Sustainable Construction Materials: Microstructural and Property Evaluation of Ambient Cured Geopolymer Foam Concrete

In the quest for sustainable building materials, this research examines geopolymer foam concrete blocks as a promising alternative for masonry construction. These blocks offer a significant environmental advantage over traditional options like Autoclaved Aerated Concrete (AAC) and Cellular Light Weight Concrete (CLC), which rely heavily on energy-intensive Portland Cement. Formulated with a 2:1 blend of Class-F Fly Ash and GGBS activated by eco-friendly aluminosilicate solutions, the geopolymer formulation boasts lower embodied energy during production. Additionally, their improved thermal insulation properties contribute to reduced operational energy within buildings. To achieve the desired lightweight target of 800–900 kg/m3, the study explores various foaming agents, ultimately employing Sodium Lauryl Sulphate for uniform distribution. A comprehensive evaluation is conducted on the geopolymer blocks, including their mechanical properties (compressive, split tensile, and flexural strengths), thermal conductivity, and shrinkage. A microstructural analysis is also performed to assess the characteristics of the foam dispersion within the concrete matrix. The observed results were found satisfactory for the mix with 0.02% of aluminium powder.