STP1061: The Importance of Petrological, Petrographical and Mineralogical Characteristics of Aggregates in Very High Strength Concrete

    Sarkar, SL
    Faculty of Applied Sciences, Université de Sherbrooke, Quebec,

    Aïtcin, P-C
    Faculty of Applied Sciences, Université de Sherbrooke, Quebec,

    Pages: 16    Published: Jan 1990


    Abstract

    Aggregate intrinsic strength, particularly that of coarse aggregates, receives scant attention from concrete technologists and researchers as long as the w/c ratio falls within the 0.50-to-0.70 range, primarily due to the fact that the cement-aggregate bond or the hydrated cement paste fail long before aggregates do.

    This, however, does not hold true for very high-strength concretes, with very low w/c ratios of 0.20 to 0.30. Compressive strength testing of very high-strength concrete has indicated that aggregates can assume the weaker role, exhibited in the form of transgranular fractures on the surface of failure, as has already been observed in some lightweight concretes.

    The authors have carried out detailed petrological, petrographical and mineralogical characterization of twelve different coarse aggregates that have performed with variable success in very high-strength concrete in Canada and the United States. Suitability for such an application has been linked to a special set of lithological characteristics: the minerals must be strong, unaltered, and fine grained. Intra- and intergranular fissures, partially decomposed coarse-grained minerals, and the presence of cleavages and lamination planes tend to weaken the aggregate, and therefore the ultimate strength of the concrete.

    Keywords:

    Aggregate, very high-strength concrete, compressive strength, failures, hcp, transition zone, petrology, mineralogy, lithology, petrography


    Paper ID: STP23457S

    Committee/Subcommittee: C09.65

    DOI: 10.1520/STP23457S


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