Chemical Composition Test - Concrete Technology Questions and Answers

This set of Concrete Technology Multiple Choice Questions & Answers (MCQs) focuses on “Chemical Composition Test”.

1. Portland cement is composed of four major oxides (CaO, SiO₂, Al₂O₃, Fe₂O₃ ≥90%).
a) True
b) False
View Answer

Answer: a
Explanation: Portland cement is composed of four major oxides ((CaO, SiO₂, Al₂O₃, Fe₂O₃2O & K₂O in P.C.?
a) =.6%
b) >6%
c) <6%
d) 0
View AnswerAnswer: c
Explanation: Alkalies (Na₂O & K₂O) may cause some dificulties if the cement is used with certain types of reactive aggregates in making concrete.

5. Insoluble Residue mainly comes from which compound?
a) Lime
b) Soda
c) Silica
d) Alumina
View Answer

Answer: c
Explanation: Insoluble Residue is that fraction of cement which is insoluble in HCl. It comes mainly from the silica which has not reacted to form compounds during the burning process in the kiln.

6. Loss on Ignition (L.O.I.) is the loss in weight of cement after being heated to _____________
a) 1000°C
b) 100°C
c) 500°C
d) 1500°C
View Answer

Answer: a
Explanation: It indicates the prehydration or carbonation due to prolonged or improper storage of cement & clinker.

7. C₄AF is not a true compound.
a) True
b) False
View Answer

Answer: a
Explanation: C₄AF is not a true compound. The ferrite phase ranges from C₂AF to C₆AF. *C₄AF represents an average.

8. On cooling below 1250^oC, C₃S decomposes ____________
a) Fast
b) Slowly
c) Never
d) Depends on the conditions
View Answer

Answer: b
Explanation: On cooling below 1250^oC, C₃S decomposes slowly but, if cooling is not too slow, C₃S remains unchanged and is relatively stable at ordinary temperatures.

Sanfoundry Certification Contest of the Month is Live. 100+ Subjects. Participate Now!

9. Gypsum reacts with ____________ to form calcium sulfo aluminates and calcium sulfo ferrite.
a) C₄AF
b) CF₄
c) SO₃
d) CaO
View Answer

Answer: a
Explanation: C₄AF work as flux material and also it accelerates the hydration of silicates. C₄AF hydrates to tricalcium aluminate hydrate and calcium ferrite CaO.Fe₂O₃ in amorphous form.

10. C₃ S and C₂S require approximately the _____________ amount of water for hydration.
a) Same
b) More
c) Less
d) Depends on the paste
View Answer

Answer: a
Explanation: C₃S and C₂S require approximately the same amount of water for hydration, but C₃S produces more than twice as much Ca(OH)₂ as is formed by the hydration of C₂S.

Sanfoundry Global Education & Learning Series – Concrete Technology.

To practice all areas of Concrete Technology, here is complete set of 1000+ Multiple Choice Questions and Answers.

« Prev - Concrete Technology Questions and Answers – Setting Time Test

» Next - Concrete Technology Questions and Answers – Classification of Aggregates

Related Posts:

Recommended Articles: