Externally bonded reinforcement in grooves (EBRIG) technique to postpone debonding of FRP sheets in strengthened concrete beams

► The performance of four methods for strengthening of beams with FRP was investigated. ► Surface preparation can't considerably improve the bond performance in EBR technique. ► FRP rupture was observed in both EBROG and EBRIG methods. ► The highest increases in ultimate loads were observed in EBRIG method.