Showing 11–20 of 34 questions
Which of the following is a measure of concrete workability?
A
Slump test
B
Compressive strength test
C
Modulus of elasticity
D
Permeability test
Correct Answer:
A. Slump test
EXPLANATION
Slump test is the most common field test to measure the workability and flow characteristics of fresh concrete.
For a M25 grade concrete, what is the approximate 28-day compressive strength?
A
20 MPa
B
25 MPa
C
30 MPa
D
35 MPa
Correct Answer:
B. 25 MPa
EXPLANATION
M25 designation means the concrete will achieve 25 MPa minimum compressive strength at 28 days with 95% probability.
Which standard specifies the code of practice for plain and reinforced concrete in India?
A
IS 383:2016
B
IS 456:2000
C
IS 1199:1959
D
IS 12269:2013
Correct Answer:
B. IS 456:2000
EXPLANATION
IS 456:2000 is the Indian Standard for plain and reinforced concrete - Code of Practice.
What is the nominal maximum size of coarse aggregate for concrete beams?
A
10 mm
B
20 mm
C
40 mm
D
80 mm
EXPLANATION
For reinforced concrete beams, nominal maximum coarse aggregate size is typically 20 mm to ensure proper placement around reinforcement.
Which of the following is NOT a type of aggregate used in concrete?
A
Coarse aggregate
B
Fine aggregate
C
Lightweight aggregate
D
Rigid aggregate
Correct Answer:
D. Rigid aggregate
EXPLANATION
Rigid aggregate is not a standard classification. Aggregates are classified as coarse, fine, and lightweight based on size and density.
Which type of cement is used for underwater construction?
A
Ordinary Portland Cement
B
Sulphate Resisting Portland Cement
C
Low Heat Portland Cement
D
White Portland Cement
Correct Answer:
B. Sulphate Resisting Portland Cement
EXPLANATION
SRPC (Sulphate Resisting Portland Cement) is used for underwater and marine structures to resist sulphate attack.
According to IS 456:2000, what is the standard cube compressive strength test age for concrete?
A
7 days
B
14 days
C
28 days
D
56 days
Correct Answer:
C. 28 days
EXPLANATION
IS 456:2000 specifies 28 days as the standard curing age for determining the compressive strength of concrete cubes.
What is the primary function of cement in concrete?
A
To bind aggregates together
B
To increase workability
C
To reduce water absorption
D
To improve color
Correct Answer:
A. To bind aggregates together
EXPLANATION
Cement acts as a binder that hydrates and binds fine and coarse aggregates together to form a solid mass.
The effective length factor K for a column fixed at both ends is:
EXPLANATION
For column fixed at both ends, effective length L_e = 0.5L (K=0.5), giving maximum buckling resistance.
The radius of gyration for a rectangular section (b×d) about the centroidal axis parallel to base is:
A
d/√12
B
d/2√3
C
b/√12
D
√(bd/12)
EXPLANATION
I = bd³/12, A = bd, r = √(I/A) = √(d²/12) = d/(2√3) for axis parallel to base.
