Design optimization and experimental validation of a novel wedge-shaped bond anchorage system for prestressed CFRP plates

An efficient anchorage system plays a significant role in the strengthening and repair of existing structures in prestressed carbon fiber reinforced polymer (CFRP) plates. In the present study, a novel wedge-bond anchor was proposed to provide a reliable anchorage load-bearing capacity for the prestressed CFRP plate. Accordingly, interface bond tests were conducted to optimize the anchor parameters. The results revealed that the minimum bond length of the wedge-bond anchor was 100 mm and 120 mm for the adhesives Tc and T1, respectively. After optimization, the weight of the anchor was reduced by 58.3%. A mechanical model was built to analyze the load transfer path and evaluate the anchorage bearing capacity. Based on these, the ultimate anchorage bearing capacity was predicted to be higher than 4.70 GPa and 4.10 GPa for the adhesives Tc and T1, respectively. Tensile tests of the optimized anchor showed that a) the stress in the anchorage zone of the CFRP plate was distributed uniformly, and b) the stress concentration of CFRP in the anchor was avoided, which provided a higher anchorage bearing capacity. The extension applications of wedge-bond anchor were carried out for a larger size of CFRP plates (100 mm x 1.4 mm). Accordingly, it successfully led to CFRP bursting, yet no debonding occurred in the anchor.