Experimental Investigation on the Sustainable Utilization of Municipal Solid Waste Landfill Materials and Recycled Face Mask Fibres in High-Performance Concrete

• The investigated MSWL material can be incorporated as a partial replacement for manufactured sand when grading, absorption and heterogeneity are controlled. • MSWL mixtures maintained medium workability, with slump reducing from 75 mm for the control to approximately 70 mm at the higher replacement levels. • MSWL replacement improved compressive strength up to an optimum level. M5 reached 41.0 N/mm² at 28 days compared with 38.0 N/mm² for M0. • M5 reached 3.60 N/mm² split tensile strength and 6.28 N/mm² flexural strength at 28 days, compared with 3.34 and 5.93 N/mm² for the control. • Replacement beyond the optimum reduced performance; M10 recorded 30.0 N/mm² compressive strength, 1.99 N/mm² split tensile strength and 4.00 N/mm² flexural strength at 28 days. • Recycled face-mask fabric progressively reduced slump, with A2 at 0.5% giving 65 mm and A3/A4 giving 60 mm. • A2 containing 0.5% face-mask fabric produced the most favourable overall mechanical response, reaching 44.0 N/mm² compressive, 3.66 N/mm² split tensile and 6.36 N/mm² flexural strength at 28 days. • The improvement in tensile and flexural performance at moderate fabric dosage is consistent with distributed crack bridging, while excessive fabric reduces homogeneity and mechanical performance. • The two waste streams provide complementary sustainability routes: MSWL can reduce demand for virgin fine aggregate, while recycled mask fabric can recover polypropylene waste as dispersed reinforcement. • The most suitable contents are controlled rather than maximum replacement levels, with M5 and A2 identified as the most promising mixtures for further investigation.

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