Stone masonry

Stone
Masonry

Chapter No.02

“Building Construction and Graphics”
FALL-2013.

By. Engr.Rahat Ullah

1

outline
• Stone and its major types based on formation
• The stone masonry and its uses
• Some pictures from the history
• Comparison between brick and stone masonry
• Technical terms
• Classification of stone masonry
• General principles to be followed in stone masonry
• ASSIGNMENT NO.03


2

Stone and its major types based on
formation
• Building stone is a natural engineering material.
• Stone is obtained from rock by applying certain disintegration
techniques like manual quarrying and blasting etc.
• Stones obtained from rocks are irregular in shape and size and thus
need proper dressing before using for construction purpose.
• Based on formation of the parent rock it has three types
• The igneous rocks
• The sedimentary rocks and
• The metamorphic rocks

3

…….continued
• Igneous rock

• formed by the solidification of molten rock such as volcanic activity
For example: Granite

• Sedimentary

• formed from silt, marine life, and rocks that have been deposited by running
water
For example: Limestone, Sandstone

• Metamorphic

• igneous or sedimentary rock that have been changed by pressure, heat, or
moisture
For example: Marble, Slate

4

The stone masonry and its uses
• Stone blocks laid with cement or lime mortar in a systematic manner
forming a structural mass which can resist load without disintegration
is called stone masonry.
• Stone masonry is used for the construction of walls, foundation,
columns, lintels, arches and other components of structures.
• If abundantly available it can serve as an economical building material
keeping in view the dressing cost and time of construction.
• Undressed or rounded shape stone masonry with insufficient mortar
is disastrous in earthquake hazard areas like Balakot, Abbottabad etc.

5

Stone masonry,

‘‘Pictures from the history’’


6

Roman aqueduct, Pont Du Gard, France (50 AD).

7

Citadel Mycenae
Stone masonry corbelled arch and dome. 1350-1225 BC.

8

Stone masonry at PalaceEngr.Rahat Ullah Crete 1350 BC
of Knossos,
By.

9

As earlier as 700 BC.

11

Rohtas Fort ,Pakistan(1451AD)

12

Taj Mahal ,India (1632-1653AD)


13

Lahore fort, Pakistan (1556-1603AD)

14

Badshahi Mosque Lahore, Pakistan (1671AD)

15

Comparison between brick and stone
masonry

Parameter for comparison

Stone masonry

Brick masonry

Material

Natural material of construction
obtained from a quarry.

Man made material manufactured
by proper moulding and burning.

Dressing

Dressing is required to bring stones to
the required shape and size.

Dressing is not required since
bricks are moulded to desired
shape/size.

Bonding

Difficult to provide required bond in
stone masonry.

Easy to provide the required bond
in brick masonry.

Skill and care

High level of skill and greater care is
required in construction.

Less expertise and ordinary labor
is required.

Lifting and laying

Inconvenient to handle and place
stones without lifting mechanism.

Convenient to handle and place
bricks without excessive effort.

Mortar

Rich and greater quantity of mortar is
required to get desired strength.

Moderate strength and lesser
quantity of mortar is required.

Thickness and continuity of mortar
joints

Thickness of mortar joints is more and
irregular and may be continuous

Thickness of mortar joint is less
and uniform, seldom continuous.


16

……continued
Thermal resistance

High thermal conductivity makes it
Low thermal conductivity thus have greater
warmer in summer and colder in winter. comfort level in extreme weathers.

Thickness of construction

It cannot be used for walls less than
12in thick.

It can be used for constructing walls having
a 4.5in thickness.

Strength

It possess greater strength.

Comparatively less strong.

Ornamental work

Costly and difficult to use in
ornamental work.

Cheap and can be easily used for aesthetic
purposes.

Appearance

Provides pleasing appearance
increasing with age.

Provides simple appearance which
deteriorates with age.

Cost

Its cost of construction is more.

Comparatively less cost of construction.

Durability

Greater resistance to weathering
agents and thus more life.

Comparatively less durable.

Maintenance cost

Maintenance cost is less.

Maintenance cost is more.


17

Technical terms
• Block in course

The course of stones provided on the top of cornice to hold down and
prevent the cornice from overturning.

• Corbel

A short stone cantilever jutting from the face of a wall to
form a bearing.

• Cornice

A projection which crowns a wall, any horizontal division of
a wall, or an architectural feature.

• Bedding plane

The plane along which the stones can be separated into different layers.

18

Corbel


Cornice and drip stone

19

…….continued


20

…….continued
• Through stone or bond stone

The stone extending through the entire thickness of a wall to increase its lateral
stability is called a through or bond stone.

•Parapet

A low wall constructed around the terrace of a building having flat roof is called
parapet wall.
• Coping
A special course provided at the top of wall preventing penetration of
rainwater from entering the wall.

• Quoins

Stones larger than those of which the wall is composed, or better shaped, and
forming the corners of walls or door and window openings; if they project they
are described as raised, and rusticated if having chamfered angles.

21

……..continued
• Frieze

The stone course provided below the cornice is called frieze.

• Spalls

The chips of stone used for filling the hollow spaces in stone masonry are called
spalls.

• Buttress

The stepped masonry projections which is intended to provide lateral strength
to the wall is called buttress.

• String course

A distinctive course or band continued across a whole facade which may be
defined by its position e.g. a sill course.

22

Identify the defects…!


24

Classification of stone masonry
• Masonry can be classified according to the thickness of joints, continuity of
courses and finish of face.
• Broadly there are two types of stone masonry, namely:
1. Rubble Masonry
2. Ashlar Masonry

• 1). Rubble masonry:

 This consists of blocks of stones either undressed or roughly dressed and laid in
suitable mortar, having wider joints which are not of uniform thickness.
b) Uncoursed random rubble masonry
a) Random rubble masonry:
c) Coursed rubble masonry
d) Dry Rubble masonry.

25

i. Uncoursed rubble masonry


26

ii. Random Rubble masonry


27

iii. Coursed Rubble Masonry


28

iv. Dry Rubble Masonry


29

Example of random rubble wall produced from six-sided sawn blocks.

30

Random rubble uncoursed

Random rubble coursed

31

Square rubble course


Square rubble Built to regular courses
33

2). Ashlar masonry:


34

Types of Ashlar Masonry
1.
2.
3.
4.
5.
6.
7.

Ashlar fine or coursed ashlar masonry
Random coursed ashlar masonry
Rough tooled ashlar masonry
Rock or quarry faced ashlar masonry
Chamfered ashlar masonry
Block in course ashlar masonry
Ashlar facing masonry.


35

……..continued
1. Ashlar fine or coursed ashlar masonry.
• In this type of masonry stone blocks of same height are used.
• Every stone is tooled on all sides and thickness of mortar is uniform.
• A satisfactory bond can be attained due to uniform sizes of stones.

1. Random coursed ashlar masonry.
• This type of ashlar masonry consists of fine or coarse ashlar but the courses
are of varying thickness.

1. Rough tooled ashlar masonry.
• sides of stones are rough tooled and dressed with chisels. thickness of joint is
uniform and not exceeding 6mm.

1. Rock or quarry faced ashlar masonry.
• Similar to rough tooled type except that there is a chisel margin left rough on
the face which is known as quarry faced.

36

……..continued
5. Chamfered ashlar masonry.

• It is similar to quarry faced ashlar masonry except that the edges are beveled or
chamfered to 450 for depth of 25mm or more.

5. Block in course masonry.

• it is the name given to a class of ashlar masonry which occupies an intermediate
place between rubble and ashlar masonry.
• the stones are all squared and properly dressed.
• It resembles coursed rubble masonry or rough tooled ashlar masonry.

5. Ashlar facing masonry.

• Ashlar is the superior but expensive type of stone masonry thus in order to reduce
the cost a wall is commonly constructed with a facing of ashlar and backing of rubble
or brick masonry,
• Such walls are also called compound or composite masonry walls.
• If the backing is of rubble masonry it is called rubble ashlar, if the backing is of brick
masonry then it is termed as brick ashlar.

37

1.

Ashlar fine or
coursed ashlar
masonry.

3. Rough tooled
ashlar masonry.

2. Random coursed
ashlar masonry.

4. Rock or quarry
faced ashlar masonry.

38

5.

Chamfered ashlar
masonry.

6. Block in course
masonry.

7. Ashlar facing
masonry.

39

Choice of wall type
• The choice of walling type is influenced by:
 The design of the building,
 Technical considerations (whether the wall is load bearing or nonload bearing),
 Its location,
 Site exposure, and
 Aesthetic considerations.


40

General principles and precautions to be
followed for stone masonry
1)The stone used shall be hard, durable and tough. All stones should be laid
on its natural bed.
2)The pressure acting on the stones should not act parallel to the bedding
planes. This will try to split the stones. Sometimes stones used in corbels
are laid with pressure acting parallel to bedding planes.
3)The bond stones and headers should not be of dumb-bell shape.
4)Large flat stones should be laid under the ends of girders, roof trusses, etc.
5)In all slopping retaining walls, the beds of the stones and the plan of the
courses should be at right angles to the slope.

41

……continued
6)
All laid fine dressed stone work should be protected against
damage during further construction by means of wooden
boxes.
7)
Jambs for door and window openings should be made of quoins
which are equal in height to the course. They should be in
breadth equal to at least 1½ times the height of the course and
their length should be at least twice the height.
8)
All the surfaces should be kept wet while the work is in progress
and also till the mortar has set.
9)
Double scaffolding will be used wherever it is difficult to fit in the
stones later on.

42

…….continued
10) All the portions of the masonry should be raised uniformly.
Wherever this is not possible, the stone work built earlier should
be raked (stepped) so that the new work can be bonded well with
the old.
11) Sufficient through stones should be used and they should form
¼th of the area in elevation.
12) The hearting of the masonry should be properly packed with
mortar and chips, if necessary, to avoid any hollows or very thick
mortar joints.

43

…….continued
13) Vertical faces of the masonry walls should be checked with a
plumb rule and the battered faces should be tested with wooden
template corresponding to the batter and a plumb rule to ensure
a
constant batter.
14) The stones used in the masonry should be wetted before use to
avoid moisture being sucked from the mortar.
• Masonry should not be allowed to take tension.
• Through or bond stone should be selected separately from
ordinary building stones.
• Double scaffolding should be used.

44

Assignment No.03
• Coursed rubble masonry may be sub-divided into three classes
Discuss these three classes of coursed rubble masonry.
• Write down specifications of stone masonry for different types of
stone masonry.
• Explain in detail cutting and dressing of stones and the tools which
are used in this process.


45

Stone masonry

Empfohlen

Empfohlen

Weitere ähnliche Inhalte

Was ist angesagt?

Was ist angesagt? (20)

Andere mochten auch

Andere mochten auch (20)

Ähnlich wie Stone masonry

Ähnlich wie Stone masonry (20)

Kürzlich hochgeladen

Kürzlich hochgeladen (20)

Stone masonry