Cement MCQ – Building Materials

181. The initial setting time of rapid hardening cement should not be less than

  1. 30 min
  2. 1 hour
  3. 8 hours
  4. 24 hours
Answer
Answer. a

182. The initial setting of cement is caused due to

  1. di-calcium silicate
  2. tri-calcium silicate
  3. tri-calcium aluminate
  4. tri-calcium alumino ferrite
Answer
Answer. c

183. The percentage of the slag component of Portland-slag cement varies from

  1. 40 to 70%
  2. 10 to 40%
  3. 80 to 90%
  4. 70 to 80%
Answer
Answer. a

184. Gypsum is added in the manufacture of Portland Cement

  1. While mixing the raw materials.
  2. At the end of grinding the clinker into powder
  3. During burning in the rotary kiln
  4. At the beginning of the grinding the clinker
Answer
Answer. b

185. The specific surface (in cm2/g) of a good portland cement should not be less than

  1. 500
  2. 1100
  3. 3200
  4. 2250
Answer
Answer. d

186. The expansion in Portland cement can be tested by

  1. Fineness test
  2. Soundness test
  3. Setting time test
  4. Normal consistency test
Answer
Answer. b

187. As per IS specifications, the heat of hydration of low-heat portland cement for 28 days is

  1. Not more than 100 calories/gm
  2. Not more than 50 calories/gm
  3. Not more than 75 calories/gm
  4. Not more than 150 calories/gm
Answer
Answer. c

188. Which of the following tests detects presence of uncombined lime in cement?

  1. Consistency
  2. Fineness
  3. Soundness
  4. Initial setting time
Answer
Answer. c

189. In cement, following compounds can be used as accelerators except

  1. CaCl2
  2. CaSO4
  3. Na2SO4
  4. NaCl
Answer
Answer. b

190. The commercial name of white and coloured cements in India is

  1. Silvicrete
  2. Colocrete
  3. Snocem
  4. All of the above
Answer
Answer. b

191. Which of the following is correct if they are arranged in decreasing order of heat of hydration?

  1. C3A > C4AF > C3S > C2S
  2. C3A > C4AF > C2S > C3S
  3. C3A > C3S> C4AF > C2S
  4. None of the above
Answer
Answer. c

192. In portland cement Calcium chloride (CaCl2) is most widely used for

  1. reducing curing time
  2. increasing strength
  3. improving consistency
  4. reducing initial and final setting times
Answer
Answer. d

193. White cement should have least percentage of

  1. Iron Oxide
  2. Aluminium oxide
  3. Sodium oxide
  4. Silica
Answer
Answer. a

194. A cement bag contains 0.035 cubic meter of cement by volume. How many bags will one tonne (1000 kg) of cement comprise?

  1. 20
  2. 18
  3. 17
  4. 16
Answer
Answer. a

195. Ultimate strength to cement is provided by

  1. Tri-calcium silicate
  2. Di-calcium silicate
  3. Tri-calcium aluminate
  4. Tetra calcium alumino ferrite
  5. All of the above options
Answer
Answer. b

196. The main constituent of fly-ash is

  1. Ferrous oxide
  2. Aluminium oxide
  3. Silica
  4. All of the above options
  5. None of the above options
Answer
Answer. d

197. Which one of the following statements regarding the cement fineness is not correct?

  1. Fine cement is more liable to suffer from shrinkage cracking than a coarse cement.
  2. Fine cement will show faster rate of hardening than coarse cement.
  3. Fine cement shows faster rate of heat evolution and total quantity of heat evolved is much larger than coarse cement.
  4. Fine cement shows the same setting time as coarse cement.
Answer
Answer. c

198. Consider the following statements:

  1. Tests on cement paste to determine initial and final setting times are done at normal consistency condition
  2. Low heat cement has a high percentage of tri-calcium aluminate.
  3. High early strength Portland cement contains a large percentage of tricalcium silicate and lower percentage of dicalcium silicate.

Which of these statements are correct?

  1. i and ii
  2. i and iii
  3. ii and iii
  4. i, ii and iii
Answer
Answer. b
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