QUALITY ASSURANCE IN HIGHWAY CONSTRUCTION - PART 5- SUMMARY OF RESEARCH FOR QUALITY ASSURANCE OF AGGREGATE

A REVIEW OF THE EVALUATION BY STATISTICAL TECHNIQUES OF HIGHWAY AGGREGATE CHARACTERISTICS IS PRESENTED AS A CONDENSED COMPILATION OF BOTH HISTORICAL DATA AND DATA FROM DESIGNED QUALITY-MEASUREMENT PROJECTS IN WHICH THE DEGREE OF CONFORMANCE TO SPECIFICATIONS WAS STATISTICALLY ESTIMATED. REPORTS FROM NINE STATES ON PROJECTS IN WHICH RESEARCH DATA HAVE BEEN OBTAINED ARE ABSTRACTED AND SUMMARIZED IN THIS COMPILATION TO ILLUSTRATE TRENDS IN GRADATION ANALYSIS, SAMPLING AND TESTING PROCEDURES, SAND EQUIVALENT ANALYSIS AS AN ALTERNATE TO GRADATION ANALYSIS, AND SOUNDNESS TESTS FOR AGGREGATE QUALITY. SPECIFICATIONS FOR BASE COURSE AGGREGATE USUALLY CONTAIN LIMITS FOR GRADATION, PLASTICITY, SOUNDNESS, AND AMOUNT OF DELETERIOUS MATERIAL. THE DEGREE OF CONFORMANCE TO GRADATION SPECIFICATIONS WAS FOUND TO VARY FROM STEP TO STEP IN THE PROCESSING. ANALYSIS OF VARIANCE WAS APPLIED DURING CONSTRUCTION TO DETERMINE CAUSES OF THE VARIATION AND TO LOCATE CONDITIONS NEEDING CORRECTIVE ACTION. FOR AGGREGATE CONTROL, THE SAND-EQUIVALENT TEST RATHER THAN GRADATION IS PREFERRED IN SOME STATES, AND STATISTICAL RESEARCH, CONDUCTED TO ASCERTAIN WHETHER THE SAND-EQUIVALENT TEST IS INFORMATIVE AND REPRODUCIBLE, HAS CONFIRMED ITS USEFULNESS, ALTHOUGH THE AMOUNT OF DATA AT PRESENT IS RATHER LIMITED. STATISTICAL RESEARCH ON SALT-SOUNDNESS DETERMINATION INDICATED THAT DRYING TIME DID NOT NEED TO BE CHANGED; THAT SODIUM SULPHATE TESTING COULD BE DISCONTINUED, AS MAGNESIUM SULPHATE TESTING IS SATISFACTORY; AND THAT IT IS POSSIBLE TO PLACE ACCEPTANCE OF FINE AGGREGATE SOURCES ON A SOUND STATISTICAL FOUNDATION. IN STATISTICALLY-ORIENTED RESEARCH ON AGGREGATE GRADATION FOR BITUMINOUS MIXTURES, INFORMATION SIMILAR TO THAT FOR BASE COURSES WAS DEVELOPED, AND INDICATED THAT VARIATION FROM THE SPECIFICATIONS DIFFERS ACCORDING TO THE POINT OF SAMPLING. THE RESEARCH ALSO INDICATED THAT SAMPLING AT THE HOT BINS WAS PREFERRED FOR PROCESS CONTROL, WHEREAS SAMPLING AT THE COMPACTED BITUMINOUS LAYER WAS BEST FOR ESTABLISHING UNIFORMITY OF THE MIXTURE. DATA INDICATED THAT AGGREGATE USED IN PORTLAND CEMENT CONCRETE HAD A SMALLER STANDARD DEVIATION THAN THE AGGREGATE USED IN BITUMINOUS MIXTURES OR IN BASE COURSES, BUT THAT STATISTICAL ANALYSIS PROVIDED INFORMATION FOR EARLY DETECTION OF UNDESIRABLE GRADATION OR UNDESIRABLE QUALITY. THE USE OF STATISTICALLY DESIGNED CONTROL CHARTS IS HIGHLY RECOMMENDED FOR CONTROL OF THE CHARACTERISTICS OF AGGREGATE BY SOME STATES.

• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/oclc/1586080
• Supplemental Notes:
  • Vol 35, No 10, PP 230-237, 5 FIG, 11 TAB, 2 PHOT, 8 REF
• Authors:
  • Kelley, J A
• Publication Date: 1969-10

Media Info

• Serial:
  • Public Roads
  • Publisher: Federal Highway Administration
  • ISSN: 0033-3735
  • Serial URL: https://www.fhwa.dot.gov/publications/publicroads/
• Publication flags:

  Open Access (libre)

Subject/Index Terms

• TRT Terms: Aggregate gradation; Aggregates; Aggregates by source; Analysis of variance; Base course (Pavements); Bituminous mixtures; Fine aggregates; Materials tests; Portland cement concrete; Quality control; Reviews; Road construction; Sampling; Sand equivalent test; Soundness test; Specifications; Statistical analysis
• Uncontrolled Terms: Aggregate sources; Aggregate testing
• Old TRIS Terms: Aggregate characteristics; Gradation analysis
• Subject Areas: Data and Information Technology; Geotechnology; Highways; Materials;

Filing Info

• Accession Number: 00216911
• Record Type: Publication
• Files: TRIS
• Created Date: Mar 9 1970 12:00AM