行车荷载引起桥梁振动对新老混凝土黏结性能影响

Effect of Traffic Load Induced Bridge Vibration on Adherence of New and Old Concrete

为了确定在混凝土早龄期时受到行车荷载引起桥梁振动对新老混凝土黏结面抗拉性能的影响,采用峰值振动加速度为0.08g,0.16g,0.32g,3种振动能量,分别模拟轻、中、重3种交通状态引起的桥梁振动,对处于早龄期的新老混凝土黏结面进行振动试验。试验结果表明:振动发生在初凝前,3种形式的交通(轻、中、重)引起的振动对新老混凝土黏结面早期抗拉强度有增加作用。振动发生在初凝至终凝阶段,轻交通引起振动对新老混凝土黏结面的强度影响不明显;中等和重交通会造成黏结面早期抗拉强度(7 d以前)下降。振动发生在终凝后,轻交通引起的振动对新老混凝土黏结面的强度影响不明显;中等交通的振动会造成黏结面早期强度的下降;重载交通会造成黏结面的强度整体下降。

In order to testify the effect of traffic vibration induced bridge vibration on the tensile property of the adherence of new and old concrete during early age of concrete,a vibration test on such adherence is conducted. In the test,the vibration energy whose peak acceleration values are 0. 08 g,0. 16 g and 0. 32 g are used to simulate the bridge vibrations induced by light,middle and heavy traffic respectively. The test result shows that（ 1） when vibrations occurred before concrete initial setting,all the 3 levels of traffic induced vibration can enhance the early age bond strength of new and old concrete;（ 2） when vibrations occurred between initial setting and final setting,light traffic induced vibration has little effect on the bond strength,middle and heavy traffic induced vibrations can decrease the early age（ before 7 d） bond strength;（ 3） as to the adherence of new and old concrete when vibration occurred after concrete finial setting,light traffic induced vibration has little effect on the bond strength of new and old concrete,its early age bond strength descends under middle traffic induced vibration,and its bond strength drops largely with heavy traffic induced vibration.