10 Interview Question asked in Afcon Company Interview?

1.What are the field tests carried out to determine the qualities of the brick?

• Ans:- Water Absorption: After immersing the brick in water for 24 hours, water absorption should not be more than 20% by weight.
• For class-I works this limit is 15%.
• Strength: Crushing strength of brick should not be less than 3.5 N/mm2. A field test for strength is that when dropped from a height of 0.9 m to 1 m on a hard ground, the brick should not break into pieces.
• Soundness: When struck with hammer or with another brick, it should produce metallic

2. What is meant by face left and face right readings in theodolite survey?

Ans. Face right is when the vertical circle of an instrument is in the right side of the observer

Face left is when vertical circle of an instrument is in left side of the observer while taking the readings during survey.

3. What is Mud mortar in Construction ?

Ans : Clay lumps are collected and are wetted with water and allowed to mature for 1 or 2 days.

Sometimes fibrous materials like gobber is added in the mix.
It prevents cracks in the plaster. If plaster is to be used for outer walls, it is sprayed or painted with bitumen

4.what is Gauge mortar?

Ans :It is the mortar obtained by adding cement to lime mortar. The usual proportion of cement, lime and sand are 1:1:6, 1:2:9 and 1:3:12. This mortar is to be used within half an hour after mixing cement.

5.What is the best Water ratio to achieve work ability and at the same time good strength ?

Ans: 0.4 to 0.45 is used, in case of machine mixing water cement ratio of 0.5 to 0.6 is used for hand mixing.

6. What is the minimum Height of Water during Pond Curing ?

Ans:The horizontal surfaces like slab and floors are cured by stagnating the water to a height of 25 to 50 mm by providing temporary small hunds with mortar

7. Why we Provide Plinth Beam ?

Ans:The function of the plinth is to keep the ground floor above ground level, free of dampness. Its height is not less than 450 mm. It is required that plinth level is at least 150 mm above the road level

8.If you are site Engineer what is the Points to be Observed in Supervising Brick Masonry Constructions ?

Ans:Before using the bricks in masonry, they should be soaked in water for 2 hours so that bricks do not absorb water from the mortar

• Walls should be raised uniformly. In no case difference between adjoining walls be more than 1 m. In a day no wall should be raised by more than 1.5 m.

• To get proper key for plastering or pointing, the face joints should be raised to a depth of 12- 20 mm, when the mortar is green. If plastering or pointing is not to be provided, face joints should be stuck flush and finished neatly.

• Brick masonry should be regularly cured for 2 weeks
• Hold fasts for doors and windows should be embedded in brick masonry with cement mortar or concrete, at the time of constructing the wall itself.

• Versatility of the wall should be ensured by frequently checking with plumb-bob.

9.What is main difference Between plastering and pointing ?

Ans:

Plastering	Pointing
It is applied to entire surface.	It is provided only at exposed joints.
It provides smooth surface.	It does not provide smooth surface.
It conceals defective workmanship in the masonry construction.	It is used to expose beauty of well built in-masonry work.
It provides a base for applying white/ colour washing	White washing or colour washing ruled out.

10.What is the formula for weight of steel?

Ans:- Weight of steel in kg can be calculate by formula

(D2*L)/162

where D is diameter of steel bar in millimeter and L is total length of steel bar in meter.