Characterization of the Behavior of Granular Road Material Containing Glass Cullet

Abstract

Granular base layers in highway pavements use large quantities of aggregate materials and are therefore good applications for possible use of waste materials such as glass. The engineering suitability of glass cullet as a granular embankment material is well documented. This paper presents results from resilient modulus tests on a blend of caliche, which is a conventional granular material used in pavement subbase layers, and glass cullet. Resilient modulus of granular material depends on factors such as aggregate mineralogy, particle characteristics, density, moisture content and gradation. However, when a material blend is used, the material response appears to also depend on relat ive strengths and compatibility of constituent materials in the blend. The general acceptance has been that by blending glass cullet with conventional materials, its engineering properties, particularly the strength, decreases. However, results from resilient modulus tests indicate that for relatively weaker granular base materials such as caliche, the introduction of glass cullet increases the strength of material blend. However, the strength gain appears to be accompanied by a likelihood of the material to fail by dilation at higher stress levels. As long as the calicheglass
cullet blend is not subjected to excessive loading, the presence of cullet in the blend appears to strengthen the resilient properties of the granular material.