Behavior of geopolymer concrete under impact

This study investigates the properties of self-compacted geopolymer concrete (SCGC) obtained by ground granulated blast furnace slag (GGBFS) as binder in both the fresh and hardened states under the combined addiction of nano-silica (NS), steel fibers (SFs) and recycled tyre rubbers (RTR). While eighteen different mixtures were used in the experimental study, a total of thirty-six beam specimens were produced for the study. Those eighteen mixtures of SCGC contained different percentages of NS (0% and 2%) and different percentages of SFs (0%, 0.5% and 1%) and different percentages of RTR (0%, 10% and 15%). 100% GGBFS with a fixed alkaline activator-to-binder ratio of 0.5 was used as a binder to prepare the SCGC mixes. A blend of sodium-silicate (Na2SiO3) solution and sodium hydroxide (NaOH) solutions with a ratio of 2.5 has been chosen as an alkaline activator. The fresh and hardened states concrete tests including slump, flow ability, workability and compressive, impact and flexural strengths were realized in the study. Experimental results were examined in detail to determine the influence of important factors on mechanical performance of SCGC. Furthermore, correlations among the empirical data were evaluated to explore the relations between the hardened and fresh states properties of SCGC. Experimental results showed that the combined use of NS and SFs affected the fresh state properties adversely, while it improved the impact and flexural properties of the SCGC samples considerably. Moreover, the influence of NS was predominant regarding the fresh state performance and compressive strength, while the effect of SFs were superior regarding flexural and impact strength. Moreover, incorporating of RTR influenced the fresh state properties reversely, while the effect of SFs with RTR was superior regarding flexural and impact strength.