Experimental and Analytical Investigation of FRP Retrofitted Glued-Laminated Beams Subjected to Simulated Blast Loading

An experimental program investigating the potential of fiber-reinforced polymers (FRPs) as a strengthening option for glulam beams subjected to simulated blast loads was undertaken. A total of four different retrofit configurations were investigated along with a fifth alternative for restoring previously damaged beams. Increases in resistance and maximum deflection in the range of 1.35–1.66 and 1.3–1.62, respectively, were obtained when FRP tension laminates with and without confinement were used. Partial-length and full-length confinement prevented premature debonding and significantly altered the failure mode from simple tension failure to a combination of brash tension and compression failure while limiting the damage to a small region. The results also showed that the addition of FRP contributed to an increase of 1.17 in the tensile failure strain relative to the unretrofitted beams. A material predictive model that accounts for strain-rate effects was developed using experimental stress–strain relationships determined from coupon tests. The proposed model compared well with resistance curves obtained from full-scale testing of glulam beam elements subjected to simulated blast loading.