UNI-MB - logo
UMNIK - logo
 
E-resources
Full text
Peer reviewed Open access
  • Experimental and analytical...
    Zhao, Jitong; Signorini, Cesare; Nobili, Andrea; Liebscher, Marco; Kohout, Jan; Hájková, Pavlína; Mechtcherine, Viktor

    Construction & building materials, 07/2024, Volume: 435
    Journal Article

    The restricted operating temperature range of fibre-reinforced polymer (FRP) systems for upgrading and retrofitting reinforced concrete structures is among the key limiting factors of this technology. Indeed, an alternative reinforcing system, known as Mineral-impregnated Carbon-Fibre (MCF), has recently emerged to address this issue. This paper presents an experimental investigation of the performance of MCF systems embedded in fine-grained, Alkali-Activated Concrete (AAC), which have been pre-heated at 100°C (or 200°C) and then tested in pull-out at the target temperature. For the purpose of assessing the bond quality against thermal exposure, results are compared with the control group (ambient temperature 20°C), as well as with an epoxy-impregnated commercial roving. In addition, specimens are characterised at the fibre-to-matrix interface by microscopy and by physical–chemical analytical techniques. Experimental data are fitted onto a one-dimensional stress-and-friction analytical model to determine the characteristic properties of the temperature-dependent bond–slip behaviour of MCFs. Findings suggest enhanced chemical compatibility and reinforcing capabilities at elevated temperature for MCFs, primarily ascribed to the impregnation quality and to the AAC capacity to withstand thermal strain. Display omitted •Bond of mineral-impregnated carbon fibre (MCF) in alkali-activated concrete is studied up to 200 °C.•A 1D stress-friction model is used to monitor the change in bond properties of MCF.•No stress transfer for epoxy based CF at 200 °C, whereby MCF retain more than 50% of their bond strength.•Profiling of MCF affects internal cracking and bond quality.•Bonding behaviour of smooth MCF proves to be the most stable up to 200 °C.