# Top 60 civil engineering interview questions and answers pdf

## TOP 20 BASIC CIVIL ENGINEERING INTERVIEW QUESTIONS AND ANSWERS PDF 2020

### Q.1) What is the Unit Weight of concrete?

As per IS: 456-2000 Unit weight of Plain cement concrete is 24KN/m3 and Reinforced cement concrete is 25KN/m3

### Q.2) Which is the worldâ€™s tallest man-made structure?

The world’s tallest man-made structure is the Burj Dubai which stands at Approx. 830 meters tall.

### Â Q.3 ) What are the steps involved in the concreting process, explain?

steps involved in the concreting process are :
1. Batching
2. Mixing
3. Transporting and placing of concrete
4. Compacting.

### Â Q.4) What are the Nominal Concrete Mix proportions for different grades?

Nominal mix concrete used for concrete of M-20 or lower.

M5- 1:5:10,Â Â  M7.5- 1:4:8,Â Â Â  M15- 1:2:4,Â Â  M20-1:1.5:3

### Â Q.5) What is ductility?

Ductility is the ability to deform under tensile stress.

### Q.6) How do you find the weight of a steel bar used in reinforcement?

Weight of Bar in kg/m = D2 /162.2Â Â  { D- Diameter of bar in mm }

### Q.7) Whatâ€™s the difference between a one-way slab and a two-way slab?

One way slab: Ratio of Longer Span / Shorter span > Â 2
Two-way slab: when the Ratio of Longer span / shorter span <= 2

### Â Q.8) What is a flat slab?

The slab which is supported on columns (Flab slab donâ€™t have beams)

### Q.9) Whatâ€™s the length of rise and tread in the Staircase?

Rise â€“ 150mm to 200mm,Â Tread â€“ 250mm to 300mm

### Q.10)Â  What Is the Difference Between Engineering Stress And True Stress?

At any load, the engineering stress is the load divided by this initial cross- area. Â At any load, the true stress is the load divided by the cross-area at that instant.

### Q.11) What is the slope of the Staircase?

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

### Q.12) What is a crank length in the slab?

The crank length in Slab is 0.42 D.

WhereÂ D = Slab thickness â€“ (Top cover + Bottom Cover)

### Q.13) What is the Honeycombing of concrete?

Honeycombs are hollow spaces and cavities left in concrete mass on the surface or inside the concrete mass where concrete could not reach. These look like honey bees nest.

### Q.14) What do you mean by segregation?

Segregation is a separation of cement, sand from aggregate. This is caused due to Water cement ratio andÂ  when concrete is poured about more than 1.5m

### Q.15) What is bleeding in concrete?

Bleeding is one form of segregation, where water comes out to the surface of the concrete, because of itâ€™s the lowest specific gravity of water among all the ingredients of concrete.

### Q.16) What is grouting?

Grout is a fluid form of concrete that is used to fill the voids.

### Q.17) What is soil analysis?

Soil analysis is the testing of soil to determine the nutritional and elemental composition of the soil. It is generally tested for knowing the contents of nitrogen, potassium, and phosphorous.

### Q.18) What is the allowable moisture content in Fine aggregate for the concrete mix?

We wonâ€™t use the aggregate if its moisture content is more than 5%.

### Q.19) 1 BHK full form?

1 Bedroom, 1 Hall, 1kitchen

### Q.20) What is the Initial & final setting time of concrete?

Initial Setting time: 30mins, Final setting time: 10hrs

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## 9 EXTRA CIVIL SITE ENGINEER INTERVIEW QUESTIONS AND ANSWERS PDF

### Q.1) What are the main reasons for building collapse?

There are several reasons for building collapse. Passage of time is the main reason. Also weak foundations, Natural calamities like earthquakes, Tsunamis, etc

### Q.2) State the applications of modulus of elasticity.

The modulus of elasticity is related to the flexibility of the material. This value of modulus of elasticity is very important in the case of the deflection of different materials used in construction.

### Q.3) What are the basic differences between absorption, adsorption, and sorption?

Absorption: It is the conversion or mixing of one material into another state.

Adsorption: The physical bonding of ions and molecules onto the surface of another phase

Sorption: It is a physical and chemical process in which one substance becomes attached to another.

Ex: cotton dipped in an ink bottle

### Q.4) How do you check the quality of cement on the site?

• Date of Mfg: Cement strength decreases with its age so it is very important to check.
• Color: The Colour should be grey with light greenish. color is an indication of excess lime or clay
• Float test: A good cement will float for some time and then sinks.
• Also, When you put your hand in a cement bag you should feel cool.

### Q.5) State the building codes.

These codes are set of specifications given by NBC ( national building code ) which states the dimensions and regulations of any building in India { Every country has different building codes}

### Q.6) What are the steps involved in the concreting process AND explain?

The major steps in the converting process are

1. Batching
2. Mixing
3. Transporting and placing of concrete
4. Compacting

Batching: The process of measurement of materials for the mixing of concrete is known as batching. It is done in two methods namely weigh batching and volumetric batching.

Mixing: In order to get a good concrete mix, Ingredients are properly mixed either by hand mixing or machine mixing.

Transportation and placing of concrete: If concrete is manufactured in Ready mix plant it should be transported within two hours and placed accordingly.

Compaction of concrete: After placing concrete air bubbles forms inside the concrete and causes a decrease in strength so it should be properly compacted using hand compactors or vibrators.

### Q.7) Describe briefly the various methods of concrete curing?

Curing is the process of maintaining temperature and moisture conditions for hardening of concrete are known as curing. This process of curing helps fresh concrete from shrinkage:

(a) Spraying of water: In this method, water is sprinkled over the concrete structures, Ex: columns, walls, etc

(b) Wet covering of surface: This can be cured by using the wet gunny bags or straw

(c) Ponding: the horizontal surfaces including the slab and floors can be cured by stagnating the water for a longer time.

(d) Steam curing: This method pf curing is used in prefabricated concrete units. steam is passed over the units that are under closed chambers. This allows faster curing and results in faster recovery.

(e) Application of curing compounds: compounds having calcium chloride can be applied on the curing surface. This keeps the surface wet for a long time.

### Q.8) Explain the cavitation process in pipes & drains?

Usually due to the air bubble formation within the fluids usually because of low-pressure conditions get even lower than the saturation pressure is defined as the cavitation process. This creates a potentially damaging situation to the durability of pipes.

### Q.9) What is the Compressive Strength of brick?

• Second class brick-70kg/cm2
• First class brick-105kg/cm2
• Fire brick-125kg/cm2

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