Glass bottles collected by councils are forming large stockpiles, particularly in the South Island, as it is uneconomic to transport the glass to the Auckland plant for recycling. An alternative method of disposal would be to crush the glass and mix it into basecourse aggregate. NZ Transport Agency currently allows up to 5% by mass of crushed glass to be mixed in the aggregate.
This study investigated the effect on aggregate performance of percentages of crushed glass up to a maximum of 50% by mass of aggregate or a third of the total mass. Performance was measured using the repeated load triaxial apparatus and associated rut depth modelling to determine the number of heavy axles until 10 mm of rutting occurred within the aggregate layer. Results found that the performance of the aggregate was not affected for percentages of crushed glass up to 30% by mass of aggregate or 23% of the total aggregate.