Sustainable Innovation in Paving Block Production: Using Semi - Crushed Shell and Semi - Concrete Waste

This study actually explores the innovative use of semi-crushed shells and semi-construction waste as a partial replacement for sand in the production of paving blocks. Addressing the challenges of diminishing natural sand resources and increasing construction waste. The objective here is to evaluate the feasibility of using alternative materials with particle sizes of 4.75mm to 0.15mm, which are commonly found in concrete mixtures, to maintain or improve the structural integrity of paving blocks while promoting sustainable construction practices. Concrete mixtures with a ratio of 1:2:4 were tested with sand replacements of 0%, 5% (2.5% shell powder and 2.5% construction waste powder) and 10% (5.0% shell powder and 5.0% construction waste powder). The results of the slump test showed a decrease in workability with increasing percentage of replacement with the result values being 14.01mm, 10.00mm and 7.99mm respectively. Despite this reduction, all mixtures remained within the acceptable actual slump range. To ensure sufficient workability for pavement applications. In particular, the compressive strength test showed that the 5% replacement mixture achieved the highest compressive strength of 45.41 MPa at 28 days, which outperformed the control mixture. This shows that using this alternative material can improve the quality of concrete while conserving natural resources and managing waste effectively. This innovation reduces environmental impact, which promotes the use of high-quality waste and is in line with the goal of sustainable construction. This solution shows potential for commercialization for the construction industry, especially in producing non-structural paving blocks. Recognizing this innovation, the study has advanced to the final stage of the "Joint Proposal Defense Session of the TRANS-TECH 4TVET Grant Technical Committee 2025" and won third place at the INNOTEX DCE Polytechnic Kota Bharu Exhibition 2024.