Repair and retrofitting of structural RC walls by means of post-tensioned tendons

The introduction of un-bonded post-tensioned tendons or bars in the critical zone for the structural repair and retrofitting of structural R/C walls is investigated by means of non linear FE analyses. The numerical models are validated through comparison against experimental data on a 1:1 scaled traditional shear walls undergoing cyclic loadings. Comparative pushover and seismic analyses were performed. The results showed that the introduction of unbonded post tensioned tendons concentrates the damage in a single large crack opening at the wall base section, whereas traditional walls develop an extended crack pattern over the critical zone. Despite similar behaviour is observed in terms of top storey maximum displacement, in case of post-tensioned structural walls the elastic behaviour of the post-tensioned bars, while reducing the energy dissipation capacity of the structure, avoids any residual displacement after a seismic event, thus limiting structural damage even under a design seismic event. © 2007 Taylor & Francis Group.