Effect of Corner Radius on Compressive Response of Steel Confined Concrete

Strengthening of Reinforced concrete structures results in much greater capacity to sustain loads. This research investigates the effect of corner radius on the compressive strength of concrete columns using steel jacket technique. Three parameters considered were the cross- sectional shape (i.e., circular, square, and rectangular), the corner radius in case of square and rectangular specimens and gauge of steel which is to be confined. Behavior and failure load of the strengthened columns were experimentally investigated on thirty specimens divided into six un-strengthened specimens and twenty-four strengthened ones. The results also indicate that the effectiveness of steel confinement decreases with an increase in sectional aspect ratio and increases with an increase in corner radius. All the confined specimens display extremely ductile behavior because of the concrete's high yielding strength, and noncircular columns effectively withstand the knife action of sharp edges. The results show that while the average ultimate axial strain is significantly underestimated by all twenty-four models, the average compressive strength of steel confined circular, square, and rectangular concrete columns is predicted correctly.