Seismic performance of circular columns rehabilitated with sprayed-GFRP composites

Abstract

This study investigates the seismic behaviour of RC circular columns rehabilitated using sprayed-glass fibre reinforced polymer (sprayed-GFRP) composites. Six large-scale RC circular columns were constructed and tested under reversal-cyclic load and constant axial load (equal to 20% of column axial load capacity). All specimens were deficient in lap splice length and had a diameter of 305-mm with 1,525-mm shear span (length). A 3.0-mm and 6.0-mm thick sprayed-GFRP coating was used for rehabilitation. Two specimens were strengthened without prior loading, two specimens were rehabilitated after being partially damaged (up to 2.5% drift ratio) and two specimens were rehabilitated after being fully-damaged. Sprayed-GFRP of 3-mm thickness is inadequate for rehabilitation of the fully damaged column. However, it can be used for strengthening and rehabilitation of partially-damaged columns. Sprayed-GFRP of 6-mm thickness not only increased the drift capacity of the column but also successfully restored the full capacity of seismically damaged RC columns.