Q 01/05

Concrete is the second-most-used substance in the world after what?

A) Steel

B) Water

C) Wood

D) Oil

Answer · why

B) Water

It is also the most widely used building material and the most-manufactured material on Earth.

Q 02/05

What are the two basic components of concrete?

A) Lime slaked with wood ash

B) Sand mixed with fired clay

C) Steel mesh set in stone

D) Aggregate bound by a cement

Answer · why

D) Aggregate bound by a cement

Cement-bound concrete differs from asphalt concrete, which uses a bituminous binder.

Q 03/05

What is the chemical process by which cement reacts with water and hardens?

A) Hydration

B) Fermentation

C) Sublimation

D) Oxidation

Answer · why

A) Hydration

The reaction is exothermic, so ambient temperature affects how fast concrete sets.

Q 04/05

How does mortar, used to bond bricks, differ from concrete?

A) It contains no cement at all

B) It is far stronger when set

C) It contains only fine aggregates

D) It is mixed without any water

Answer · why

C) It contains only fine aggregates

Mortar is mainly used as a bonding agent for bricks and tiles; grout also lacks coarse aggregate.

Q 05/05

The word 'concrete' comes from a Latin word meaning what?

A) Hard as rock

B) Compact or condensed

C) Poured together

D) Grey stone

Answer · why

B) Compact or condensed

Concretus is the perfect passive participle of concrescere, 'to grow together'.