1. Home
  2. TRID
  3. View Record
https://nap.nationalacademies.org/catalog/27432/critical-issues-in-transportation-for-2024-and-beyond

APPLICATION OF END-RESULT SPECIFICATIONS TO THE PRODUCTION AND LAYDOWN OF BITUMINOUS MIXTURES WITH DISCUSSION

A BITUMINOUS CONCRETE END-RESULT SPECIFICATION BASED ON STATISTICAL CONCEPTS WAS LET TO CONTRACT IN ILLINOIS IN OCTOBER, 1969, AND ESSENTIALLY COMPLETED BY TWO CONTRACTORS AS A JOINT VENTURE IN 1970. THE SECTION WAS 6.5 MILES IN LENGTH AND CONSISTED OF FOUR 10-FT. LANES. THE PAY ITEM (IN SQUARE YARDS) FOR BINDER AND SURFACE COURSE WAS ADJUSTED IN PRICE BASED ON MIXTURE CONTROL, THICKNESS, AND DENSITY. EACH ITEM WAS GIVEN EQUAL WEIGHT. THE BID PRICE WAS ADJUSTED FROM 40 TO 110 PERCENT DEPENDING ON THE DEGREE OF CONTROL. SPECIFIC REQUIREMENTS FOR PLANT AND LAY-DOWN EQUIPMENT WERE NOT INCLUDED IN THE SPECIFICATION; HOWEVER, THE CONTRACTORS ESSENTIALLY CONFORMED TO NORMAL SPECIFIED PRACTICE. THE QUALITY CONTROL WAS THE RESPONSIBILITY OF THE CONTRACTOR WHO HIRED A CONSULTING ENGINEER TO PROVIDE THIS SERVICE. HIGHWAY DEPARTMENTS HAVE TRADITIONALLY PERFORMED THE QUALITY CONTROL FOR THE CONTRACTOR AND ACCEPTED THE RESULTING PRODUCT. THE CHANGE TO THE CONTRACTOR'S PROVISION OF QUALITY CONTROL AND THE STATE'S ACCEPTANCE OF THE PRODUCT ON THE BASIS OF RANDOM SAMPLES IS SIGNIFICANT. THE MAJOR OBJECTIVE OF THIS CONTRACT WAS TO DEMONSTRATE TO THE CONTRACTORS AND ENGINEERS THAT THE APPROACH IS FEASIBLE AND CAN RESULT IN ACCEPTABLE PRODUCT QUALITY AT A REASONABLE PRICE. ANALYSIS OF THE DEGREE OF CONTROL OBTAINED ON THIS SECTION INDICATES THAT GREATER UNIFORMITY CAN BE OBTAINED ON A JOB LET UNDER CONTRACT THAN WAS EXPECTED FROM A SIMULATED END-RESULT APPROACH ON JOBS LET AND CONTROLLED UNDER EXISTING SPECIFICATIONS. BASED ON THE AVERAGE OF FIVE SAMPLES, TOLERANCES OF 3.0 PERCENT ON AGGREGATES, 1.0 PERCENT ON MINUS 200 MATERIAL AND 0.25 PERCENT ON ASPHALT CONTENT WERE ESSENTIALLY COMPLIED WITH ON THIS CONTRACT. MAJOR ITEMS IN THE END-RESULT SPECIFICATION AND ADJUSTMENTS IN BID PRICE ARE DISCUSSED IN THE REPORT. SAMPLING AND TESTING PROCEDURES ARE ALSO INCLUDED, AS ARE COMMENTS FOR IMPROVEMENT IN THE SPECIFICATION AFTER COMPLETION OF THE PROJECT. THE SUCCESSFUL COMPLETION OF THE PROJECT HAS DEMONSTRATED THAT THE MAJOR ITEMS IN THE SPECIFICATION ARE WORKABLE AND THAT IT IS POSSIBLE TO CONTROL THE PRODUCTION AND LAY-DOWN TO OBTAIN A POSITIVE ADJUSTMENT IN BID PRICE. ADDITIONAL SECTIONS ARE PLANNED IN THE FUTURE TO OBAIN MORE EXPERIENCE THAT WILL AID IN THE ACCEPTANCE OF THIS PROCEDURE BY BOTH THE CONTRACTORS AND ENGINEERS. A DISCUSSION IS INCLUDED WHICH DEALS WITH VARIOUS QUESTIONS CONCERNING THIS STUDY. /AUTHOR/

Media Info

  • Features: References; Tables;
  • Pagination: p. 21-48
  • Serial:
    • Volume: 41

Subject/Index Terms

Filing Info

  • Accession Number: 00211817
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Sep 17 2002 12:00AM