Experimental Research On Recycled Aggregate Concrete Filled Circular Steel Tubular Long Columns Under Axial Compression

With the development of China’s economy and the acceleration of urbanization, a large number of construction waste is produced every year, which will not only bring pressure to the city’s environment, but also bring burden to the sustainable development of China’s economic and social. It is one of the hot issues in the current research that how to utilize these construction wastes scientifically and reasonably. Waste concrete accounted for 30%-50% of this construction waste. Therefore, the research of recycled aggregate concrete-filled steel tube columns is introduced, the waste concrete replaces ordinary concrete coarse aggregate after crushing and screening, and then gets recycled concrete. Pour the recycled concrete into the circular steel tube, get the recycled aggregate concrete-filled circular steel tubular columns.Currently the study of recycled aggregate concrete-filled long circular steel tube columns is not systematic enough, this paper carry out in-depth experimental study and theoretical analysis to the performance of recycled aggregate concrete-filled long circular steel tube columns under axial compression, analysis the influence factors of the axial compressive performance of recycled aggregate concrete-filled long steel tube columns, main contents include:(1) Through the study of the axial compressive performance of the 8 recycled aggregate concrete-filled long steel tube columns, considering the influences of slenderness ratio, the thickness of steel tube, and the addition of the waste concrete blocks, study the ultimate bearing capacity, failure modes and deformation capacity. During the whole loading process, pay attention to the changes of the specimens, get the main parameters through the collected data, such as bearing capacity, peak strain and yield strain and so on, analyze the influence of the factors on the axial compression performance of the specimens. Research shows that:the specimens were as an elasto-plastic failure; the axial compression bearing capacity decreases as the slenderness ratio increases, and increases as the tube thickness increases, but the addition of a small amount of waste concrete blocks on the axial load has little effect to the axial compression bearing capacity.(2) On the basis of experiment, established the finite element analysis model by using the finite element software ABAQUS, compared the finite element software simulation curves and experimental curves. It is found that numerical simulation results can be in accurate agreement with the experimental results, using the model to simulate the actual stress process of recycled aggregate concrete-filled steel tube structure may be explained.