Advanced Materials Research Vol. 1172

Abstract: Epoxy was loaded with varying concentrations of fly ash and was characterized for its structural properties using XRD and SEM. The XRD results revealed reduction of crystallinity with increase in filler content indicating that the composites are semi crystalline in nature. The SEM images showed that at lower concentration of filler content, fly ash is uniformly distributed within the epoxy and at higher concentrations of fly ash, agglomerates were observed. Mechanical properties such as tensile and compressive properties were estimated and the results showed that, the composites exhibit enhanced tensile strength and compressive strength for epoxy with 20 wt% fly ash. Flammable properties such as heat release rate, peak heat release rate, time to ignition, CO and CO₂ yields are estimated and reported. Decrease in combustion time, peak heat release rate, time to ignition, CO and CO₂ yields with increase in filler content clearly indicates the superior flammability performance of epoxy composites loaded with fly ash.

Abstract: In this study, fly ash was used to synthesize geopolymer mortar by using an activating solution prepared from a different concentration of NaOH and a highly viscous Na-silicate. The NaOH concentration prepared were 8M, 12M, and 14M. The prepared geopolymers were cured at different temperatures (ambient, 40°C, and 60°C) and were studied to determine their strength, bond structure, mechanical properties, and resistance in an acidic and salty environment using an accelerated durability test. FTIR results showed distinctive peaks of aluminosilicate bond structures. Maximum strength was achieved for 14M samples cured at room temperature. Higher alkalinity resulted in higher compressive and flexural strength and lower water absorption. Lower water absorption capacity and higher resistance to the extreme environment were achieved for samples cured at higher temperatures and higher molarities. The maximum mass loss was 10.9% for 8M cured at ambient temperature exposed to an acidic environment.