IUT f2w
- Match List-I with List-II and select the correct answer using the codes given below the
lists:
List-I List-II
(Oxide of cement)(Function)
A. CaO 1. deficiency, causes slow setting
B. SiO 2 2. deficiency, reduces setting time
C. Al 2 O 3 3. excess, causes cracks
4. excess, lowers the strenghth
Codes:
(a) A B C (b) A B C
21 4 1 24
(c) A B C (d) A B C
23 1 2 13 - The temperature range in a cement kiln is
(a) 500 to 1000° C (b) 1000 to 1200° C (c) 1300 to l500°C (d) 1600 to 2000°C - Consider the following statements:
When cement is tested for setting time; on gauging its shows quick setting. This
phenomenon known as “Flash set” of cement is due to the presence of high- tricalcium Aluminate (C 3 A) in cement
- alkalis in cement
- tricalcium silicate (C 3 S) in cement
Which of these statements are correct?
(a) 1, 2 and 3 (b) 2 and 3 (c) l and 2 (d) l and 3
- Pick out the incorrect statement.
(a) For hydraulic structures, a cement with small percentage of C 3 S and more C 2 S is
recommended.
(b) Setting and hardening of cement stop as soon as the concrete becomes dry.
(c) The product C-S-H gel is known as tobermorite gel.
(d) The stiffening of cement without strength development is caused because of C 4 AF - The rate of heat evolution of the following four compounds in decending order is
- C 3 S 2. C 2 S 3. C 3 A 4. C 4 AF
(a) 1, 2, 3, 4 (b) 3, 1 ,4, 2 (c) 3, 4, 1, 2 (d) 3, 4, 2, 1
- C 3 S 2. C 2 S 3. C 3 A 4. C 4 AF
- The rate of heat of hydration of the four Bogue compounds in decending order is
(a) C 3 S, C 2 S, C 3 A, C 4 AF (b) C 3 S, C 3 A, C 2 S, C 4 AF
(c) C 4 AF, C 3 A, C 2 S, C 3 S (d) C 4 AF, C 3 S, C 3 A, C 2 S - The bound water (by weight) % required for complete hydration of cement is about
(a) 15 (b) 23 (c) 38 (d) 40 - Which of the following pairs is not matched correctly?
(Cement test) (Apparatus)
(a) Fineness Nurse and Blains
(b) Consistency Vicat
(c) Soundness Le-Chatelier
(d) Sp. gravity Lea and Nurse