RETENTION OF COVERSTONE BY ASPHALT SURFACE TREATMENTS

INVESTIGATIONS WERE CONDUCTED BY TEXAS A & M COLLEGE IN THE LABORATORY TO DETERMINE THE INFLUENCE OF CERTAIN FACTORS UPON THE RETENTION OF COVERSTONE IN SURFACE TREATMENTS. IN THE EXPERIMENTS, THE KEARBY METHOD WAS USED TO DETERMINE THE AMOUNT OF BINDER. USING THREE KINDS OF ASPHALT BINDER AND TWO TYPES OF AGGREGATES, PEA GRAVEL AND CRUSHED LIMESTONE, IT WAS CONCLUDED THAT THE TIME INTERVAL BETWEEN THE APPLICATION OF THE BINDER AND THE AGGREGATES AS WELL AS THE GRADATION OF THE AGGREGATES GREATLY INFLUENCE THE RETENTION OF THE COVER AGGREGATE. THE KEARBY METHOD OF DETERMINING THE OPTIMUM ASPHALT CONTENT APPEARS TO BE SATISFACTORY FOR AGGREGATE SIZES ABOVE ONE-HALF INCH. HOWEVER, THE METHOD OUGHT TO BE MODIFIED FOR SMALLER SIZE AGGREGATES. /AUTHOR/