Strength, durability, and microstructure of geopolymers based on recycled-glass powder waste and dolomitic lime for soil stabilization

Abstract

Glass waste in soil stabilization is a promising use as a precursor of forming geopolymers and avoid its discard in landfills as well as decreasing the consumption of traditional binders like lime and cement. Thus, the impact of low, intermediate, and high contents of recycled-glass powder (GP) waste on soil behavior was evaluated by determining the unconfined compressive strength (qu), splitting tensile strength (qt), and durability against wetting/drying cycles (W-D) for the long-term. GP contents were defined as 5%, 15%, and 30% by weight, and a fixed percentage of 5% for lime was selected to ensure the pozzolanic activity of blends based on the pH criterion of optimum lime content. The results indicated improvement in the microstructure and the mechanical properties (qu and qt) of soil-GP-dolomitic lime compacted blends with increasing GP contents, as well as decreases in the accumulated loss of mass (ALM). All of these results were dependent on a novel index given by the ratio of the porosity η to the sum of the percentages of GP and lime in volumetric terms (volumetric binder content Biv), or η/Biv. None of the blends may be used for subbase applications after 7 days of curing time, but all of them are suitable for engineering earthworks after 90 days of curing time.