These slides are describes regarding different types of stone masonry used in construction of walls, plinth, compound wall etc. and also the terms used in the stone masonry.
2. MASONRY WALL
A masonry wall is built of individual blocks of materials such as
stone, brick, concrete blocks, hollow blocks, usually in horizontal
courses connected together with some form of binding material
called mortar.
Masonry classification-
1. Stone masonry
2. Brick masonry
3. Hollow block concrete masonry
3. STONE MASONRY
It is the art of building the structures in stones.
Terms used in stone masonry
1. Face- exterior of a wall exposed to weather is called as face
2. Facing-the material used in the face of wall is known as facing
3. Back- the inner surface of wall which is not exposed to weather
4. Backing- the material forming the back is known as backing
5. Hearting- it is the interior portion of a wall between the facing and backing
6. Trough stone- some stones in one piece or in two pieces at regular interval are
placed right across the walls are termed as through stones/bond stones.
increases the bonding capacity between backing and facing.
7. Joint- It is the junction of two or more bricks or stones in a wall
8. Course- is a horizontal layer of bricks or stones in a wall
9. Stretcher- is a brick or stones which lies with its longest side parallel to the face
of work.
10. Header- is a brick or stone which lies with its greatest length at right angles to the
face of the work.
4. Quoin header- it is the block of stone used at the
corner of two walls meeting at 90 degree
Plinth Course- it is the top most layer/ course of
the plinth masonry.
6. SELECTION OF STONE FOR STONE
MASONRY OR PRINCIPLE FOR
STONE MASONRY
Availability of stone-
the stone used for masonry should be easily available from
nearby sources.
Ease of working-
the stone should permit easy dressing and shaping to facilitate
working on it easily
Appearance-
the appearance of the stone should attractive and colour
should be uniform
Strength-
the crushing strength of stone should permit the use of stone in wall
masonry
Polishing characteristics-
the stone when polished should look attractive with shining
texture.
7. CLASSIFICATION OF
STONE MASONRY
Rubble –
1. Dry rubble
2. Uncoursed rubble masonry
3. Coursed rubble
4. Squared rubble (uncoursed)
5. Squared rubble (coursed)
Ashlar
1. Ashlar fine
2. Ashlar chamfered
3. Ashlar rock quarry faced
4. Ashlar facing
10. DRY RUBBLE MASONRY
It is most inferior type of masonry in which
either quarry dressed or undressed stones
are used without help of any mortar.
Bigger pieces of stones are arranged at the
bottom in such a way that these should
have min. of voids and have proper
interlocking with each other.
Smaller pieces of stones are used at the
top.
These walls are generally broader at the
bottom and thinner at the top.
This type of masonry is used for the
construction of retaining walls, breast
walls, boundary walls of a building at
quarry sites etc.
The strength and durability of masonry
does not depend on the quality of materials
used but on the workmanship.
11. UNCOURSED/RANDOM
RUBBLE MASONRY
• Stones or rubbles are used
without any dressing, shape and
size of rubbles or stones used
into the stone masonry is not
same but it varies.
• The mason select the stone at
random from heap and lays them
in line and plumb so as to form a
strong bond.
• Before laying the stones, all
projecting corners are slightly
knocked off with a hammer. The
joints are filled with mortar by
steel travel and finished to flush.
12. • The joints should not exceed 13 mm
tk. Large stones are used at corners
and jambs to increase the strength
• Through stones are also provided at
intervals to interlock the portion in
between facing and backing which
increases the strength of masonry.
• It affords a very rough appearance
• If wall is greater than half a meter in
tk., a line of stone header or through
stones overlapping each other by at
least 15 cm should be laid in the
masonry wall.
• Used for compound wall of jail,
boundary wall, plinth wall, retaining
wall..
13. COURSED RUBBLE MASONRY
Stones are laid to level course in each
course header stones of full course height
are placed at certain intervals.
Each header stone has a width of not less
than its height and inserted into the wall at
least three times its height.
Size-50-200mm
Joints-15mm
Stones used between the head or stone
should not be smaller than 50 mm in
thickness
Header stones in successive courses
should not be placed one above the other
Quoins are of to be same height and about
half meter long
Used in the construction of walls of
residential building, public building, piers,
abutments of small bridges for small height.
14. SQUARED RUBBLE
MASONRY UNCOURSED
Squared stone means stone whose
edges have been made roughly
straight, square does not mean that
the stones are square in section.
The stones are roughly dressed and
are laid at random on their natural
beds so that they are interlocked.
Joints should not exceed 13 mm
The voids filled by mortar and stone
chips
Use- residential building, public
bldg, boundary walls
15.
16. SQUARED RUBBLE
MASONRY COURSED
Semi dressed (sharp at edges but surface are rough) stones
are used
Stones are arranged in regular courses
Stones of equal height should be used in a course or two or
three stones are kept above each other to make the ht. of
course.
Mortar joints should not exceed 13 mm
Stones should be of uniform colour
17. ASHLAR MASONRY
In which well dressed stones
having sharp & straight edges and
smooth faces are used.
Expensive , highly skilled labour
requires
Uniform colour stone with pleasing
apperance dense structure with no
cracks
18.
19.
20. ASHLAR FINE
Stones are dressed to confirm the desired pattern
Height of stone–min. 300mm
Width of stone should not be less than ht.
Length of stones should not be more than two times the ht.
of course
Stones are laid in header and stretcher pattern
Vertical joints in two courses should be staggered
Tk. of joints should be 3mm
21. ASHALAR
CHAMFERED
Similar to ashlar fine
Edges of stones are bevelled off or chamfered at an angle of
39⁰ to 45⁰ for depth of about 2.5cm
The joints are thin and faces are smooth
22. ASHLAR ROCK
QUARRY FACED
Edges are straight and sharp so as to have thin mortar joint
but the faces are left in condition as acquired from quarry (
natural rock like appearance)
It increases the architectural appearance
23. ASHLAR FACING
Best grade of masonry and very expensive
Therefore to achieve economy as well as appearance only
the exposed faces of walls are constructed of ashlar masonry
where backing are constructed with brick/rubble masonry
24. COL-GROUT
MASONRY
The resultant masonry by injection of col grout mortar in
prepacked stones is called as col grout masonry
It is a mixture of cement fine aggregate and water admixture, if
any mixed at high speed in col grout double drum mixer.
It is constructed in UCR masonry it was observed in that
masonry the voids in the rubbles are not filled up properly with
cement mortar which led to heavy seepages through the body of
dam after commission.
This was mainly due to the fact that the placement of mortar was
not done properly by unskilled in experienced masons
Col grout mortar is a flowy mortar and gets filled in each and
every void in rubbles providing dense strong and impermeable
masonry.
25.
26. IMPORTANT POINTS TO BE OBSERVED IN THE
CONSTRUCTION OF STONE MASONRY
Stones should be well seasoned, hard, tough, uniform in
texture, free from defects (cracks, cavities, patches of
loose/soft materials,soil)
Stones should be laid on their natural beds.
Proper bond should be maintained
Vertical joints should be staggered
Vertical faces should be truly in plumb and should be
checked by plumb bob.
Stones should be wetted before use
Masonry should be cured for at least two weeks
27. MORTAR
Definition-
the workable paste prepared by mixing a binding material such
as cement, lime etc. fine aggregates (sand, surkhi,cinder) and water in
suitable proportion is called as mortar.
Types-
1. Cement mortar- (cement+sand+water, 1:2-1:8)
2. Lime mortar- ( lime+sand/surkhi+water, 1:5-1:6)
3. Gauged mortar/composite mortar- ( mixture of cement and lime)
used for bedding and jointing rubble flint
proportion- 1 part cement, 3 parts of lime, 2-12 parts of sand
use within 2 hrs after addition of cement