Effects of Quarry Dust on the Engineering Properties of Lateritic Soils for Highway Construction in Imo State, Nigeria

Abstract

Abstract This study investigated the impact of quarry dust on the engineering properties of lateritic soils with a focus on its potential application in highway construction within Imo State, Nigeria. Lateritic soils, widely used in road projects due to their availability, often exhibit suboptimal engineering properties such as low strength and high plasticity, posing challenges to highway performance and durability. From a borrow pit in Obinze, Owerri West Local Government Area, Imo State, a soil sample was taken at a depth of 2m below the surface, and subjected to laboratory tests which include; Specific gravity, Particle size distribution, Atterberg limits, Compaction test and California Bearing Ratio (CBR) tests, all in accordance to British Standard 1377-2:1990. The results from the tests carried out revealed a specific gravity of 2.52, coefficient of uniformity of 3.15, plasticity index of 16.72%, and a CBR value of 3.16%. These findings indicated that the soil was unsuitable for road construction due to its high plasticity and low CBR value. To mitigate these shortcomings, the soil was stabilized with varying proportions of quarry dust (ranging from 15% to 75%). The addition of quarry dust resulted in reduced plasticity indices (ranging from 16.19% to 12.40%) and increased CBR values (ranging from 3.51% to 9.44%). However, even with the highest 75% quarry dust addition, the transformed soil still fell short of highway construction standards, highlighting the need to explore alternative materials or more effective soil stabilization methods to meet the required engineering specifications.