Effect of macro polypropylene, polyamide and steel fibers on the residual properties of SCC at ambient and elevated temperatures


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Güler S. , Akbulut Z. F. , Siad H., Lachemi M.

Construction And Building Materials, vol.289, pp.1-13, 2021 (Journal Indexed in SCI Expanded)

  • Publication Type: Article / Article
  • Volume: 289
  • Publication Date: 2021
  • Doi Number: 10.1016/j.conbuildmat.2021.123154
  • Title of Journal : Construction And Building Materials
  • Page Numbers: pp.1-13

Abstract

This paper considers the effect of equivalent macro size fibers of polypropylene (PP), polyamide (PA) andsteel (ST) on the properties of reinforced self-compacting concrete (FRSCC) exposed to normal andelevated temperatures. Different fiber concentrations of 0%, 0.3%, 0.6% and 1% were investigated undertemperatures of 20°C, 300°C, 500°C and 800°C. Mass loss, residual compressive strength (RCS), residualflexural strength (RFS), toughness indices (TI), residual strength factors (RSF) and residual toughness (RT)capacities of FRSCCs were studied at hardened state based on their initial results at ambient curing.Meanwhile, slump-flow diameter, T500time and L-box parameters were also tested at fresh state. In addi-tion, the microstructural changes due to the use of various fibers and temperatures were examined byscanning electron microscope (SEM) analysis. The effect of macro PA and PP was comparable in termsof their minor influence on the mass loss, RCS and RFS of FRSCC compositions. However, macro PA pre-sented greater contribution than PP in preserving the toughness capacity, particularly in the post-peakstage. Unlike PA and PP, the use of macro ST fibers caused noticeable increments in RFS and RT capacities.The superior outcome of using macro ST was confirmed through its higher effect in mitigating the crackformation of FRSCC, especially under elevated temperatures of 500°C and 800°C.