TTI STUDY EXPLORES DURABILITY OF STRUCTURAL LIGHTWEIGHT CONCRETE FOR HIGHWAY BUILDING

AS PART OF A PROGRAM OF SYNTHETIC AGGREGATE RESEARCH, THE TEXAS TRANSPORTATION INSTITUTE INVESTIGATED THE PHYSICAL, MECHANICAL, CHEMICAL, AND VOLUME CHANGE DURABILITY OF SIX STRUCTURAL LIGHTWEIGHT AGGREGATES HAVING AT LEAST 10 YEAR SERVICE RECORDS. ADDITIONAL, NON-COMMERICAL AGGREGATES WERE INCLUDED WHOSE PROPERTIES VARIED OVER A WILDER RANGE. TESTS INDICATED THAT THE AGGREGATES CONTINUE TO ABSORB WATER FOR LONG PERIODS AND HAVE TOTAL POROSITIES RANGING WIDELY AROUND 40%, THAT THE CONCRETE CAN BE MADE PHYSICALLY DURABLE IF THE AGGREGATE IS DRY WHEN INTRODUCED, THAT COARSE LIGHTWEIGHT AGGREGATES WILL ABRADE OVER A LONG PERIOD OF WEAR, AND THAT CERTAIN LIGHTWEIGHT AGGREGATES CAUSE DISRUPTIVE CONCRETE EXPANSISONS. CONCLUSIONS DRAWN FROM THESE RESULTS ARE: (1) LIGHTWEIGHT COARSE AGGREGATES MORE THAN 25% SATURATED AT MIXING TIME SHOULD NOT BE USED IN CONCRETE EXPOSED TO FREEZING AND THAWING; (2) AN ABRASION-RESISTANT SURFACE SHOULD BE USED ON SUCH CONCRETE EMPLOYED IN BRIDGE DECKS OR PAVEMENTS; (3) THE AGGREGATES SHOULD NOT BE USED IF CONCRETE PRISMS MADE WITH THE EXHIBIT, IN THE AUTOCLAVE EXPANSION TEST, MORE THAN 0.0015 STRAIN; AND (4) WHERE HYDRATION SHRINKAGE MAY BE A PROBLEM, UNRESTRAINED SHRINKAGE MIGHT BE USED TO PREDICT RESTRAINED SHRINKAGE STRESS FOR A WIDE RANGE OF CURING ENVIRONMENTS.

  • Supplemental Notes:
    • No 41, pp 31-38, 6 FIG , 2 TAB, 17 REF
  • Authors:
    • Ledbetter, W B
    • Buth, E
  • Publication Date: 1970

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Filing Info

  • Accession Number: 00213848
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Feb 8 1971 12:00AM