Effects of CNT modified adhesives and silane chemical pre-treatment on CFRP/steel bond behaviour and durability

摘要

Carbon fibre reinforced polymers have shown an ability to provide increased strength and rehabilitation properties to steel. However, under extreme environmental conditions adhered CFRP/steel joints undergo detrimental reductions in strength and durability. This paper explores the use of silane chemical barriers and adhesive modifications to improve bond durability and retard environmental damage and restrict bond degradation. Carbon nano tube immersion in adhesives created increases in mechanical properties however the cost, time and dispersion difficulties prevented viable industrial applications. The study experimentally tested steel-CFRP double-lap specimens prepared with combinations of epoxy adhesives and silane pre-treatment. Samples experienced ongoing static service loading while submerged in 5% NaCl solutions of varying temperatures. After immersion for different durations, samples were fatigue loaded for a set number of cycles, after which, static failure loads were determined. Comparing tensile bond strengths quantified the impact that environmental conditioning, fatigue loading and retarding barriers have on the bond durability of CFRP to steel. Crown Copyright (C) 2020 Published by Elsevier Ltd. All rights reserved.