Question

As per IS 456 : 2000, the minimum percentage of tension reinforcement (up to two decimal places) required in reinforced concrete beams of rectangular cross-section (considering effective depth in the calculation of area) using Fe 500 grade steel is :

आईएस 456: 2000 के अनुसार, Fe 500 ग्रेड स्टील का उपयोग करके आयताकार क्रॉस-सेक्शन (क्षेत्र की गणना में प्रभावी गहराई पर विचार करते हुए) के प्रबलित कंक्रीट बीम में आवश्यक तनाव सुदृढीकरण (दो दशमलव स्थानों तक) का न्यूनतम प्रतिशत है :

0.17

0.13

0.21

0.23

Answer ( Option A)

0.17

Solution

Given: Grade of steel = Fe500

Characteristic strength of steel, f _y= 500 N/mm2

To find: Minimum percentage of tension reinforcement, P % =?

As per IS456:2000,clause 26.5.1.1,

The minimum area of tension reinforcement shall not be less than the following:

Hence, the minimum percentage of tension reinforcement (up to two decimal places) required in reinforced concrete beams of rectangular cross-section (considering effective depth in the calculation of area) using Fe 500 grade steel is 0.17%.

&Key Points:-

(I) As per clause 26.5.1.1 mentioned in IS456:2000, Maximum area of tension reinforcement shall not exceed 4% of gross area of beam cross section i.e., 0.04 db.

(II) As per clause 26.5.1.2 mentioned in IS456:2000, Maximum area of compression reinforcement shall not exceed 4% of gross area of beam cross section i.e., 0.04bD.

The compression reinforcement in beams shall be enclosed by stirrups for effective lateral restraint.