Post-consumer Cullet and Potential Engineering Applications in North America

Finding viable markets for post-consumer cullet generated in North America has been very challenging due to the predominant collection practice of glass commingled with other recyclables such as paper, ceramics, food particles, and glass of fluctuating colors and compositions. Thus, more than 60% cullet still ends up in the landfill. In this paper, potential end markets that could utilize this type of cullet with minimal level of processing have been identified. Based on several field trials conducted as well as the evaluation of the engineering properties, environmental impact, and safety issues, mixed cullet aggregates could be successfully blended with natural aggregates at different proportions for road-based applications, asphalt pavement, and concrete, utility and other construction projects. The debris level of the cullet aggregates for most of the applications should be maintained at 5%. Despite the vast potential end markets being identified, market demands still remain low. One of the major obstacles is the relatively high processing cost for cullet in comparison to competing natural aggregates. Therefore, to enhance recovery and develop strong market demands for cullet, there is a need for government interventions through the provision of recycling incentives, landfill ban, raising of tipping fees, and enforcing laws on the use of cullet as a construction aggregate.