FRP confinement of high-aspect ratio concrete columns

An important limitation in the majority of the globally available guidelines, with regard to concrete strengthening, is the confinement of vertical members of high-aspect ratio cross-sections by means of externally applied FRP. For that matter, the paper investigates FRP confinement of wall-like reinforced concrete columns, by examining a number of parameters, namely the effectiveness of different types of carbon FRP anchors, the role of different cross-section aspect-ratios (3 and 4), the number of externally applied FRP layers, local strengthening at the corners and the reduction of aspect-ratio by cross-section enlargement. It is concluded that properly dimensioned anchoring system, nearly doubles the confining effectiveness of FRP. Moreover, the use of additional FRP layers near the edges of the cross-section increases the confining effectiveness of the jacket by approximately 50%, and shape enlargement of the cross section with mortar is practically as effective as the use of FRP anchors.