15 important interviews questions and answers

Q 1. What is the Unit Weight of concrete?

A:- The unit weight of concrete depends on the type of aggregates and amount of voids. As per IS : 456-200 Unit weight of PCC is 24KN/m3 and RCC is 25KN/m3

Q 2. What is the unit weight of Steel?

A. The unit weight of Steel is 78.5KN/m3

Q 3. What are the Nominal Concrete Mix proportions for different grades?

A. Important:

 M20-1:1.5:3, 

M7.5- 1:4:8,
Less imp: M5- 1:5:10 

M25- 1:1:2,

M30-1:1:3 (Cement:Sand:aggregate)

Q 4. What is ductility?

A. Ductility is the Ability to deform under tensile stress.

Q 5. How to find the weight of steel bar used in reinforcement?

A. Weight of Bar in kg/m = D^2/162.2 D- Dia of bar in mm

Q 6. What’s the difference between one-way slab and two-way slab?

A. One way slab: Ratio of Longer Span / Shorter span > 2
Two way slab: Ratio of Longer span/ shorter span <= 2

Q 7. What is flat slab?

A. The slab which is supported on columns (Flab slab don’t have beams)

Q 8. What do you mean by One storeyed, Two storeyed building?

A. The building which has two floors is called two storeyed building.

Q 9. What’s the height of each floor?

A. 3m (12ft)

Q 10. What’s the length of rise and tread in Stair case?

A. Rise – 150mm to 200mm, 

Tread – 250mm to 300mm

Q 11. What’s the slope of Staircase?

A. As per IS 456, the slope or pitch of stair should be between 25 degrees to 40 degrees.

Q 12. What do you mean by the moment of inertia?

A. A quantity expressing a body’s tendency to resist angular acceleration, which is the sum of the products of the mass of each particle in the body with the square of its distance from the axis of rotation.

Q 13. What is a crank length in the slab?

A. The crank length in Slab is 0.42 D. Where D is Depth of Slab- Top cover – Bottom Cover.

Q 14. What are the types of a slump?

A. True Slump: The concrete mass after the test when slumps evenly all around without disintegration is called the true slump.

Shear Slump: When one-half of the concrete mass slide down the other is called the shear slump. This type of slump is obtained in a lean concrete mix.

Collapse Slump: When the sample is collapsed due to adding excessive water, it is known as collapse slump.

Zero Slump: For very stiff or dry mixes it does not show any changes of the slump after removing the slump cone.

Q 15. What is honeycomb in concrete? How is it formed? How to eradicate honey comb in concrete?

A. Learn about Honeycomb concrete