Development of Eco-Friendly Paving Blocks Using Indigenous Materials

The demand for sustainable construction materials has increased due to environmental concerns and the high cost of conventional materials. This research aims to develop eco-friendly paving blocks using locally sourced indigenous materials as partial replacements for cement and fine aggregate. Specifically, the research explores the incorporation of clay soil and sawdust ash (SDA) with river sand to produce paving blocks with reduced environmental impact and enhanced sustainability. Three different mix compositions were prepared: Sample A (control) containing 0% SDA, Sample B with 10% SDA, and Sample C with 20% SDA. All mixtures maintained a constant water-to-cement ratio of 0.5. The paving blocks were subjected to a curing regime of 7, 14, and 28 days, after which key physical and mechanical properties—compressive strength, water absorption, and density—were evaluated in accordance with standard testing procedures. Results indicated that the compressive strength of the blocks increased with curing age across all samples, with 28-day strengths recorded as 23.2MPa for Sample A, 21.4 MPa for Sample B, and 18.6 MPa for Sample C. While a slight reduction in strength was observed with higher SDA content, the values remained within acceptable limits for non-load-bearing pedestrian applications. Water absorption decreased progressively with increased curing time, demonstrating values of 5.2% for Sample A, 4.8% for Sample B, and 4.2% for Sample C at 28 days, indicating improved durability characteristics with the addition of SDA. The bulk densities of the blocks ranged from 2,200 to 2,350 kg/m³, affirming their suitability for pavement applications. Overall, the findings suggest that partial substitution of cement with SDA and the utilization of clay soil and river sand can produce environmentally friendly paving blocks with adequate performance for pedestrian walkways. This approach not only contributes to the conservation of natural resources but also offers a cost-effective and sustainable alternative for construction in developing regions.