内嵌钢筋外包CFRP布复合加固中长圆形木柱轴压性能试验研究  

Experimental study on axial compression performance of circular medium-long timber columnsstrengthened with CFRP sheets and near surface-mounted steel bar

作　　者：周长东[1] 苏宝强 罗廷惜 郑玉槟 ZHOU Changdong;SU Baoqiang;LUO Tingxi;ZHENG Yubin(School of Civil Engineering,Beijing Jiaotong University,Beijing 100044,China)

机构地区：[1]北京交通大学土木建筑工程学院,北京100044

出　　处：《建筑结构学报》2024年第9期227-239,共13页Journal of Building Structures

基　　金：国家自然科学基金面上项目(52078030,51678039)。

摘　　要：为了研究内嵌钢筋外包碳纤维布(carbon fiber reinforced polymer,CFRP)复合加固中长圆形木柱的轴压性能,完成了8根中长木柱的轴心受压试验,获取了中长木柱的荷载-位移曲线及荷载-应变曲线,进而分析了内嵌钢筋数量、CFRP布包裹方式对中长木柱轴压性能的影响。研究结果表明:中长圆形木柱轴心受压时有压溃破坏和弯曲破坏两种形式,破坏位置均为初始缺陷较为集中的木节区域;嵌筋加固可以有效提升木柱的受弯性能,较未加固木柱,轴压承载力提高幅度为58.11%~100.68%,在荷载达到965 kN时,纵向应变减小范围为12.03%~28.89%、横向变形减小范围为20.72%~38.57%;包裹CFRP布加固木柱可以使木柱处于三向受压状态,轴压承载力提高65.19%,在荷载达到965 kN时,纵向应变与横向应变分别减小8.7%与67.02%;内嵌钢筋外包CFRP布复合加固木柱可以充分发挥CFRP布的约束作用和钢筋的承压作用,轴压承载力提升幅度为45.66%~121.03%,在荷载达到965 kN时,纵向应变减小范围为19.24%~28.49%,横向应变减小范围为34.05%~79.93%,延性最大可提高22.86%。基于复合加固理论,对试验数据进行拟合,进而提出了复合加固中长圆形木柱的轴压承载力计算公式,并将所得计算值与试验值对比,两者吻合较好,验证了计算公式的可靠性。To study the axial compression performance of medium-long circular timber columns strengthened with carbon fiber reinforced polymer(CFRP)sheets and near surface-mounted steel bars,8 specimens were conducted and tested under axial compression force.The load-displacement curves and load-strain curves were obtained.Furthermore,the effects of the number of embedded steel bars and the wrapping form of CFRP sheets on the axial compression performance of medium-long timber columns were analyzed.The test results indicate that medium-long circular timber columns show two failure modes under axial compression,including crushing failure and bending failure,both of which occur in the initial defect area with wood knot concentrated.The bending performance of timber columns can be effectively improved with embedded steel bars.The axial compressive bearing capacity of timber columns is increased by 58.11%-100.68%,the longitudinal strain is reduced by 12.03%-28.89%,and the transverse deformation is reduced by 20.72%-38.57%at the load of 965 kN.Wrapped with CFRP sheets,the timber column is subjected to triaxial compression,and the axial compressive load capacity of the timber column is increased by 65.19%,and the longitudinal and transverse strains under the same load were reduced by 8.7%and 67.02%,respectively,at the load of 965 kN.The composite strengthened timber columns maximized the use of the confinement effect of CFRP sheets and the bearing effect of steel bars.Its axial compressive capacity can be increased by 45.66%-121.03%,the longitudinal strain under the same load is reduced by 19.24%-28.49%,the transverse strain is reduced by 34.05%-79.93%,and the ductility can be increased by 22.86%at the load of 965 kN.Based on the theory of composite reinforcement,the experimental data was fitted,and a calculation formula was proposed to estimate the axial compression bearing capacity of medium-long circular timber columns.The calculated values were compared with the experimental values,and the results are in good agreement,which

关 键 词：中长木柱 内嵌钢筋 CFRP布 复合加固 轴压试验 受力性能 

分 类 号：TU336.203[建筑科学—结构工程]