Effect of high temperature exposure on epoxy-coated glass textile reinforced mortar (GTRM) composites. (10th July 2019)

• Record Type: Journal Article
• Authors: Messori, Massimo; Nobili, Andrea; Signorini, Cesare; Sola, Antonella
• Is Part Of: Construction & building materials. Volume 212(2019)
• Page Start: 765
• Page End: 774
• Publication Date: 2019-07-10
• Subjects: TRM -- High temperature -- Epoxy coating; Building materials -- Periodicals; 624.18
• DOI: 10.1016/j.conbuildmat.2019.04.026
• Languages: English
• ISSNs: 0950-0618

Abstract

Highlights: Temperature degradation of epoxy-coated GTRM is generally mild and strongly dependent on the resin formulation. Temperature induced post-curing is beneficial in terms of strength and data scattering. Yet, ductility is a decreasing function of temperature. Energy dissipation decreases with temperature in power-law fashion. This behaviour corresponds to a cumulative Weibull distribution adopted in thermal damage models for resins. Abstract: An experimental investigation on the mechanical performance of epoxy-coated Alkali-Resistant (AR) glass textile reinforced mortar subjected to elevated temperature is presented. Two epoxy coatings are considered, which differ by the hardening agent alone. After 56 days dry curing, specimens are heated up to four different temperatures. After cooling down to ambient temperature, specimens are assessed in uni-axial tensile test according to Annex A of AC434. First cracking strength and elongation, ultimate tensile strength and elongation, cracked and uncracked moduli, transition point location and energy dissipation capability are evaluated. It is found that, in the explored temperature range, degradation is surprisingly mild and strongly dependent on the resin which is taken as coating agent. Indeed, temperature exposure may lead to strength enhancement. This positive outcome takes place at the expense of ductility and it is traced back, through Differential Scanning Calorimetry (DSC), to a post-curing process. Nonetheless, energy dissipation still decreases with temperature and, remarkably, with the same power-law behaviour for both resins. Such behaviour is compatible with a cumulative Weibull distribution, that is adopted in thermal damage models for resins, and it indicates that the underlying damage mechanism indeed operates on the resin at the fabric-to-matrix interface.