Effects of using screening materials in the graded aggregate base layer of flexible pavements

Abstract

In this paper, the potential use of screening materials in Graded Aggregate Base (GAB) layer of pavements was investigated using aggregate sources in Georgia. Three content levels of screening materials in GAB, i.e. 0%, 25% and 50%, were studied. Morphological analysis of aggregates and Proctor test were conducted to reveal the characteristics of the modified GAB materials, followed by the California Bearing Ratio (CBR) test and Mechanistic-Empirical Pavement Design Guide software simulation to evaluate how the GAB strength and overall pavement performance change with varying amount of screening materials in the GAB layer. The results indicated that the effect of using screening materials in GAB varies and depends on the amount of screening materials used, which changes gradation, and the aggregate types and sources, which exhibit significantly different morphological properties.