Ultimate Compressive Behavior Of Double Skin Composite Wall With Ultra-high Performance Concrete

This study develops double skin composite wall(DSCW)for the containment building of small modular nuclear reactor(SMNR)and the core wall of high rise buildings.Efficient use of ultrahigh performance concrete(UHPC)with novel J-hook connectors and traditional overlapped headed stud connectors were focused to reduce the thickness of the concrete core and to ensure higher strength of double skin composite wall.Besides,this study established construction efficiency and durability of double skin composite wall by replacing complex steel to steel interfacial connectors with novel Jhook connectors and traditional overlapped headed stud connectors.Axial compressive load-bearing capacity of a total 18 specimens was tested under inplane compression.Total 9 scaled ultrahigh performance concrete infilled double skin composite wall with J-hook connectors and 9 scaled double skin composite wall with headed stud connectors was involved in the test matrix.Several structural failure modes of the double skin composite wall were inspected and deeply studied.Moreover,the axial shortening behavior of the double skin composite wall and the buckling behavior of the steel faceplate were investigated and reported.Based on the experimental data,diverse parametric studies were conducted to analyze the influence of increasing steel faceplate thickness,vertical and horizontal spacing of connectors and scattered compressive strength of the concrete on the ultimate compressive load-bearing capacity,stiffness,ductility,and axial shorting response of double skin composite wall.In addition,this paper reported the method to detect the initial geometrical imperfection of external steel faceplate.Furthermore,this study developed an analytic model to design the ultrahigh performance concrete infilled double skin composite wall under gravity load.The acceptability of the proposed analytic model was substantiated by the experimental results.Finally,a simplified finite element model was developed to reduce the modeling complexity of J-hook and headed stud connector.The outcomes of nonlinear finite element analysis(NLFEA)easily detected structural damages of double skin composite wall under compressive load similar to experimental findings.Moreover,axial shortening response and the ultimate compressive load-bearing capacity of the double skin composite wall from nonlinear finite element analysis were compared with experimental results.The proposed finite element model well predicted the compressive resistance of ultrahigh performance concrete infilled double skin composite wall.Based on the results of validated finite element model,the effect of the increasing thickness of steel faceplate,vertical and horizontal spacing of the connectors on the compressive behavior of the double skin composite wall was studied accordingly.