Foamed geopolymer concrete is a sustainable and environmentally friendly construction material, but it is typically prepared using high concentrations of alkaline solutions (8M to 16M), which presents issues with high cost and negative impacts on humans and the environment. This study addresses the problem by validating the geopolymerization process of zeolite-based foamed geopolymer concrete reinforced with Cellulose Nanofibril (CNF) using a low concentration of Potassium Hydroxide (KOH) solution (below 2M). The research evaluates the material's porosity, compressive strength, and water permeability to provide a more sustainable option for the concrete industry.

The RSM analysis on porosity yielded an R² value of 88.20%, indicating a strong relationship between the terms and the response. The most significant factors affecting porosity were SLES/BAC and H₂O₂/CNF. The terms Seawater/Potassium Silicate and Potassium Hydroxide/Potassium Chloride had p-values of 0.360 and 0.279, respectively, indicating they were less significant for porosity. A combination of high SLES and H₂O₂ content resulted in the highest porosity, exceeding 45%. This finding suggests a synergistic effect between H₂O₂ and SLES, where SLES helps stabilize the foam created by H₂O₂. The study found that increasing the concentration of the KOH solution increased porosity, compressive strength, and water permeability. Conversely, increasing the CNF content led to a decrease in porosity and water permeability while increasing compressive strength. The presence of CNF in the geopolymer matrix improved its strength due to strong interfacial adhesion.

The study concluded that zeolite-based foamed geopolymer concrete reinforced with CNF, prepared in a low-concentration KOH solution (below 2M), has the potential for use as porous concrete, particularly for pervious pavement. The use of low-concentration alkaline solutions reduces material costs and negative environmental impacts, promoting cleaner production practices. However, the compressive strength of the samples in this study was low, which could limit their practical application. Therefore, the authors recommend future research to focus on ways to enhance the compressive strength of geopolymer materials prepared using low-concentration alkaline solutions. The optimized composition predicted a porosity of 61.46%, which was experimentally validated with an acceptable error margin of 14%. The study's findings on the correlation of CNF and material properties align with other research on nanoparticles in common geopolymers and composites.

Figure 1: Zeolite based foamed geopolymer concrete reinforced with Cellulose Nanofibril prepared in low concentration alkaline solution: Porosity, compressive strength, and water permeability

Figure 2: FESEM image of zeolite

Figure 3: Processing route of Foamed Geopolymer Concrete (FGC)

Source:

Chai Hua Tay, Norkhairunnisa Mazlan, Aimrun Wayayok, Mohd Salahuddin Basri, Mohd Mustafa Albakri Abdullah

(https://www.sciencedirect.com/science/article/pii/S0959652624040587?via%3Dihub)

Date of Input: 18/08/2025 | Updated: 18/08/2025 | roslina_ar