全预制拼接槽形UHPC梁抗弯抗剪性能试验研究  

Experimental Study on Flexural and Shear Behavior of Full Precast Splicing Channel-shaped UHPC Beams

作　　者：周云[1,2] 聂晶鑫 张保证 胡锦楠 朱正荣[1] ZHOU Yun;NIE Jingxin;ZHANG Baozheng;HU Jinnan;ZHU Zhengrong(College of Civil Engineering,Hunan University,Changsha 410082,China;Hunan Provincial Key Laboratory of Damage Diagnosis for Engineering Structures(Hunan University),Changsha 410082,China)

机构地区：[1]湖南大学土木工程学院,湖南长沙410082 [2]工程结构损伤诊断湖南省重点实验室(湖南大学),湖南长沙410082

出　　处：《湖南大学学报（自然科学版）》2023年第7期1-11,共11页Journal of Hunan University:Natural Sciences

基　　金：国家自然科学基金资助项目(51878264,52278306);湖南省重点研发计划项目(2022SK2096);湖南省交通厅科技进步与创新项目(201912)。

摘　　要：为实现UHPC结构在房屋建筑中的应用,提出了一种全预制拼接槽形UHPC梁,该梁截面呈槽形,带螺栓肋且肋上设贯通螺栓孔,梁柱可由两片槽形带肋梁正拼接和反拼接形成工字形和回字形两种梁、柱全装配式组合连接模式.为研究全预制拼接槽形UHPC梁的抗弯抗剪性能,共完成3根梁抗弯试验,分别为现浇工字形梁、回字形拼接梁、工字形拼接梁.通过抗弯试验发现,拼接梁的刚度略高于现浇梁,而反接槽形拼接梁的抗弯承载力高于现浇梁,以此证明UHPC拼接梁的抗弯性能优于UHPC现浇梁.为研究工字形拼接梁的抗剪性能,设置了不同剪跨比和箍筋间距,通过正交试验设计完成了9根反拼接槽形拼接梁的抗剪试验研究,获得开裂和破坏荷载、变形和裂缝分布规律等.通过抗剪试验发现,在箍筋间距相同时,工字形拼接梁随剪跨比由1增大为2、3,破坏模式由斜压破坏转变为剪压破坏;对于有腹筋梁,箍筋间距相同时,剪跨比越大,槽形拼接梁承载力越低,延性越大,且有腹筋梁的箍筋对主裂缝的发展具有有效的约束作用.To apply the UHPC elements in building construction,this paper proposes a fully prefabricated spliced channel-shaped section UHPC beam.The beam is designed with bolt ribs that have through bolt holes.Two ribbed channel-shaped section beams are installed through forward and reverse splicing to form two kinds of fully assembled combination connection modes of beams and columns,i.e.,I-type and box-type.To study the bending and shear resistance of the spliced UHPC beams,three beam bending experiments were conducted,including cast-in-place I-beam,box-type spliced beam,and I-type spliced beam.Through the bending test,it was found that the stiffness of the spliced beam was slightly higher than that of the cast-in-place beam,and the bending capacity of the I-type spliced beam was higher than that of the cast-in-place beam,thus proving that the bending resistance of the UHPC spliced beam was better than that of the UHPC cast-in-place beam.To study the shear resistance of the I-type spliced beams,shear tests of nine I-type spliced beams were completed by setting different shear-to-span ratios and stirrup spacing through orthogonal test design.The cracking load,failure loads,deformation,and crack distribution laws were obtained.The shear test revealed that,with the same stirrup spacing,the failure mode of the I-type spliced beam was diagonal-compression and shear-compression failure,respectively,as the shear-span ratio was increased from 1 to 2 or 3.For the beam with stirrups and the same stirrup spacing,the larger the shear-span ratio,the lower the load-carrying capacity and the better the ductility of the channel-spliced beam.Moreover,the stirrups in the beams had a restraining effect on the development of the main cracks.

关 键 词：预制拼接槽形UHPC梁 剪跨比 配箍率 抗弯承载力 抗剪承载力 

分 类 号：U448.35[建筑科学—桥梁与隧道工程]