RIM FORMATION ON IOWA HIGHWAY CONCRETE DOLOMITE AGGREGATE: THE EFFECTS OF DEDOLOMITIZATION REACTIONS

Electron microprobe analysis, as well as scanning electron microscope and petrographic studies, reveal a sequence of rims at dolomite coarse aggregate-cement paste interfaces in Iowa highway concretes. These rims are superimposed on unaltered dolomite aggregate particles (zone A) and cement paste (zone E). Non-durable concretes (service life of <16 years) exhibit better developed and more abundant rims, a higher density of micro-cracks, and contain dolomite with a more variable grain size and higher porosity than durable concretes (service life of >40 years). The compositional variations, mineralogy, and reaction products strongly suggest that rims formed as the result of dedolomitization reactions involving aggregate and cement paste. The present investigation represents one of the first accounts of alkali-carbonate reactions associated with dolomite aggregate in highway concrete rather than with limestone or dolomitic limestone aggregate.

  • Availability:
  • Corporate Authors:

    Texas A&M University, College Station

    College Station, TX  United States  77840
  • Authors:
    • GAN, G-L
    • Spry, P G
    • Cody, R D
    • Cody, A M
  • Publication Date: 1996

Language

  • English

Media Info

Subject/Index Terms

Filing Info

  • Accession Number: 00726542
  • Record Type: Publication
  • Source Agency: Transport Research Laboratory
  • Files: ITRD
  • Created Date: Oct 28 1996 12:00AM