The Transport and Road Research Laboratory is studying synthetic aggregates with an exceptional resistance to polishing by traffic. Such arrregates are required for the surface treatment of difficult road sites where a high resistance to skidding is required and where the polishing action of traffic is most severe. This report describes a study of a class of corundum-rich aggregates, including calcined bauxites, which owe their high polishing-resistance to their extreme hardness. The report gives the results from such aggregates of chemical tests, mineral analyses by x-ray diffraction and an examination of surface micro- texture using a stereoscan electron microscope; it includes a discussion of these results in relation to the aggregates' physical and mechanical characteristics and their performance in road trials. (Author/publisher)
Abstract