Monitoring of steel-concrete bond using pull-out test with the acoustic emission technique
Résumé
Cracking in reinforced concrete structure is of major concern since it may impact their durability and their structural integrity. Cracking is mainly influenced by the stress distribution along the interface between steel and concrete which is responsible of transferring load from steel bar to the surrounding matrix. Thus, quantitative evaluation of the influence of steel-concrete bond on the fracture properties is important. An experimental investigation on pull-out and tensile tests on reinforced concrete ties is reported in this study. Pull-out and tensile tests are conducted on cubic specimens with different reinforcement diameters of high adhesion in parallel with a continuous monitoring using the Acoustic Emission (AE) technique and the Digital Image Correlation (DIC). The AE technique allows real time monitoring of the fracturing stages and can provide useful information about the location of defects and damage characteristics. Two failure modes are observed according to the steel bar section: concrete cover splitting and pull out with damage concentrated near the concrete rebar interface. The results show a good correlation between the loading force and the AE activity with AE signal of different characteristics indicating different active fracture mechanisms. The order of apparition of cracks, their width and their spacing was also measured in correlation with the loading level for short ties with different lengths and bar diameters. In addition, the location of AE events is consistent with the actual crack development.
Origine : Fichiers produits par l'(les) auteur(s)
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