Durability of near-surface-mounted FRP-to-clay brick masonry retrofits under environmental exposure

Abstract

This study presents an experimental investigation of the effect of environmental exposure on the fiber-reinforced polymer (FRP) to clay brick masonry bond when the reinforcement is near-surface-mounted. Three alternate types of exposure are considered: (1) thermal loading with single or multiple thermal exposure cycles, (2) water immersion, and (3) hygrothermal cycling. The latter two treatments were used to condition the samples over a long-term period with testing undertaken after 3, 6, 15, and 24 months from initial exposure. Since previous tests on externally bonded FRP have shown that environmental conditioning can often cause failure in the adhesive, both an epoxy and cementitious adhesive are investigated. The results of the study indicate that although environmental conditioning caused some degradation in the mechanical properties of the various constituents, the strength of the FRP-to-masonry bond remained highly durable regardless of the adhesive used.