Seismic behavior of steel-concrete composite columns under cyclic lateral loading

Document Type: Original Article


1 Department of civil engineering, college of engineering, kermanshah branch, Islamic azad university, Kermanshah, Iran.

2 Department of civil engineering, college of engineering, sanandaj branch, Islamic azad university, Sanandaj, Iran.



As one of the important structural members in most buildings and non-building structures, columns may be found to require strengthening. For reasons such as loss of column capacity under repetitive loading, failure to comply with the seismic provisions and requirements, and increased dead or live load applied to the structure, the designer can turn to integrate concrete and steel to achieve a stronger structure, leading to the increased column strength. In this study, the concrete columns are strengthened using the steel jackets and the behavior of columns is analyzed under cyclic lateral loading to determine how well the jacket can reduce the damages incurred to the columns. Therefore, a concrete column is modeled as an example and then, the steel jackets are used to strengthen the columns. The steel layers of composite columns have different thicknesses, and the maximum displacement of columns is obtained under the lateral load. The results of the present study show that the stress-induced in the composite columns decreases under the lateral load with increasing the thickness of steel layer. Furthermore, the damage incurred to the composite concrete column is 0.75 times the initial value when the jacket of higher thickness is used. However, in case of using a thicker steel jacket, the plastic strain throughout the column can be 0.35 times the initial value, and it can be stated that the increased steel thickness leads to the improved behavior of composite column.