Ceramic Roadway Aggregates
SourceThrough a cooperative program between the Bureau of Mines, Tuscaloosa Research Center, and the Federal Highway Administration, ceramic aggregates having high wear- and polish-resistance were developed. Three-hundred aggregate compositions, incorporating a variety of low-cost “waste” materials were evaluated over a 30-month period. Aggregates were produced using conventional ceramic processing techniques and fired at temperatures ranging from 900 to 1500°C. British Wheel and Los Angeles Abrasion tests were used for initial screening of the aggregates. These data, in addition to raw materials costs, its availability, and energy requirements, were used to select nine compositions for circular track tests at Maryland and North Carolina Highway Department facilities. Economic evaluations showed that present production costs, based on a 1000 ton-per-day operation ranged from $10 to $120 per ton of material produced. Guyana bauxite was used as a standard, and several of the selected compositions developed surpassed the bauxite in performance and were lower in cost.