Numerical investigation of parameters influencing fire evaluation tests of chemically bonded anchors in uncracked concrete. (15th April 2020)

• Record Type: Journal Article
• Authors: Al-Mansouri, Omar; Mège, Romain; Pinoteau, Nicolas; Guillet, Thierry; Piccinin, Roberto; McBride, Kenton; Rémond, Sébastien
• Is Part Of: Engineering structures. Volume 209(2020)
• Publication Date: 2020-04-15
• Subjects: Adhesive resin -- Bonded anchor -- Fire tests -- Thermal distribution -- Numerical model -- Resistance Integration Method; Structural engineering -- Periodicals; Structural analysis (Engineering) -- Periodicals; Construction, Technique de la -- Périodiques; Génie parasismique -- Périodiques; Pression du vent -- Périodiques; Earthquake engineering; Structural engineering; Wind-pressure; Periodicals; 624.105
• DOI: 10.1016/j.engstruct.2020.110297
• Languages: English
• ISSNs: 0141-0296

Abstract

Highlights: Heat transfer model for bonded anchors under fire. Calculation of bond strength vs. time relationship by resistance integration. Comparison of 2D and 3D modelling approaches for bonded anchors under fire. Analysis of the predicted bond failure for each modelling approach. Abstract: European guidelines for fire performance evaluation of post-installed anchoring systems are limited to mechanical (e.g., expansive, undercut) mechanisms of load transfer and the steel failure mode, whereas the adhesive bond mechanism remains unaccounted for in chemically bonded anchors. Furthermore, current evaluation methods do not account for the influence of practical testing conditions on temperature profiles along the bonded depth. This paper presents 3D finite element thermal simulations of chemically bonded anchors in uncracked concrete exposed to ISO 834 fire conditions with comparisons to experimental specimens. Five parameters representing application and testing conditions are investigated to assess their influence on temperature profiles along the embedment depth of bonded anchors. A numerical model is proposed based on the results of the numerical simulations to determine thermal data necessary for predicting the load-bearing capacities of bonded anchors using the Resistance Integration Method. The model adopts Eurocode material properties for concrete and steel, with 3D analysis yielding conservative capacity prediction compared to physical fire tests. 3D and 2D simulation results are compared, demonstrating that modelling using 2D heat transfer analysis yields inaccurate temperature profiles compared to 3D modelling. After experimental validation of the proposed model, additional parameters are explored in a numerical parametric study: embedded depth, external length of the anchor element, insulation of the anchor element, and insulation of the concrete element. Results show that the embedded depth has a significant influence on temperature profiles along the bond. Moreover, the external length of the anchor influences temperature profiles, but not beyond 20 mm from the concrete surface.