Behaviour of Cold Formed Steel Built-Up Channel Columns Strengthened Using CFRP

This paper presents experimental findings of carbon fibre reinforced polymer (CFRP) strengthened cold-formed steel built-up channels subjected to axial load. In order to sensitively detect the buckling strengths and failure modes, twenty-four built-up columns were tested in which twelve columns were unadorned and another twelve columns were strengthened using CFRP sheets. The columns were tested for ultimate load, lateral displacement and failure modes. Tension coupon tests were conducted to determine the material properties of test specimens. The experimental results were compared with the design load calculated according to AISI S100-16 specification and are found to be in good agreement. It is established that the use of CFRP for strengthening increases the ultimate load and delays the buckling.