Geotechnical Evaluation of Crushed Sandstone Waste Materials from Amasiri Quarries, Southeastern Nigeria for Use in Civil Engineering Projects

Abstract

This paper presents the study of crushed sandstones wastes (CSW) aiming at their utilization as main materials for the base layer of flexible pavements with series of geotechnical laboratory tests contained in American Society for Testing and Materials adopted for their evaluations. The tests conducted included particle size distribution, Atterberg limits, compaction characteristics, California bearing ratio, unconsolidated undrained compressive strength, free swell index and one-dimensional consolidation tests. Statistical analyses using proprietary computer software were used to investigate the spatial variations of the geotechnical data, and degrees of relationships that exist among the tested parameters. From the results, the Atterberg limits tests revealed intermediate plasticity with less than 35% fines (percentage passing No. 200 British Standard sieve) in majority of the samples; an indication of good highway materials. The relatively high maximum dry density, low optimum moisture content and high shear strength recorded by the tested CSW materials proved their usability in most road projects such as sub-base and subgrade. The strength indicators adopted to evaluate the validity of the CSW as pavement materials showed relatively high shear strength as the undrained cohesion values satisfy the requirement of greater than 103 kN/m2 values specified for base course materials. The empirical correlations analyses verified the influence of moisture on the strength parameters and gave a general overview of the geotechnical behaviors of the examined quarry wastes. Therefore, CSW materials are adjudge suitable but in order to achieve long term strength gain and stability especially in high volume applications, stabilizations will be required.