Concrete Technology Questions and Answers - Manufacture of Portland Cement

1. ________ is not use to make Portland Cement (PC).
a) Calcareous Rocks
b) Argillocalcareous Rocks
c) Argillaceous Rocks
d) Sand

Answer: d
Explanation: Sand is mixed with Cement to make concrete instead of making cement. Materials which we get from these 3 rocks are useful to make healty PC.

2. Which one doesn’t comes under Calcareous Rocks?
a) Limestone
b) Cement rock
c) Chalk
d) Marine shell deposits

Answer: b
Explanation: Cement Rock comes in Argillocalcareous Rocks. And Calcareous Rocks have Limestone, Marl, Chalk, Marine Shell Deposits.

3. What is the percentage of CLINKER in PC?
a) 2-3%
b) 4-6%
c) 2-6%
d) 3-5%

Answer: c
Explanation: Portland cement is made by mixing substances containing CaCO3 with substances containing SiO2, Al2O3, Fe2O3 and heating them to a clinker which is subsequently ground to powder and mixed with 2-6 % gypsum.

4. As the materials pass through the kiln their temperature is rised upto ____
a) 1300-1600 °C
b) 1100-1500 °C
c) 1300-1500 °C
d) 1100-1600 °C

Answer: a
Explanation: 1300-1600 °C is the best range to melt the raw materials for a healty PC. Below 1300 °C the materials whcih we added to make PC won’t melt perfectly and the result will be unhealty PC.

5. What is the diameter and length of the kiln respectively?
a) 6m and 200m
b) 200m and 6m
c) 6m and 6m
d) 200m and 200m

Answer: a
Explanation: They are produced in a range of sizes and units with diameters up to 6 m and lengths up to 200 m have been made.

6. What is the range of CaCO3 in Argillocalcareous Rocks?
a) >75%
b) 40-75%
c) <45%
d) 75%

Answer: b
Explanation: It is the standard value for in Argillocalcareous Rocks (40-75% CaCO3 such as clayey limestone, clayey marl).

7. Prepared raw mix is fed into the rotary kiln.
a) True
b) False

Answer: a
Explanation: Cement kilns are used for the pyroprocessing stage of manufacture of Portland and other types of hydraulic cement, in which calcium carbonate reacts with silica-bearing minerals to form a mixture of calcium silicates.

8. What is the diameter of Clinker for making of Portland Cement?
a) .15-5 cm
b) .15-5 m
c) .3-4 cm
d) .3-4 m

Answer: a
Explanation: As the materials pass through the kiln their temperature is rised upto 1300-1600 °C. The process of heating is named as “burning”. The output is known as “clinker” which is 0.15-5 cm in diameter.

9. What is the composition of making the Mortar?
a) P.C. + Water
b) P.C. + Water + Sand
c) P.C. + Water + Sand + Gravel
d) Water + Sand + Gravel

Answer: b
Explanation: Mortar is a mixture of 3 materials i.e. cement, water and sand (P.C. + sand + water = Mortar), used in building for holding bricks or stones together.

10. Cement is a material with adhesive and cohesive properties
a) True
b) False

Answer: a
Explanation: Cement is a material with adhesive and cohesive properties which make it capable of bonding mineral fragments into a compact whole.