Wearing surfaces of Kentucky rock asphalt applied in thin layers were used extensively in Kentucky for many years. Sand asphalts, which generically include rock asphalt, are now a reemergent generation of surfacings to be investigated (1,2,3). An interim report (4) related the construction and interim performance of trial surfacings in Logan County. Two bridge deck sand-asphalt surfacings have been reported (5). This report covers sand-asphalt construction and performance since 1966. Pertinent project data and comments are contained in Appendix A. The several Special Provisions are included in Appendix B.

Interest in sand-asphalt wearing surfaces issues from the skid-resistant qualities which are inherent in angular (unpolished) quartz sands. Blends of quartz sands together with crushed limestone sands have been employed experimentally to obtain strength and durability--and to evaluate the effect of limestone or carbonate sands on skid-resistance. Quartz concentrations in the order of 50 percent of the combined sand have not provided the desired assurances of persistent skid resistance; therefore, recourse to mixtures richer in quartz has become imperative. Experimental work is continuing in that direction.

Report Date


Report Number

No. 299

Digital Object Identifier



The opinions, findings and conclusions in this report are not necessarily those of the Department of Highways or the Federal Highway Administration.