D68 QUIZ OF THE DAY

Which IS code provides guidelines for bending and fixing bars in reinforcement work?

• IS 456
• IS 2502
• IS 10262
• IS 800

Answer explanation

IS 2502 is the code of practice for bending and fixing bars, including standard bend deductions and shapes.

As per IS 456:1962, the minimum clear cover for slabs is:

• 20 mm
• 25 mm or diameter of bar, whichever is more
• 15 mm or diameter of bar, whichever is more
• 40 mm

Answer explanation

Clear cover for slabs is specified as 15 mm or the bar diameter, whichever is greater.

The length of one hook in reinforcement is approximately:

• 10 times the diameter of the bar
• 12 times the diameter of the bar
• 8 times the diameter of the bar
• 9 times the diameter of the bar

Answer explanation

Hook length = 9φ, where φ is the diameter of the bar.

In cranked bars, the excess length on one side is taken as:

• 0.25d
• 0.42d
• 0.5d
• 0.84d

Answer explanation

Excess length of one side of cranked bar is taken as 0.42 times the effective depth (d).

Which type of hook is generally provided in reinforcement bars?

• J-type
• U-type
• Circular
• L-type

Answer explanation

Generally, U-type hooks are provided for better anchorage with concrete.

The main purpose of distribution bars in slabs is to:

• Distribute loads and resist temperature & shrinkage stresses
• Increase bending strength
• Replace main reinforcement
• Reduce slab thickness

Answer explanation

Distribution bars provide lateral distribution of loads and handle temperature/shrinkage stresses.

The unit weight of 12 mm diameter steel bar is:

• 0.62 kg/m
• 1.58 kg/m
• 2.45 kg/m
• 0.89 kg/m

Answer explanation

From the given table, 12 mm dia bar weighs 0.89 kg per metre.

Which steel grade saves about 10% steel compared to Fe 415?

• Fe 550
• Fe 500
• Fe 600
• Fe 250

Answer explanation

Fe 500 is stronger and allows reduction of steel quantity by about 10% compared to Fe 415.

For each 90° bend in reinforcement, the deduction length is:

• 2d
• 1d
• 0.42d
• 8d

Answer explanation

For a 90° bend, deduction of 2 times the bar diameter is considered.

Purpose of a Bar Bending Schedule (BBS) is to:

• Replace concrete mix design
• Reduce curing time
• List bar details for cutting and bending
• Increase cement content

Answer explanation

BBS is a detailed list of all reinforcement bars with dimensions, shape, and quantity.