###### Abstract  
This study investigates the alterations in the ratios of components such as class C fly ash (FA), blast furnace slag (BFS), and waste stone powder (WSP) types of limestone powder (LP) used in the production of geopolymer concrete. These components are meticulously examined concerning the physical and mechanical attributes of geopolymer concrete. Using the mixture-design method, 10 different mixing ratios were determined using FA, BFS, and LP, and experimental research on the mechanical attributes and workability of geopolymer mortar is presented. A series of experimental tests, including tests for compressive strength, impact strength, setting time, flow table, flexural strength, and water absorption, were carried out on the geopolymer mortars that were made using FA, BFS, and LP, to investigate and enhance their overall performance. The experimental study aimed to ascertain the extent to which variations in the materials used in the formation of geopolymer mortar affected its mechanical and physical properties. To achieve this objective, certain parameters for geopolymer mortar formulation were fixed, according to the literature (molarity: 10; aggregate/binder ratio: 2.5; plasticizer ratio: 2%; sodium silicate (SS)/sodium hydroxide (SH): 1.5; additional water content: 14.5%; alkali activators/binder: 0.5). Subsequently, mortars were produced according to the 10 different mixing ratios determined by the mixture-design method, and the experiments were completed. The samples of the 10 different mixes were subjected to air curing at an ambient temperature (23 \({}^{\circ}\)C \(\pm\) 2 \({}^{\circ}\)C) for 28 days. Following the curing period, the tests revealed that mix No. 9 exhibited the best compressive, flexural, and impact strengths, while mix No. 10 demonstrated superior workability of geopolymer mortar. It was shown that impact, compressive, and flexural strength values decreased as the ratios of FA and LP increased. In contrast, the increases in the ratios of FA and LP positively influenced the workability of geopolymer mortar. blast furnace slag; compressive strength; fly ash; geopolymer; impact strength; limestone powder +
Footnote †: journal: Applied Sciences  
In recent years, there has been a growing emphasis on recycling industrial waste materials such as fly ash, blast furnace slag, and waste stone powder (WSP). These materials can be activated with various alkalis, resulting in the production of binding materials used in geopolymer concrete [6; 7; 8; 9; 10; 11; 12]. According to American Material Test Standard (ASTM) C618-19, fly ashes obtained from bituminous coal, with a content of SiO\({}_{2}\) + Al\({}_{2}\)O\({}_{3}\) + Fe\({}_{2}\)O\({}_{3}\) exceeding 50%, are classified as class C. Furthermore, in the class C fly ash classification, it has been indicated that the calcium oxide (CaO) content is above 10%. The fly ash chosen in this study was class C fly ash [13]. Polymerization is a heterogeneous chemical reaction. The exposure of aluminosilicate hydrates to heat causes the dissociation of OH ions, forming water, and initiates the formation of Si-O-Al bonds [14]. This reaction, occurring between solid aluminosilicate oxides and alkali metal silicate solutions under highly alkaline conditions and moderate temperatures, results in amorphous semi-crystalline polymeric structures containing Si-O-Al and Si-O-Si bonds [15]. Various geopolymers have been defined in the literature based on the Si/Al ratio. Some of these include water glass-based geopolymer, polysiloxonate (Si:Al = 1:0), kaolin hydrosyodalite-based geopolymer, polysilate (Si:Al = 1:1), metakaolinite-based geopolymer, poly (silate-siloxo) (Si:Al = 2:1), calcium-based geopolymer, (Ca, K, Na)-silate, (Si:Al = 1, 2, 3), rock-based geopolymer, poly (silate-multisloxo) (1 < Si:Al \(\leq\) 5), and fly ash-based geopolymers [16].