Experimental Study On Mechanical Performance Of Steel Encircled With Reactive Powder Concrete Beams

Reactive powder concrete is a new type of cement-based composite materials,which not only has high compressive strength,tensile and flexural strength,but also has good durability and resistance to high temperature performance,is a kind of superior performance of building materials.In recent years,RPC applies widely in the railway engineering,bridge engineering and the building structure.With the development of the society,long-span structure,high-rise structure and heavy structure are widely used,which puts forward higher requirements on the cross section of structure size and carrying capacity.Solid-web steel reinforced concrete composite structures have been widely used in the large-span structure,high-rise structure,urban roads and Bridges,city elevated stations,with high bearing capacity,good ductility,good seismic performance,good fatigue performance and the small dimensions.If the ordinary concrete of the steel reinforced concrete structure is replaced by RPC,the section size of artifacts can be greatly reduced,which can increase the use space of the structure.At the same time,it can effectively control the crack width of concrete,increase the durability of the components and extend the service life of the structure.One pure steel contrast beam and three steel encircled with RPC beams were designed for the test to observe the test beam deformation,crack development and failure pattern,test the deflection,cracking load and ultimate load of the test beams and analyse the the mechanical performance of steel encircled with RPC beams.The test results show that,the bearing capacity is improved a lot when the steel beam is encircled with a cover of RPC.The cracking load and bearing capacity of the steel encircled with RPC composite beams increase with the RPC strength grades,but the range is not obvious.Under the condition of shear span ratio ?=1.5,the steel encircled with RPC beams finally fail in flexural failure.The adhesive failure can be effectively avoided by the minimum stirrup ratio referred to the Chinese existing code.At the same time,the theory calculation formulas of cracking load,flexural bearing capacity and shear bearing capacity are deduced,which has a good agreement with the test result.The ANSYS software is used for the finite element analysis of the test beams,which can simulate the crack development and the bearing capacity limit state through the finite element model of the test beams.The results showed that the simulation results of test beams finite element model has accorded with the experiment phenomenon of the test beams,which has verified the correctness of the experimental phenomena at the same time.