Physico-Mechanical Properties of Rukuba Granitic Rock as a Source of Construction Aggregate: Laboratory Assessment and Engineering Evaluation

Abstract

This study investigated the physico-mechanical properties of Rukuba granitic rock from Jos Plateau, North-Central Nigeria, to assess its viability as construction aggregate. Despite ongoing commercial quarrying in the area, comprehensive, standardised engineering characterisation data for Rukuba granite remains limited, creating a knowledge gap for regional infrastructure development. Five rock samples were systematically collected from spatially distributed locations within an active quarry and subjected to comprehensive laboratory testing following American Association of State Highway and Transportation Officials (AASHTO T85, T19, T2), British Standards (BS 812), and American Society for Testing and Materials (ASTM C127, C131, D7012) protocols. Physical characterisation revealed mean specific gravity of 2.65 ± 0.02, water absorption of 0.55 ± 0.11%, and bulk density between 1485 and 1615 kg/m³. Mechanical testing demonstrated a uniaxial compressive strength (UCS) of 162 ± 9 MPa, aggregate crushing value (ACV) ranging from 18.7% to 21.7% (mean: 20.2 ± 1.2%), aggregate impact value (AIV) from 17.0% to 19.7% (mean: 18.4 ± 1.2%), and Los Angeles abrasion value (LAAV) from 22.3% to 26.0% (mean: 24.0 ± 1.6%). All measured parameters satisfied the requirements specified in AASHTO, BS, and ASTM standards for high-quality construction aggregates. The findings indicate that Rukuba granite is highly suitable for structural concrete applications, high-strength concrete production, flexible pavement construction, and other engineering purposes requiring durable aggregate materials.