薄壁圆钢管再生混凝土混合中长柱轴压力学性能

Mechanical Performance of Recycled Concrete- Filled Circular Steel Tubular Middle Long Columns under Axial Compression

目的研究薄壁圆钢管再生混凝土混合中长柱的受力机理和力学性能,为钢管再生混凝土中长柱轴心受压设计提供理论依据.方法以截面含钢率、再生块体取代率和长细比为试验参数,设计了12根薄壁圆钢管再生混凝土混合中长柱,并对其破坏形式和特征、荷载-跨中挠度曲线、荷载轴向位移曲线以及承载力的敏感影响因素进行深入的研究.结果试验结果表明:当块体取代率由20%增至60%时,试件的极限承载力有一定程度的下降,延性无明显变化;当含钢率由0.038增至0.079时,其后期承载力提高约30%;当长细比由25增至35时,试件的极限承载力有所下降,但下降幅度不明显.结论含钢率能够明显提高试件的极限承载力和延性,再生块体取代率、长细比对承载力和延性的影响较小.

In order to master the mechanical behavior and mechanical properties of mechanical performance of recycled concrete-filled circular steel tubular middle long columns,the theoretical basis is provided for the design of long column axial compression in recycled concrete filled steel tube. The test parameters were selected as the section steel ratio,the replacement ratio of the recycled blocks and ratio of long and thin,in the design of 12 built in mechanical performance of recycled concrete-filled circular steel tubular middle long columns,and its failure modes and characteristics,load deflection curves,load displacement curves and the sensitive factors of bearing capacityare studied in depth. Test results show that：when the block replacement rate increased from 20%to 60%,the ultimate bearing capacity of the specimen is decreased to a certain extent,there is no obvious change in ductility;when the steel ratio is increased from 0. 038 to 0. 079,its late bearing capacity increased by about 30%;when the ratio of the length to 35 is increased from 25,the ultimate bearing capacity of the specimen has been decreased. But the decline is not obvious. The ultimate bearing capacity and ductility of the specimens can be significantly improved with the steel ratio,the effect of replacement ratio and length to diameter ratio on the bearing capacity and ductility of the recycled bulk is small.