Influence of the processing techniques on the bond characteristics in externally bonded joints: Experimental and analytical investigations

This paper investigates the bond characteristics between the concrete substrate and fiber-reinforced polymer (FRP) material processed with advanced manufacturing techniques. Tests provide further understanding regarding the interface behavior of the joints manufactured with a heated vacuum bag only (HVBO), vacuum-assisted resin infusion (VARI), wet lay-up, and pultrusion techniques. A specific criterion, the equalization of the processing techniques, is proposed to compare the characteristics of the joints. Based on the outcomes, the advanced processing techniques such as HVBO and VARI can be successfully applied to achieve a high-quality bond in strengthening of the reinforced concrete structures. Furthermore, a new analytical approach is presented to determine the interface behavior, which can be applied to any type of the FRP processing technique.