钢筋网水泥砂浆加固旧砖墙的试验研究

Experimental study of old brick masonry wall strengthened with steel-meshed cement mortar

经过长时间使用后,砖砌体易发生由于砖风化、砂浆粉化、墙体裂缝和底层受潮等导致的砖砌体承载力下降、安全性降低,需采取合理的维修加固措施。已有研究表明,钢筋网水泥砂浆是一种砖墙抗震加固的有效方法。通过8片旧墙体的对比试验,研究钢筋网水泥砂浆加固旧砖墙受压承载力和水平承载力的效果,研究参数包括水泥砂浆层数、掏缝置换等。研究结果表明,采用双侧钢筋网水泥砂浆加固后旧砖墙的受压承载力提高121%～134%,而仅采用单侧钢筋网水泥砂浆加固旧砖墙的受压承载力没有明显改善。采用双侧钢筋网水泥砂浆加固后旧砖墙的水平承载力大幅提高,提高幅度达250%～612%,同时加固旧墙体的耗能能力明显提高。对原灰缝进行30mm深掏缝置换可对砖墙的加固效果略有提高。

Most of the historic buildings in China are masonry. After long-time usage, many of them are in degradation and need to be strengthened. Steel-meshed cement mortar is an effective means for seismic strengthening of masonry walls. A total of 8 old brick masonry walls strengthened with steel-meshed cement mortar were experimentally studied, in which five specimens were strengthened for the purpose of improving their vertical compressive strength, and the other three were strengthened in order to improve their seismic strength. Test results indicate that the vertical compressive strength of the old masonry walls strengthened with double-faced steel-meshed cement mortar has a 121% - 134% increase, whereas the old masonry walls strengthened with single-faced steel-meshed cement mortar has no obvious increase. The horizontal bearing capacity of the old masonry walls strengthened with double-faced steel-meshed cement mortar has a 250% -612% increase, and the increase in the energy dissipation capacity is also significant. Replacing the original low-strength mortar of the old masonry wall with high-strength cement mortar for a depth of 30mm would slightly increase the strengthening performance.