Alkali Activation of Stabilized Rammed Earth Bricks: A State-of-the-Art Review

The construction industry’s increasing focus on sustainability has led to a growing interest in Stabilized Rammed Earth (SRE) as a low-carbon and affordable building material. However, SRE’s widespread adoption has been hindered by its relatively low strength and durability. This review explores the potential of alkali activation to enhance the mechanical properties of SRE. Alkali activation involves using alkaline solutions to activate pozzolanic materials, such as fly ash, slag, or calcined clay, to form a hardened binder. The review compares the mechanical properties of traditional stabilized rammed earth with its alkali-activated counterparts, investigating the effects of alkali activation on structural integrity, durability, and overall performance. Various methodologies of alkali activation are discussed, along with an explanation of the underlying chemical reactions and mechanisms involved. Additionally, the review examines the use of lime-gypsum and cement additives to improve the compressive strength and durability of SRE. The incorporation of fibers, such as polypropylene, straw, plastic, and marble dust, is explored for further enhancing the mechanical properties. The findings highlight the potential of alkali activation in improving the mechanical properties of SRE. Optimal binder compositions, replacement percentages, and selection of alkali activators are crucial factors in achieving high-performance SRE structures. Further research is needed to fine-tune these parameters and fully unlock the potential of alkali-activated SRE for sustainable construction practices.