Design of Masonry Structures Quiz | Design of Masonry Structures Objective Type Questions and Answers

21 For masonry built in 1:1:6 cement-lime-sand mix mortar or equivalent, the horizontal shear stress permissible on the area of a mortar bed joint is

22 Consider the following statements:

1. Masonry in rich cement mortar though having good strength with high shrinkage is much liable for surface cracks.

2. Lime mortar possesses poor workability and poor water retentivity and also suffers high shrinkage.

3. Masonry in lime mortar has better resistance against rain penetration and is less liable to crack when compared to masonry in cement mortar.

Which of these statements are correct?

23

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:

24 The basic stress in masonry units having height to width ratio of 1.5 may be increased by a factor of

25 200 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

26 A 200 mm thick wall made of modular bricks is 5 m long between cross walls and 3.8 m clear height between RCC slabs at top and bottom. The slenderness ratio of the wall is

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

28 The mortars used for masonry construction are classified based on strength in IS 2250 and IS 1905 according to their designations L1,L2, H1, H2, M, M2. The correct sequence of increasing order of their strengths is

29 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

30 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?

31 In the case of panel wall subjected to horizontal loads at right angles to the plane of the wall, with the mortar not leaner than Ml type, tensile stress in bending in the vertical direction may be allowed to the extent of

32 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

33 Consider the following statements regarding provision of chases in masonry,

(i) No chase should be permitted in a half brick load-bearing wall,

(ii) Vertical chases should not be closer than 2 m in any stretch of a wall,

(iii) Chases should be provided near to bearings of beams and lintels. Of these statements

34

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:

35 In a cavity wall, both leaves of which are load bearing, the effective thickness is taken as

36 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

37 For earthquake resistant masonry buildings, where seismic coefficient is less than 0.08, the horizontal distance between two openings shall not be less than

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

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

40 Minimum compressive strength in N/mm2 for H1 type mortar used for masonry is