A FIELD EXPERIMENT OF ASPHALT-TREATED BASES IN COLORADO

THICKNESS REQUIREMENTS FOR SEVERAL DIFFERENT ASPHALT- TREATED BASES WERE EVALUATED AND THEIR PERFORMANCE COMPARED TO OTHER BASES CONSTRUCTED BOTH AT THE TEST SITE AND AT THE AASHO ROAD TEST. THE EXPERIMENT CONSISTS OF TWENTY 550-FOOT LONG TEST SECTIONS CONSTRUCTED IN 1965 NEAR PUEBLO, COLORADO . IT INCLUDES TWO COMPLETE INTERRELATED FACTORIAL EXPERIMENTS. THE FIRST IS COMPRISED OF 3 THICKNESSES /5.5-, 7.0- AND 8.5-INCHES/ OF 3 BASE COURSE TYPES /ASPHALT CONCRETE, LOW-STABILITY SAND-ASPHALT AND HIGH-STABILITY SAND -ASPHALT/ ON A-7-6 SOIL. THE SECOND IS COMPRISED OF 2 THICKNESSES /5.5- AND 7.0-INCHES/ OF 2 OF THE SAME BASE COURSE TYPES /ASPHALT CONCRETE AND LOW-STABILITY SAND- ASPHALT/ ON A-6 SOIL. FOR FURTHER COMPARISON, TEST SECTIONS COMPRISED OF THE STATES STANDARD SECTION FOR THE GIVEN CONDITIONS, WERE INCLUDED ON EACH SOIL. A 2-INCH ASPHALT CONCRETE SURFACE COURSE IS COMMON TO ALL SECTIONS. THE TEST SECTIONS WERE RANDOMIZED AND SEVERAL WERE REPLICATED. LABORATORY TESTS WERE CONDUCTED ON SAMPLES OF THE VARIOUS PAVEMENT SYSTEM LAYERS. TEMPERATURES WERE OBTAINED FROM THERMOCOUPLE INSTALLATIONS AT VARIOUS DEPTHS IN THE PAVEMENT STRUCTURE. BENKELMAN BEAM AND DEHLEN CURVATURE METER MEASUREMENTS WERE MADE. AS-BUILT SURFACE COURSE AND BASE THICKNESS WERE MEASURED. PRESENT SERVICEABILITY INDEX VALUES /PSI/ WERE DETERMINED FOR EACH SECTION FROM BOTH CHLOE PROFILOMETER AND BPR ROUGHMETER MEASUREMENTS. BENKELMAN BEAM DEFLECTIONS WERE USED WITH LAYERED SYSTEM THEORY TO DETERMINE ELASTIC MODULI FOR THE VARIOUS ASPHALT BASE TYPES. THE MODULI ARE IN GOOD AGREEMENT WITH THOSE DETERMINED IN THE LABORATORY FOR SIMILAR TEMPERATURE CONDITIONS AND A LOADING FREQUENCY OF ONE CYCLE PER SECOND. THEORY AND INFERRED ASPHALT BASE MODULI WERE USED TO DERIVE THICKNESS- DEFLECTION RELATIONS FOR AVERAGE MEASURED SURFACE COURSE AND BASE TEMPERATURES. SUCH RELATIONS WILL PROVIDE A MEANS OF OBTAINING EQUIVALENT THICKNESSES OF THE DIFFERENT MATERIALS WHEN CRITICAL DEFLECTION VALUES BECOME AVAILABLE.

  • Supplemental Notes:
    • Hpr-1/4/, BPR-5, STATE 1475
  • Corporate Authors:

    Colorado Department of Highways

    4201 East Arkansas Avenue
    Denver, CO  USA  80222
  • Authors:
    • KINGHAM, R I
    • Reseigh, T C
  • Publication Date: 1966-10-5

Subject/Index Terms

Filing Info

  • Accession Number: 00206283
  • Record Type: Publication
  • Source Agency: Bureau of Public Roads /US
  • Files: TRIS, STATEDOT
  • Created Date: Dec 1 1994 12:00AM