Experimental Work on Reinforced Concrete Slender Columns Enhanced by Partial Strengthening Using Steel Plate Strips

Many methods have been developed for strengthening and repairing damaged reinforced concrete (RC) structures as alternatives to removal or replacement. The conventional way of strengthening RC columns is to use a steel jacketing composed of four steel angles plus battens. This study offered an alternative strengthening technique that is simple to use and low-cost. They are strengthened by thin (0.5 mm thick) steel plate strips that are placed transversely and longitudinally at the middle height and 0.25 length of the column, as well as the full length of the column. This research focused on RC slender columns and experimentally studied the effect of this technique of strengthening under different eccentric loads on six RC slender columns using self-compacting concrete. The experiment’s results illustrated the impact of strengthening, as well as eccentric loads, on the behaviour of the columns. The reduction of lateral deflection increased from 3.83% to 5.10%, and column capacity increased from 4.25% to 36.55%. There was a clear rise in eccentricity as the energy absorption capacity improved by 9.65% to 72.63%. Furthermore, regarding strengthening efficiency measured per unit volume of steel was range 13.22% to 19.10%. In addition, by strengthening the columns, failure was delayed, the failure position changed, and strain was decreased. This technique gives structural engineers a dependable, safe way to strengthen RC slender columns easily and economically.