MERITS AND ECONOMICS OF PREFABRICATED TYPES OF AGGREGATES

ALTHOUGH SEVERAL ACCELERATED TESTS OF AGGREGATES HAVE BEEN DEVISED TO SIMULATE WEATHERING, NO TRUE LABORATORY MEASURE OF SOUNDNESS HAS YET BEEN EVOLVED. THE USE OF MAGNESIUM SULPHATE SOLUTION IS PROPOSED AS A SUBSTITUTE FOR THE COMMONLY USED SODIUM SULPHATE, BECAUSE THE SOLUBILITY OF THE FORMER ONLY VARIES FORM 26.2 PERCENT TO 29 PERCENT FOR TEMPERATURES FROM 68 TO 86 F., WHEREAS THE SOLUBILITY OF SODIUM SULPHATE VARIES FROM 19.4 PERCENT TO 40.8 PERCENT WITHIN THE SAME RANGE OF TEMPERATURE. MOREOVER THE MAGNESIUM SULPHATE HAS ONLY ONE CRYSTALLINE FORM AT THESE TEMPERATURES WHILE SODIUM SULPHATE HAS THREE. A DIRECT RELATIONSHIP WAS FOUND BETWEEN A FREEZING AND THAWING TEST AND THE MAGNESIUM SULPHATE TEST. THE DATA SHOW THAT THE LOSS IN A FIVE CYCLE MAGNESIUM SULPHATE TEST WAS ABOUT TWICE THE LOSS UNDER A 60 CYCLE FREEZING AND THAWING TEST. THE ABSORPTIVE POWER OF SAND WAS ALSO FOUND TO BEAR A GENERAL RELATION TO THE RESULTS OF THE SOUNDNESS TEST. THE RESULTS OF THE PROPOSED TEST HAVE BEEN CORRELATED WITH THE SERVICE RECORDS OF PAVEMENTS IN NEW YORK STATE. A NUMBER OF CONCRETE ROADS BUILT BETWEEN 1921 AND 1931 WITH FINE AGGREGATE HAVING A MAGNESIUM SULPHATE TEST LOSS OF 20 PERCENT OR MORE SHOWED POOR SERVICE RECORDS. ON THE OTHER HAND, CONCRETE PAVEMENTS IN WHICH THE FINE AGGREGATE SHOWED LOSSES OF 17 PERCENT OR LESS IN THIS TEST HAVE GOOD SERVICE RECORDS. /AUTHOR/

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• Supplemental Notes:
  • Vol 12, Pt1, PP 319-330, 5 FIG
• Authors:
  • PAUL, I
  • Ulman, M H
• Publication Date: 1933

Media Info

• Serial:
  • Highway Research Board Proceedings
  • Publisher: Highway Research Board

Subject/Index Terms

• TRT Terms: Absorption; Accelerated weathering; Aggregates; Concrete aggregates; Concrete pavements; Fine aggregates; Freeze thaw tests; Magnesium compounds; Materials tests; Serviceability; Soundness test; Sulfates
• Uncontrolled Terms: Aggregate testing
• Subject Areas: Design; Geotechnology; Highways;

Filing Info

• Accession Number: 00217830
• Record Type: Publication
• Files: TRIS, TRB
• Created Date: Jun 1 1971 12:00AM