Fire Retardant Performance of Rice Husk Ash-Based Geopolymer Coated Mild Steel - A Factorial Design and Microstructure Analysis

Abstract

Higher content of silica in geopolymer coating resulted in better thermal properties. Since rice husk ash (RHA) has the highest silica content compared to other aluminosilicate sources available, it offers the best potential to be an alternative silica source in producing geopolymer coating binder. In this study, five factors including ratio of alkaline activator (AA) (A), ratio of RHA/AA (B), curing temperature (C), curing time (D) and concentration of NaOH (E) were analyzed using statistical analysis to identify the significant factors that mostly influence fire retardant performance of RHA-based geopolymer coating. The fire retardant tests were conducted and results recorded included (i) time taken to reach 300°C and (ii) temperature at equilibrium. Sample S7 (coating composition of A=5.5, B=0.3, C=50°C, D=7days, E=8M) which produced the best fire retardant performance was selected for further detailed investigation using thermogravimetry analysis (TGA) and scanning electron microscopy (SEM). It was found that the back temperature of mild steel plate of sample S7 reached 300°C after 17 minutes and achieved an equilibrium state at 398°C. SEM micrographs showed the presence of needle-like structures formed after fire test might be the reason for the best fire performance of sample S7.

Rice Husk Ash/Silicone Rubber-Based Binary Blended Geopolymer Coating Composite: Fire Retardant, Moisture Absorption, Optimize Composition, and Microstructural Analysis

“…For the control sample, which is without the addition of silicone rubber, the recorded highest temperature at equilibrium and the level of highest moisture absorption was 350 °C and 22.0%, respectively. The results are in agreement with those of other studies which recorded the two values at 350 °C [ 6 ] and 30% [ 56 ], respectively. The result establishes that the incorporation of silicone rubber improves the fire retardant and moisture absorption properties of geopolymer.…”

“…Geopolymer is an amorphous solid inorganic polymer with a tri-dimensional aluminosilicate structure produced from the chemical reaction known as geopolymerization between the alkaline solution and aluminosilicate source [ 5 ]. Biomass wastes such as rice husk ash and palm oil fuel ash have been recycled as sources [ 6 , 7 ]. Other common sources are metakaolin [ 8 , 9 ], fly ash [ 10 ], and ground granulated blast-furnace slag (GBBS) [ 11 ].…”

“…Geopolymer coating using RHA as the aluminosilicate source has shown excellent fire retardant properties. Mohd Basri, Mustapha, Mazlan, and Ishak [ 6 ] studied the fire retardant performance of rice husk ash-based geopolymer coated mild steel. Five factors including the ratio of alkaline activator (AA), ratio of RHA/AA, curing temperature, curing time, and concentration of sodium hydroxide, were analyzed using a statistical analysis to identify the significant factors that most influence the fire retardant performance of RHA-based geopolymer coating.…”

Optimization of Rice Husk Ash-Based Geopolymers Coating Composite for Enhancement in Flexural Properties and Microstructure Using Response Surface Methodology

“…Geopolymer is a material that has attracted wide interests among many scientists around the world due to its excellent properties which include high compressive strength, low shrinkage, acid, and fire resistance [4][5][6]. Studies have been conducted on different forms of geopolymer including geopolymer concrete [7,8], precast paving cement-free brick [9], and lightweight geopolymer composite [10].…”

Optimization of Adhesion Strength and Microstructure Properties by Using Response Surface Methodology in Enhancing the Rice Husk Ash-Based Geopolymer Composite Coating

“…Geopolymers are attractive materials for scientists globally for their excellent properties, including high compressive strength, low shrinkage and resistance to fire and acid [ 3 , 4 , 5 ]. Studies on numerous geopolymer types, including geopolymer concrete [ 6 ], precast paving cement-free brick [ 7 ] and lightweight geopolymer composites [ 8 ] have been conducted.…”