无粘结预应力筋涂层粘滞系数的试验测定

Testing measurement of viscous coeffcient of coating on the unbonded prestressing tendon

通过一个刚架的自由振动试验 ,记录了与工程实际较接近的两种振动频率下 ,在不同的侧向压力下无粘结预应力筋在涂层材料中的振动时程曲线。通过对时程曲线进行系统识别 ,确定了无粘结预应力筋涂层材料的粘滞系数 ,分析了粘滞系数与侧向压力等级的关系。试验表明 :振动频率对粘滞系数有较大的影响 ,并且随着侧向压力的增加 ,粘滞系数呈现增大的趋势 ,粘滞系数与侧向压力间的关系曲线大致可以分为四个阶段 :缓慢增大区段、急剧增大区段、再缓慢增大区段、再急剧增加区段。

By a free vibration test of a rigid frame, vibration curve with time history of the unbonded prestressing tendon in the coating is recorded under different lateral pressure and two different frequencies which are similar to site construction. The viscous coefficient of tendon coating is determined by systematic discrimination of the test data. The relation between viscous coefficient and lateral pressure is analyzed. The test shows that the viscous coefficient is effected obviously by the vibrating frequency and increases with the increasing of lateral pressure. The relation curve between viscous coefficient and lateral pressure may be divided into four stages: slowly increasing stage, rapidly increasing stage, the second slowly increasing stage and the second rapidly increasing stage.