复杂状态下桥用高强混凝土收缩徐变性能试验

针对大量大跨度预应力混凝土桥梁长期变形难以准确预测的现状,分析了多种高强混凝土收缩徐变预测模型分别在实验室和实际桥梁工程条件下的适用性,指出了现有预测模型并没有考虑大跨度预应力桥梁桥用混凝土早期受循环荷载作用等特点.制作了7组不同应力比、不同荷载循环周期的试件,对混凝土的收缩徐变性能进行了测试与分析.研究结果表明,高强...

Creep and shrinkage of high strength concrete for bridges under complex condition

Given that the long time distortion of most big span prestressed concrete bridges could not be predicted accurately, the applicability of several creep prediction models of high strength concrete in the respective conditions of laboratory and real bridge engineering was studied, and the specialties of the existing prediction models such as excluding the effect of repeated load affected on the concrete at early age for big span prestressed concrete bridges were illuminated. Then 7 groups of concrete specimens for different stress ratios and different loading periods were made, and their creep performances tested and analyzed. The research shows that the repeated load affected on high strength concrete at early age will aggravate its creep remarkably, and the creep value is influenced by stress ratio,loading periods, and etc.