Two series of tests were made to study the behavior of jacketed columns. The first series consisted of uniaxially loaded specimens, and the behavior of jacketed columns was compared with a monolithic reference specimen. The main objective of this series was to study the effectiveness of repair and strengthening jackets and the differences between jackets made under load and after unloading. Specimens with repair and strengthening jackets behaved well when jacketing was introduced after unloading. Repair jacketing made wider load exhibited poor behavior In the second series, jacketed columns were tested under combined axial load and bending (monotonic and reversed cyclic). Two monolithic specimens also were tested to serve as reference specimens. Effectiveness of repair and strengthening jackets was studied considering strength, stiffness, and energy dissipation. The influence of load history (monotonic and reversed cyclic) on the behavior of jacketed columns also was studied. Repair and strengthening jackets behaved well both under monotonic and reversed cyclic loadings.