Concrete paver blocks are widely used in pavement applications due to their durability, ease of maintenance, and structural efficiency. However, conventional paver blocks manufactured using ordinary Portland cement (OPC) are associated with high carbon emissions and moderate durability performance under severe environmental exposure. This study investigates the influence of metakaolin as a partial replacement of cement on the fresh, mechanical, and durability properties of concrete paver blocks. Five concrete mixes were prepared with metakaolin replacement levels of 0%, 5%, 10%, 15%, and 20% by weight of cement while maintaining a constant water–cement ratio of 0.40. Fresh concrete properties were evaluated using slump tests, while hardened properties were assessed through compressive strength, flexural strength, split tensile strength, water absorption, and abrasion resistance tests. The results indicated that the incorporation of metakaolin reduced workability due to its high fineness and increased water demand. However, mechanical and durability properties improved significantly up to an optimum replacement level of 10%. The mix containing 10% metakaolin achieved the highest compressive strength of 48 MPa at 28 days, along with improved flexural and split tensile strengths. Water absorption and abrasion loss were reduced considerably, indicating enhanced durability performance. Beyond 10% replacement, strength and durability properties declined due to reduced workability and dilution effects caused by excessive cement replacement. The study concludes that 10% metakaolin replacement provides the best balance between strength, durability, and workability, making it suitable for sustainable high-performance concrete paver block production.

Keywords: Metakaolin, Concrete paver blocks, Compressive strength, Durability, Sustainable concrete