PSI - Issue 64

Shehroze Ali et al. / Procedia Structural Integrity 64 (2024) 1394–1401 Shehroze Ali et al. / Structural Integrity Procedia 00 (2019) 000 – 000

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intensive, i.e., 1 ton of cement production involves 866 kg of CO 2 emissions. Overall, cement industry is considered as one of the major greenhouse gas emitters accountable for 5% of the total CO 2 emissions (Farfan et al. 2019). The increasing awareness of global warming issue led to the consumption of environment friendly concrete such as geopolymer concrete. Geopolymer concrete has gained a significant attention from the researchers as well as the construction industry, as it can be produced using various industrial by-products, such as slag and fly ash as well as agricultural by products, such as sugarcane bagasse and corncob ashes rather than the conventional (ordinary Portland cement) OPC (Ghafoor et al. 2024; Umer at al. 2023). The production of slag/fly ash based geopolymer concrete (SFGC) involves a geopolymerisation of binder material (slag and fly ash) in the presence of alkaline solution (sodium silicate and sodium hydroxide blended liquids) (Davidovits 1991). Overall, the fresh and the hardened properties of an ambient cured geopolymer concrete is as good as OPC concrete and can be efficiently used for onsite construction of the structural members (Hadi et al. 2017; Ma et al. 2018; Ali et al. 2021). Apart from the advantageous properties, geopolymer concrete exhibits high brittleness and low flexural strength (Pan et al. 2011; Steinerova 2017). Generally, the development of micro and macro cracks due to the plastic shrinkage led to the overall reduction in strength and ductility of the concrete. The use of reinforcing fibres in the concrete is an effective technique to stop or control the propagation of cracks. In fact, fibre reinforced concrete exhibits higher ductility and flexural strength compared to plain concrete (Foti 2011). In recent years, studies have been carried out to enhance the ductility of geopolymer concrete by adding different types of steel fibres. Farhan et al. (2018) found that, the addition of hybrid steel fibres improved the overall mechanical properties of geopolymer concrete. However, the metallic nature of steel fibres and corrosion issues led to the use of non-metallic fibres such as glass fibres in geopolymer concrete. Ganesh and Muthukannan (2019) found that the strength properties of heat-cured geopolymer concrete were improved with the addition of glass fibres. The use of heat cured glass fibre reinforced geopolymer concrete limit its use to precast conditions. On the other hand, the addition of glass fibers in ambient cured geopolymer still need to be investigated. Hence, the aim of this study is to investigate the effect of the addition of glass fibres on the workability, density, compressive strength and flexural strength of slag/fly ash based geopolymer concrete (SFGC).

Nomenclature FA fly ash GF

glass fibre GGBFS ground granulated blast furnace slag OPC ordinary Portland cement SFGC slag-fly ash based geopolymer concrete SSD saturated surface dry

2. Experimental Details 2.1. Materials

In this study, a surface saturated dry (SSD) coarse and fine aggregates were used. The aggregates were uniformly graded with coarse aggregate of size 5-10 mm and fine aggregate (river sand) of maximum size 4.75 mm. Both coarse and fine aggregate were provided by a local supplier. The source material used to produce geopolymer concrete comprised ground granulated blast furnace slag (GGBFS) and fly ash (FA). The GGBFS and FA were supplied by the Australasian (Iron & Steel) Slag Association and Boral Group of Companies, Australia, respectively. In order to determine the chemical composition of slag and FA, X-ray fluorescence (XRF) tests were conducted at the School of Earth and Environmental Sciences, University of Wollongong, Australia. The slag contained approximately 42.7% calcium oxide (CaO) by mass and were considered as reactive compound. The FA contained approximately 62.4% silicon dioxide (SiO 2 ), 26.2% aluminium