FINAL REPORT ON THE ZACA-WIGMORE ASPHALT TEST ROAD

DURING 1954 THE CLIFORNIA DIVISION OF HIGHWAYS INTRODUCED IMPROVED SPECIFICATIONS FOR PAVING GRADE ASPHALTS. IN ORDER TO DETERMINE THE EFFECT OF THESE SPECIFICATIONS UNDER FIELD CONDITIONS, TEN DIFFERENT ASPHALTS WERE PLACED ON A MAJOR CONSTRUCTION PROJECT CONSISTING OF ENTIRELY NEW CONSTRUCTION, AND ALSO AN OVERLAY OVER AN OLD PORTLAND CEMENT CONCRETE PAVEMENT. A PROGRESS REPORT DESCRIBING THE CONSTRUCTION AND EARLY OBSERVATIONS ON SERVICE PERFORMANCE WAS REPORTED IN 1959 IN ASTM, STP277. ALL OF THE ASPHALTS WERE OF THE 200-300 PENETRATION GRADE, AND WITH ONE EXCEPTION, REPRESENTED DIFFERENT CRUDE SOURCES AND METHODS OF PRODUCTION AS FOUND IN CALIFORNIA. COMPLETE FIELD STUDIES WERE CARRIED ON DURING CONSTRUCTION, AND ABSON RECOVERY TEST WERE MADE ON THE PAVING MIXTURES. OBSERVATIONS AND TEST RESULTS CONFIRM THE FACT THAT ASPHALTS MANUFACTURED BY DIFFERENT METHODS AND FROM DIFFERENT CRUDE SOURCES, ALTHOUGH PLACED UNDER VIRTUALLY IDENTICAL CONDITIONS, EXHIBIT VARYING DEGREES OF HARDENING DURING THE MIXING PROCESS. A COMPARISON OF STANDARD THIN FILM TEST RESULTS AND HARDENING IN THE MIXER SHOWS AN EXCELLENT CORRELATION. FROM MARCH 1955 THROUGH APRIL 1964 PERIODIC INSPECTIONS WERE PERFORMED FOR RATING THE SERVICE RECORD OF THE RESPECTIVE TEST SECTIONS. A NUMBER OF SECTIONS OVER NEW AND EXISTING ALIGNMENT FAILED WITHIN THE NINE YEARS SERVICE PERIOD. TEN TEST SECTIONS FAILED BETWEEN 38 MONTHS AND 92 MONTHS OF SERVICE LIFE. SEVEN SECTIONS REMAINED IN SATISFACTORY CONDITION AFTER NINE YEARS OF SERVICE LIFE, MAINLY IN THE OVERLAY SECTIONS OVER THE OLD PORTLAND CEMENT CONCRETE PAVEMENT. THE INITIAL VOID CONTENT AND THE RATE OF CHANGE IN VOID CONTENT DURING SERVICE LIFE TOGETHER WITH THE ASPHALT CONTENT APPEAR TO BE DOMINANT FACTORS IN THE HARDENING RATE OF THE VARIOUS ASPHALTS. HOWEVER, THE RATE OF HARDENING UNDER EQUIVALENT WEATHERING, AND PAVEMENT CONDITIONS IS ALSO INFLUENCED BY THE ASPHALT SOURCE. NUMEROUS ROUTINE AND RESEARCH TESTS WERE PERFORMED ON THE ASPHALTS. THE BEST TEST FOR PREDICITING THE DURABILITY PROPERTIES OF THE ASPHALT APPEARS TO BE THE MODIFIED SHELL DURABILITY TEST. /AUTHOR/

• Supplemental Notes:
  • Vol 38, pp 1-38, 21 FIG, 14 TAB, 11 REF
• Authors:
  • Zube, E
  • Skog, J
  • Epps, J
  • Petersen, J C
• Discussers:
  • Warden, W
• Conference:
  • Association of Asphalt Paving Technologists Proc
• Publication Date: 1969-2

Subject/Index Terms

• TRT Terms: Asphalt; Asphalt content; Asphalt pavements; Bituminous overlays; Concrete hardening; Concrete pavements; Durability; Experimental roads; Field studies; Hardness; Mixing; Oven tests; Overlays (Pavements); Pavements; Pendulum tests; Portland cement concrete; Service life; Specifications; Test procedures; Test sections; Thin films; Void ratios; Weathering
• Uncontrolled Terms: Thin film oven test
• Subject Areas: Design; Highways; Materials; Pavements;

Filing Info

• Accession Number: 00211499
• Record Type: Publication
• Files: TRIS
• Created Date: Jul 27 1970 12:00AM