Experimental Study On Mechanical Properties Of Nano-SiO₂ Concrete Filled Steel Tube

CFST structures has many virtues such as high load bearing capacity, good ductility and convenience of construction.It caters to the need of modern structures that are developing to long-span, towering, heavy loaded and withstanding adverse environment conditions.resist tough conditions. With the development of high-rise building and large-span structure in our country, CFST has been more and more widely used nowadays, theories on CFST structures design also has been lucubrated increasingly.In the past, large number of research studies on the behaviour of CFST subjected to various kinds of load were reported, there were also a few research studies on the behaviour of RPC Filled Steel Tube and High Strength Concrete Filled Steel Tube. Mechanical properties of CFST depends on the interaction effect of tube and core concrete, this results in a higher requirement on core concrete properties when CFST structures were subjected to complex load path or particular surroundings.Based on previous study results, this paper has carried out the experimental study on behaviour of Nano-concrete Filled Steel Tube members subjected to axial and triaxial compressive load by means of adding core concrete to Nano-SiO2.The main achievements can be summarized as follows:(1)Experimental tests on Nano-SiO2 doped concrete were carried out. behaviours such as compression strength and workability of Nano-SiO2 doped concrete in different Nano-SiO2 content were determinated.(2)Experimental tests on seven team of Nano-concrete Filled Steel Tube columns were carried out. The behaviour of Nano-concrete Filled Steel Tube axial compressed columns was studied and compared with CFST. Effect on mechanical properties of Nano-SiO2 content was discussed. Based on the current test results, the rational Nano-SiO2 content was recommended.(3)Based on the test results of Nano-concrete Filled Steel Tube columns subjected to triaxial compressive loading history, influence of load path and confining pressure was discussed. (4)Based on the test results of Nano-concrete Filled Steel Tube columns subjected to axial and triaxial compressive load, Applicability on bearing capacity computational formula of CFST columns compared to Nano-concrete Filled Steel Tube columns was discussed.