Abstract
The present paper attempts to explore the impact of grading scale, or changes in maximum particle size of graded aggregates, on triaxial test results. The study is based on a series of repeated load triaxial tests on three unbound granular materials at different grading scales. The experimental results show clearly that the structural response observed depends on the maximum grain size used in the triaxial specimen. The reduction of grading scale is shown to have a significant impact on both resilient and permanent strain responses of the materials tested. However, the nature and the extent of this impact are complex and inconsistent when different materials are compared, It is therefore recommended that triaxial testing of granular materials be performed at natural gradings.