邓宗才,李万超
AuthorsHTML:邓宗才，李万超
AuthorsListE:Deng Zongcai,Li Wanchao
AuthorsHTMLE:Deng Zongcai，Li Wanchao
Unit:北京工业大学城市与工程安全减灾省部共建教育部重点实验室，北京 100124
Unit_EngLish:Key Laboratory of Urban Security and Disaster Engineering of Ministry of Education， Beijing University of Technology，Beijing 100124，China
Abstract_Chinese:CFRP-UHPC-钢管组合短柱是一种具有广阔应用前景的组合柱，用超高性能混凝土(UHPC)取代组合短柱 中的传统混凝土可提高其力学性能和耐久性．为研究 CFRP-UHPC-钢管组合短柱的轴压性能，对 18 个 CFRP\u0002UHPC-钢管组合短柱进行了轴心受压试验，分析了其破坏过程、破坏形态及轴压承载力，研究了碳纤维增强复合材 料(CFRP)厚度、空心率以及钢管厚度对约束 UHPC 轴压性能的影响，并基于双剪统一强度理论建立了 CFRP\u0002UHPC-钢管组合短柱轴压承载力计算公式．结果表明：CFRP-UHPC-钢管组合短柱的组合形式充分发挥了 UHPC 的 抗压性能、CFRP 的抗拉性能以及钢管的抗压性能，在三者协同工作下，组合短柱的轴压承载力明显高于各个材料 轴压承载力的简单叠加，最大提高幅度可达 81%；随着 CFRP 厚度的增加，约束 UHPC 的抗压强度和极限应变均有 不同程度提高，组合短柱的轴压承载力提高明显；空心率较小(φ＝0.28 和 φ＝0.50)时，空心率对约束 UHPC 的抗压 强度和极限应变影响不显著，空心率较大(φ＝0.76)时，约束 UHPC 的极限应变明显提高；钢管厚度对约束 UHPC 轴向应力-应变曲线、抗压强度和极限应变影响很小；各个影响因素对约束 UHPC 轴压性能影响程度排序为：CFRP 厚度＞空心率＞钢管厚度；所建立的 CFRP-UHPC-钢管组合短柱轴压承载力计算公式计算简便，且计算值与试验值 吻合良好，可供工程应用参考．
Abstract_English:Short columns made from carbon fiber reinforced polymer(CFRP)-ultra-high performance concrete (UHPC)-steel tubes are composite columns with great application prospects. The mechanical properties and durability of composite short columns can be improved by replacing traditional concrete with UHPC. To investigate the axial compressive behavior of CFRP-UHPC-steel tube composite short columns，this work tested 18 CFRP-UHPC-steel tube composite short columns under axial compression. The failure process，failure modes，and axial compression bearing capacity were analyzed. The effects of CFRP thickness，void ratio，and steel tube thickness on the axial compressive behavior of the confined UHPC were also studied. On the basis of the twin shear unified strength theory，the calculation formula for the axial compression bearing capacity of the CFRP-UHPC-steel tube composite short columns was established. Results showed that the combined form of the CFRP-UHPC-steel tube composite short columns maximized the compressive performance of UHPC，the tensile performance of CFRP，and the compressive performance of the steel tube. Under the cooperation of the three materials，the axial bearing capacity of thecomposite short columns was significantly higher than that given the simple superposition of each material，and the maximal improvement degree was 81%. With an increase in the thickness of CFRP，the compressive strength and ultimate strain of the confined UHPC increased，and the axial bearing capacity of the composite short columns increased significantly. A low void ratio (φ＝0.28 and φ＝0.50) exerted little effect on the compressive strength and ultimate strain of the confined UHPC. By contrast，a large void ratio (φ＝0.76) obviously increased the ultimate strain. The thickness of the steel tube exerted a minimal effect on the axial stress-strain curve，compressive strength， and ultimate strain of the confined UHPC. The influence degree of each factor on the axial compression behavior of the confined UHPC was established in the following order：CFRP thickness＞void ratio＞steel tube thickness. The calculation formula for the axial compression bearing capacity of the CFRP-UHPC-steel tube composite short columns was simple，and the results agreed well with the experimental values. Hence，this work can be used as a reference for engineering applications.
Keyword_Chinese:超高性能混凝土(UHPC)；CFRP-UHPC-钢管组合短柱；轴压承载力；影响因素
Keywords_English:ultra-high performance concrete(UHPC)；CFRP-UHPC-steel tube composite short columns；axial bearing capacity；influence factors

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