# Design of Concrete Structures 8

Objective Questions and Answers of Civil Engineering: Design of Concrete Structures 8

Subject: Design of Concrete Structures 8

Part 8: Objective questions and answers of Design of Concrete Structures

Q1. A free standing brick wall 20 cm thick is subjected to a wind pressure of 75kg/m^2. The maximum height of wall from stability consideration is

a) 0.64 m

b) 0.96 m

c) 1.28 m

d) 1.5 m

Q2. Which of the following will give higher ratio of brickwork strength to mortar strength?

a) 1 : % : 3

b) 1 : Vz: 4>/2

c) 1:1:6

d) 1:2:9

Q3. Rich cement mortars are more liable to cracking as compared to lean mortars because rich mortars have

a) high shrinkage

b) less strength

c) both (a) and (b)

d) none of above

Q4. For designing masonry components of a structure, seismic forces provision in the design calculation is not necessary for buildings constructed in

a) Zone I only

b) Zone I and II

c) Zone I, II and III

d) Zone I, II, III and IV

Q5. Assertion

A : For eccentricity ratio exceeding 1/6, effective thickness of masonry will get reduced.

Reason R : For eccentricity ratio exceeding 1/6, there will be tension on one side of the member. Select your answer according to the codes give below:

a) Both A and R are true and R is the correct explanation of A.

b) Both A and R are true and R is not the correct explanation of A.

c) A is true but R is false.

d) A is false but R is true.

Q6. The timber floor not spanning on the masonry wall but properly anchored to the wall gives

a) lateral restraint but not rotational restraint

b) rotational restraint but not lateral restraint

c) both lateral and rotational restraints

d) neither lateral nor rotational restraint

Q7. For masonry work with solid bricks, consistency of mortar should be

a) 5 to 8 cm

b) 9 to 13 cm

c) 14 to 18 cm

d) 19 to 23 cm

Q8. For earthquake resistant masonry buildings, the vertical distance between openings one above the other in a load bearing wall shall not be less than

a) 50 cm

b) 60 cm

c) 75 cm

d) 100 cm

Q9. Consider the following statements regarding bands to be provided for strengthening masonry work in masonry buildings constructed in zone III, IV and V.

(i) Lintel band is provided at lintel level on partition walls,

(ii) Gable band is provided at top of gable masonry below the purlins,

(iii) The bands shall be to full width of the wall and not less than 7.5 cm in depth,

(iv) The bands shall be made of reinforced concrete only.

Of these statements, the correct statements are

a) (i) and (ii)

b) (i) and (iii)

c) (ii) and (iv)

d) (ii) and (iii)

Q10. Assertion A : Limiting value of slenderness ratio for a column is less than that of a wall. Reason R : A column can buckle around either of the two horizontal axes while a wall can

buckle around only one axis. Select your answer according to the codes given below:

a) Both A and R are true and R is the correct explanation of A.

b) Both A and R are true but R is not the correct explanation of A.

c) A is true but R is false.

d) A is false but R is true.

Q11. Consider the following statements:

The use of relatively weak mortar

1. Will accommodate movements due to loads and, cracking if any, and will be distributed as

thin hair cracks which are less noticeable or harmful.

2. Will result in reduction of stresses due to differential expansion of masonry units.

Of these statements

a) 1 alone is correct

b) 2 alone is correct

c) both 1 and 2 are correct

d) neither 1 nor 2 is correct

Q12. For strengthening a 50 m long and 5 m high straight compound wall built in brick work, which one of the following would be most suitable?

a) providing buttresses at certain intervals

b) providing a deeper foundation

c) using a richer mortar

d) using stronger bricks

Q13. Consider the following statements:

A high lime content in a composite cement-lime mortar results in

1. Slow hardening.

2. Quick setting.

3. Weaker mortar. Of these statements

a) 2 and 3 are correct

b) 1 and 2 are correct

c) 1 and 3 are correct

d) 1, 2 and 3 are correct

Q14. Direct load carrying capacity of a brick masonry wall standing freely as against when it supports RC slab will be

a) more

b) less

c) the same in both the cases

d) 100%

Q15. A 200 mm thick brick masonry wall made of modular bricks carries an axial load of 30

kN/m from wall above and an eccentric load of 20 kN/m from RCC floor acting at a distance of 47.5 mm from the centre line of the wall. The resultant eccentricity ratio is

a) 0.090

b) 0.095

c) 0.100

d) 0.105

Q16. Assertion A : For identical strength, a composite cement-lime mortar is preferred over cement mortar.

Reason R : Composite cement-lime mortar has higher drying shrinkage than cement mortar.

Select your answer based on the codes given below. Codes:

a) Both A and R are true and R is the correct explanation of A.

b) Both A and R are true but R is not a correct explanation of A.

c) A is true but R is false.

d) A is false but R is true.

Q17. Maximum slenderness ratio of load bearing walls for a dwelling having more than 2

storeys

(i) shall not exceed 12 if lime mortar is used

(ii) shall not exceed 18 if cement lime mortar 1:2:9 is used

(iii) shall not exceed 24 if cement mortar 1:6 is used Of these statements

a) (i) and (ii) are correct

b) (ii) and (iii) are correct

c) (i) and (iii) are correct

d) (i) and (ii) and (iii) are correct

Q18. The effective height of free standing non load bearing wall and column respectively will be

a) 1.OH and 1.OH

b) 1.5Handl.5H

c) 2.0Handl.5H

d) 2.0H and 2.0H

Where H is the height of wall or column between centers of supports

Q19. The thickness of each leaf of a cavity wall shall not be less than

a) 5 cm

b) 7.5 cm

c) 10 cm

d) 15 cm

Q20. If the horizontal cross-sectional area of a wall is 1200 cm2, then the basic stress shall be multiplied by a reduction factor equal to

a) 0 6

b) 0.75

c) 0.85

d) 0.95

Part 8: Objective questions and answers of Design of Concrete Structures