If H is the height of wall between centers of supports, then the effective height of wall where concrete floors have a bearing on wall irrespective of the direction of span will be
0.75 H
0.85 H
1.0 H
1.5 H
Correct Answer :
A. 0.75 H
Related Questions
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
0.4 kg/cm²
0.7 kg/cm²
1.0 kg/cm²
1.2 kg/cm²
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?
1, 2 and 3
1 and 2
2 and 3
1 and 3
The basic stress in masonry units having height to width ratio of 1.5 may be increased by a factor of
1.2
1.4
1.6
2.0
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
0 6
0.75
0.85
0.95
Water retentivity for brick masonry should not be less than
50 %
60 %
70 %
80 %
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?
Providing buttresses at certain intervals
Providing a deeper foundation
Using a richer mortar
Using stronger bricks
For designing masonry components of a structure, seismic forces provision in the design calculation is not necessary for buildings constructed in
Zone I only
Zone I and II
Zone I, II and III
Zone I, II, III and IV
If the eccentricity ratio is more than 1/24, then increase in the permissible stress in the design of wall subjected to eccentric loading as per code is
10 %
25 %
33 %
50 %
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
0.15 MPa
0.125 MPa
0.1 MPa
0.075 MPa
Assertion A : Lime based mortars give higher ratio of brickwork strength to mortar strength as compared to non-lime mortar. Reason R : Lime based mortars have lower bond strength as compared to non-lime mortars. Select your answer according to the codes given below:
Both A and R is true and R is the correct explanation of A
Both A and R is true but R is not the correct explanation of A
A is true but R is false
A is false but R is true
In a cavity wall, both leaves of which are load bearing, the effective thickness is taken as
Sum of thickness of both leaves
Two-third of the sum of thickness of both the leaves
Actual thickness of the stronger leaf
Larger of (B) and (C)
The bending stress in a wall or column subjected to effective vertical load need not be considered, if the eccentricity ratio is
Less than or equal to 1/24
Less than or equal to 1/6
More than 1/24
Less than or equal to 1/12
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
(i) and (ii)
(i) and (iii)
(ii) and (iv)
(ii) and (iii)
The mode of failure of a very short masonry member having h/t ratio of less than 4 is by
Shear
Vertical tensile splitting
Buckling
Any of the above
If H is the height of wall between centers of supports, then the effective height of wall where concrete floors have a bearing on wall irrespective of the direction of span will be
0.75 H
0.85 H
1.0 H
1.5 H
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
2 and 3 are correct
1 and 2 are correct
1 and 3 are correct
1, 2 and 3 are correct
Full restraint is provided by
(i) Foundation footing of a wall
(ii) Timber floor spanning on the wall and anchored to the wall
(iii) RCC slab with a minimum bearing of 10 cm on the wall
Of these statements
(i) and (iii) are correct
(i) and (ii) are correct
(ii) and (iii) are correct
(i), (ii) and (iii) are correct
The effective height of free standing non-load bearing wall and column respectively will be
1.0H and 1.0H
1.5H and 1.5H
2.0H and 1.5H
2.0H and 2.0H Where H is the height of wall or column between centers of supports
If the ratio of center to center spacing of intersecting walls to actual thickness of intersecting wall is more than 20, then the stiffening coefficient for wall proper will be
0
Between 0 and 1
1
Greater than 1
The thickness of each leaf of a cavity wall shall not be less than
5 cm
7.5 cm
10 cm
15 cm
For earthquake resistant masonry buildings, the vertical distance between openings one above the other in a load bearing wall shall not be less than
50 cm
60 cm
75 cm
100 cm
Rich cement mortars are more liable to cracking as compared to lean mortars because rich mortars have
High shrinkage
Less strength
Both (A) and (B)
None of above
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
0.090
0.095
0.100
0.105
A free standing brick wall 20 cm thick is subjected to a wind pressure of 75kg/m². The maximum height of wall from stability consideration is
0.64 m
0.96 m
1.28 m
1.5 m
The timber floor not spanning on the masonry wall but properly anchored to the wall gives
Lateral restraint but not rotational restraint
Rotational restraint but not lateral restraint
Both lateral and rotational restraints
Neither lateral nor rotational restraint
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
1 alone is correct
2 alone is correct
Both 1 and 2 are correct
Neither 1 nor 2 is correct
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:
Both A and R is true and R is the correct explanation of A
Both A and R is true but R is not a correct explanation of A
A is true but R is false
A is false but R is true
Minimum compressive strength in N/mm² for H1 type mortar used for masonry is
3
5
7.5
10
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
15
19
20
25
Assertion A : From consideration of structural soundness and economy of design, most codes control the maximum slenderness ratio of masonry walls and columns.
Reason R : By controlling the maximum slenderness ratio, failure is by excessive stress and not by buckling. Select your answer according to codes given below:
Both A and R is true and R is the correct explanation of A
Both A and R is true but R is not the correct explanation of A
A is true but R is false
A is false but R is true