Performance of FRP bonding systems under fatigue loading

This study investigates and compares the behavior of the bond between fiber reinforced polymer (FRP) materials and concrete in various bonding systems under fatigue conditions. The FRP bond systems studied include externally bonded FRP (EB-FRP), near-surface mounted FRP (NSM-FRP), fiber anchored FRP (FB-FRP), and a newly developed hybrid bonded FRP system (HB-FRP). In the HB-FRP system, the mechanical fastener was fixed in two conditions, and five groups of bonding systems were studied. To achieve the objectives of the study, a double-face shear-type bond test (direct pullout test) was developed. The influence of the load amplitude and number of cycles on the bond performance is scrutinized and discussed through analyzing the failure mechanism, load–slip curves, and strain measurements taken during both the fatigue and monotonic tests. Based on the test results, the advantages and disadvantages of different bond systems are discussed in terms of the fatigue bond performance.