EFFECT OF ILLITIC CLAY ON CHEMICAL STABILITY OF CARBONATE AGGREGATES

A SUMMARY OF SEVERAL EXPERIMENTAL PROJECTS IS PRESENTED ON THE ILLITIC CLAY FRACTION OF CARBONATE AGGREGATES REACTING WITH SILICON IN A MANNER WHICH IS DISTINCT FROM THE PROCESSES INVOLVED IN THE ALKALI-AGGREGATE REACTION. FLAME PHOTOMETRIC ANALYSES OF AGGREGATE PARTICLES FOR SODIUM AND POTASSIUM WERE MADE BEFORE AND AFTER SHELL GROWTH, DEMONSTRATING THAT THE SODA AND POTASH CONTENT OF THE PERIPHERAL ZONE WAS NOT INCREASED. REACTION SHELLS WERE CAUSED TO FORM IN CONCRETE BARS UNDER CONTROLLED CONDITIONS. SIMILAR BARS MADE WITH ACCEPTABLE CARBONATE AGGREGATE WERE SUBJECTED TO THE SAME CONDITIONS FOR COMPARISON. LENGTH CHANGES WERE MEASURED AND COMPRESSIVE STRENGTH TESTS WERE RUN ON BOTH TREATED AND UNTREATED BARS. IT WAS SHOWN THAT THE GROWTH OF PROMINENT REACTION SHELLS THROUGHOUT THE CONCRETE WAS NOT ACCOMPANIED BY EXCESSIVE EXPANSION OF THE BARS. PRELIMINARY TESTS INDICATE THAT THE INCREASE IN COMPRESSIVE STRENGTH WHICH NORMALLY ACCOMPANIES HYDRATION IS DEFINITELY DIMINISHED WHEN SHELL GROWTH OCCURS IN THE CONCRETE. /AUTHOR/

Media Info

  • Monograph Title: Concrete quality control, aggregate characteristics and the cement-aggregate reaction
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00217746
  • Record Type: Publication
  • Files: TRIS, TRB
  • Created Date: Aug 12 1994 12:00AM