250+ TOP MCQs on Plain and Reinforced – Cement – 1 and Answers

Building Construction Multiple Choice Questions & Answers (MCQs) on “Plain and Reinforced – Cement – 1”.

1. The colour of natural cement is __________
a) Brown
b) Black
c) White
d) Yellow
Answer: a
Clarification: The colour of natural cement is brown. Natural cement sets very quickly after adding water. The best variety of natural cement is called Roman Cement.

2. Portland cement was invented by ___________
a) John Raymond
b) Joseph Aspdin
c) Charles Frank
d) James Watson
Answer: b
Clarification: The common variety of artificial cement is called ordinary cement or normal setting cement. This cement after setting closely resembles a variety of sandstone abundantly found in Portland in England. Portland cement was invented by Joseph Aspdin in 1824.

3. Clay predominates in calcareous materials while calcium carbonate predominates in argillaceous materials.
a) True
b) False
Answer: b
Clarification: The two basic ingredients of ordinary cement are argillaceous and calcareous. Calcium carbonate predominates in calcareous materials while clay predominates in argillaceous materials.

4. Calcium sulphate is present in ordinary cement in the form of __________
a) Lime
b) Alumina
c) Gypsum
d) Magnesia
Answer: c
Clarification: Various ingredients of ordinary cement are lime, alumina, calcium sulphate, iron oxide, magnesia, etc. Calcium sulphate is present in ordinary cement in the form of gypsum. The function of calcium sulphate in cement is to increase its initial setting time.

5. It results in the failure of concrete made from the cement if the amount of alkali oxides in it exceeds _________
a) 1%
b) 5%
c) 12%
d) 17%
Answer: a
Clarification: The presence of alkali oxides and magnesium oxide badly affects the quality of the cement. It results in the failure of concrete made from the cement if the amount of alkali oxides in it exceeds 1%.

6. Which of the following compounds is not formed during the setting action of the cement?
a) Tricalcium aluminate
b) Tricalcium silicate
c) Dicalcium silicate
d) Dimagnesium carbonate
Answer: d
Clarification: Important compounds that are formed during the setting action of the cement are tricalcium aluminate, tricalcium silicate, dicalcium silicate and tetra-calcium alumino-ferrite. The setting action of the cement persists for a long time.

7. During the setting action of the cement, tricalcium aluminate is formed within ________ after adding water to the cement.
a) 6 hours
b) 24 hours
c) 4 days
d) 1 week
Answer: b
Clarification: During the setting action of the cement, tricalcium aluminate and tetra-calcium alumino-ferrite are formed within 24 hours after adding water to the cement. However, tricalcium silicate is formed within a week.

8. Which of the following is the quickest to react with water when the water is added to the cement?
a) Tetra-calcium alumino-ferrite
b) Tricalcium silicate
c) Dicalcium silicate
d) Tricalcium aluminate
Answer: d
Clarification: Tricalcium aluminate is the quickest to react with water when the water is added to the cement. In the order of decreasing rate are tetra-calcium alumino-ferrite, tricalcium silicate and dicalcium silicate.

9. The percentage of dicalcium silicate in belit is more than ________
a) 10%
b) 15%
c) 30%
d) 35%
Answer: d
Clarification: Portland cement is classified into alit, aluminate, belit, alumoferrite, etc. depending on the percentage of the mineralogical composition of clinker. The percentage of dicalcium silicate in belit is more than 35%.

10. High-alit contains tricalcium silicate more than ________
a) 10%
b) 13%
c) 30%
d) 60%
Answer: d
Clarification: High-alit contains tricalcium silicate more than 60%. However, alit contains tricalcium silicate more than 50-60%.

11. In the wet process in the manufacturing of portland cement, argillaceous material is thoroughly mixed with water in _________
a) Wash mill
b) Ball mill
c) Reverberatory furnace
d) Blast furnace
Answer: a
Clarification: In the manufacturing of portland cement, the raw materials can be mixed either in dry conditions or in wet conditions. In the wet process, argillaceous material is thoroughly mixed with water in a wash mill while calcareous materials are crushed and stored in storage tanks.

12. The ratio of the percentage of alumina to that of oxide of iron in the cement should not be less than ________
a) 0.24
b) 0.39
c) 0.66
d) 0.79
Answer: c
Clarification: The ratio of the percentage of alumina to that of oxide of iron in the cement should not be less than 0.66. However, the ratio of the percentage of lime to those of iron oxide, alumina and silica should not be greater than 1.02.

13. Total sulphur content in the cement should not be more than _________
a) 1.75%
b) 2.75%
c) 5.25%
d) 7.25%
Answer: b
Clarification: Sulphur content in the cement is calculated as sulphur trioxide. Total sulphur content in the cement should not be more than 2.75%.