STUDIES ON THE RELATIONSHIPS BETWEEN THE PROPERTIES OF ROAD BITUMENS AND THEIR SERVICE PERFORMANCE

TWO LARGE-SCALE ROAD TRIALS WERE CONDUCTED IN EUROPE INVOLVING 8 BITUMENS OF DIFFERENT PHYSICAL CHARACTERISTICS WITHIN THE 70/100 PENETRATION GRADE RANGE TO ASSIST IN THE DEVELOPMENT OF SIGNIFICANT SPECIFICATIONS FOR PAVING GRADE BITUMENS. THE DESIGN AND CONSTRUCTION OF THE TWO ROAD TRIALS AND A PROGRESS REPORT ON THE FIELD PERFORMANCE OF THE TEST SECTIONS ARE DESCRIBED. ONE ROAD TRIAL AREA WAS A LARGELY HOT AND DRY CLIMATE, THE OTHER HAS A COLD WINTER. IN EACH TRIAL, TWO TYPES OF MIX DESIGN, THREE BINDER CONTENTS FOR EACH TYPE OF MIX, AND TWO TYPES OF AGGREGATE WERE USED WITH EACH BITUMEN. VISUAL ASSESSMENTS MADE TWICE A YEAR INDICATE THAT THE DETERIORATION OF THE TWO ROADS HAS BEEN SLIGHT AND THAT NO SIGNIFICANT DIFFERENCE BETWEEN THE 8 BITUMENS IS APPARENT. SLIGHT DEFORMATION WAS OBSERVED ON A NUMBER OF THE SECTIONS, BUT NO CORRELATION WITH BITUMEN PROPERTIES HAS YET BECOME EVIDENT. SKID-RESISTANCE MEASUREMENTS INDICATE THAT THE SKID-RESISTANCE IS BEING CONTROLLED PREDOMINANTLY BY THE AGGREGATE TYPE. VISCOSITY DATA ON BITUMENS RECOVERED FROM SAMPLES TAKEN AT DIFFERENT STAGES OF THE MIXING/LAYING OPERATIONS INDICATE THAT MUCH OF THE HARDENING NORMALLY ATTRIBUTED TO THE FIRST FEW MONTHS IN SERVICE REALLY OCCURS DURING THE LAYING/COMPACTION OPERATION. THE DIFFERENT MIX DESIGNS, IN SPITE OF WIDELY DIFFERENT FILLER CONTENTS, DID NOT APPEAR TO HAVE MUCH INFLUENCE ON BITUMEN HARDENING DURING MIXING. CHEMICAL COMPOSITION DATA SHOW THAT A MOST SIGNIFICANT CHANGE DURING THE MIXING/LAYING OPERATION WAS AN INCREASE OF N-HEPTANE ASPHALTENES. VISCOSITY TESTS AFTER 20 MONTHS SERVICE INDICATE THAT THE BITUMENS RECOVERED FROM THE COARSE-GRADED MIXES HAVE NOT SHOWN SIGNIFICANTLY MORE HARDENING THAN HAVE THE CORRESPONDING BITUMENS RECOVERED FROM THE DENSE-GRADED MIXES.

• Supplemental Notes:
  • Vol 36, pp 421-488, 29 FIG, 23 TAB, 15 REF, 3 APP
• Authors:
  • Chipperfield, E H
  • Welch, T R
• Conference:
  • Assoc Asphalt Paving Technol Proc
• Publication Date: 1967-2

Subject/Index Terms

• TRT Terms: Asphaltene; Bitumen; Bituminous mixtures; Climate; Concrete hardening; Experimental roads; Hardness; Mix design; Skid resistance tests; Specifications; Viscosity
• Old TRIS Terms: Viscosity test
• Subject Areas: Highways; Materials;

Filing Info

• Accession Number: 00210719
• Record Type: Publication
• Files: TRIS
• Created Date: May 1 1994 12:00AM