免拆纤维板底模钢筋桁架叠合板受弯性能试验  

Test of Flexural Performance on Rebar Truss Composite Slabs with Permanent Fiberboard Formwork

作　　者：张锡治 黄俊伟[2] 马相 张磊 陶宏斌[3] Zhang Xizhi;Huang Junwei;Ma Xiang;Zhang Lei;Tao Hongbin(Tianjin University Research Institute of Architectural Design and Urban Planning Co.,Ltd.,Tianjin 300072,China;School of Civil Engineering,Tianjin University,Tianjin 300072,China;Duowei Union Group Co.,Ltd.,Beijing 102401,China)

机构地区：[1]天津大学建筑设计规划研究总院有限公司,天津300072 [2]天津大学建筑工程学院,天津300072 [3]多维联合集团有限公司,北京102401

出　　处：《天津大学学报（自然科学与工程技术版）》2024年第9期902-911,共10页Journal of Tianjin University：Science and Technology

基　　金：国家自然科学基金资助项目(52278203);天津市科技计划资助项目(19YDLYSN00120).

摘　　要：免拆纤维板底模钢筋桁架叠合板适用于民用建筑和工业建筑,具有较好的经济性与施工便利性.为研究底模与混凝土的协同受力情况,对12块足尺纤维板底模钢筋桁架叠合板进行静力试验,分别研究桁架间距和跨度对免拆底模叠合板力学性能的影响及免拆底模对叠合板的抗裂性能和破坏模式的影响,测得了相应的荷载-挠度曲线、荷载-应变曲线、裂缝开展及分布状况、破坏形式及相应的破坏荷载等.结果表明:免拆纤维板底模钢筋桁架叠合板破坏模式均为受弯破坏,但由于纤维板的材料特性,其破坏模式与混凝土底板存在差异,水泥基纤维板开裂无明显前兆,开裂突然,表现为纤维板整体性拉断,且多为半贯通、贯通裂缝;纤维板底模与后浇混凝土的协同受力性能良好,叠合面未出现滑移现象,所采用的自攻螺丝连接方式可满足叠合面的抗剪需求;减小桁架间距会提升叠合板的极限承载力,桁架间距对屈服荷载影响较小;下弦与上弦钢筋应变均得到了充分的发展,桁架腹杆应变较为复杂,在整个受力过程均保持弹性状态,各部位应变随着纤维底板的开裂也产生一定波动;采用截面换算法,提出纤维板底模钢筋桁架叠合板底板开裂应力近似计算公式,计算结果表明纤维底板的开裂应力较混凝土底板有较大程度提升,即采用纤维底板可提升叠合板的抗裂性能.The rebar truss composite slab with permanent fiberboard formwork is suitable for civil and industrial buildings owing to its good economy and construction convenience.To study the cooperative stress between the bottom formwork and concrete,static tests were conducted on 12 full-sized rebar truss composite slabs with fiberboard formwork to study the impacts of truss spacing and span on the mechanical properties of composite slabs with permanent fiberboard formwork,as well as the impacts of permanent fiberboard formwork on the cracking resistance and failure modes of composite slabs.The load-deflection curves,load-strain curves,development and distribution of cracks,and the failure modes and corresponding failure loads were measured.Results show that the failure modes of all the rebar truss composite slabs with permanent fiberboard formwork were bending damages.However,due to the material properties of fiberboard,its failure mode was different from that of the concrete bottom plate.The cracking of cementitious fiberboard occurred suddenly without obvious precursors,and it was manifested as integral tensile failures of the fiberboard,most of which were half-through and through cracks.The cooperative stress performance of the fiberboard formwork and post-cast concrete was satisfying,the phenomenon of slipping did not occur on the laminated surface,and the self-tapping screw connection can meet the shear demand of the laminated surface.Reducing the truss spacing can improve the ultimate bearing capacity of the composite slab,and the truss spacing had less effect on the yield load.Both the bottom and top chord reinforcement strains were fully developed.The strains of truss web were more complicated,which remained elastic in the whole loading process.In addition,the strains of each part of the truss web also fluctuated with the cracking of the fiberboard.The cross-section conversion method was used to formulate an approximate calculation formula for the cracking stress of bottom plate of the rebar truss composite slab

关 键 词：免拆纤维板底模 钢筋桁架 叠合板 协同受力 受弯性能 

分 类 号：TU375.2[建筑科学—结构工程]