CITB Construction Methods and Materials 4

Question 1

What is the primary purpose of using admixtures classified as air-entraining agents in concrete?

Accepted Answer

To improve freeze-thaw durability by creating microscopic air bubbles

Answer

To increase compressive strength

Answer

To speed up setting time in cold weather

Answer

To reduce the amount of cement required

Question 2

In tilt-up concrete construction, what is the purpose of the bond breaker applied to the slab-on-grade?

Accepted Answer

To prevent the wall panel from bonding to the floor so it can be tilted up

Answer

To waterproof the floor slab

Answer

To increase the strength of the wall panel

Answer

To protect the slab from construction traffic

Question 3

Which foundation type is best suited for supporting a heavy structure over deep soft soils that cannot support spread footings?

Accepted Answer

Deep pile foundation

Answer

Mat (raft) foundation

Answer

Spread footings with grade beams

Answer

Cantilever retaining wall

Question 4

What is the term for the minimum distance reinforcing steel must be embedded into concrete to develop its full tensile strength?

Accepted Answer

Development length

Answer

Cover distance

Answer

Splice length

Answer

Clear spacing

Question 5

In curtain wall systems, what is the purpose of the 'pressure equalization' design principle?

Accepted Answer

To balance air pressure between inside and outside the wall to prevent water infiltration

Answer

To ensure even wind loading on all panels

Answer

To equalize thermal expansion across adjacent panels

Answer

To distribute the weight of glass panels equally to mullions

Question 6

What distinguishes 'stick-built' curtain wall from 'unitized' curtain wall systems?

Accepted Answer

Stick-built is assembled piece by piece on-site; unitized panels are pre-fabricated and lifted into place

Answer

Stick-built uses aluminum while unitized uses steel

Answer

Unitized systems cannot be used above 10 stories

Answer

Stick-built systems always cost more than unitized systems

Question 7

What is the primary function of geotextile fabric placed beneath aggregate base course in road construction?

Accepted Answer

To separate subgrade soil from base aggregate, preventing contamination and migration

Answer

To increase the bearing capacity of the aggregate

Answer

To waterproof the subgrade

Answer

To reflect heat and prevent frost penetration