Behavior of RC Columns Strengthened with Steel Jacket Under Static Axial Load

Abstract

One of the most important structural elements, the column is primarily intended to support compressive loads. The strengthening is carried out for existing reinforced concrete columns to increase the ductility of the column and to increase load capacity to sustain the applied load as sometimes there may be a use change, which leads to increased loads. This work aims to study the behavior and efficiency of RC columns strengthened with steel jackets and subjected to axial load. An experimental program was performed on columns specimen till failure. Aspect ratio (t is the long side of the cross-section /b is the short side of the cross-section), the volume of steel straps, and the spacing of steel straps at centers(S) were the primary research variables in this work. Ten specimens were rectangular concrete columns with aspect ratios equal to 1, 1.56, and 2.04. the cross sections of the column were (200*200mm), (160*250 mm) and (140*286 mm) respectively. the total height of the specimens was 1200 mm,960mm, and 840mm respectively. Under an axial load, three control columns and seven strengthened columns were tested. The results showed that using this method of strengthening is very effective and an increase in the axial load capacity of the strengthened columns is obtained. This increase was due to the confining effect of the steel jacket, and the ability of the steel angle to withstand a large part of the applied axial load.

Keywords

• reinforced concrete column
• strengthening
• confinement
• steel angles
• steel strips