Threaded sleeve bonded anchorage for carbon fiber reinforced polymer tendons in glulam beams: experimental testing and parametric simulations

Abstract Using prestressed carbon fiber reinforced polymer (CFRP) tendons to strengthen glulam beams is a promising approach to improve their load-carrying capacity and crack resistance. Reliable anchorage is critical for ensuring the overall performance of the beam. In this paper, a threaded sleeve bonded anchorage was developed for CFRP prestressing tendons in glulam beams. Pullout tests were conducted on a series of bonded anchorage specimens with different sleeve lengths. The test results show that the main failure modes of the anchorage were the fracture of CFRP tendons. Increasing sleeve length reduced the maximum slip at the CFRP-adhesive interface but enhanced its capacity. As the sleeve length increased from 150 to 250 mm, the maximum slip decreased by 13.6%, with the ultimate tensile capacity increasing by 4.6%. A finite element model was then developed for the bonded anchorage. It was verified based on the pullout test results and utilized in a parametric study to further explore the anchorage behavior. The results indicate that longer sleeve length led to more uniform distributions of both axial and radial stresses along the CFRP tendon. Increasing elastic moduli of adhesive reduced the maximum slip and resulted in less uniform radial stress distributions of CFRP tendons.