集中荷载作用下预应力钢骨超高强混凝土梁受剪性能试验研究  

Experimental study on shear performance of prestressed steel ultra-high reinforced concrete beam under concentrated load

作　　者：贾金青[1] 姚大立[1,2] 余芳[2] 

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116024 [2]沈阳工业大学建筑工程学院,辽宁沈阳110178

出　　处：《建筑结构学报》2013年第12期112-120,共9页Journal of Building Structures

基　　金：国家自然科学基金项目(51078059);科技部'863'计划重大交通基础设施核心技术项目(2007AA11Z133)

摘　　要：为研究预应力钢骨超高强混凝土梁的受剪性能,对14个预应力钢骨超高强混凝土梁试件与7个预应力超高强混凝土梁试件进行受剪性能试验,研究剪跨比、预应力度、箍筋间距和腹板厚度等因素对预应力钢骨超高强混凝土梁受剪性能的影响。结果表明:加入钢骨后,梁试件的受剪承载力及剪切延性均有提高,并且钢骨对斜截面开裂后刚度的影响更为显著;增大腹板厚度可以提高组合梁试件的斜截面开裂荷载、受剪承载力和剪切延性,而增大箍筋间距会降低组合梁试件的受剪承载力和剪切延性。剪跨比越小,组合梁试件的斜截面开裂荷载和受剪承载力越大,剪切延性越差,预应力度对组合梁试件的斜截面开裂荷载和剪切延性均有影响,但当预力度小于0.34时,预应力度对剪切延性几乎无作用。提出预应力钢骨超高强混凝土梁的受剪承载力计算式,计算结果与试验结果符合较好,可供工程设计应用中参考。In order to investigate the shear performance of prestressed steel ultra-high reinforced concrete beams, 14 prestressed steel ultra-high reinforced concrete beams and 7 prestressed ultra-high reinforced concrete beams were tested. The influences of shear span-depth ratio, degree of prestress, space of stirrups and thickness of web on the shear performance of prestressed steel ultra-high reinforced concrete beams were investigated. Test results show that encasing structural steel into prestressed ultra-high reinforced concrete beams can improve shear capacity and shear ductility, and the influence of structural steel on post-cracking stiffness of diagonal section is more obvious. The first shea~ crack load, shear capacity and shear ductility increase with the increase of thickness of web, but increasing the spacing of stirrups decreases shear capacity and shear ductility of prestressed steel ultra-high reinforced concrete beams. A decrease in the shear span-depth ratio improves the first shear crack load and shear capacity, but it decreases shear ductility of prestressed steel ultra-high reinforced concrete beams. Degree of prestessing has an influence on the first shear crack load and shear ductility of prestressed steel ultra-high reinforced concrete beams, but it has little effect on the shear ductility for degree of prestressing of less than approximately 0. 34. A formula for calculating the shear capacity is proposed, and the research achievements will provide reference for the design calculation and engineering application.

关 键 词：预应力钢骨超高强混凝土梁 箍筋间距 剪跨比 受剪试验 剪切延性 

分 类 号：TU398.9[建筑科学—结构工程] TU317.1