新、老混凝土粘结抗剪强度试验

依托高速公路桥梁加固工程，以切槽深度、粘结面倾角、振动频率及植筋为参数，对102个新、老混凝土粘结试件进行了抗剪试验。试验结果表明：当倾角相同时，切槽深度对粘结面抗剪强度的影响较小；随着倾角增大，口粘结面的抗剪强度不断增大；当倾角超过30°时，试件不从粘结面破坏，此时粘结面不再是最薄弱部位。当频率低于9Hz时，振动能提高粘结面的抗剪强度；当频率大于9Hz时。振动会削弱粘结面的抗剪强度。植筋可提高粘结面的抗剪强度，且提高值与植筋率呈线性关系；当植筋方向垂直于粘结面时，能获得最好的粘结效果；在一定范围内，随着植筋深度的增加，粘结面的抗剪强度逐渐增大。

Study on shear strength of new and old concrete bonding interface

Based on highway bridge strengthening engineering, shear experiments were conducted on 102 specimens to explore the effect of different parameters on the shear strength of new and old concrete bonding interface.Grooving depth, dip angle, vibration frequency and bonded bar were considered.Experimental results show that the effect of grooving depth on the shear strength of the bonding interface is indistinctive while the bond strength varies dramatically with different dip angles of the bonding interface. When the dip angle exceeds 30 degree,specimens isn＇t broken from the bonding inter- face.The vibration can improve the shear strength of the bonding interface when frequency is less than 9 Hz,otherwise vibration will make its shear property weakened. Be- sides, planting steel bars can improve the shear strength of the bonding interface noticea- bly and the value improved changes linearly with the planting steel ratio, specimens can get greater shear strength when the direction of planting steel bar is vertical to the bonding interface compared with other directions. In a certain range, by increasing the anchorage depth, the shear strength of the bonding interface can be improved.