老旧钢筋混凝土梁性能退化试验研究

Experimental study on degradation performance of old reinforced concrete beam

针对老旧混凝土结构性能退化研究时实测数据匮乏的不足,本文利用辽宁旅顺沿海地区上世纪20年代的一批老旧钢筋混凝土梁,对钢筋混凝土结构各项材料性能进行试验研究。通过钻芯取样等手段对混凝土强度、钢筋强度和钢筋混凝土粘结性能进行分析,同时对比钢筋混凝土梁的有限元建模与实际加载结果,分析粘结力不足对梁抗弯承载力的影响。结果表明,钢筋混凝土的粘结性能是影响RC构件承载力的主要因素之一,不考虑粘结力不足的梁抗弯承载力与实际加载结果相差较大。老旧钢筋混凝土结构普遍存在粘结力不足或者退化的情况,迫切需要引入考虑钢筋粘结滑移的RC结构抗震能力分析方法,本文的试验结果可为此类研究提供实测数据。

The research on the performance degradation of old reinforced concrete structure is lack of measured data. Aiming at the deficiency,this paper uses a group of old reinforced concrete beam from Liaoning Lvshun coastal area,which date from 20＇s last century,to do experimental research on the material properties of RC structure. By drilling core sampling method,we analyze the concrete strength,steel bar strength and reinforced concrete bonding performance.The finite element modeling method was used at the same time,and the results of modeling and actual loading of RC beam were contrasted. Then the influence of bond stress on the bearing capacity of beams was analyzed. The results show that the bonding performance of reinforced concrete is one of the main factors affecting the bearing capacity of RC components. Without considering the lack of bond stresses,the flexural bearing capacity differs greatly from actual loading results. With the widespread lack of bonding force in old RC structure,to introduce a new method for analysis of structural seismic capacity with bond slip is in urgent need,and the experimental results in this paper can provide experimental data for such research.