A SYSTEM FOR THE JUDGEMENT OF COMPLIANCE WITH SPECIFICATIONS FOR ROLLED ASPHALT TO B.S. 594

A SYSTEM FOR THE JUDGEMENT OF COMPLIANCE WITH SPECIFICATIONS FOR ROLLED ASPHALT IS DESCRIBED, BASED ON THE COMPARISON OF A GIVEN JOB WITH A 'STANDARD JOB.' INDIVIDUAL SAMPLE ANALYSES ARE CLASSIFIED AS ACCEPTABLE OR DEFECTIVE ACCORDING TO CERTAIN LIMITS OF COMPOSITION. THESE LIMITS ARE CHOSEN TO EXCLUDE 10 PERCENT OF SAMPLE RESULTS FROM THE STANDARD JOB, WHICH REPRESENTS A LIMITING LEVEL OF ACCEPTABLE QUALITY IN STATISTICAL TERMS. THE ACTUAL RATE OF OCCURRANCE OF DEFECTIVE RESULTS IS THEN COMPARED WITH THE RATE EXPECTED FROM THE STANDARD JOB, IN TERMS OF THE PERMISSIBLE NUMBER OF DEFECTIVES FOR A GIVEN NUMBER OF SAMPLE ANALYSES. THE SYSTEM GUARANTEES THAT, IN THE LONG RUN, WORK OF THE SAME QUALITY AS THE STANDARD JOB WILL BE ACCEPTED AT LEAST 95 PERCENT OF THE TIME. THE EFFECT OF APPLYING THIS SYSTEM IS DISCUSSED IN THE CONTEXT OF THE DISTRIBUTION OF QUALITY OF ROLLED-ASPHALT MANUFACTURE ACHIEVED IN THE U.K. OVER THE PAST FEW YEARS AND IT IS SUGGESTED THAT AN ECONOMIC LIMITATION OF THE CONSUMER'S RISK WILL BE OBTAINED IF THE ACCEPTANCE DECISION IS BASED ON A RUNNING SEQUENCE OF 20 SAMPLE ANALYSES. WITH REJECTION AS THE SANCTION AGAINST INFERIOR QUALITY, THE APPLICATION OF THE SUGGESTED SYSTEM WOULD RESULT IN NOT LESS THAN 75 PER CENT OF ROLLED-ASPHALT SURFACING BEING OF BETTER QUALITY FOR ANY CONSTITUENT THAN THAT ENVISAGED IN THE CURRENT PROPOSALS FOR THE REVISION OF B.S.594:1961; AND NOT LESS THAN 90 PER CENT BEING OF BETTER QUALITY FOR ANY CONSTITUENT THAN THAT COMMONLY ADOPTED IN MAJOR ROAD AND MOTORWAY WORKS AS 'SLIGHTLY OUTSIDE SPECIFICATION'. THE ADVANTAGES ARE DISCUSSED OF LINKING THE SYSTEM OF JUDGEMENT WITH A SYSTEM OF REDUCED PAYMENT FOR INFERIOR QUALITY, INSTEAD OF REJECTION AS THE ONLY PENALTY FOR NON-COMPLIANCE. WHATEVER THE FORM OF PENALTY, HOWEVER, USE OF THE SYSTEM OF JUDGEMENT SHOULD IMPROVE THE QUALITY, AND HENCE THE DURABILITY, OF ROLLED-ASPHALT SUPPLIED. SINCE THE ACCEPTABLE STANDARD OF QUALITY AND THE CONTRACTUAL RISKS ARE ALSO DEFINED MORE CLEARLY THAN HITHERTO THE SYSTEM SHOULD ENABLE MANUFACTURERS TO STABILIZE A PRICE STRUCTURE WHICH MORE ACCURATELY REFLECTS THE QUALITY OF MANUFACTURE AND THUS RESTORES PROPER COMPETITION IN TENDERS FOR WORK. /RRL/

  • Supplemental Notes:
    • Rrl Rept Lr 276, 47 PP, 11 FIG, 7 TAB, 7 PHOT, 5 REF
  • Corporate Authors:

    MINISTRY OF TRANSPORT, LONDON (UK)

    ,    
  • Authors:
    • Hardman, R
  • Publication Date: 1969

Subject/Index Terms

Filing Info

  • Accession Number: 00215035
  • Record Type: Publication
  • Source Agency: Road Research Laboratory /UK
  • Files: TRIS, ATRI
  • Created Date: Feb 12 1971 12:00AM