CIVIL
ENGINEERING MCQ – PART:07
1.
Pick out the incorrect statement
a)
Cement is adhesive as well as cohesive material
b)
Portland cement is of hydraulic type
c)
For civil engineering works generally calcareous cements are used
d) Portland cement is an example of natural cement
2.
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
3.
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
1)
Tricalcium Aluminate (C3A) in cement
2)
Alkalis in cement
3)
Tricalcium silicate (C3S) 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
4.
Pick out the incorrect statement.
a)
For hydraulic structures, a cement with small percentage of C3S and more C2S 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 C4AF
5.
The rate of heat evolution of the following four compounds in descending order is
1. C3S 2. C2S 3. C3A 4. C4AF
(a) 1, 2, 3, 4 (b) 3, 1 ,4, 2 (c) 3, 4, 1, 2 (d) 3, 4, 2, 1
6.
The rate of heat of hydration of the four Bogue compounds in descending order is
a) C3S, C2S, C3A, C4AF (b) C3S, C3A, C2S,
C4AF
(c) C4AF, C3A, C2S, C3S (d) C4AF, C3S, C3A, C2S
7.
The bound water (by weight) % required for complete hydration of cement is about
(a) 15 (b) 23 (c) 38 (d) 40
8. Ordinary Portland cement should have surface area not less than (in mm2 / g x 102)
(a) 2250 (b) 3000 (c) 3250 (d) 4000
9.
To produce low heat cements, it is necessary to reduce the compound
(a)
C3S (b) C2S (c) C3A (d) C4AF
10. For complete hydration of cement, the w / c ratio needed is
a)
less than 0.25
b)
more than 0.25 but less than 0.35
c) more than 0.35 but less than 0.45
d)
more than 0.45 but less than 0.60
11. High alumina cement is produced by fusing together a mixture of
a) limestone and bauxite
b)
limestone, bauxite and gypsum
c)
limestone, gypsum and clay
d)
limestone, gypsum, bauxite, clay and chalk
12. Consider the following statements: High early strength of cement is obtained as a result of
1)
fine grinding
2)
decreasing the lime content
3)
burning at higher temperatures
4)
increasing the quantity of gypsum
of these statements
(a) 1 and 2 are correct (b) 1 and 3 are correct
(c) 2, 3 and 4 are correct (d) 1, 3 and 4 are correct
13. Four main oxides present in ordinary Portland cement are: CaO, A12O3, SiO2 and Fe2O3.
Identify the correct ascending order of their proportions in a typical composition of OPC
(a) Al2O3,
Fe2O3, CaO, SiO2 (b) A12O3,
CaO, Fe2O3, SiO2
(c) Fe2O3, Al2O3, SiO2, CaO (d) Fe2O3, SiO2, Al2O3, CaO
14. If p is the standard consistency of cement, the amount of water used in conducting the initial setting time test on cement is
(a) 0.65 p (b) 0.85 p (c) 0.6 p (d) 0.8 p
15. Increase in fineness of cement
a)
reduces the rate of strength development and leads to higher shrinkage.
b)
increases the rate of strength development and reduces the rate of deterioration.
c)
decreases the rate of strength development and increases the rate of diterioration.
d) increases the rate of strength development and leads to higher shrinkage.
16. 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?
(a) 1 and 2 (b) 1 and 3 (c) 2 and 3 (d) l, 2 and 3
17. Which one of the following statement regarding the cement fineness is NOT correct?
a)
Fine cement is more liable to suffer from shrinkage craking than a coarse cement.
b)
Fine cement will show faster rate of hardening than coarse cement.
c) Fine cement shows faster rate of heat evolution and total quantity of heat evolved is much larger than coarse cement.
d)
Fine cement shows the same setting time as coarse cement.
18. For marine works, the best suited cement is
(a) low heat Portland cement (b) rapid hardening cement
(c) ordinary Portland cement (d) blast furnace slag cement
19. Which of the following aggregates gives maximum strength in concrete?
(a) Rounded aggregate (b) Elongated aggregate
(c) Flaky aggregate (d) Cubical aggregate
20. The maximum bulking of sand is likely to occur at a moisture content of
(a) 5% (b) 8% (c) 11% (d) 14%
21. The aggregate crushing value of coarse aggregates, which is used for making concrete, which in turn is used for purposes other than wearing surfaces should not exceed
(a) 30% (b) 40% (c) 45% (d) 50%
22. Which of the following coarse aggregate require minimum cement paste?
(a)
Rounded (b) Irregular (c) Angular (d) Flaky
23. For high strength concrete the best aggregate is
(a)
rounded (b) irregular (c) angular (d) all-in-aggregate
24. Aggregate affecting durability of concrete most are
(a) rounded (b) all-in-aggregate
(c) flaky (d) irregular
25. The best reflection of strength of coarse aggregate is given by
(a) crushing
(b) impact
(c) 10 per cent fines (d) hardness
26. The effects of impurities in water are expressed in terms of
(a) initial setting time (b) final setting time
(c) compressive strength (d) soundness of Portland cement.
27. The difference in 7 days compressive strength of cubes and cylinders prepared with impure and pure waters should not differ by more than
(a) 2% (b) 5% (c) 10% (d) 12%
28. The upper limit of suspended particles in water for the preparation of concrete is
(a) 200 ppm (b) 2000 ppm
(c) 5000 ppm (d) 10,000 ppm
29. Organic matter in water for making concrete should not be more than
(a) 1000 ppm (b) 3000 ppm
(c) 10000 ppm (d) 15,000 ppm
30. Consider the following statement in making concrete with sea water.
1)
Strength of concrete is reduced by about 10-20%
2)
Setting time accelerates
3)
Corrosion of reinforcement is not a problem if concrete is of good quality Of the above statements
(a) 1 and 2 are correct (b) 1 and 3 are correct
(c) only 1 is correct (d) 1, 2, 3 are correct
31. Consider the following statements: The effect of sea water on hardened concrete is to
1. increase its strength 2. reduce its strength
3. retard setting 4. decrease its durability
Of these statements
(a) 1 and 3 are correct (b) 2 and 3 are correct
(c) 2 and 4 are correct (d) 1 and 4 are correct
32. Pick up the correct statement(s)
1)
CaCO3 is the raw material for manufacturing lime
2)
Kankar is an impure limestone
3)
Coral for manufacturing lime is a sea animal
Of the above the correct statements are
(a) 1, 2 (b) 2, 3 (c) 1, 2, 3 (d) 1 only
33. Which of the following is caustic lime?
(a) Quick lime (b) Fat lime (c) Milk lime (d) Hydraulic lime
34. Quick lime coming out of the kiln is also known as
(a) hydrated lime (b) lump lime (c) fat lime (d) hydraulic lime
35. Hydrated lime for making mortars is slaked for
(a) 1 day (b) 3 days (c) 7 days (d) 14 days
36. Which of the following is not used for producing fat lime?
(a) Oolitic limestone (b) Calcareous tufa (c) Marble (d) Raw lime stone
37. The lime sets on absorbing CO2 from atmosphere is
(a) lean lime (b) feebly hydraulic lime
(c) rich lime (d) fat lime
38. The lime used for finishing coat in plastering is
(a) semi hydraulic lime (b) kankar lime
(c) magnesium lime (d) eminently hydraulic lime
39. Hydraulic lime is obtained by burning
(a) oolitic lime stone (b) kankar
(c) marble (d) tufa
40. Fat lime slakes between
(a) 2-3 hours (b) 24 hours (c) 3 days (d) 7 days