Abstract
The construction industry is placing significant emphasis on finding alternative binders to completely replace ordinary Portland cement (OPC) due to its environmental consequences. In this study, an experiment for the geopolymer concrete (GPC) made with fly ash and reinforced with glass fibers was conducted. GPC, in contrast to OPC which utilizes water for its binding effect, relies on an alkaline activator. This activator comprises solutions of sodium silicate (SS) and sodium hydroxide (SH) to achieve the binding process. The experiment investigated the specific combination of alkali activator liquid to fly ash ratio and, SS to SH ratio to produce the highest compressive strength result as well as the best workability performance. The aggregates used in the concrete are subject to grading and classification as per Australian standards and fly ash used in the production of concrete using Collie coal power stations, Western Australia, derived fly ash (Class F) activated by Sodium Silicate (SS) and Sodium Hydrate (SH) as the alkaline solution at 14 M. Glass fibers were added in a proportion of 2% by weight of concrete. The design mixes were applied by altering the SS to SH ratio of 1.25, 1.5, and 2.6, the alkaline activator liquid (AA) to fly ash (FA) ratio of 0.4, 0.5, 0.57, and 0.58. Also, the percentage of water to alkaline solution of 11%, 18%, and 20%. Concrete samples were cured in an oven at 60℃ for 24 h and at room temperature. The result indicated alkali activators liquid with SS to SH ratio of 1.5 and 2.6 achieved a maximum compressive strength after 28 days of 35 MPa and 40 MPa, respectively. Compressive strength decreases as the alkaline liquid to fly ash ratio is increasing. The workability for AA to FA of all ratios and for all percentages of water to AA shows good workability specified by Australian Standard.