PERFORMANCE EVALUATION OF HOT MIX ASPHALT INCORPORATING VITRIFIED TILE WASTE AS FINE AGGREGATE REPLACEMENT

Abstract

The performance of hot mix asphalt (HMA) largely depends on the properties and gradation of the aggregates used in the mixture. The depletion of natural aggregates and improper disposal of construction waste have posed serious environmental challenges, leading to the need for alternative sustainable materials in asphalt production. This study investigates the influence of vitrified tile waste (VWT) as a partial substitute for natural fine aggregates on the mechanical and volumetric properties of hot mix asphalt (HMA). Fine aggregates were replaced at 0%, 10%, 20%, 30%, and 40% by weight, and mixtures were evaluated based on standard Marshall parameters, including stability, flow, bulk density, air voids (Va), voids in mineral aggregate (VMA), and voids filled with bitumen (VFB), using ASTM D6926–20 and D6927–20. Results show that as the percentage of vitrified tile waste increased, the stability of the mix also increased from 4.68 kN (control) to 5.41 kN at 30% replacement level, while flow decreased from 3.88 mm to 2.40 mm. Bulk density also increased with replacement up to 30%, indicating improved compaction. Air voids and VMA reduced, while VFB increased, signifying better densification and lower permeability. At 40% replacement, stability slightly decreased, showing that excessive substitution of fine aggregate reduces cohesion in the asphalt mix. All properties at 30% VWT met the Nigerian General Specification requirements for wearing course. The findings demonstrate that vitrified tile waste is a viable fine aggregate replacement that improves mixture performance while supporting sustainable material utilization in asphalt production.