were loaded and strengthened under load. The load, deflection, strains and crack widths were measured and analyzed. There were two failure modes of the specimens, flexural failure and debonding failure between the interface of new and existing concretes. The beams failed in flexural failure mode demonstrated highly improved load carrying capacity, stiffness and good ductility. The first crack load and ultimate bending capacity can be calculated by elastic and plastic method. However, the existing method for calculating deflection prescribed in codes could not accurately predict the deflection of the strengthened beams.