Reinforced Cement Concrete

Q. As per IS 456-2000, in the Limit State Design of a flexural member, the strain in reinforcing bars under tension at ultimate state should not be less than

1. $\frac{f_y}{E_s}$
2. $\frac{f_y}{E_s}+0.002$
3. $\frac{f_y}{1.15E_s}$
4. $\frac{f_y}{1.15E_s}+0.002$

Q. The maximum strain in the tension reinforcement in the section at failure when designed for the limit state of collapse should be

1. $>(\frac{f_y}{1.15E_s}+0.002)$
   
   where, $f_y=$ Characteristic strength of seel, and $E_s=$ Modulus of elasticity of steel
2. $<(\frac{f_y}{1.15E_s}+0.002)$
   
   where, $f_y=$ Characteristic strength of seel, and $E_s=$ Modulus of elasticity of steel
3. exactly equal to $(\frac{f_y}{1.15E_s}+0.002)$
   
   where, $f_y=$ Characteristic strength of seel, and $E_s=$ Modulus of elasticity of steel
4. $<0.002$

Q. The design for the limit state of collapse in flexure is based on the following assumptions:

1. Plane sections normal to the axis remain plane after bending
2. The maximum strain in concrete at the outermost tension fibre is 0.0035.
3. The relationship between the compressive stress distribution in concrete and the strain in concrete may be assumed to be rectangular, trapezoidal, parabolic or any other shape which results in prediction of strength in substantial agreement with the result of tests.

Select the correct answer using the codes given below:

1. 1 and 3
2. 1, 2 and 3
3. 
   2 and 3
4. 1 and 2

Q. Consider the following statements:
The reinforcement in reinforced concrete beam shall have concrete cover, the thickness of such cover shall be not less than
1. 25 mm
2. the diameter of bar
3. the spacing between bars
4. 5 mm
Which of these statements are correct?

1. 3 and 4
2. 1 and 4
3. 2 and 3
4. 1 and 2

Q. The 'plane section remains plane' assumption in bending theory implies.

1. strain profile is linear
2. stress profile is linear
3. both strain and stress profiles are linear
4. shear deformations are neglected

Q. As per IS 456-2000, in the Limit State Design of a flexural member, the strain in reinforcing bars under tension at ultimate state should not be less than

1. $\frac{f_y}{E_s}$
2. $\frac{f_y}{E_s}+0.002$
3. $\frac{f_y}{1.15E_s}$
4. $\frac{f_y}{1.15E_s}+0.002$

Q. Directions: The following items consists of two statements; one labelled as 'Assertion (A)' and the other as 'Reason (R}'. You are to examine these two statements carefully and select the answers to these·, items using the codes given below:

Codes:
(a) both A and R are true and R is the correct explanation of A
(b) both A and Rare true but R is not a correct explanatio·n of A
(c) A is true but R is false
(d) A is faise but R is true

Assertion (A) : In limit state design, overreinforced sections are not permitted.

Reason (R) : As the concrete failure is brittle, the structure fails suddenly without any warning.

1. both A and R are true and R is the correct explanation of A
2. both A and R are true and R is not a correct explanation of A
3. A is true but R is false
4. A is true but R is true

Q. The minimum strain at failure in tension steel having yield stress $f_y=415$ MPa and Young's modulus $E_s=200$ GPa, as per Limit State Method of Design, is

1. 0.0025
2. 0.0038
3. 0.0045
4. 0.0050

Q. A simply supported beam has an effective span of 16 m. What shall be the limiting ratio of span to effective depth as per IS 456- 2000?

1. 26
2. 20
3. 12.5
4. 7

Q. Stress-strain curve of concrete is

1. A perfect straight line upto failure
2. Straight line upto 0.002 strain value and then parabolic upto failure.
3. Nearly parabolic upto 0.002 strain value and then a straight line upto failure
4. Hyperbolic upto 0.002 strain value and then a straight line upto failure