Experimental And Analytical Investigations on RC Short Columns Strengthened by Ferrocement Jacketing And Aramid Fibre Sheet Wrapping

Reinforced concrete columns are the main load bearing structural elements in the building. These columns need to be repaired or strengthened due to material deficiencies, design deficiencies, poor construction and quality control. The axial load carrying capacity of RC short columns of Grade M25 and of size 150 mm x 150 mm and height 1 m were determined as per IS 456:2000. Seven RC short columns were cast – three columns were strengthened by ferrocement jacketing, two columns were strengthened by aramid fibre sheet wrapping and the remaining two columns were reference columns. In ferrocement jacketing technique, woven wire mesh of size 12 mm x 12 mm opening and diameter of 0.96 mm were wrapped around the three columns in two layers and mortar of mix ratio 1:3 with a water cement ratio of 0.45 were applied around the columns to cover the wire mesh for a thickness of 20 mm from each face of the columns. In the aramid fibre sheet wrapping technique, the RC columns were wrapped by a single layer of aramid fibresheet using epoxy resin. All the RC short columns hinged at both ends were tested under axial compression in a loading frame of capacity 1200 kN using a hydraulic jack of capacity 1000 kN. Two LVDT’s were placed – one perpendicular to the base plate to measure the longitudinal displacement and the other perpendicular to the face of the column to measure the lateral displacement of the columns.