Building Materials Questions & Answers - Page 5

21.

Asbestos cement

A.

is brittle

B.

warps due to changes in humidity

C.

strength is lowered when saturated by water

D.

all the above

Correct answer is D

No explanation has been provided for this answer.

22.

For the manufacture of Portland cement, the proportions of raw materials used are

A.

lime 63% ; silica 22% ; other ingredients 15%

B.

lime 22% ; silica 63% ; other ingredients 15%

C.

silica 40% ; lime 40% ; other ingredients 20%

D.

silica 70% ; lime 20% ; other ingredients 10%

Correct answer is A

No explanation has been provided for this answer.

23.

Brittleness of cold is due to an excess of

A.

sulphur

B.

carbon

C.

phosphorus

D.

silicon

Correct answer is C

No explanation has been provided for this answer.

24.

Due to attack of dry rot, the timber

A.

cracks

B.

shrinks

C.

reduces to powder

D.

none of these

Correct answer is C

No explanation has been provided for this answer.

25.

Which one of the following is acid resistant asbestos

A.

actinolite asbestos

B.

amosite asbestos

C.

anthophylite asbestos

D.

crocidolite asbestos

E.

All the above

Correct answer is E

No explanation has been provided for this answer.