Experimental study on impact parameters of fiber GGBFS-based geopolymer concrete plates

Concrete is one of the most common structural materials., but it is a brittle material and haselastoplastic behavior. A suitable way to improve ductility and increase the resistance of concrete structuresagainst dynamic loads such as impact, earthquake, and fatigue is to add fibers to concrete. In addition, manyexperimental results have shown that compared to cement concrete, geopolymer concrete has fewerinherent defects and a denser internal structure, which leads to stronger impact resistance. In this paper, theimpact behavior of Geopolymer Concrete using (GGBS) under the effect of varying concentrations of alkaliactivators and steel fibers was experimentally investigated. The dimensions of the unreinforced concreteplates under the impact-resisting test were ۳۰۰×۳۰۰×۳۰ mm. Sodium Hydroxide (NaOH) and SodiumSilicate (Na۲SiO۳) with an Alkali Activator ratio (AAR) of ۱:۲.۵ as alkali activators were used. Also, themolarity of NaOH was altered for ۴ Molar and ۶ Molar. percentages (by volume of concrete) of steel fibersused are ۰.۵%, ۱%, and ۱.۵%. The specimens were cast for impact-resisting tests and were tested after ۲۸days of ambient curing. It was observed that maximum energy absorption and impact strength occur inmolarity ۴ and ۶ and in the amount of ۱% of steel fibers, Where the impact strength and energy absorptionfor molarities ۴ and ۶ increase by ۵۸.۸۸% and ۳۴.۲۶% and ۷% and ۱۱.۱۱% to the control mix, respectively.Also, the results showed that the amount of ۱.۵% of steel fibers hurt the process of increasing impactstrength and energy absorption of geopolymer plates, So the impact strength and energy absorption formolarity ۶ decreased by ۲۳.۱۳% and ۲۳.۹۳% compared to the control mix.

کلیدواژه ها:

Geopolymer Concrete ، Alkali Activators ، GGBFS ، Steel Fibre ، Impact Strength ، Energy Absorption