From waste textile fibres to circular building materials: a problem-oriented review of functional performance, risk boundaries and governance pathways

Growing textile waste generation and demand for low-carbon construction materials have increased interest in using waste textile fibres as circular resources in building materials. However, research remains focused on individual performance metrics, with limited attention to systematic classification, application matching and risk boundaries for heterogeneous waste streams. This review synthesised studies published between 2010 and 2026 from Web of Science Core Collection, Scopus, ScienceDirect and Engineering Village Compendex, supplemented by citation tracking and targeted searches. Following screening and eligibility assessment, 131 studies were analysed by waste source, fibre composition, physical form, pretreatment, application pathway, performance evidence, risk boundaries and circular-governance relevance. Waste textile fibres have been investigated in cementitious composites, crack-control applications, thermal insulation, acoustic products and lightweight non-structural components. However, evidence remains fragmented because of inconsistent material classification, variable processing conditions, limited long-term durability evaluation, insufficient fire and indoor environmental assessment, and unclear end-of-life pathways. This review therefore proposes a problem-oriented circular governance framework comprising five decision gates: material identity, application relevance, evidence sufficiency, boundary control and governance readiness. The framework supports responsible matching of waste textile resources with suitable building applications under defined evidence and governance conditions.