Virtual Labs

Q1. As per IS: 456, for a singly reinforced rectangular section,

a: X_u,max/d for Fe415 steel is 0.48 b: The depth of centroid of compression is 0.48 X_u,max c: The depth of the rectangular portion of the stress block is 0.38 X_u,max d: The maximum value of lever arm d - X_u,max

Q2. Consider the following statements: 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 results of tests.

Select the correct answer using the codes given below:

a: 1 and 3 b: 2 and 3 c: 1, 2 and 3 d: 1 and 2

Q3. If σ_cbc is permissible compressive stress in flexural compression in N/mm² in service, the modular ratio is of the order of

a: 280/3σ_cbc b: 280/4σ_cbc c: 19 d: 13

Q4. Stress-strain curve of concrete is

a: A perfect straight line up to failure b: Straight line up to 0.002% strain value and then parabolic up to failure c: Parabolic up to 0.002% strain value and then a straight line up to failure d: Hyperbolic up to 0.002% strain value and then a straight line up to failure

Q5. Consider the following statements :
Under-reinforced concrete flexural members
1. are deeper
2. are stiffer
3. can undergo larger deflection

Which of these statements is/are correct?

a: 1, 2 and 3 b: 2 only c: 1 and 2 d: 1 and 3

Q6. What is the value of flexural strength of M 25 concrete?

a: 4.0 MPa b: 3.0 MPa c: 3.5 MPa d: 1.75 Mpa

Q7. Consider the following statements :
Modulus of elasticity of concrete is
1. tangent modulus
2. secant modulus
3. proportional to √f_ck
4. proportional to 1/√f_ck

Which of the statements given above are correct?

a: 1 and 3 only b: 2 and 3 only c: 1 and 4 only d: 2 and 4 only

Q8. Working stress method of design for reinforced concrete is

a: not a Limit state design b: a serviceability limit state design c: a limit state for crack width d: a collapse limit state

Q9. Consider the following statements :
1. In reinforced cement concrete, the modular ratio is defined by the ratio:
2.

3. Modulus of rupture of cement concrete is a function of its characteristic compressive strength.
The characteristic compressive strength of M 20 grade cement concrete at 7 days is 20 N/mm²

Which of the statements given above are correct?

a: 1, 2 and 3 b: 2 and 3 only c: 1 and 2 only d: 1 and 3 only

Q10. At what stress does the first flexural crack appear in RCC beams made of M25 grade concrete?

a: 3.0 MPa b: 4.0 MPa c: 3.5 MPa d: 4.5 Mpa

Experiment name 1