# Design of Concrete Structures 4

Objective Questions and Answers of Civil Engineering: Design of Concrete Structures 4

Subject: Design of Concrete Structures 4

Part 4: Objective questions and answers of Design of Concrete Structures

Q1. For concreting of heavily reinforced sections without vibration, the workability of concrete expressed as compacting factor should be

a) 0.75-0.80

b) 0.80-0.85

c) 0.85 – 0.92

d) Above 0.92

Q2. For walls, columns and vertical faces of all structural members, the form work is generally removed after

a) 24 to 48 hours

b) 3 days

c) 7 days

d) 14 days

Q3. One of the criteria for the effective width of flange of t-beam is bf =—+ bw +6df 6 in above formula, l0 signifies

a) Effective span of t-beam

b) Distance between points of zero moments in the beam

c) Distance between points of maximum moments in the beam

d) Clear span of the t-beam

Q4. For a simply supported beam of span 15m, the minimum effective depth to satisfy the vertical deflection limits should be

a) 600 mm

b) 750 mm

c) 900 mm

d) More than 1 m

Q5. According to is: 456-1978, the flexural strength of concrete is

a) Directly proportional to compressive strength

b) Inversely proportional to compressive strength

c) Directly proportional to square root of compressive strength

d) Inversely proportional to square root of compressive strength

Q6. According to is: 456- 1978, minimum slenderness ratio for a short column is

a) Less than 12

b) Less than 18

c) Between 18 and 24

d) More than 24

Q7. The minimum cover in a slab should neither be less than the diameter of bar nor less than

a) 10 mm

b) 15 mm

c) 25 mm

d) 13 mm

Q8. The ratio of the diameter of reinforcing bars and the slab thickness is

a) 1/4

b) 1/5

c) 1/6

d) 1/8

Q9. The percentage of reinforcement in case of slabs, when high strength deformed bars are used is not less than

a) 0.15

b) 0.12

c) 0.30

d) 1.00

Q10. Which of the following statements is incorrect?

a) Higher vee-bee time shows lower workability.

b) Higher slump shows higher workability.

c) Higher compacting factor shows higher workability.

d) None of the above

Q11. Maximum distance between expansion joints in structures as per is : 456 – 1978 is

a) 20 m

b) 30 m

c) 45 m

d) 60 m

Q12. Critical section for shear in case of flat slabs is at a distance of

a) Effective depth of slab from periphery of column/drop panel

b) D/2 from periphery of column/capital/ drop panel

c) At the drop panel of slab

d) At the periphery of column

Q13. If the storey height is equal to length of rcc wall, the percentage increase in strength is

a) 0

b) 10

c) 20

d) 30

Q14. The slab is designed as one way if the ratio of long span to short span is

a) Less than 1

b) Between 1 and 1.5

c) Between 1.5 and 2

d) Greater than 2

Q15. A higher modular ratio shows

a) Higher compressive strength of concrete

b) Lower compressive strength of concrete

c) Higher tensile strength of steel

d) Lower tensile strength of steel

Q16. In working stress design, permissible bond stress in the case of deformed bars is more than that in plain bars by

a) 10%

b) 20%

c) 30%

d) 40%

Q17. Half of the main steel in a simply supported slab is bent up near the support at a distance of x from the center of slab bearing where x is equal to

a) 1/3

b) 1/5

c) 1/7

d) 1/10

Where 1 is the span

Q18. For a slab supported on its four edges with corners held down and loaded uniformly, the marcus correction factor to the moments obtained by grash off rankine’s theory

a) Is always less than 1

b) Is always greater than 1

c) Can be more than 1

d) Can be less than 1

Q19. The limits of percentage p of the longitudinal reinforcement in a column is given by

a) 0.15% to 2%

b) 0.8% to 4%

c) 0.8% to 6%

d) 0.8% to 8%

Q20. The bending stress in a wall or column subjected to effective vertical load need Not be considered, if the eccentricity ratio is

a) less than or equal to 1/24

b) less than or equal to 1/6

c) more than 1/24

d) less than or equal to 1/12

Part 4: Objective questions and answers of Design of Concrete Structures