Highway Engineering Multiple Choice Questions on “Soil-Cement Stabilization”.
1. In soil cement stabilisation the bond is imparted between cement and __________
a) Water
b) Fine aggregate
c) Coarse aggregate
d) Soil
Answer: d
Clarification: In the soil cement stabilisation, the bond is imparted between hydrated cement and compacted soil.
2. Making of solid into fine powder is called __________
a) Powdering
b) Crushing
c) Pulverising
d) Refining
Answer: c
Clarification: The crushing of the solid into the fine powder is called as pulverising, mostly pulverised materials are used.
3. The chemical that can harm the hydrated cement is __________
a) Calcium sulphate
b) Calcium di sulphate
c) Calcium tri sulphate
d) Magnesium sulphate
Answer: d
Clarification: The magnesium sulphate is a very strong chemical and it may even effect the hydrated cement reducing its strength.
4. The increase of cement causes __________
a) Increase in weight
b) Increase in void ratio
c) Increase in strength
d) Increase in porosity
Answer: c
Clarification: The increase in cement causes the increase in strength and durability, and of water is added then it’s strength decreases.
5. Presence of unpulverised dry lumps reduce the __________
a) Strength
b) Durability
c) Strength and durability
d) Water content
Answer: c
Clarification: The strength and durability of the soil are badly affected by the unpulverised powder.
6. If compaction efforts increase, then __________
a) Dry density increase
b) Dry density decrease
c) Wet density increase
d) Wet density decrease
Answer: a
Clarification: If compaction efforts increase, then dry density increases and wet density doesn’t change.
7. The high temperature in soil cement stabilisation accelerates __________
a) Strength
b) Dry density
c) Shear
d) Compaction
Answer: a
Clarification: The higher temperature leads to rapid drying of the sample, which leads to the gain in strength.
8. The additive not used in soil cement stabilisation is?
a) Sodium hydroxide
b) Sodium carbonate
c) Calcium chloride
d) Sugar
Answer: d
Clarification: Sugar is a retarder and it should not be used in soil cement stabilisation, whereas other chemicals like calcium chloride and sodium carbonate can be used.
9. The BIS for soil cement stabilisation is based on __________
a) British
b) ASTM
c) PCA
d) British and ASTM
Answer: d
Clarification: The BIS method is based on both British and ASTM for the soil cement stabilisation.
10. What is the soil samples are prepared in a mould of diameter?
a) 5 cm
b) 10 cm
c) 15 cm
d) 20 cm
Answer: a
Clarification: The samples are tested in a sample of diameter 5 cm and height 10 cm, by compacting them into the mould.
11. The graph between cement content and compressive strength is plotted for how many days of curing?
a) 3 days
b) 5 days
c) 7 days
d) 9 days
Answer: c
Clarification: The graph is plotted for cement content and compressive strength for a curing period of 7 days.
12. What is the maximum brushing loss for A6 A7 soil type?
a) 5
b) 6
c) 7
d) 10
Answer: c
Clarification: The PCA recommends a loss of not more than 7% for soil type of A6 and A7, after 12 cycles of freeze and thaw.
13. The plasticity index of soil cement base course should be less than __________
a) 28
b) 18
c) 38
d) 48
Answer: b
Clarification: From practical considerations, the results obtained tell that the plasticity index should be less than 18.
14. How many methods are available for the construction of a soil cement base course?
a) One
b) Two
c) Three
d) Four
Answer: b
Clarification: The two available methods are mix in place method, plant mix method.
15. The degree of pulverisation is checked by sieve of __________
a) 10 mm
b) 6.25 mm
c) 4.75 mm
d) 2.36 mm
Answer: c
Clarification: The degree of pulverisation is checked by the sieve passing through 4.75 mm and it should exceed 50%.