玻璃纤维增强复材管自密实微膨胀活性粉末混凝土短柱轴压性能试验研究

EXPERIMENTAL STUDY ON AXIAL COMPRESSION PERFORMANCE OF SHORT COLUMN COMPOSED OF GFRP TUBE FILLED WITH SELF-COMPACTING AND MICRO-EXPANDED RPC

配制出了一种常温养护下流动度大于255 mm的高性能、高强度的自密实微膨胀活性粉末混凝土(RPC),并填充至玻璃纤维增强复材(GFRP)管。对GFRP自密实微膨胀RPC短柱进行轴压性能试验,考虑GFRP管材成型工艺、混凝土膨胀剂和构件受力方式等设计参数,重点分析试件破坏过程及形态、应力-应变曲线及构件承载力。结果表明:GFRP纤维丝±45°缠绕的GFRP管RPC短柱力学性能优越,该组合柱应力-应变曲线呈二次线性增长,组合柱破坏时,GFRP纤维丝被拉断,管内约束混凝土被压碎,其极限承载能力是无约束RPC短柱的1.6倍左右。混凝土膨胀剂改善了组合短柱的变形性,其极限应变约为无膨胀剂柱的1.4倍。Teng的理论计算模型能较好地适用全截面受压的GFRP管自密实微膨胀RPC短柱。

A kind of self-compacting micro-expanded reactive powder concrete(RPC)with high performance and high strength was prepared.The RPC was cured at conventional temperature and its fluidity was greater than 255 mm.The RPC was filled into glass fiber-reinforced plastic(GFRP)tubes.The axial compression performance tests of GFRP tube filled with self-compacting micro-expaned RPC tube filled with short column were carried out.The axial compression performance tests of GFRP tube filled with self-compacting micro-expanded RPC short column were carried out.The effects of design parameters such as GFRP tube forming process,concrete expansion agent and the stress mode of members on the mechanical properties of the structure were considered in the tests.The failure mode,stress-strain curve and member bearing capacity were analyzed emphatically.The results showed that the mechanical properties of GFRP tube RPC short column with GFRP filament wound±45°were the best,and the stress-strain curve of the composite column increased in a quadratic linear manner.When the composite column was damaged,the GFRP fibers were broken and the confined concrete in the tube was crushed.Its ultimate bearing capacity was about 1.6 times that of the unconstrained RPC short column.The concrete expansion agent improved the deformability of the combined short column,and its ultimate strain was about 1.4 times that of the column without the expansion agent.The theoretical calculation model of Teng was suitable for the GFRP tube filled with self-compacting micro-expaned RPC short column under full-section compression.