06 February 2013
Posted in Center Information
Options for Cathode-Ray Tube (CRT) glass disposal are limited due to high levels of leachable lead. Prior to this study, the use of CRT-glass in concrete mixtures was evaluated as an alternative recycling option through experiments designed to evaluate the structural impacts to conventional concrete as well as environmental leaching experiments to tests its hazardousness. However, a recommendation was made to study how the durability and deterioration of these concrete specimens affects the release of hazardous contaminants. This study exposed the CRT-Concrete composite to three different deterioration mechanisms (i.e. alkali-silica reactions, Arrhenius aging, and freezing/thawing) that are typical during the service life of the material; the objective was to study how contaminant release, primarily lead, is stimulated. Results show that temperature was found to have a direct impact on the leaching of lead by changing the microstructure of the material and in turn, accelerating the release of lead. Additionally, no correlation was found between alkali-silica reactions and lead release due to the quick saturation of the leaching solution. Lastly, surface deterioration was found to increase the flux release of contaminants but was not directly related to mass loss of the specimens. Overall, this study indicates that deterioration of concrete materials containing hazardous aggregates will increase its contaminant release, but ultimately CRT-Concrete is still a feasible composite material for use in architectural as well as structural concrete since it meets the regulatory leaching limits.