Accession Number : AD0751601

Title :   Alkali-Silica and Alkali-Carbonate Reactivity of a South Dakota Sand,

Corporate Author : ARMY ENGINEER WATERWAYS EXPERIMENT STATION VICKSBURG MISS

Personal Author(s) : Buck,Alan D.

Report Date : SEP 1962

Pagination or Media Count : 15

Abstract : Examinations were made on concrete cores and 1-yr-old mortar bars made with high-alkali cement and a natural sand from Watertown, South Dakota. They revealed evidence of alkali-aggregate reaction associated with particles of montmorillonitic shale. Further studies revealed that the alkali-aggregate reaction of the shale particles involved low cristobalite-tridymite, concurrently with the alkali-aggregate reaction, there was a cation exchange involving the montmorillonite, there was alkali-aggregate reaction was that of dedolomitization in which brucite is a reaction product. These observations represent the first evidence of the alkali-carbonate rock reaction, dedolomitization, involving concrete materials used by the Corps of Engineers.

Descriptors :   (*CONCRETE, *DEGRADATION), (*CARBONATE MINERALS, CHEMICAL REACTIONS), (*CLAY MINERALS, CHEMICAL REACTIONS), SAND, SILICON DIOXIDE, SHALE, MONTMORILLONITE, PARTICLES, X RAY DIFFRACTION, TEST METHODS

Subject Categories : Construction Equipment, Materials & Supplies

Distribution Statement : APPROVED FOR PUBLIC RELEASE