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Terms in this set (61)

Aggregates (coarse or fine) are selected based on their physical (size, shape, texture, specific gravity, etc.), chemical (reactivity, as in resistance to chemical attacks), and mechanical (impermeability, volume stability, hardness, toughness, soundness, porosity, etc.) properties. Please choose from the statements below the one that is most appropriate.
1) When selecting a coarse aggregate (CA) for portland cement concrete (PCC), rounded shape and smoother texture, as opposed to angular shape and porous texture, would be considered ideal, as such properties promote better economy of the paste of the PCC, and would lower stress concentration in the hardened paste, as the PCCis loaded — compared to angular, elongated, porous CA
2) When selecting a coarse aggregate (CA) for asphalt concrete (AC), angular shape, and rougher and porous texture, as opposed to rounded shape and smoother texture, would be considered ideal, as such properties promote better particle-to-particle interlocking among the CA in the AC, thus adding to the stability of the AC, as the AC softens in the heat of hot Summer days while loaded
3) As the trend to use recycled concretes and crushed rocks to supply coarse aggregate (CA) for portland cement concrete (PCC) — in response to diminishing naturally available gravel along river beds — the use of chunky but angular, and less than completely smooth-textured CA is now normal.
4) In subscribing to the philosophy of "what is available, that is the best", increasingly, there seems to be little distinctive differentiation between the coarse aggregates (CAs) used in portland cement concrete (PCC) and asphalt concrete (CA)
5) All of the above are true statements