Aggregates for Concrete - Memphis

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The importance of using the right type and quality ofaggregates cannot be overemphasized. The fine andcoarse Aggregates generally occupy 60% to 75% of theconcrete volume (70% to 85% by mass) and strongly influ-ence the Concrete s freshly mixed and hardened proper-ties, mixture proportions, and economy. Fine Aggregates (Fig. 5-1) generally consist of natural sand or crushedstone with most particles smaller than 5 mm ( in.).Coarse Aggregates (Fig. 5-2) consist of one or a com-CHAPTER 5Aggregates for Concretebination of gravels or crushed stone with particlespredominantly larger than 5 mm ( in.) and generallybetween mm and mm (3 8in.)

of rocks and minerals (see Table 5-1). A mineral is a natu-rally occurring solid substance with an orderly internal structure and a chemical composition that ranges within narrow limits. Rocks, which are classified as igneous, sedi-mentary, or metamorphic, depending on origin, are gener-ally composed of several minerals. For example, granite

  Rocks, Igneous