Design of Pavement Surface for Sustainable Development Using Silica Fume

Abstract

This study evaluates the use of silica fume as a supplementary cementitious material in high-performance concrete intended for durable infrastructure applications. Ordinary Portland cement was partially replaced with silica fume at 0, 2.5, 5.0, 7.5, 10.0 and 12.5% by mass. The concrete was proportioned for an M60 target strength at a water-to-binder ratio of 0.30, with a polycarboxylate-based or other high-range water-reducing admixture, the exact product requiring verification. Cubes, cylinders and beams were tested at 7, 14, 28 and 56 days for compressive, splitting-tensile and flexural strength. Within the reported 28-day dataset, the 7.5% silica-fume mixture produced the highest compressive strength (74.07 MPa), flexural strength (4.12 MPa) and splitting-tensile strength (5.17 MPa). Relative to the control values reported in the manuscript, these correspond to increases of approximately 29.3%, 26.4% and 52.1%, respectively; the stated 25%, 23% and 22% increases should therefore be recalculated and reconciled. The results indicate that silica fume can improve strength when dispersion, workability and curing are adequately controlled. However, the optimum dosage is mixture-specific and should not be generalized without reporting variability, fresh-concrete properties and durability data.