The principal objective of this study was to investigate the feasibility of using coal, and to a lesser extent coal mine wastes, as aggregate in bituminous paving mixtures. These local aggregates were laboratory tested in bitumen-aggregate mixtures and, more particularly, in so-called cold-mixes. The bitumen-aggregate mixtures were evaluated by the Immersion-Compression Test, ASTM D 1075-60, with modifications for cold mixtures recommended in the Public Roads Journal (4).

In this initial study, since it was not possible to evaluate all types of mixtures, the primary question of whether coal and its waste products can be used as road aggregate could not be answered with finality. Aggregates are used in different types of mixtures, and serve in different degrees of importance in a pavement system. Therefore, other possibilities of the use of these aggregates must be evaluated before the primary question can be answered. Some definite conclusions were reached, and they are based upon the evaluation of the properties of the bitumen-aggregate mixtures made from the materials employed in this study. All of the combinations of binders and aggregates tested, however, lacked some property required in highway pavements.

Report Date


Report Number

No. 213

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