Characterization of Sustainable Paver Blocks Incorporating Textile Dyeing Effluent Sludge: Mechanical and Microstructural Perspectives

The Malaysian construction industry faces sustainability challenges owing to the environmental impact of concrete, particularly the carbon emissions from Portland Cement production. This study investigated the incorporation of Textile Dyeing Effluent Sludge (TDES) as an admixture into green paver blocks to promote sustainable practices. Paver blocks (200 mm × 100 mm × 60 mm) were produced with varying TDES contents (2.5, 5, 7.5, and 10%). The mechanical properties (sieve analysis, compressive strength, density, and water absorption) and microstructural characteristics (SEM–EDX) were evaluated. The results indicate that increasing the TDES content generally reduces the compressive strength and density owing to its lightweight and porous nature. However, the 2.5% TDES blend demonstrated the most balanced performance, achieving an 18.00 MPa compressive strength and 2000 kg/m3 density at 28 days, compared to the control’s 23.6 MPa and 2054.2 kg/m3, respectively. Although 2.5% TDES exhibited moderate water absorption of 12.22%, it remains acceptable for nonstructural applications. SEM–EDX analysis confirmed that the 2.5% TDES mix maintained stable cementitious chemistry, unlike higher concentrations, which exhibited increased carbon and reduced essential cementitious compounds. Thus, 2.5% TDES is deemed optimal for nonstructural applications, offering a sustainable waste repurposing solution without significantly compromising material performance.