Research On Eccentric Compressive Behavior Of Square Steel Tube Long Columns Filled With Demolished Concrete Blocks

The rapid advance of urbanization in China has brought a huge demand for construction, but also generated a lot of construction waste, the use of recycled aggregate concrete manufacturing waste is inevitable road construction sustainable development. For this reason the introduction of thin-walled steel mixing concrete regeneration member, namely via a simple waste concrete crushing and screening to obtain a larger particle size recycled aggregate to partially replace natural aggregate made of recycled concrete, recycled concrete and then pouring into thin wall tubes,thin-walled steel pipe become regenerated mixed concrete member. Based on existing research, through simulation analysis and experimental research on thin-walled square steel mechanical properties of concrete mixed regeneration bias long columns were studied.With the finite element software ANSYS, thin-walled square steel column regeneration mix concrete eccentric numerical simulation analysis, the load- stress curves and recycled concrete and steel deformation strain distribution. The results show that: the specimen was bent overall damage, the Carrying Capacity increases slenderness ratio decreases with increasing eccentricity decreases.Slenderness ratio, eccentricity, mixing ratio parameters designed 4-axis pressure test specimens, 14 specimens were biased test. The results showed that:(1)thin-walled square steel column regeneration mix concrete eccentric with good bearing properties and deformation capacity, failure mode and ordinary concrete filled steel tube long columns similar, both overall flexural failure;(2) the finite element and the test results are in good agreement you can use that type of specimen finite element numerical analysis; the main factors bearing capacity(3) thin-walled square steel column regeneration mix concrete eccentric is slenderness ratio and eccentricity, slenderness ratio increases, the specimen carrying capacity decreases;increases, the specimen eccentricity carrying capacity is reduced and the non-linear trend, while mixing ratio on the limited carrying capacity;(4) the performance of thin-walled square steel tube deformation regeneration eccentric mix concretecolumns good, large slenderness ratio specimen ductility slightly better than slenderness ratio is small specimens, eccentric compression ductility specimens better than axial compression specimen, specimen ductility with increasing mixing ratio and slightly reduced trend.Use of GB50936-2014, CECS159: 2004, DBJ13-51-2003, ANSI /AISC360-2005, AIJ-1997, BS5400-2005, EC4-2004 7 kinds of eccentric columns method procedures given calculated bearing capacity of the specimen. Wherein the calculated results and the experimental results are in good agreement procedure DBJ recommended procedure to calculate the renewable mix concrete steel eccentric Columns. Based on the study has been Stub Columns capacity calculation method,based on the regression test proposed practical calculation method for ultimate bearing capacity of thin-walled square steel tube regeneration mixed concrete eccentric columns...