Performance Analysis of Steel-Concrete Composite Columns using non-linear analysis.

Abstract

Steel-concrete composite construction has gained wide acceptance worldwide as an alternative than pure steel and pure concrete construction because composite column has both compression and tension resistance. However, this system is a relatively new concept for the construction industry in Ethiopia. This study presents the performance of fully encased composite column subjected to axial load and at the same time increase the accuracy of results. The ES EN 2015 code and Eurocode 4 mainly are used codes in this paper. The Performance of steel concrete composite columns presented using tables, graphs and charts from finite element analysis by using ABAQUS software. In order to achieve the goal of the study, a parametric investigation procedure is undertaken, on a series of eighteen (18) samples column with different study parameters. An Independent Variables used are Compressive strength of concretes, Length of column, and Diameter of rebar. A parametric study was conducted using the numerical model to investigate the influences of geometric properties of fully encased composite (FEC) columns. The material quality used for composite columns are C25, C30, C35 and C50 grades, The structural steel encased in concrete adopts the standard British steel section UC152 * 152 * 30,Longitudinal reinforcement bars with diameters(12mm,13mm,14mm and 16mm) and for transverse reinforcement bar(10mm) were used. The nonlinear combined hardening and the concrete damage plasticity (CDP) model were used to define properties of steel and concrete respectively. In the Finite Element Analysis (FEA) C3D8R was used for solid elements and T3D2 was used for reinforcements. The load capacity of the composite columns increased by 6.38% and 5.93% with increasing concrete strengths from C25 to C30 and C35 decreased from 3.50% to10.20% with increasing column lengths from 600mm to 800mm and 1000mm.The same area effects of longitudinal bars and the confinement effects with different diameter and spacing of transverse longitudinal bars are introduced. As the diameter of longitudinal reinforcement of Composite Column increased from 12mm to 14mm and 16mm the load carrying capacity of composite column is increased from 4.14% to 4.77% respectively.