Blending of marginally suitable tropical sub-base materials for use in base course construction

摘要

In some parts of Ghana, road construction costs can be very high because of the limited opportunity of locating suitable base material within economic haul distances. Due to extensive infrastructural development in areas where suitable road base materials occur, the city of Kumasi is experiencing a general paucity of such materials within 10 km of project sites. Three marginally suitable but abundant sub-base materials, typical of the soils within the Kumasi metropolis of Ghana, have been blended with varying proportions of readily available crushed rock aggregates and alluvial gravel for road construction. All the soils were improved by these stabilizers for use in base course construction. This study revealed that it would be uneconomical to haul borrow gravel beyond 13 km for road construction in the metropolis. Rather, these abundant but inferior naturally-occurring materials within the corridors of proposed roads, should be blended with both stabilizers but preferably alluvial gravel due to its relative cheapness, to construct the base course.