Recent Publications
Sri Lanka generates approximately 1.2 million tons of C&D waste annually. The conventional paving block production consumes 100 kg of virgin aggregates per square meter. This study evaluates the technical and environmental feasibility of incorporating high proportions (50–75%) of C&D waste crushed concrete demolition waste as fine aggregate and ceramic tile waste as coarse aggregate into interlocking concrete paving blocks for light-traffic applications under tropical conditions (23 ± 2°C, 7085% RH). A two-stage experimental program produced Grade 25 paving blocks tested for compressive strength (7 and 28 days) and water absorption per ASTM standards. All recycled aggregate mixtures exceeded the SLS 1425:2010 minimum (15 MPa). Optimal mixtures achieved 26.16 MPa at 75% fine aggregate replacement and 24.93 MPa at 60% coarse aggregate replacement 76% and 72% of control strength respectively exceeding requirements by 66–74%. Water absorption ranged 4.02–5.30%, well within acceptable limits. ANOVA confirmed statistically significant differences (p < 0.001) across replacement levels. Overall, 60–75% C&D waste in paving blocks is technically feasible for tropical climates, diverting approximately 135–165 kg of waste per cubic meter from landfills, reducing carbon emissions by 7,800–24,900 tons CO₂-eq annually, and reducing raw material costs by 35–45%.