TY - JOUR N2 - Setting time in geopolymers is known as the time taken for the transition phase of liquid to solid of the geopolymer system in which is represented in the initial setting and final setting. Setting time is significant specifically for application in the construction field. This study intends to determine the setting time of high calcium fly ash geopolymers and the properties of the geopolymers after setting (1-day age). This includes the determination of heat evolved throughout geopolymerization using Differential Scanning Calorimeter. After setting properties determination includes compressive strength and morphology analysis at 1-day age. High calcium fly ash was used as geopolymer precursor. Meanwhile, for mixing design, the alkali activator was a mixture of sodium silicate and sodium hydroxide (concentration varied from 6M-14M) with a ratio of 2.5 and a solid-to-liquid ratio of 2.5. From this study, it was found that high calcium fly ash geopolymer with 12M of NaOH has a reasonable setting time which is suitable for on-site application as well as an optimal heat evolved (–212 J/g) which leads to the highest compressive strength at 1-day age and no formation of microcracks observed on the morphology. Beyond 12M, too much heat evolved in the geopolymer system can cause micro-cracks formation thus lowering the compressive strength at 1-day age. L1 - http://www.journals.pan.pl/Content/123281/PDF/AMM-2022-2-23-Razak.pdf L2 - http://www.journals.pan.pl/Content/123281 PY - 2022 IS - No 2 EP - 567 DO - 10.24425/amm.2022.137791 KW - high calcium fly ash geopolymers KW - Setting time KW - heat evolved KW - early age properties KW - concentration of sodium hydroxide A1 - Mohamed, Rosnita A1 - Abd Razak, Rafiza A1 - Al Bakri Abdullah, Mohd Mustafa A1 - Sofri, Liyana Ahmad A1 - Aziz, Ikmal Hakem A1 - Shahedan, Noor Fifinatasha PB - Institute of Metallurgy and Materials Science of Polish Academy of Sciences PB - Committee of Materials Engineering and Metallurgy of Polish Academy of Sciences VL - vol. 67 DA - 2022.06.10 T1 - Setting Time and after Setting Properties of High Calcium Fly Ash Geopolymers with Different Concentration of Sodium Hydroxide SP - 563 UR - http://www.journals.pan.pl/dlibra/publication/edition/123281 T2 - Archives of Metallurgy and Materials ER -