From Soil to Structure: A Systematic Review of Bamboo-Reinforced Earth Composites for Sustainable Building

The construction industry's carbon footprint has driven renewed interest in earthen materials and bio-based reinforcements. This systematic review examines bamboo-reinforced earth composites, synthesising research on mechanical performance, durability, and sustainable construction applications. Following structured searches of Scopus, Web of Science, and Google Scholar, 42 studies (2004–2025) met the inclusion criteria and were assessed using a validated quality assessment tool (κ = 0.84). Bamboo reinforcement transforms brittle earthen materials into ductile composites. At optimal fibre contents of 0.5–0.8% by weight, compressive strength increases range from 0.9 to 2.3 MPa in unstabilised matrices and 2.5 to 5.5 MPa in stabilised matrices. Flexural strength gains of 0.5 to 1.8 MPa and shear strength improvements of 0.05 to 0.08 MPa accompany ductility factor increases from 1.0 to 3.2–7.2. However, increased fibre content correlates with water absorption increasing by up to 5.4 percentage points and porosity increasing by 9.8 percentage points, presenting durability challenges. Critical gaps include absent standardised protocols, no long-term durability data beyond five years, limited understanding of interfacial mechanics, and insufficient structural-scale validation. Publication bias analysis suggests effect sizes may be overestimated by 16–18%. Bamboo-reinforced earth composites offer a promising pathway toward sustainable housing, requiring systematic durability investigation and performance-based design guidance. A five-phase research roadmap is proposed: standardisation (2026–2028), field validation (2027–2029), model development (2028–2030), code development (2029–2031), and technology transfer (2031–2035).