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**

Q1. Answer d

Q2. Answer a

Q3. Answer b

Q4. Answer b

Q5. Answer c

Q6. Answer a

Q7. Answer b

Q8. Answer d

Q9. Answer b

Q10. Answer d

Q11. Answer c

Q12. Answer b

Q13. Answer b

Q14. Answer d

Q15. Answer b

Q16. Answer d

Q17. Answer c

Q18. Answer a

Q19. Answer c

Q20. Answer a