Comparative study of fire-resistant behaviors of high-calcium fly ash geopolymer mortar containing zeolite and mullite

Abstract

This study examined the fire resistance behaviours of high calcium fly ash (HCFA)-based geopolymer mortar incorporating natural zeolite (Z) and mullite (M). Fly ash was replaced by Z and M at the replacement levels of 10%, 20%, and 30% by weight. Workability and compressive strength were investigated. The specimens were then exposed to temperatures of 300 °C, 600 °C, and 900 °C before their compressive strength and microstructure were analysed. The result showed that the use of either Z and M alone and together improved the fire resistance of HCFA geopolymer composite. The improvement in strength was due to the presence of Ye’elimite and Wallastonite formed at high temperatures with the incorporation of Z and M and this was confirmed by SEM and EDX analysis. This study, thus, shows the promising future for a new fire-resistant material in the construction industry.

Keywords:

• Fly ash
• geopolymer
• fire resistance
• natural zeolite
• mullite

Disclosure statement

No potential conflict of interest was reported by the authors.

A: Anhydrite (Ca(SO₄)), Q: Quartz (SiO₂), O: Lime (CaO), Ma: Magnesioferrite (MgFe₂O₄), H: Heulandite (CaAl₂Si₇O₁₈·6H₂O), An: Anorthite (CaAl₂Si₂O₈), M: Mullite (Al₆Si₂O₁₃).

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Additional information

Funding

The authors would like to acknowledge the financial supports from the Sustainable Infrastructure Research and Development Center (SIRDC), Department of Civil Engineering, and Farm Engineering and Automation Technology (FEAT), Khon Kaen University, Thailand.