Mechanical and environmental performance of engineered earthen walls reinforced with waste carpet fibers

This study evaluates the mechanical and environmental performance of rammed earth (RE) walls reinforced with waste polyacrylic carpet fibers (WPCF) and stabilized using either cement or ground granulated blast furnace slag (GGBS). Unconfined compressive strength (UCS), Brazilian tensile strength (BTS), and microstructural analyses (FESEM–EDS) were performed to examine performance mechanisms, while a cradle-to-gate Life Cycle Assessment (LCA) using ReCiPe 2016 in SimaPro assessed sustainability. Results showed that adding 10% stabilizer increased UCS by 85%, and 3% WPCF enhanced strength 1.2 times; combining both achieved 3.7-fold higher UCS and up to 6.2-fold higher BTS than untreated RE. LCA indicated that GGBS-based RE wall (S ₇ F ₃ ) had a 12% lower footprint (3.96 Pt) than the cement-based RE wall (C ₇ F ₃ ) and substantially lower impacts than brick–cement and concrete block walls. Overall, GGBS-stabilized RE reinforced with recycled WPCF demonstrates high mechanical performance, lower embodied impacts, and strong potential as a sustainable alternative to conventional construction materials.