ACI Concrete Materials & Mix Proportioning 3

Question 1

What ASTM standard governs the specification requirements for normal Portland cement used in concrete?

Accepted Answer

ASTM C150

Answer

ASTM C150 is the Standard Specification for Portland Cement, covering all five types (I through V).

Question 2

In mix design, the 'fineness modulus' is a property of which concrete ingredient?

Accepted Answer

Aggregate

Answer

Fineness modulus is an index number derived from sieve analysis of fine or coarse aggregate, indicating the average size of particles.

Question 3

Which admixture type is classified under ASTM C494 Type A?

Accepted Answer

Water-reducing admixture

Answer

ASTM C494 Type A admixtures are water reducers that reduce the water requirement of concrete without changing set time.

Question 4

What effect does increasing the nominal maximum aggregate size have on the water requirement of a concrete mix?

Accepted Answer

Water requirement decreases

Answer

Larger maximum aggregate size reduces the total surface area of aggregate, requiring less water (and cement) to achieve the same workability.

Question 5

Ground granulated blast-furnace slag (GGBFS) is classified as which type of supplementary cementitious material?

Accepted Answer

Latent hydraulic binder

Answer

GGBFS is a latent hydraulic binder that reacts with water in the presence of an alkali activator (calcium hydroxide from cement hydration) to form cementitious products.

(ACI) American Concrete Institute Concrete Finisher Practice Test

(ACI) American Concrete Institute Concrete Finisher Practice Test

ACI Concrete Materials & Mix Proportioning 3