Viable seismic strengthening solutions for RC wide beam-column joints

Beam-column joints play a key role on the seismic behavior of reinforced concrete buildings. Many of these buildings, although they belong to earthquake prone countries, were designed only to withstand gravity loads, thus without appropriate strength and ductility capacity with respect to seismic actions. Beam-column joints with flat or wide beam are rather widespread in the European residential building stock. Contrarily to joints provided with stiff beams, there are a few studies devoted to evaluate their performance and, especially, the arrangement and effectiveness of strengthening solutions for this type of joints. For this reason an experimental program has been setup in order to evaluate the effectiveness of simple and easy to apply strengthening techniques derived from the CAM technique. Three identical specimens were tested, one in the as-built condition and two specimens after the application of steel based strengthening solutions. The present paper shows a preliminary analysis of the test results highlighting the effectiveness of the techniques proposed in improving the seismic behavior of the specimens under study