Concrete Midterm Exam

The mixture of cement, water, coarse aggregate and fine aggregate is called concrete.

• True

• False

Clay is a source of SiO₂ for cement production.

• True

• False

The cements derived from the calcination of gypsum or calcium carbonates are nonhydraulic because their products of hydration are resistant to water.

• True

• False

Sulfate can be added to the clinker during grinding to increase the quick-setting tendency of ground portland clinker.

• True

• False

C₃A have large structural holes in their crystal structures. This results in low reactivity C₃A.

• True

• False

MgO is less harmful than CaO for unsoundness because the oxygen ions are in close contact and the Mg²⁺ ions are well packed.

• True

• False

In addition to the compound composition, the fineness (surface area) of cement also affects its reactivity with water.

• True

• False

Generally, the finer the cement, the more slowly it will react.

• True

• False

1.      The aluminates are known to hydrate at a slower rate than the silicates.

• True

• False

More heat makes cement harden too slow, resulting in loss of workability.

• True

• False