EXPANSION OF REACTIVE CARBONATE ROCKS UNDER RESTRAINT

It is suggested that the degree of expansion of alkali- reactive carbonate rocks is not only a function of the volume of dolomite contained in the rock but also of the texture of the material as reflected by its deformation characteristics under sustained loading. Theoretical equations are presented that can be used for calculating the expansion of a two-phase system composed of certain volumes of expanding elastic particles enclosed and restrained within an elastic matrix. A comparison of calculated expansions with the expansions of concrete measured experimentally indicates that the theoretical relationship gives a good approximation of the expansion of a two-phase system such as concrete. The solution is then applied to the analogous carbonate rock case, which is considered as a two-phase system composed of dolomite particles enclosed within a calcite-clay matrix. Carbonate rock samples, which were chosen with regard to their expansive reactivity in alkaline solution, were analyzed physically, chemically, and petrographically. The experimental data thus obtained, supported by the theoretical analysis, indicate that the degree of expansion of a reactive carbonate rock depends on a complex interplay of its structural texture and compositional properties. The deformation characteristics of a carbonate rock under sustained loading tend to reflect its structural rigidity, which in turn is a significant property when the effects of either textural or external restraints to expansion are considered. Thus a reactive carbonate rock with low textural restraints could be highly expansive when unrestrained, but when restrained in a mass of concrete it would be more compressible and less expansive.

Media Info

  • Media Type: Print
  • Features: Figures; Photos; References; Tables;
  • Pagination: pp 9-22
  • Monograph Title: Cement-aggregate reactions
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00097195
  • Record Type: Publication
  • Files: TRIS, TRB
  • Created Date: Sep 30 1975 12:00AM