D64 CHECK YOUR LEVEL

What is the main reason for providing steel reinforcement in RCC?

• To improve compressive strength
• To resist tensile forces
• To reduce weight
• To improve aesthetics

Answer explanation

Concrete is strong in compression but weak in tension; steel resists tensile forces.

Which IS code is used for steel reinforcement in RCC?

• IS 456
• IS 383
• IS 1786
• IS 269

Answer explanation

IS 1786 covers specifications for high strength deformed steel bars and wires for RCC.

In RCC lintels, where should the main steel be placed?

• At the top
• At the bottom
• At the center
• Anywhere

Answer explanation

Main steel is placed at the bottom in RCC lintels to resist tensile stress.

The minimum bearing for a lintel end is:

• 50 mm
• 75 mm
• 100 mm
• 150 mm

Answer explanation

Lintels should have at least 100 mm end bearing on the supporting wall.

What is the detention period of a septic tank for small installations?

• 6-12 hours
• 12-24 hours
• 24-48 hours
• 48-72 hours

Answer explanation

Septic tanks typically have a detention period of 24–48 hours for proper sedimentation and digestion.

The vertical distance between dip and crown weir in a trap is called:

• Trap depth
• Water seal
• Freeboard
• Clear space

Answer explanation

Water seal prevents the passage of foul gases through the trap.

Which tank has separate compartments for sedimentation and digestion?

• Septic tank
• Imhoff tank
• Aeration tank
• Sedimentation tank

Answer explanation

Imhoff tanks have separate chambers to avoid mixing of fresh sewage and sludge.

The solvent used in rapid curing cutback bitumen is:

• Diesel
• Kerosene
• Petrol
• Furnace oil

Answer explanation

Rapid curing cutback bitumen uses petrol or naphtha as the solvent.

Which test determines the temperature at which bitumen softens?

• Flash point test
• Softening point test
• Ductility test
• Viscosity test

Answer explanation

The softening point test measures the temperature at which bitumen attains a certain softness.

Minimum CBR value for subgrade in NH as per IRC is:

• 2%
• 4%
• 6%
• 8%

Answer explanation

IRC recommends a minimum CBR value of 6% for National Highway subgrades.