IJBTT

Mechano-Physical Properties and Microstructure of Colloidal Nanosilica-Incorporated Volcanic Ash-Based Geopolymer Mortar after Exposure to Elevated Temperatures

Mechano-Physical Properties and Microstructure of Colloidal Nanosilica-Incorporated Volcanic Ash-Based Geopolymer Mortar after Exposure to Elevated Temperatures
	© 2024 by IJETT Journal
	Volume-72 Issue-5
	Year of Publication : 2024
	Author : Samson Kiprop, Richard Ocharo Onchiri, Naftary Gathimba
	DOI : 10.14445/22315381/IJETT-V72I5P108

How to Cite?

Samson Kiprop, Richard Ocharo Onchiri, Naftary Gathimba, "Mechano-Physical Properties and Microstructure of Colloidal Nanosilica-Incorporated Volcanic Ash-Based Geopolymer Mortar after Exposure to Elevated Temperatures," International Journal of Engineering Trends and Technology, vol. 72, no. 5, pp. 66-85, 2024. Crossref, https://doi.org/10.14445/22315381/IJETT-V72I5P108

Abstract
Due to the expansion of construction activities and the increased threat of fires to civil structures and lives, there has been a need to find alternative fire-resistant materials that meet sustainability and green material standards. This study reports on using Colloidal Nanosilica (CNS) to modify the elevated temperature resistance of Volcanic Ash-Based Geopolymer Mortar (VAGPM). The volcanic Ash (VA) locally sourced in Kenya was partially replaced with between 1-5% CNS by mass of VA and activated with sodium or potassium hydroxide and sodium silicate. The workability of the resulting mixtures was determined. Following a curing period of 28 days, the VAGPM specimens were exposed to temperatures ranging from 200-8000C for durations of 1 and 2 hours, and their compressive strengths, mass losses, volumetric changes, visual appearances, and microstructural properties were analysed. Results indicated that replacing VA with CNS up to 5% by mass resulted in a reduction in the flowability of the fresh mortar and that adding 2% CNS improved compressive strength and elevated temperature resistance. In contrast, higher levels did not significantly improve performance. Specimens recorded increased compressive strengths up to 400 and 6000C. Increasing CNS levels decreased mass loss and volume shrinkage. The samples also displayed changes in colour and mineralogical phases after exposure to elevated temperatures. CNS yielded a denser microstructure.

Keywords
Colloidal Nanosilica, Elevated temperature, Geopolymer mortar, Mechano-physical properties, Volcanic ash.

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