Uniform asphalt pavement and production method therefore

A highly stable dense graded asphalt friction overlay of substantial area for covering a pavement surface, said overlay containing less than 3.5% by volume of air voids V.sub.EA under a standard compaction and having a Marshall stability exceeding 1800 psi with a Marshall flexibility between 8 and 16, said friction overlay comprising asphalt cement and a mixture of a coarse aggregate blending and a fine aggregate blending, the aggregates of said fine aggregate blending being variable in absorption, specific gravity, particle shape, size distribution, or consolidation under a standard compaction, and wherein the proportion of said coarse and fine aggregate blending is below the bulking point of the mixture, said proportion being periodically determined during the production of said friction overlay by the steps of:

• A. demarcating the aggregates to define coarse and fine aggregates,
• B. mixing a reference sample including said fine aggregate and a quantity of asphalt cement,
• C. compacting said reference sample under said standard compaction,
• D. determining an Index quantity that represents the quantity of fine aggregate per unit volume of said reference sample compacted under said standard compaction, and
• E. selecting a proportion of coarse and fine aggregates according to said volumetric relationship:
• V.sub.CA +V.sub.FA +V.sub.EA +V.sub.EAC =1 unit volume
• for differing proportions of coarse and fine aggregate, wherein the quantity of fine aggregate per unit of the combined volumes V.sub.FA and V.sub.EAC substantially equals said Index quantity, where V.sub.EAC is the volume effective asphalt cement, V.sub.CA is the volume of the coarse aggregate, and V.sub.FA is the volume of the fine aggregate.

A compacted asphalt paving composition containing a predetermined air void volume V.sub.EA under a standard compaction;

• said composition comprising a mixture of coarse aggregate, fine aggregate, and asphalt cement;
• the respective proportions of coare aggregate, fine aggregate, and asphalt cement being determined by the steps of:
• A. demarcating the aggregates to define coarse and fine aggregates,
• B. mixing a reference sample including said fine aggregate and a quantity of asphalt cement,
• C. compacting said reference sample under said standard compaction,
• D. determining an Index quantity that represents the quantity of fine aggregate per unit volume of said reference sample compacted under said standard compaction, and
• E. selecting a proportion of coarse and fine aggregates according to said volumetric relationship:
• V.sub.CA +V.sub.FA +V.sub.EA +V.sub.EAC =1 unit volume
• for differing proportions of coarse and fine aggregates, wherein the quantity of fine agregates per unit of the combined volumes V.sub.FA and V.sub.EAC substantially equals said Index quantity, where V.sub.EAC is the volume effective asphalt cement, V.sub.CA is the volume of the coarse aggregate, and V.sub.FA is the volume of the fine aggregate.

An asphalt surface of substantial area having a substantially constant volume V.sub.EA of air voids under a standard of compaction according to the Marshall method of compaction, said pavement comprising asphalt cement and a mixture of a coarse aggregate blending and a fine aggregate blending, the aggregates of said fine aggregate blending being variable in absorption, specific gravity, particle shape, size distribution, or consolidation, and wherein the proportion of coarse and fine aggregate blending is below the bulking point of the mixture, said proportion of coarse and fine aggregates being periodically determined during the production of said asphalt surface by the steps of:

• A. demarcating the aggregates by a sieve size approximating the No. 4 sieve to define coarse and fine aggregates,
• B. mixing a reference sample including said fine aggregate and a quantity of asphalt cement,
• C. compacting said reference sample according to the Marshall method of compaction,
• D. determining an Index quantity that equals the weight of fine aggregate per unit volume of said reference sample compacted under the Marshall method of compaction, and
• E. selecting a proportion of coarse and fine aggregates according to said volumetric relationship:
• V.sub.CA +V.sub.FA +V.sub.EA +V.sub.EAC =1 unit volume
• for differing proportions of coarse and fine aggregate, wherein the weight of fine aggregates per unit of the combined volumes V.sub.FA and V.sub.EAC substantially equals said Index quantity, where V.sub.EAC is the volume effective asphalt cement, V.sub.CA is the volume of the coarse aggregate, and V.sub.FA is the volume of the fine aggregate.