Next-Generation Rammed Earth Architecture: A Systematic Review of Geopolymer Stabilization Techniques

Rammed earth, a traditional construction material, faces environmental concerns due to its susceptibility to water when stabilized with high-energy calcium-based binders. This study examines the potential of geopolymers, composed of aluminosilicate materials activated by alkaline solutions, as an in-situ stabilization method to enhance the durability of rammed earth. Geopolymerization technology, favored for its mechanical stiffness, reduced carbon footprint, and cost-effectiveness, was assessed through a comprehensive review of literature from 2013 to 2023. This involved analyzing six critical articles from a pool of 443, focusing on compressive strength tests and details such as study location, clay content, stabilizers, precursors, and alkali activators used. The results show that geopolymers significantly enhance the structural integrity of rammed earth, with higher compressive strengths compared to those stabilized with Ordinary Portland cement (OPC) or lime. The performance of geopolymer stabilization varies depending on the composition, particle size distribution of the soil, and curing conditions. This research underscores the challenges and provides substantial data, supporting the development of eco-compatible architecture. It highlights the necessity for a research consensus on methodological approaches to advance earthen architecture. These insights demonstrate the potential of geopolymers in promoting sustainable building practices and reducing CO2 emissions, acknowledging the context-dependent roles of traditional materials like OPC.