Durability of cementitiously stabilized aggregate bases for pavement application.

Abstract

Cementitious stabilization has been extensively used to improve the performance of pavement materials. In the past, emphasis has been placed on observing the macromanifestation of stabilized pavement materials, but to the author's knowledge, very little effort has been directed toward the micro-manifestation. In this study, selective existing techniques, namely, X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive spectrometry (EDS), are used to assess the micro-structural development of cementing compounds in stabilized aggregate specimens. Specifically, the reference intensity ratio (RIR) method is employed to semi-quantify the mass percent of minerals and cementing compounds in the mixtures. Results reveal the formation of cementing compounds (due to stabilization) such as ettringite, calcium silicate hydrate (C-S-H), calcium aluminum hydrate (C-A-H) and calcium aluminum silicate hydrate (C-A-S-H), which are responsible for the increase in strength. Findings from this study shed light on the use of semi-quantification techniques in cementitious stabilization. These techniques would provide a better understanding of cementitious reactions related to their short- and long-term roles. (Abstract shortened by UMI.)