锚贴钢板加固锈蚀钢筋混凝土梁试验研究
Experimental analysis of strengthening effect of corroded reinforced concrete beams strengthened with bolted steel plates

为了研究锈蚀钢筋混凝土梁采用钢板锚贴加固后的力学性能，设计了12根钢筋混凝土梁，以设计锈蚀率为10%进行电化学快速锈蚀。在锚贴钢板加固前进行预压试验，裂缝宽度控制为0.2 mm。按保护层厚度分为3组，每组1根对比梁，其余3根分别按钢板厚度3、4、5 mm进行锚贴钢板加固。加载对比试验研究表明：锚贴钢板加固锈蚀钢筋混凝土梁的跨中截面应变基本符合平截面假定，正常使用性能得到明显改善，且极限承载力亦有明显提高。锚贴钢板有效地减小了锈蚀钢筋混凝土梁的裂缝宽度和裂缝延伸高度，在相同保护层和锈蚀率相近时，钢板厚度增加3~5 mm导致其挠度减小，且减小幅度为13%~51%。保护层厚度对加固梁的极限承载力影响不明显。
In order to study the mechanical behavior of corroded reinforced concrete beams strengthened with bolted steel plates, this paper designed 12 reinforced concrete beams. These beams were corroded by using accelerated electrochemical corrosion method with a designed corrosion ratio of 10%. The pre-compression experiments were performed for all RC beams before strengthening and the maximum crack width was controlled as 0.2 mm. According to the thickness of concrete cover, the beams were divided into 3 groups. Each group was composed of one comparative beam and three tested beams strengthened by steel plates bolted with study according to the thickness of steel plates which were 3 mm, 4 mm and 5 mm, respectively. It was shown that the strain distributions along the height of the strengthened beams at middle-span were in good agreement with the plain section assumption basically. The serviceability performances of corroded RC beams were significantly improved and these ultimate bearing capacities increased obviously. The steel plate bolted with stud effectively reduced the crack width and the extension height of reinforced concrete beams. It was indicated that an increase of steel plates with 35 mm resulted in a decrease of deflection by 13%51% when beams had the same thickness of concrete cover and corrosion ratio. Influence of the thickness of concrete cover on the ultimate bearing capacity was not obvious.