Reinforcement Cement Concrete (General Engineering) (SSC JE)

Total Questions: 56

1. Based on the assumptions made in the design for the limit state of collapse in flexure at IS : 456 - 2000, the limiting values of the depth of neutral axis for Fe-415 grade of steel is_______. [JSSC JE (GEN. ENGG.) 04.11.2022]

Correct Answer: (d) 0.48
Solution:

2. According to IS : 456-2000 'Plain and Reinforced Concrete-Code of Practice, and based on the assumptions made in the design for the limit state of collapse in flexure, for design purposes the compressive strength of concrete in the structure shall be assumed to be _______times the characteristic strength. [JSSC JE (GEN. ENGG.) 04.11.2022 ]

Correct Answer: (d) 0.67
Solution:

Limit state of collapse : Flexure Assumptions–
(a) Plain sections normal to the axis remain plane after bending.
(b) The maximum strain in concrete at the outmost compression fiber is taken as 0.0035 in bending.
(c) The relationship between the compressive stress distribution in concrete and the strain in concrete may be assumed to be rectangle, trapezoid, parabola or any other shape which results in prediction of strength in substantial agreement with the result of test.
(d) For design purposes, the compressive strength of concrete in the structure shall be assumed to be 0.67 times the characteristic strength. The partial safety factor γₘ = 1.5 shall be applied in addition to this.
(e) The tensile strength of the concrete is ignored.

3. According to IS : 456-2000 'Plain and Reinforced Concrete-Code of Practice', ______ is the partial safety factor taken for concrete in assessing the strength of a structure of structural member for the limit state of collapse. [JSSC JE (GEN. ENGG.) 04.11.2022 ]

Correct Answer: (a) 1.5
Solution:

According to IS : 456-2000 for partial safety factor γₘ for material strength–
• When assessing the strength of a structure or structural member for the limit state of collapse, the value of partial safety factor, γₘ should be taken as 1.5 for concrete and 1.15 for steel.

4. Reinforced concrete sections in which tension steel reaches yield strain at loads lower than the load at which concrete reaches failure strain are called______. [JSSC JE (GEN. ENGG.)-23.10.2022 ]

OR
If the actual neutral axis of a beam lies above the critical neutral axis, then the beam is said to be a/an:
OR
In which of the following sections will the position of actual neutral axis (n) shift above the critical neutral axis (nₙ) i.e. n < nₙ and steel is fully stressed and concrete is under stressed?

Correct Answer: (a) under reinforced section
Solution:

Under reinforced section–
In which tension steel reaches yield strain at loads lower than the load at which concrete reaches failure strain are called under reinforced sections. It should be remembered that yielding of steel does not mean ultimate failure of the beam.

5. The stripping time of props to beams spanning: [JSSC JE (GEN. ENGG.)- 31.10.2022]

Correct Answer: (a) 21 days
Solution:

6. The distance between the centre of tensile reinforcement and the bottom edge of the beam is called. [JSSC JE (GEN. ENGG.)-23.10.2022 ]

Correct Answer: (b) effective cover
Solution:

7. A concrete cylinder of size 150 mm diameter and 300 mm long is tested for split tensile strength of concrete. It failed at a load of 100 kN, the split tensile strength (in N/mm²) is [JPSC AE (GEN. ENGG)-2013 ]

Correct Answer: (c) 1.42
Solution:

8. If the depth of critical neutral axis in a beam is less than the depth of actual neutral axis then the beam is called: Or In a singly Reinforced Beam, if the permissible stress in concrete reaches earlier than the permissible stress in steel, the Beam section is called: [RRB S.S.E (Bilaspur/Secunderabad) 21.12.2014]

Correct Answer: (c) Over reinforced beam
Solution:

Over Reinforced section– In over reinforced section the percentage of steel provided greater than the balanced section. In this section stress in concrete reaches its permissible value while steel is not fully stressed.

9. The partial safety factor used for steel in reinforced concrete is: [JSSC JE (GEN. ENGG.)- 03.11.2022]

Correct Answer: (d) 1.15
Solution:

10. If fᵧ is the yield stress in steel and Eₛ is the Young's modulus of elasticity of steel, then the maximum strain in tension reinforcement at failure should NOT be less than: [JSSC JE (GEN. ENGG.)- 03.11.2022 ]

Correct Answer: (b)
Solution:

As per IS 456 : 2000 strain diagram in concrete