HOT-MIXED BLACK BASE CONSTRUCTION USING NATURAL AGGREGATE- SYMPOSIUM-ASPHALT BOUND BASES

THE ECONOMIC ADVANTAGES OF LOCAL AGGREGATES CAN BE USED FOR BLACK BASE CONSTRUCTION IF CERTAIN LIMITING FACTORS INHERENT TO GRAVEL, SANDS AND FILLERS AS THEY OCCUR IN NATURE ARE PROPERLY TAKEN INTO ACCOUNT IN THE DESIGN AND CONTROL OF THE MIX. FIVE SEPARATE STUDIES OR PROJECTS ARE SUMMARIZED TO PRESENT DATA PERTINENT TO THE USE OF NATURAL AGGREGATES IN HOT-MIXED BLACK COURSE CONSTRUCTION: (1) FIELD EXPERIENCE WITH THE SAND-GRAVEL BLACK BASE USED ON THE GARDEN STATE PARKWAY IN NEW JERSEY, (2) AN INVESTIGATION OF PRACTICAL GRADATION LIMITS FOR NATURAL AGGREGATE BITUMINOUS CONCRETE, (3) A STUDY OF PHYSICAL TEST PROPERTIES OF SAND- ASPHALT MIXES MADE WITH KANSAS SANDS, (4) AN EVALUATION OF NATURAL FILLERS MADE IN COOPERATION WITH THE NORTH CAROLINA STATE HIGHWAY COMMISSION, AND (5) WEST GERMAN EXPERIENCE, CRITERIA AND PRACTICES IN THEIR USE OF NATURAL AGGREGATES FOR HOT-MIXED BLACK BASE CONSTRUCTION. EVALUATION TECHNIQUES AND SOME SUGGESTED TOLERANCES AND CRITERIA BASED ON FIELD EXPERIENCE AND ON THESE STUDIES ARE OFFERED. TEST RESULTS AND FIELD EXPERIENCE WITH BLACK BASE CONSTRUCTION USING NATURAL AGGREGATE LEAD TO THE CONCLUSION THAT: (1) A WIDE RANGE OF SAND-GRAVEL MAY BE USED AS FAR AS GRADATION IS CONCERNED, (2) AS THE LOWER COURSES OF THE PAVEMENT DO NOT REACH AS HIGH TEMPERATURES AS THE SURFACE, PARTIAL STABILITY AT 140 F. IS NOT CRITICAL, (3) TO PROVIDE ADEQUATE PROTECTION AGAINST SURFACE RUTTING IT IS ADVISABLE TO MAINTAIN TOTAL VOIDS AT 5 TO 7 PERCENT FOR BOTH SAND AND SAND-GRAVEL MIXTURES AND THE ACCEPTABLE RANGE OF VOID FILLED WITH ASPHALT APPEARS TO BE 60-70 PERCENT FOR SAND-GRAVEL AT 65-75 PERCENT FOR SAND MIXTURES, (4) NATURAL FILLERS OCCURING AS MINUS NO. 200 MATERIAL IN AGGREGATE DEPOSITS SHOULD BE TESTED IN ADVANCE AND NATURAL FILLERS WHICH HAVE A PRONOUNCED EFFECT ON PENETRATION AND DUCTILITY OF THE FILLER-BITUMEN ORDER SHOULD BE AVOIDED, (5) FIELD EXPERIENCE INDICATES THAT, DUE TO THE SOFTENING EFFECT OF SOLVENTS AND SOLVENT VAPORS ON ASPHALT BOUND BASES, EMULSION RATHER THAN CUT-BACK SHOULD BE USED FOR TACK COATS, AND (6) ECONOMICAL AND SATISFACTORY BLACK BASE MIXTURE CAN BE PRODUCED USING A WIDE RANGE OF LOCAL MATERIALS.

• Supplemental Notes:
  • Vol 30, pp 291-312, 12 FIG, 12 TAB
• Authors:
  • Warden, W B
  • Hudson, S B
• Conference:
  • Assoc Asphalt Paving Technol Proc
• Publication Date: 1961

Subject/Index Terms

• TRT Terms: Aggregate gradation; Asphalt concrete; Bituminous aggregates; Control; Economics; Emulsified asphalt; Fillers (Materials); Gravel; Hot mix asphalt; Mix design; Natural aggregates; Physical properties; Sand; Tack coats; Void ratios
• Old TRIS Terms: Physical tests
• Subject Areas: Economics; Highways; Materials;

Filing Info

• Accession Number: 00210895
• Record Type: Publication
• Files: TRIS
• Created Date: May 21 1994 12:00AM