Case Studies in Construction Materials (Dec 2023)
Thermal curing effects on alkali-activated treated soils with palm oil fuel ash
Abstract
Regarding the significance of binder quantity, alkali activator molarities, and thermal curing, this work was utilized to geopolymerize with a potassium-based alkaline activator to strengthen soils. Five different molarities of palm oil fuel ash (POFA) in four different amounts were utilized to activate the clayey soil. POFA admixtures have been used to test soils. The results showed that for mixtures with 10 and 12.5 molarities, the unconfined compressive strength (UCS) with 15 % and 20 % of POFA was stronger. Comparing the strengths of the blends with various POFA amounts and concentration molarities allowed for this determination. To increase the strength, it is crucial to consider how the geopolymerization method's temperature and curing time affect the UCS of the soil-POFA mixture with and without fibers. The UCS of the treated soil mixtures was changed by heating at 30, 50, 70, and 90 °C. The outcomes demonstrate that increasing the curing temperature will hasten the alkaline activation process. After seven days of heating, the treated soil specimens with and without fibers exhibit the best mechanical properties at a healing temperature of about 70 °C, with compressive strengths of 16.7 and 11.4 MPa. The interaction between the geo-polymeric matrix and the fiber surface, the molarities of the alkaline solution, and the heating temperature were the most important aspects, according to an investigation of the microstructures, in improving the behavior of the reinforced mixes. By offering an efficient approach for increasing the qualities of soil treated by the alkali activation of POFA through the inclusion of glass fibers with adequate molarities of reagent and cure heating temperature, the current work offers new insights into soil stabilization operations. This has advantages over conventional calcium-based binders due to their emission of carbon dioxide during manufacture, which is one of the major causes of global warming.
