MECHANICAL STRENGTH DETERMINATION OF CRUSHED STONE AGGREGATE FRACTION FOR ROAD PAVEMENT CONSTRUCTION (CASE STUDY: SELECTED QUARRIES IN WESTERN NIGERIA)

Abstract

In this research work, the mechanical strength of crushed stone aggregate fractions for road pavement construction in Western Nigeria was assessed. Samples of crushed stone aggregates were collected from nine (9) representative quarries spread across the states in Western Nigeria.The physical and mechanical properties of the aggregates were evaluated. The results were then compared with the specifications in international standards (BS and ASTM Standards). All the aggregate samples met the required limit for Loose Density, Water Absorption, Aggregate Crushing Value (ACV) and Aggregate Impact Value (AIV) tests. Aggregates samples from Samchase, Kopek, CCECC and SaliwaYetidipe quarries have flakiness indices exceeding the permissible limit (29.5%, 25.7%, 27.9% and 34.5% respectively). Hi-Tech and Western quarries samples have elongation indices of 44.5% and 40.3% respectively which are higher than the permissible limit. The two samples that failed Aggregate Abrasion Value test (AAV) are Hi-Tech and Western quarries, having 30.8% and 30.4% respectively. These two aggregates samples have AAV less than 35% which means they are still good for pavement construction only if the appropriate guidelines are followed (since any aggregate with AAV more than 35% is deemed weak for pavement construction). The study concluded that aggregates from Julius Berger quarry have the highest mechanical strength