A descriptive view of rammed earth performance: bibliometric analysis and systematic literature review

Rammed earth is a sustainable material with several features that warrant being studied and analysed for safe use as a green building for low-rise buildings due to its minimal CO₂ emissions. The initial section of this paper used bibliometric analysis to review various studies conducted on rammed earth from 2010 to 2024, comprising 960 publications. The subsequent section presents a systematic literature review of 52 publications, focusing on the mechanical properties of rammed earth, such as compressive strength, tensile strength, shear strength, and shear parameters (friction angle and cohesion), as well as thermal performance. The analysis of the outcomes of the previous studies showed that the compressive strength of unstabilised rammed earth ranges from 1 to 2.75 MPa, while stabilised rammed earth exhibits a range of 1.2 to 9.40 MPa, which is adequate for single-story and double-story buildings. The tensile strengths are reported to be between 0.16 and 0.38 MPa for unstabilized rammed earth, and the incorporation of fibres and chemical stabilisers increases them to the range of 0.73 to 1.16 MPa. Furthermore, the seismic behaviour of rammed earth is affected by its shear strength, which is only a small fraction of compressive strength, ranging from 7% to 10%, and is dependent on cohesion and friction angle. This study also developed an expression for predicting the tensile strength of rammed earth based on the percentage of fibres and chemical stabilisers used.