2. Brick
A brick is rectangular in shape and of size that can be conveniently handled with one
hand.
density of brick range= 2.5 – 2.8 g/cm3
.
Modulus of elasticity = 5-30 N/mm2
.
Size of brick = 19 x 9 x 9 cm or 19 x 9 x 4 cm.
An indent called frog 1-2 cm deep is provided
Size of frog = 10 x 4 x 1 cm.
2
3. Ingredients of good brick
earth
Sr no Ingredients Limit (%)
1 Silica 50-60%
2 Alumina 20-30%
3 Lime 10%
4 Magnesia
Ferric Oxide
Alkalis
< 1%
<7%
<10%
5 Carbon Dioxide
Sulphur trioxide
Water
Very small percentage
3
4. Function of Various
Ingredients
Silica
It enables the brick to retain its shape, impart durability, and prevent shrinkage and warping.
Excess of silica makes the brick brittle and weak on burning.
Alumina
Absorb water and renders the clay plastic. If it present in excess, it produce crack in brick on
drying.
Lime
Reduces the shrinkage on drying
Causes silica in clay to melt on burning and thus help to bind it
In carbonated form, lime lowers the fusion point.
Excess of lime causes the brick to melt and the brick looses its shape.
Magnesia
Affects the color and makes the brick yellow. In burning, it causes the clay to soften at slower
rate than does lime and reduces warping.
Iron
Gives red color on burning when excess of oxygen is available and dark brown or even black
color when oxygen available is insufficient. However, excess of ferric oxide makes the brick
dark blue. 4
5. Classification of Clay Bricks
Based on field practice
Clay bricks are classified as first class, second class, third class and fourth class based
on physical and mechanical properties.
First clay bricks
Thoroughly burnt and are of deep red, cherry or copper color
Surface should be smooth and rectangular, with parallel, sharp and straight edges
and square corners.
Should be free from flaws, cracks and stones
Should have uniform texture
No impression should be left on the brick when a scratch is made by finger nail.
A metallic or ringing sound should come when two bricks are struck against each
other.
Water absorption should be 12-15% of its dry weight when immersed in cold water
for 24 hours.
The crushing strength should not be less than 10 N/mm2
.
These bricks recommended for pointing, exposed face work in masonry
structures, flooring and reinforced brick work.
5
6. Cont’d…
Second Class Bricks
Are supposed to have the same requirement as the first class bricks except that
Small cracks and distortions are permitted
A little higher water absorption of about 16-20% of its dry weight is allowed.
The crushing strength should not be less than 7.0 N/mm2
.
These bricks are recommended for all important or unimportant masonry works
and centering of reinforced brick and reinforced cement concrete structures
6
7. Cont’d…
Third Class Bricks
These are under burnt. They are soft and light-colored producing a dull
sound when struck against each other. Water absorption is about 25%
of dry weight.
it is used for building temporary structures.
7
8. Cont’d…
On strength
On the basis of use : Common bricks, Facing Bricks, Engineering Bricks
On the basis of finish: Sand-faced bricks, Rustic Brick
On the basis of Manufacture: Hand Made, Machine Made
On the basis of Burning: Pale Bricks, Body Bricks, Arch Bricks
On the basis of types: Solid, Perforated, Hollow, Cellular
8
9. Brick Masonry
Brick masonry is made of brick units, bonded together with mortar. Two essential components
of brick masonry are therefore.
I. Bricks
II. Mortar
Mortar acts as a cementing material and unites the individual brick units together to act as
a homogeneous mass. Following types of mortar may be used in brick masonry.
1. Cement Mortar
2. Lime Mortar
3. Lime-Surkhi Mortar
4. Mud Mortar
5. Lime-Cement Mortar 9
10. Cont’d…
Cement mortar are used for high-rise buildings, where strength is of prime importance.
Lime mortar and lime-surkhi mortars are used for all types of construction
Mud mortar is used only for low-rise building which carry light loads.
Lime cement mortar known as guarded mortar or gauged mortar is made by mixing
cement and lime. The advantages are increased water retentivity, workability, bonding
properties and frost resistance. The mortar gives good and smooth plaster finish.
The chief properties of hardened mortar are strength, development of good bond with
building units, resistance to weathering and those of green mortar mixes are mobility,
playability and water retention. In addition, the mortar should be cheap and durable and
should not affect the durability of building units in contact. The joint made with mortar
should not develop cracks. 10
13. Cont’d…
Stretcher : A stretcher is the longer face of the brick (i.e. 19 cm x 9 cm) as seen in
the elevation of the wall. A course of brick in which all the bricks are laid as
stretchers on facing is known as a stretcher course or stretching course
Header : A header is the shorter face of the brick (i.e. 9 cm x 9 cm) . A course of
bricks in which all the bricks are laid as header on the facing is known as header
course or heading course.
Lap : Lap is the horizontal distance between the vertical joints of successive brick
courses.
Perpend: A perpend is an imaginary vertical line which includes the vertical joint
separating two adjoining bricks.
Bed: Bed is the lower surface (19cm x 9cm) of the brick when laid flat
13
14. Cont’d…
Closer : It is a portion of a brick with the cut made longitudinally,
and is used to close up bond at the end of the course. A closer helps
in preventing the joints of successive sources (higher or lower) to
come in vertical line. Closer may be of various types, defined below.
14
15. Cont’d…
Queen Closer: it is a portion of a brick
obtained by cutting a brick lengthwise
into two portions. Thus a queen closer is
a brick which is half as wide as full brick.
This is also known as queen closer half.
When a queen closer is broken into two
pieces, it is known as queen closer
quarter. Such as closer is thus a brick
piece which is one quarter of the brick
size.
15
16. Cont’d…
King Closer
It is the portion of a brick which is so
cut that the width of one its end is half
that of a full brick, while the width at
the other end is equal to the full
width. It is thus obtained by cutting
the triangular piece between the
center of one end and the centre of
the other side. It is half header and
half stretcher face.
16
17. Cont’d…
Beveled Closer
It is a special form of a king closer in
which the whole length of brick (i.e.
stretcher face) is beveled in such a
way that half width is maintained at
one end and full width is maintained
at the other end
17
18. Cont’d…
Mitred Closer
It is a portion of a brick whose one
end is cut splayed or mitred for full
width. The angle of splay may vary
from 45° to 60°.
Thus one longer face of the mitred
closer is of full length of the brick
while the other longer face is smaller
in length.
18
19. Cont’d…
Bat : it is the portion of the brick cut across the width. Thus, a bat
smaller in length than the full brick. If the length of the bat is equal to
half the length of the original brick, it is known as half bat. A three
quarter bat is the one having its length equal to three quarter of the
length of a full brick. If a bat has its width beveled, it is known as
beveled bat.
19
20. Cont’d…
Arris: it is the edge of the brick
Bull Nose: it is a special molded brick with one edge rounded (single bull
nose) or with two edge round (double bull nose). These are use in
copings or in such positions were rounded corners are preferred to sharp
arises.
Splays: these are special molded bricks which are often used to form
plinth. Splay stretcher (plinth stretcher) and splay header (plinth
header)
20
21. Cont’d…
Dogleg or angle : it is also special form of molded bricks which are
used to ensure a satisfactory bond at quoins which are at an angle
other than right angle. The angle and lengths of the faces forming
the dogleg vary according to requirements. These are preferred to
mitered closer.
Quoin: it is a corner on the external angle on the face side of a wall.
Generally, quoin are at right angles. But, in some cases, they may be
at angle greater than 90°also.
21
22. Cont’d…
Frog or kick
A frog is an indentation in the face of a brick to form a key for
holding the mortar. When frog is only on one face, that brick is laid
with that face on the top. Sometimes, frog are provided on both
the faces. However, no frogs are provided in wire cut bricks. A
pressed brick has two frogs and a hand made brick has only one
frog.
22
23. Cont’d…
Racking Back: It is the termination of a wall in a stepped
fashion
Toothing: it is the termination of the wall in such a fashion that
each alternate course at the end projects in order to provide
adequate bond if the wall is continued horizontally at a later
stage.
23
24. Bonds in Brick Work
Bond is the interlacement of bricks, formed when they lay (or
project beyond) chose immediately below or above them. It is the
method of arranging the bricks in courses so that individual units
are tied together and the vertical joints of the successive courses
do not lie in same vertical line. Bond of various types are
distinguished by their elevation or face appearance. Bricks used in
masonry are of all of uniform size.
If they are not arranged properly continuous vertical joint will
result. An unbonded wall, with its continuous vertical joints has
little strength and stability. Bonds help in distributing the
concentrated loads over a larger area.
24
25. Cont’d…
Types of Bonds
Stretcher Bond Header Bond
English Bond Flemish Bond
Facing Bond English Cross Bond
Brick on edge bond Dutch Bond
Raking Bond Zigzag Bond
Garden wall bond
25
26. Stretcher Bond
In this bond all the bricks are laid as stretchers on the faces of walls.
The length of the bricks are thus along the direction of the wall. This
pattern is used only for those walls which have thickness of half
brick, such as those used in partition walls, sleeper walls, division
walls or chimney stacks. The bond is not possible if the thickness of
the wall is more
26
27. Header Bond
Header bond is the one in which all the bricks are laid as headers
on the face of walls. The width of the brick are thus along the
direction of the walls. The pattern is used only when the
thickness of the wall is equal to one brick. The overlap is kept
equal to half the width of the brick. This is achieved by using
three-quarter brick bats in each alternate courses as quoins. This
bond does not have strength to transmit pressure in the
direction of the length of the wall. As such it unsuitable for load
bearing walls.
27
29. English Bond
This is the most common used bond, for all wall thickness. This bond
is considered to be the strongest. The bond consist of alternate
courses of header and stretchers. In this bond, the vertical joints of
the header courses come over each other. Similarly, the vertical joints
of the stretcher courses also come over each other. In order to break
the vertical joints in the successive courses, it is essential to place
queen closer after the first header (quoin header) in each heading
course. Also, only header are used for hearting of thicker wall.
29
34. Essential Features
1. Alternative courses will show either headers or stretchers in
elevation
2. Every alternate header comes centrally over the joint between two
stretchers in course below.
3. In the stretcher course, the stretchers have a minimum lap of 1/4th
their length over headers.
4. There is no continuous joint
5. Wall of even multiple of half bricks (i.e. 1 brick thick wall, 2-brick
thick wall, 3- bricks thick wall) present the same appearance on both
faces. Thus a course showing stretchers on the front face will also
show stretchers on the back face.
34
35. Cont’d…
5. Wall of odd multiple of half bricks (i.e. 1 ½ brick thick wall, 2 ½
brick thick wall etc.) will show stretchers on one face and header on
the other face.
6. The hearting (middle portion) of each of the thicker walls consist
entirely of header.
7. At least every alternate transverse joint is continuous from face to
face.
35
36. Cont’d…
8. A header course should never start with queen’s closer, as it will
get displaced. The queen’s closer should be placed just next to the
quoin header. Queen’s closers are not required in stretcher
courses.
9. Since the number of vertical joints in the header course are twice
the number of vertical joints in the stretcher course, the joint in
the header course are made thinner than the joints in the
stretcher course.
36
37. Flemish Bond
In this type of bond, each course is comprised of alternate headers and
stretchers. Every alternate course starts with a header at the corner
(i.e. quoin header). Quoin closer are placed next to the quoin header in
alternate courses to develop the face lap. Every header is centrally
supported over the stretcher below it.
Flemish bond are of two type.
Double Flemish Bond
Single Flemish Bond
37
38. Cont’d…
In the double Flemish bond, each course presents the same
appearance both in the front face as well as in the back face.
Alternate headers and stretcher are laid in each course.
Because of this, double Flemish bond present better
appearance than English bond
38
39. Cont’d…
39
S H S H
Q
S
S
S
H
H
H
H
Q
Q
Q
S
S
S
S
H
H
H
H
H
H
H
H
S
S
S
S
Fig- Double Flemish Bond (Elevation)
40. Cont’d…
Special Features of Double Flemish Bond
1. Every course consists of headers and stretchers placed alternately
2. The facing and backing of the wall, in each course, have the same
appearance
3. Quoin closer are used next to quoin headers in every alternate
course.
4. In wall having thickness equal to odd multiple of half bricks, half bats
and three quarter bats are amply used.
5. For walls having thickness equal to even multiple of half brick, no
bats are require. A header or stretcher will come out as header or
stretcher on the same course in front as well as back faces. 40
44. Single Flemish Bond
Single flemish bond is comprised of double flemish bond
facing and English bond backing and hearting in each course.
This bond thus used the strength of English bond and
appearance of flemish bond. However this bond can be used
for those walls having thickness at least equal to 1 ½ brick.
Double flemish bond facing is done with good quality
expensive bricks. However cheaper bricks can be used for
backing and hearting.
44
45. Cont’d…
45
Q
1,3,5 -----Course 2,4,6 -----Course
S
S S S
H
B3
B2
H
S = Stretcher
Q= Queen’s Closer
B2 = Half Bat
B3 = ¾ Brick; B1 = Quarter Bat
Q
S H S H S
B3
S
46. Cont’d…
Comparison of English Bond and Flemish Bond
1. English bond is stronger than Flemish bond for wall thicker than 1
½ brick.
2. Flemish bond gives more pleasing appearance than the English
bond
3. Broken bricks can be used in the form of bats in Flemish bond.
However, more mortar is required.
4. Construction with Flemish bond requires greater skill in
comparison to English bond.
46
47. Facing Bond
This bond is used where bricks of different thickness are to be used in
the facing and backing of the wall. In this bond, a header course is
provided after several stretcher course. Since the thickness of bricks are
different in the facing and backing, the vertical distance between the
successive header course is kept equal to the least common multiple of
the thickness of backing and facing bricks. Thus, if the nominal
thickness of facing bricks is 10 cm and that of backing bricks is 9 cm, the
header course is provided at a vertical interval of 90 cm. this type of
bond is not structurally good and load distribution is not uniform.
47
48. English Cross Bond
This is a modification of English bond, used to improve the
appearance of the wall. This bond combines the requirements of
beauty and strength. Special features of the bond are as follows:
1. Alternate courses of header and stretchers are provided as in
English bond
2. Queen closer are placed next to quoin headers
3. A header is introduced next to the quoin stretcher in every
alternate stretcher course.
48
50. Brick on Edge Bond
This type of bond uses stretcher bricks on edges instead of bed.
This bond is weak in strength, but is economical. Hence it is used
for garden walls, compound walls etc. Bricks are kept standing
vertically on end. The bricks are arranged as headers and
stretchers in such a manner that headers are placed on bed and
stretchers are placed on edge thus forming a continuous cavity.
Due to this, the bond consumes less number of bricks.
50
51. Dutch Bond
This is another modified form of English Bond. In this bond
the corners of the wall are strengthened. Special features of
this type of bond is as follows.
1. Alternative courses of headers and stretchers are provided
as in English bond.
2. Every stretcher course start at the quoin with a three-
quarter bat.
3. In every alternate stretcher course, a header is placed next
to the three-quarter brick bat provided at the quoin.
51
53. Raking Bond
This bond is used in thick wall. In this type of bond, the bonding bricks are
kept at an inclination to the direction of the wall. Due to this, the
longitudinal stability of thick wall built in English bond is very much
increased. This bond is introduced at certain intervals along the height of
the wall. Special feature of raking bond is
1. The bricks are arranged in inclined direction, in the space between the
external stretchers of the wall
2. The raking or inclination should be opposite direction in alternate
courses of raking wall.
3. Raking bond is not provided in successive courses. It is provided at a
regular interval of four to eight courses in the height of a wall
4. The raking course is generally provided between the two stretcher
courses of the wall having thickness equal to even multiple of half- bricks,
to make the bond more effective.
Raking bonds are of two types:
Diagonal bond Herring-bone bond 53
55. Zig Zag Bond
This bond is similar to herring-bone bond, except that the
bricks are laid in zig-zag fashion. This bond is commonly
used for making ornamental panels in the brick flooring
55
57. Garden Wall Bonds
As the name suggests, this type of bond is used for the
construction of garden walls, boundary walls, compound walls,
where the thickness of wall is one brick thick and the height
does not exceed two meters. This type of bond is not so strong
as English Bond, but is more attractive. De to this reason, it is
sometimes used in the construction of outer leaves of cavity
walls. Garden wall bonds are of three types:
57
58. Cont’d…
Garden wall English bond
Garden wall Flemish bond
Garden wall Monk bond
58
60. Junctions
Junctions is that connection which is formed at the meeting of
one (subsidiary) wall at same intermediate position of another
wall. When both these walls meet at right angles, we get a tee-
junction, we have a cross-junction or intersection. However, if
the subsidiary wall meets the main wall at some intermediate
point, and if the angle formed between the two is other than a
right angle, a squint junction is formed.
60
61. Cont’d…
Junctions are of the following types:
(a) Right angled junction
i. Tee Junction
ii. Intersection or cross junction
(b) Squint junction
61
62. Tee Junction
(a) External and Internal walls in English Bond
Tee junction is formed when the internal walls at its
end meets external wall at some intermediate
position. Tee-junctions can be either in English bond
or in Flemish bond
62
63. Cont’d…
Figure shows a one-brick thick external
wall and a half brick thick internal wall
(partition wall), both walls being
constructed in English bond. Bond is
obtained by making alternate courses of
internal wall entering into the stretcher
course of the main wall. Due to this, lap
of half brick is obtained through the
brick (shown shaded). Alternate courses
of both the walls remain unbonded
63
64. Cont’d…
Figure shows the tee junction
between 1 ½ brick thick external wall
and one-brick thick internal (cross)
wall, both the walls being constructed
in English bond. Here, the header
course of internal wall centers the
stretcher course of the main through
half of its width. Due to this, lap of
quarter –brick is obtained through the
tie-brick, which is placed near the
queen closer (Q). Alternate course of
both the walls remain unbonded.
64
65. Cont’d…
It shows the Tee-junction between 1
½ brick thick external wall and 1 ½
brick thick internal wall, both the
walls being constructed in English
bond. In alternate courses, the
header brick at the junction enters
the stretcher courses of the main
wall. The tie-brick (shown shaded),
placed near the queen closer (Q)
furnishes a lap of quarter brick.
Additional courses of both the walls
remain unbonded.
65
66. Cont’d…
Figure shows the Tee-junction between
2- brick thick main wall and 1 ½ brick
thick cross wall, both the walls being
constructed in English bond. Here the
header course of internal wall enters the
stretcher course of the main wall through
half of its width. Due to this, lap of
quarter brick is obtained through the tie-
brick (header brick) which is placed
near the queen closer (Q). Additional lap
is obtained in the same course, through
placing a ¾ brick bat. Here also, alternate
courses of both the walls remain
unbonded.
66
67. External wall in Flemish bond and
internal wall in English bond
It shows the Tee-junction for a brick
thick external wall in Double Flemish
bond and one brick thick internal
wall in English bond. The header
course of internal wall enters into the
main wall, thus getting a lap of one-
quarter brick. The tie-brick (header
course) is placed adjacent to a queen
closer. Alternate courses of both the
walls remain unbonded.
67
68. Cont’d
Figure shows the Tee-junction for 2 brick thick
external wall in Double Flemish bond and 1 ½
brick thick internal wall in English bond. Here
also, the header course of the cross wall
(internal wall) enters the main wall, thus
getting a lap of quarter brick. The tie brick
(header brick) is placed next to a queen closer.
Additional lap is obtained through the
stretcher brick of the same course of the
internal wall, which is placed adjacent to a ¾
brick bat of the main wall. The alternate
courses of both the walls remain unbonded.
68
69. Both external and internal
walls in double Flemish bond
Figure shows the Tee- junction for a 1-brick thick main wall and ½
brick thick cross wall, both being constructed in Double Flemish
bond. The stretcher bricks of alternate courses of the cross wall enter
into the main wall through half brick length. Due to this, it is necessary
to place a half-brick bat adjacent to it, in the main wall. The alternate
courses of each wall remain unbonded.
69B2 = Half Brick
70. Cont’d…
Figure shows the Tee-junction for a
1 ½ brick thick main wall and one-
brick thick cross wall, both being
constructed in double Flemish
bond. In alternate course, the
stretcher bricks of the cross wall
enter into the main wall through
quarter brick. A queen closer (Q) is
placed next to it in the main wall.
Alternate courses of both the walls
remain unbonded 70
B2 = Half Brick
Q= Queen Closer
71. Cont’d…
Figure shows the Tee-junction for
two-brick thick main wall and 1 ½
brick thick cross-wall. Bonding is
obtained through a lap of one-
quarter brick. It is essential to use a
queen closer and a ¾ brick bat in
the main wall, at the alternate
courses in which both the walls are
bonded.
71
72. Cross Junction or Intersection
A cross-junction is formed when two
internal walls cross each other at right
angles. One of the walls may be called as
the main wall while the other of lesser
thickness as cross wall.
Figure (a) shows a cross junction between
1 ½ brick thick main wall and 1 brick thick
cross-wall, both being constructed in
English bond. The header course of cross-
wall enter into the main wall: the tie
bricks thus give a lap of quarter brick on
both sides. Alternate courses of both the
walls remain unbonded. 72
73. Cont’d…
Fig. (b) shows a cross junction
between two walls, each of 1 ½
brick thick constructed in English
bond. A lap of quarter brick is
obtained through header courses,
on both the sides. Alternate courses
thus remain unbonded.
73
74. Cont’d…
Fig. (c) shows a cross junction
between a 2 brick thick main wall
and 1 ½ brick thick cross wall. A
quarter brick lap is obtained on both
sides thick main wall and 1 ½ brick
thick cross wall. A quarter brick lap is
obtained on both sides through the
header course. Additional lap is also
obtained through ¼ stretcher brick
on one side and ¾ stretcher brick on
the other side. Alternate courses of
both the walls remain unbonded. 74
75. Squint Junction
A squint junction is formed when an internal wall meets an
external continuous wall at an angle other than 90°. Usually,
the angle of squint is kept at 45°, though squint junctions are
not very common in brick work.
75
76. Cont’d…
Fig. show a squint junction between
1 ½ brick thick external wall and a 1
brick thick internal wall, both being
constructed in english bond. The
header courses of the cross-wall is
taken inside the main wall, thus
getting the required bond. Alternate
courses of both the walls remain
unbonded.
76
77. Cont’d…
Fig. (b) shows a squint junction
between two walls each of 1 ½
brick thickness and constructed in
English both. The header bricks are
taken inside the main wall.
Alternate courses remain
unbonded.
77
78. Squint junction in Double
Flemish bond
Fig. Shows the squint junction for
the walls constructed in Double
Flemish bond. These junctions
are quit difficult to be
constructed.
78
79. Load Bearing Walls
Load bearing walls are those which are designed to carry
super-imposed loads (transferred through roofs etc.,) , in
addition to their own weight (self weight). Non-load-bearing
walls carry their own load only. They generally serve as
divide walls or partition walls. The external non-load bearing
wall, commonly related to framed structure is termed as
panel wall.
79
80. Cont’d…
Load bearing walls may further be divided into following steps
a) Solid masonry wall
b) Cavity wall
c) Faced wall
d) Veneered wall
Solid Masonry Wall
It is one most commonly used. These walls are built of individual
blocks of material, such as bricks, clay or concrete blocks, or stone,
usually in horizontal courses, cemented together with suitable
mortar. A solid wall of the same type of building units throughout its
thickness. However, it may have opening for doors, windows etc.
80
81. Cavity Wall
A cavity wall is a wall comprising two leaves, each leaf being
built of structural units and separated by a cavity and tied
together with metal ties or bonding units to ensure that the
two leaves act as one structural unit. The space between the
leaves is either left two leaves act as one structural unit. The
space between the leaves is either left as a continuous cavity
or is filled with non-load-bearing insulating and water proofing
material
81
82. Faced wall
It is a wall in which the facing and backing are of two different
materials which are bonded together to ensure common action
under load
Veneered wall
It is a wall is a wall in which the facing is attached to the
backing but not so bonded as to result in a common action
under load.
82
83. Cont’d…
In order to carry vertical loads, the wall has to be continuous
from top to bottom. Ideally, openings should be rather narrow
and in-line vertically, rather than wide or haphazardly located
on the elevation.
Since walls rely on intersecting with each other to provide
some of their stability, continuous vertical openings would turn
the wall into a series of isolated piers. This layout would only
be efficient if the floors each served to tie the separate piers
together at each level.
83
85. Stability of load bearing walls
In order to resist the horizontal loads, walls rely on either
their own thickness, or the support provided when two walls
meet at right angles. In modern buildings there is no need to
use the very thick walls and adequate stability can usually be
achieved either by having a lot of intersecting walls or by
articulating the wall itself to provide both strong modelling
and stability.
85
86. Cont’d…
The principal vertical loads acting on any wall will be its
own weight, and if it is load bearing, also the loads
from parts of the building's floors and roofs. It must be
able to support these loads.
86
87. Cont’d…
An external wall will be subjected to horizontal wind
loads. It must be able to resist the effect of the wind,
which will be either to overturn the wall as a unit, or to
bend a panel of walling inward or outward between its
supports. In this respect, a load bearing wall is stabilized
to some extent by the effect of the vertical load on top of
it. Because of being attached to a floor or roof structure at
the top of the wall, it also is stabilised more than a
freestanding wall would be.
87
89. Multi-storey load bearing
buildings
Buildings up to 10 or 12 storeys have been constructed from
loadbearing brickwork, both in Australia and overseas. In these
cases the structural requirements become more severe, both
because of the additional load of the building, and also because of
the increased effect of wind loads. Usually the strength of the
bricks and of the mortar have to be increased, and it is common for
the lower storeys to require full-brick (230mm) thick walls, at least
in parts.
Many brickworks can and do produce high-strength bricks, but if
they are required to test and certify them at a particular strength,
the cost will increase, and the range of colours and finishes might
be reduced. Testing and certification of the mortar strength and
the techniques of laying (such as ensuring full bed joints) might also
add something to the cost. On the other hand, in a multistorey
building with an appropriate plan layout, the use of loadbearing
brick walls can save the cost of a separate structural frame, and of
the details where the walls abut columns and beams 89
91. Non-Load bearing Walls
The base of the walls in large nineteenth-century buildings were quite thick
(up to a meter or more), because of the heavy loads to be carried and, before
the use of cement mortar, the low strength of the joints. Modern masonry
walls can be made to carry considerable loads by the use of high-strength
bricks and mortar, but often a framed structure allows more freedom in the
design of the facade as well as in the planning of the interior.
A structural frame of reinforced concrete or steel can support the loads of the
floors and roof, and also of the non-load bearing walls. The external walls
then perform all the 'enclosure' functions. Each wall panel also carries its own
weight and resists wind and seismic loads, but only those that act on the
panel itself.
91
93. Brick Panel Walling
A wall panel is single piece of material, usually flat and cut
into a rectangular shape, that serves as the visible and exposed
covering for a wall. Wall panels are functional as well as
decorative, providing insulation and soundproofing, combined
with uniformity of appearance, along with some measure of
durability or ease of replacability. While there is no set size
limit for a piece of material fulfilling these functions, the
maximum practical size for wall panels has been suggested to
be 24 feet by 8 feet, to allow for transportation
93
94. Cont’d…
Use of wall panels can reduce construction costs by providing a
consistent appearance to the paneled surface without requiring
the application of paint or another finishing material. Wall panels
may be finished on only one side, if the other side is going to be
against a brick or concrete wall, or a comparable
structure. Alternately, the panels may, if assembled to an
appropriate framework, substitute for having any other kind of
wall at all. Holes may be cut or drilled into a wall panel to
accommodate electrical outlets and other devices coming out of
the wall.
94
96. Reinforced Masonry
Reinforced brick work is the one in which the brick masonry is
strengthened by the provision of mild steel flats, hoop iron, expended
mesh or bars. It is adopted or used in the following circumstances:
1. When the brick work has to bear tensile and shear stresses
2. When it is required to increase the longitudinal bond.
3. When the brick work is supported on soil which is susceptible to large
settlement
4. When the brick work is supposed to act as a beam or lintel over
opening.
5. When the brick work is to resist lateral loads, such as in retaining
walls etc.
96
97. Cont’d…
6. When the brick work is to carry heavy compressive loads.
7. When the brick work is to used in seismic areas, since it can
also resist lateral loads.
Reinforced brick work uses first class bricks with high
compressive strength. Dense cement mortar is used to
embed the reinforcement. The reinforcing material may be
(i) hoop steel bars, (ii) mild steel bars (iii) mild steel flats
(iv) Expended metal. The reinforcement is laid either
horizontally or vertically.
97
98. Horizontal Reinforcement
Horizontal Reinforcement for wall
consists of either (i) wrought iron
flat bar, known as hoop iron, or (ii)
steel mesh.
Fig shows hoop iron reinforcement
for a brick wall. Generally, two
strips of hoop iron are used per
header brick and one hoop iron per
stretcher brick i.e., one strand of
hoop iron for each half brick
thickness of wall
98
99. Cont’d…
Mild steel flats may also be used in
place of hoop iron. It is usually to
reinforce every 6th course (width 22
to 32 mm and thickness 0.25 to
1.6mm). Protection against rust is
provided by dipping the bars in hot
tar; these are then at once sanded
to increases the adhesion of the
mortar.
99
100. Cont’d…
Another form of horizontal r/f, which is more
commonly used, is the provision of steel
meshed strips called Exmet (Expended
Metal). It is provided at every third course.
Sizes available are (width 65 mm, 178 mm and
230 to 305 mm, with thickness of 0.6 mm, 0.8
mm and 1 mm). To prevent the corrosion, the
metal in the coil form is coated with oil and
then dipped in asphaltum paint. Cement
mortar is first trowelled on the bed and the
Exmet is uncoiled and pressed down in the
mortar. Another form of meshed r/f, called
bricktor, is made of a number of straight
tension wires (1.4 mm) interlaced with binding
wires (1.1 mm). One such strip is provided for
every half-brick thickness of wall. 100
101. Cont’d…
Horizontal reinforcement is also used
for brick lintels as shown in fig.
Generally mild steel bars (6mm to 12
mm) are provided, through the vertical
joint, all along the span of lintel. If the
lintel carries heavy loads, resulting in
heavy shear force, 6mm dia. Steel wire
stirrups are provided at every 3rd
vertical joint. The longitudinal steel
bars (main reinforcement) should
extend 150 mm beyond the jambs. 101
102. Vertical reinforcement
Vertical reinforcement, in the form of
mild steel bars, is provided in brick
columns, brick walls and brick
retaining walls. In such a
circumstances, special bricks, with
one or two holes extending upto the
face, are used. Vertical mild steel
bars are then placed in the holes.
These bars are anchored by steel
plate or wire-tie bars at some
suitable intervals.
102
103. Cont’d…
Brick retaining walls are often reinforced
since such a work is cheaper than the RCC,
when the height of the wall is upto 3 m.
Vertical reinforcing bars are placed vertically
near each face, in addition to steel meshed
stris at every fourth course. The bricks
opposite each bar are purpose made, having
a groove. The size of the groove is kept
slightly more than the diameter of the bar so
that it may be grouted in with cement
mortar, to prevent corrosion. Steel wire ties
may be provided at every fourth course. 103
104. Cont’d…
In all type of reinforced brick work, it is essential to embed
the steel reinforcement in rich cement mortar (usually 1:3),
with proper cover so that reinforcement is not corroded.
Corrosion will result in expansion of the joint and consequent
cracking. The bricks should also be of high quality, possessing
high compressive strength so that optimum use is made of all
the materials (i.e., bricks, mortar and reinforcement).
104
