Reinforced concrete (RC) jacketing is most frequently used to strengthen columns.
The common practice to prepare the interface is empirically based and consists on increasing the surface roughness, applying a bonding agent and eventually steel connectors. An experimental study was performed to analyze the influence of the interface treatment on the structural behavior of columns strengthened by RC jacketing. Seven column-footing, full-scale models were built.
Three months later, the columns were strengthened by RC jacketing after their surface had been prepared considering different techniques. Later, the models were tested under monotonic loading. It was concluded that, for current undamaged columns (that is, where a bending moment-shear force ratio is greater than 1.0 m), a monolithic behavior of the composite element can be achieved even without increasing their surface roughness, using bonding agents, or applying steel connectors before strengthening it by RC jacketing.
Jacketing is one of the most frequently used techniques to strengthen reinforced concrete (RC) columns. With this method, axial strength, bending strength, and stiffness of the original column are increased.
It is well known that the success of this procedure is dependent on the monolithic behavior of the composite element. To achieve this purpose, the treatment of the interface must be carefully chosen. The common practice consists of increasing the roughness of the interface surface and applying a bonding agent, normally an epoxy resin.
Steel connectors are also occasionally applied. These steps involve specialized workmanship, time, and cost. Concerning the added concrete mixture and due to the reduced thickness of the jacket, the option is usually a grout with characteristics of self-compacting concrete (SCC) and high strength concrete (HSC).