Flexural strengthening of RC beams using GFRP grid bonded with sprayed polyurea

Abstract

Flexural strengthening of reinforced concrete (RC) beams with fiber reinforced polymer (FRP) was investigated in this research. The bonding agents were an epoxy paste and a sprayed polyurea. Four RC beams were strengthened with FRP composites according to the following techniques: (a) sprayed polyurea with and without glass FRP (GFRP) grid reinforcement; (b) manual layup with one GFRP grid; and (c) manual layup with one GFRP sheet. Experimental results clearly shows that flexural strengthening with polyurea technique is an effective scheme. Other than fast setting, the major advantages of using polyurea over other organic or inorganic matrices are as follows: (a) no slippage of the FRP grid from the polyurea or cracking of the polyurea occurred during the tensile test; (b) no debonding of the polyurea system from strengthened RC beams was observed during the bending test. Application of the polyurea system, key experimental results, and comparison with findings from other research programs reported in literature are presented in this paper.