新老混凝土结合面抗剪性能试验研究

对6组共18个Z型抗剪试件的新老混凝土结合面进行了全过程抗剪试验，考察了新老混凝土结合面不同处理方法对其抗剪性能的影响．试验结果表明：结合面的不同处理方法对其抗剪性能影响较大，涂刷水泥净浆的效果远好于直接浇筑新混凝土和涂刷商品界面剂，植入抗剪钢筋能显著提高结合面抗剪性能．根据研究结果建议，在实际加固工程中，抗剪钢筋植入深度最好大于钢筋直径的10倍．

Experimental Research on Shear Properties of New-to-Old Concrete Interface

Shear experiments were conducted on 18 Z-shape specimens from 6 different groups to investigate the shear properties of the interface of new and old concrete. The effects of different interfacial techniques, i. e. , smearing cement paste, directly casting new concrete, and smearing commercial interfacial agents, on the shear properties were investigated. The experimental results show that the interfacial techniques have a great effect on the shear properties of a new-to-old concrete interface. The shear strength of specimens is greatest when the technique of smearing cement paste is used in the three interfacial techniques. Furthermore, reinforcing steel bar planting can improve the shear properties of the interface remarkably. The experiments show that the depth of reinforcing steel bar planting should be greater than ten times the diameter of a reinforcing steel bar in the repair and strengthening of structures.