重复荷载作用下无粘结部分预应力高强混凝土梁变形及延性试验研究  

Experimental research on deformation and ductility of unbonded partially prestressed high-strength concrete (PPC) beams under repeat loading

作　　者：宋永发[1] 宋玉普[1] 许劲松[1] 

机构地区：[1]大连理工大学海岸和近海工程国家重点实验室,辽宁大连116023

出　　处：《中国公路学报》2001年第3期44-50,共7页China Journal of Highway and Transport

基　　金：海岸和近海工程国家重点实验室基金项目 ( LP910 4)

摘　　要：通过 1 5根单调荷载和 1 1根低周重复荷载作用下的无粘结部分预应力高强混凝土梁的试验 ,研究了影响无粘结梁变形及延性的主要因素 :预应力筋配筋率、非预应力筋配筋率、跨高比、荷载作用方式。将预应力筋和非预应力筋对无粘结梁跨中最大挠度的影响 ,用无粘结配筋指标和综合配筋指标之比 η和换算配筋率 αpρ这两个参数来反映 ,并且采用与国内有关规范相一致的直接双直线法 ,在单调荷载作用下无粘结部分预应力高强混凝土梁变形计算基础上 ,建立了任意荷载作用下的无粘结部分预应力高强混凝土梁变形计算公式。试验结果表明 ,随着受拉区非预应力筋配筋率和预应力筋配筋率的增大 ,梁的延性逐渐减小 ;随着受压区非预应力筋配筋率的增大 ,梁的延性逐渐增大 ;荷载作用方式对梁的延性有一定影响 ;跨高比对延性的影响有待进一步研究。依据试验结果建立了位移延性比与综合配筋指标的关系式 ,计算结果与试验结果吻合较好。Based on the experimental results of 26 unbonded partially prestressed high strength concrete beams under monotonic and low cycle loading respectively,the main factors which influence the deformation and ductility of unbonded beams are studied.They are prestressed reinforcement ratio,nonprestressed reinforcement ratio,the ratio of the span to depth and the types of loading.The maximum effect deflection upon prestressed and nonprestressed reinforcement in the mid span of unbonded beams are reflected with the ratio of unbonded reinforcement index to composite method in accordance with the present codes.The deformation formula of unbonded PPC beams with high strength concrete under arbitrary loading is obtained based on that under monotonic loading.The test result shows that the ductility decreases gradually,with the growth of non prestressed and prestressed reinforcement ratio in the strained zone,and the ductility enlarges,with non prestressed reinforcement ratio increasing in the compression zone.The loading types have certain effect on the ductility also;and the influence of the ratio of span to depth on the ductility expects further study.Based on the test result,the related formula on parameter of deflection ductility and integrated reinforcement index is established.The calculating results agree well with experimental results.

关 键 词：高强混凝土梁 刚度 挠度 延性 重复荷载 无粘结预应力混凝土结构 

分 类 号：TU378.2[建筑科学—结构工程]