改性活性粉末混凝土面层加固砌体墙抗震性能试验研究

EXPERIMENTAL RESEARCH ON SEISMIC BEHAVIOR OF MASONRY WALL REINFORCED BY MRPC SURFACE LAYER

改性活性粉末混凝土(MRPC)具有强度高、延性好、黏结性强、抹面可塑性好等特点,在砌体墙的加固工程中具有广泛的应用价值。通过对6片砌体墙(其中2片未加固墙体,4片墙体采用MRPC材料双面加固)的低周反复荷载试验,并对加固后试件的破坏形态、耗能能力、骨架曲线、延性特征分别与未加固墙体进行对比分析。结果表明:1)加固后的未受损墙体可大幅度提高抗震承载力,加固后的受损墙体不仅能恢复原有承载力,还有一定程度的提高;2)MRPC面层加固后墙体的整体性明显提高,改变了砖墙的脆性破坏模式;3)MRPC面层的脱开过程和面层与墙体的摩擦过程显著提高了墙体的抗震耗能能力;4)加固后墙体在达到极限承载力后会有一个承载力“稳定期”,在此阶段承载力基本保持不变,变形可稳定增加,表现出较好的塑性特征。

Modified Reactive Powder Concret (MRPC) has high strength,good ductility,strong adhesive plaster, good operability and other characteristics,which will be widely used in the reinforcement of masonry wall. 6 masonry walls were tested under quasi - static loading,including 2 unreinforced walls,4 walls reinforced with MRPC materials. The failure mechanism,failure mode,energy dissipation capacity,skeleton characteristics and ductility characteristics of the specimens were compared and analyzed. The results showed that: 1) the reinforced undamaged wall could greatly improve the seismic bearing capacity. The reinforced damaged wall could not only restore the original bearing capacity,but also improve it to a certain extent;2) the integrity of the wall reinforced by the MRPC surface layer was obviously improved,and the brittle failure mode of the brick wall was changed;3) the separation process of the MRPC surface layer and the friction process between the surface layer and the wall significantly improved the seismic energy dissipation capacity of the wall;4) after strengthening the wall,there would be a“stable period”of bearing capacity after reaching the ultimate bearing capacity. At this stage,the bearing capacity remained basically unchanged,and the deformation could increase steadily,showing an ideal plastic property.