Basic Civil Engineering Multiple Choice Questions on “Mortar”.
1. Mortar comes from the Latin word:
a) Mortare
b) Mortarum
c) Mortaer
d) Mortarium
Answer: d
Clarification: The word Mortarium means crushed. Mortar consists of binding material, fine aggregate and water.
2. The first used Mortar was:
a) Lime mortar
b) Mud mortar
c) Cement mortar
d) Organic mortar
Answer: b
Clarification: In ancient times, mud was extensively used for various purposes. It was also used as mortar material. Mud was mixed with water and used.
3. Polymer Cement Mortar (PCM) is used primarily for:
a) Repairing concrete structure
b) Stone masonry
c) Tile masonry
d) Brick masonry
Answer: a
Clarification: In PCM, a part of cement is replaced by polymer admixtures like latex, emulsion, monomers, etc. These mortars have low permeability, reduces shrinkage and is suited for repairing works.
4. MM 1.5 means:
a) Masonry Mortar of cement content 1.5 bags
b) Mild Mortar of cement content 1.5 bags
c) Masonry Mortar of compressive strength 1.5N/mm2.
d) Mild Mortar of compressive strength 1.5N/mm2.
Answer: c
Clarification: MM stands for Masonry Mortar. The number after that represents the compressive strength of that mortar mix.
5. For pointing works, the ratio of mortar used is:
a) 1:3 – 1:4
b) 1:2 – 1:3
c) 1:7 – 1:8
d) 1:5 – 1:6
Answer: b
Clarification: The ratio 1:2 indicates cement to fine aggregate ratio. For plastering works, 1:3 – 1:4 ratio is used. For masonry, 1:6 – 1:8 is used.
6. The guidelines for preparation for mortar is given in:
a) IS 4455
b) IS 2250-1981
c) IS 3350-1981
d) IS 5567
Answer: b
Clarification: The method of hand mixing and machine mixing can be employed. First cement is laid on a flat platform. The required amount of sand is spread on top of it. Finally, water is added slowly till required consistency is reached.
7. Light weight mortar is prepared by using:
a) Lime
b) Surkhi
c) Wood chips
d) Flyash
Answer: c
Clarification: Wood chips, powder or sawdust is added to lime or cement and mixed with water. This results in lightweight mortar. It is used in heat and sound proof construction.
8. Packing mortars are used to pack:
a) Oil wells
b) Retaining walls
c) Bricks
d) Cracks in masonry
Answer: a
Clarification: It is prepared by mixing loam instead of sand. It has properties of water resistant, water pressure resistant, high homogeneity, etc.
9. The bulk density of X-ray shielding mortar is:
a) 6-12 kN/m3
b) 5 kN/m3 and above
c) 22 kN/m3 and above
d) 10-20 kN/m3
Answer: c
Clarification: X-ray shielding mortar is prepared using heavy rocks and suitable admixtures. It’s aheavy mortar with bulk density above 22 kN/m3. It is used in plastering coats to walls and ceiling of X-ray cabinets.
10. Which of the below is added to make mortar fire proof?
a) Gypsum
b) Asbestos cement
c) Powdered glass
d) Aluminous cement
Answer: d
Clarification: This mortar is prepared by adding one part of aluminous cement to 2 parts of powder of fire bricks. It can be used to line furnaces, ovens, fire places, etc.
11. The setting speed of mortar can be increased using:
a) Lime
b) Sulphur
c) Pozzolana
d) Gypsum
Answer: a
Clarification: Lime (hydraulic lime) mortar sets on contact with water. It results in speedy work. It does not offer flexibility as in case of cement mortar.
12. Which of the below mortar can settle under water?
a) Hydrolytic
b) Pozzolana
c) Lime
d) Flyash
Answer: b
Clarification: Finely powdered Pozzolana is added to lime or cement mortar can rapidly set the mortar. It can be used under water as it allows quick setting.
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