普通钢筋锈蚀后预应力混凝土桥梁疲劳试验研究

发布时间：2018-04-24 09:15

本文选题：桥梁工程 + 预应力混凝土梁　；参考：《公路交通科技》2014年04期

【摘要】：借助传统应变片和891拾振器的疲劳试验实时测试系统,通过9片1/6缩尺模型梁疲劳试验,研究了普通钢筋锈蚀后预应力混凝土桥梁疲劳破坏形态以及振幅、刚度、非预应力筋和预应力筋应变、混凝土应变随重复荷载次数的变化规律。研究表明:梁底普通钢筋锈蚀后(预应力筋不锈蚀),只要钢筋没有发生锈蚀断裂破坏,混合配筋合适的预应力混凝土梁的静载承载力与普通没有锈蚀梁的承载力相差不大。锈蚀率超过一定界限后(20%),钢筋在坑蚀处断裂,梁的静载承载力会急剧降低,表现为少筋梁的脆性破坏特征。疲劳反复荷载作用下构件的中性轴位置基本保持不变,不像非锈蚀试件那样呈现出明显的3阶段变化过程;锈蚀率超过7%以后,容许疲劳疲劳寿命会急剧减少,达40%左右。
[Abstract]:With the help of the traditional strain gauge and 891 vibration pick-up system, the fatigue failure pattern, amplitude and stiffness of prestressed concrete bridge after corrosion of common steel bar were studied by 9 1 / 6 scale model beam fatigue tests. The variation of strain and concrete strain of non-prestressed tendons and prestressed tendons with repeated loads. The results show that the static load bearing capacity of the prestressed concrete beams with suitable mixed reinforcement is similar to that of the normal non-corroded beams after the corrosion of the common steel bars at the bottom of the beam (the prestressed bars are not corroded), as long as the steel bars do not occur rusting fracture damage. If the corrosion rate exceeds a certain limit and the steel bar breaks in the pit, the static load bearing capacity of the beam will decrease sharply, which is characterized by the brittle failure of the beam with less reinforcement. The neutral axis position of the member under fatigue repeated load basically remains unchanged, which does not show the obvious three-stage change process as the non-rust specimen does, and the allowable fatigue life decreases sharply, about 40%, when the corrosion rate exceeds 7%.
【作者单位】：中南大学土木工程学院;高速铁路建造技术国家工程实验室;
【基金】：国家高技术研究发展计划(八六三计划)资助项目(2009AA11Z101)
【分类号】：U446;U441.4

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