Experimental study on bond strength of GFRP bars

Abstract

Abstract Composite materials in the form of bars is good alternative to conventional steel due to their non corrosiveness. To work out effectiveness of GFRP bars as internal reinforcement in Civil Engineering structures, it is necessary to find its bond performance with concrete. Good bonding results into effective transfer of stresses from concrete to reinforcement. Many of available FRP bars in Indian market are with plain surface texture, lacking ribs on it as that of steel. In this study experimentation is done for pull out test on plain GFRP bars and ribbed steel bars, based on IS 2770:1967. To find variation in bond strength, bars of diameter 8 , 10 and 12 mm were used. Enhancement in bond strength due to change in surface texture was also studied by roughening the surface through application of fine and coarse ennore sand on bar surface. Bond strength of plain GFRP bars was found to be lesser than that of steel. Also by roughening the surface using ennore sand and epoxy resin, no considerable rise was observed, may be due to lack of bond transfer between bar, sand and concrete