Alkali Activated Class F-Fly Ash Based Geopolymer Concrete at Elevated Temperatures

Jonathan Glover

Abstract


Geopolymer concrete is becoming a viable alternative to Ordinary Portland Cement concrete because of its excellent physical, economic and environmental properties. This is due to the large global production of fly ash, which can be used as the main ingredient in geopolymers. It is cheap and readily available, in comparison to the massive amount of energy that is used to produce Ordinary Portland Cement. The aim of this research is to analyse the physical properties of low-calcium (Class F) fly ash-based geopolymer concrete while it is elevated to high temperatures, and how it will behave with varying types of coarse aggregate. While studies have been conducted on the hot strength of the geopolymer binder without aggregates, limited research has been submitted on the properties of geopolymer concrete at elevated temperatures. This project analysed the compressive strength and elastic modulus of GPC at varying temperatures and also looked at the residual strength after the samples were allowed to cool. The experimental results showed varying strength losses and gains with increased temperatures and found that stiffness decreases with increasing temperature. It was also found that samples made with artificial aggregates initially produced weaker geopolymer concrete but performed better in terms of relative strength loss at higher temperatures.

Keywords


geopolymer; fly ash; temperature

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