Bond stress-slip models and behavior of externally bonded aluminum alloy (AA) plates to concrete surface

Abstract

This paper aims to assess the feasibility of employing high strength aluminum alloys (AA) with a rough (R) surface as externally bonded reinforcement (EBR) material. A comprehensive experimental investigation was carried out to evaluate the bond strength and behavior through single shear tests. The variables considered were concrete strength and bonded length, while the remaining parameters were kept constant. The study measured the ultimate load, extension, and strain values, and subsequently calculated the bond stress and slip. It was observed that the ultimate load, bond stress, and failure modes exhibited variations depending on the concrete strength and bond length. For a concrete strength of 60 MPa and a bonded length of 80 % of the concrete prism length, the ultimate load and maximum bond stress increased by 54.0 % and 66.0 % respectively, compared to those with a concrete strength of 20 MPa and the same bonded length. Additionally, when comparing a bonded length of 80 % (200 mm) of the concrete prism length to a bonded length of 20 % (50 mm), the ultimate load and maximum bond stress increased by 20.0 % and 99.0 % respectively for a concrete strength of 60 MPa. The study also developed bond stress-slip models for the AA-concrete interface, as well as models for predicting the ultimate load based on concrete strength and bonded length. These models displayed high accuracy in their predictions. In conclusion, the results indicate that AA plates are effective and suitable as EBR materials for the reinforcement of RC members.