Axially loaded reinforced concrete composite columns using steel angles and strips: An experimental and analytical assessment

This paper investigates the utilization of composite columns achieved by incorporating four steel angles at the corners of columns, interconnected with transverse plates. The experimental program involves ten columns, varying slenderness ratio, angle thickness, and transverse reinforcement spacing to evaluate the effect of variable parameters on the load-carrying capacity, Failure modes and behavior of these type of composite columns. Also, The objective of this research is revised the analytical calculations from the different international codes/standards to test their reliability in predicting the load-carrying capacity of composite columns compared to experimental results. Next, using ANSYS and validated finite element method, a parametric analysis is carried out for cases under eccentric loading. According to results, Steel-angled composite columns perform better than regular columns, demonstrating increases in load carrying capability because of improved confined concrete within steel angles. As the thickness of the steel angles increased (reinforcement ratio increased from 2.91% to 4.75%), increasing load capacity to 28% and lowering axial and lateral displacements to 20% and 30%, respectively. There was a difference in the experimental and finite element ' load capacities at failure that ranged from (-3%) to (+6%). The effect of slenderness ratio in columns with eccentric load is clear that the load capacities of the slender columns are 10% less than those of the shorter ones when axial eccentric loads are taken into account according to parametric investigation. In addition, both AISC and ECP 205 included the slenderness ratio when estimating load capacity; however, AISC was less cautious than ECP 205. Both ACI 318 and ECP 203 neglect the slenderness ratio when calculating load capacity that ECP 203 understates while ACI 318 code overstates load capability.