THE BEHAVIOR AND PERFORMANCE OF ASPHALT PAVEMENTS WITH LIME- FLY ASH-AGGREGATE BASES

THE FIELD PERFORMANCE IS EXAMINED OF SEVERAL PAVEMENTS WITH POZZOLANIC MATERIALS AND THE ESTIMATED STRENGTH OF THE PAVEMENT IN THE FIELD IS COMPARED WITH THE REQUIRED STRENGTH OR THICKNESS INDICATED BY THE PROPOSED DESIGN PROCEDURE. A TOTAL OF 16 PAVEMENTS ARE EXAMINED. THESE INCLUDE PAVEMENTS WITH BOTH LIGHT AND HEAVY TRAFFIC, AND BOTH OVERDESIGNED AND UNDERDESIGNED PAVEMENTS. PROPERTIES ARE REVIEWED OF POZZOLANIC MATERIALS. THE FIELD PERFORMANCE OF THE PAVEMENTS WITH POZZOLANIC BASE MATERIALS ARE REVIEWED AND A DISCUSSION PRESENTED OF THE SIGNIFICANCE OF THE FINDINGS. IT IS APPARENT FROM THE PAVEMENTS EVALUATED THAT IF THE ULTIMATE STRENGTH OF THE BASE LAYER UNDER EDGE LOAD IS FROM 1.5 TO 2.0 TIMES THE APPLIED WHEEL LOAD THE PAVEMENTS ARE LIKELY TO GIVE GOOD PERFORMANCE. A MAJOR FACTOR IN THE DISTRESS OF MANY EARLY PAVEMENTS APPEARS TO BE POOR WORKMANSHIP. MANY OF THESE PAVEMENTS MADE WITH LIME-FLYASH-AGGREGATE MATERIALS WERE CONSTRUCTED WITH MAKESHIFT CREWS AND POOR CONSTRUCTION EQUIPMENT. WELL COMPACTED LIME-FLYASH-AGGREGATE MIXTURES ARE GENERALLY HIGHLY STABLE AND CAN FUNCTION AS A STANDARD FLEXIBLE PAVEMENT UNTIL THE MATERIAL TAKES SUFFICIENT SET TO CAUSE IT TO DEVELOP SLAB ACTION. THE THICKNESS OF THE BASE LAYERS IS GENERALLY ADEQUATE TO DISTRIBUTE THE LOAD SO LONG AS THE SUB-GRADE REMAINS FIRM. SOME PROBLEM OF SHRINKAGE CRACKING HAS BEEN OBSERVED WITH THE LIME FLYASH-AGGREGATE MATERIALS. EXPERIENCE SHOWS THAT IF THESE MATERIALS ARE COMPACTED TO 100 PERCENT OF STANDARD DENSITY, AND IF THE MOISTURE CONTENT IS HELD TO OPTIMUM OR BELOW, THE PROBLEM OF SHRINKAGE CRACKS IS LARGELY OVERCOME AND THE CRACKS WHICH DO DEVELOP ARE MORE A CONCERN OF APPEARANCE THAN OF PAVEMENT PERFORMANCE. THE STUDY DOES INDICATE THAT THE ULTIMATE STRENGTH APPROACH FOR THE DESIGN OF ASPHALT PAVEMENTS WITH POZZOLANIC MATERIALS IS SUCCESSFUL. IN FACT, IT WOULD APPEAR THAT THIS APPROACH IS MORE SUITABLE FOR USE WITH MATERIALS WHICH ATTAIN A MAJOR PORTION OF THEIR STRENGTH AT AN EARLY AGE AND ARE MORE SUSCEPTIBLE TO FATIGUE FAILURE WITH THE LOADS APPLIED OVER A LONG PERIOD OF TIME. MANY SOIL CEMENT MIXTURES AND LEAN CONCRETES WOULD FALL IN THIS CATEGORY.

• Supplemental Notes:
  • Preprint, pP 511-526, 13 FIG, 4 TAB, 8 REF
• Authors:
  • Barenberg, E J
• Conference:
  • Intl Conf Struct Design Asphalt Pvmts
• Publication Date: 1967-8

Subject/Index Terms

• TRT Terms: Aggregates; Asphalt pavements; Base course (Pavements); Compaction; Lean concrete; Lime fly ash; Moisture content; Pavement design; Pavement performance; Pavements; Performance; Pozzolan; Soil cement; Thickness; Ultimate load design; Wheel loads
• Uncontrolled Terms: Field performance; Pavement thickness
• Old TRIS Terms: Lean mix concrete; Ultimate strength design
• Subject Areas: Geotechnology; Highways; Pavements;

Filing Info

• Accession Number: 00206719
• Record Type: Publication
• Files: TRIS
• Created Date: May 24 1994 12:00AM