Analysis Of Encased Reactive Powder Concrete Composite Columns Fabricated With Shaped Steel Subjected To Bearing Capacity

With the rapid development of economic and technological,various functions of complex and diverse use,modeling new and exotic high-rise buildings in large numbers.With the height of the high-rise and high-rise buildings continue to increase,the pressure column to withstand the axial load is also increasing,occupying more use of the area,has affected the full use of building functions.Engineering practice shows that if the use of traditional concrete has been difficult to meet the modern engineering structure to the long-span heavy load and bear the direction of the development of harsh conditions.As a result,structural engineers need an ultra-high performance concrete substitute for conventional concrete.In the high strength grade concrete,the active powder concrete has the advantages of high compressive strength,good tensile strength and excellent durability,and the steel structure has good seismic performance.Therefore,this paper combines the active powder concrete material with the steel to form an outer powder coated concrete column.In this paper,three groups of active powder concrete columns were fabricated by using active powdery concrete with different mechanical properties.The shear strength of the steel was set up and the axial load bearing capacity was tested.The experimental results show that the steel has a good working ability with the active powder concrete,and the peeling phenomenon of the protective layer does not occur when the specimen is destroyed.The main failure mode of the specimen is the end of the damage,the specimen reaches the ultimate bearing capacity,the column shows no obvious cracks,only a few small cracks at the end,with the continuation of the load,the end of the cracks gradually to the column The middle of the development,and near the flange at the edge of the formation of a longitudinal split the main cracks.The finite element simulation of the external steel powder was carried out by means of finite element ANSYS software.Considering the interaction between the steel and the concrete interface,the proper constitutive relation between the binder sliding interface and the pin was selected.The linear spring element(combin39)simulates the effect of the interface normal force,longitudinal tangential force and lateral tangential force.And the establishment of the interface at the consideration of non-cohesive effect,part of the bonding effect and complete bonding of the three models were compared,indicating that the outsourcing of active powder concrete column structure has a good synergistic performance.Based on the comparison of the results of finite element analysis and the experimental results,the stress distribution,axial force distribution and interfacial bonding properties of the steel and the reactive powder under different axial compression loads are analyzed.The results show that under the axial compression load,And calculate the approximate bearing capacity formula of the composite structure by referring to the relevant specification.The formula calculation value,the test value are compared with the finite element simulation value,and the difference of the calculation result is analyzed.