THE UHTHOFF QUARRY ALKALI-CARBONATE ROCK REACTION: A LABORATORY AND FIELD PERFORMANCE STUDY

This report, concerned with alkali-carbonate rock reaction in concrete, is a laboratory and field study of the performance of aggregate from one of the largest commercial quarries in Ontario. Laboratory studies included the fabrication of sets of concrete prisms containing a high alkali content by the addition of sodium hydroxide to the concrete mix. Field performance studies of highway structures included taking cores for petrographic examination, summarizing pattern cracking, and testing of selected structures by pulse-velocity techniques. It is concluded that the presence of approximately 20 percent reactive rock in the quarry material was responsible for widespread surface pattern cracking of the structures. Such cracking has apparently reduced the potential durability of some concrete exposed to almost continuously moist conditions but to date has not affected the serviceability of high-quality reinforced concrete. When applied, existing specifications concerned with the expansion of carbonate rocks, will in all probability produce durable concrete, although some of the symptoms of reactivity--namely, surface pattern cracking--may still occur in field concrete exposed to moist conditions.

Media Info

  • Media Type: Print
  • Features: Figures; Photos; References; Tables;
  • Pagination: pp 43-54
  • Monograph Title: Cement-aggregate reactions
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00097199
  • Record Type: Publication
  • Files: TRIS, TRB
  • Created Date: Sep 30 1975 12:00AM