1 of 35

Masonry

Brick and Stone

2 of 35

Masonry

Masonry is the building of structures from individual units laid in and bound together by “mortar”
Construction of building units bonded together with mortar
Brick and concrete block are the most common types of masonry
Basically a wall material

Load bearing walls
Non-load bearing walls
Retaining walls

3 of 35

Wall types

Load bearing

Designed to carry superimposed loads from floors and roofs
Have continuous foundation to carry the entire superimposed load including the self load

Non-load bearing

Also known as panel wall, curtain wall or filler wall
Wall which carry no superimposed load
Load from floors and roof above is borne either by brick piers or RCC/ steel beam and column frames

Retaining wall

Wall built to resist the pressure of earth, granular material or liquid filled behind it after it is built

4 of 35

Masonry

Depending upon the type of material used

Stone
Brick
Reinforced brick
Composite
Hollow concrete
Load bearing wall tile

5 of 35

Stone masonry

6 of 35

Stone vs Brick masonry

Stone masonry	Brick masonry
High strength, durable, weather resistant	Much less
High crushing strength – piers, docks, dams and other marine structure	Not considered for such uses
Shining texture, no treatment to enhance appearance	Plastering is necessary
Suitable for heavy mouldings with large projections	Suitable for light ornamental work
No effect of dampness	Exposed brick gets damp leading to disintegration of masonry
High cost of extraction and transport to most areas, used in hilly or stone districts	Available everywhere and comparatively cheap
Not regular in size → requires dressing and time taken in construction is more	Regular shape and size, offer great facility in maintaining proper bond
Expensive when moulding in desired shape	Less expensive in moulding
Skilled labour	Not so skilled labour
Minimum thickness is restricted to 30cm	Could be as thin as 10cm

7 of 35

Process

Quarrying

Extracted from where it is found

Dressing & cutting

Large blocks are further cut and dressed for use

Hammer dressed or Quarry faced surface
Rough tooled surface
Cut stone surface
Rubbed surface
Polished surface

8 of 35

Process

Setting of stone work

Lifting

Lewis: Pin, Chain and three legged
Nippers

Joints

Butt
Lapped
Table
Cramped
Plugged
Dowel
Joggle
Rusticated or Rebated

9 of 35

Lifting

10 of 35

Joints

11 of 35

General principles to be observed

Stone should be well seasoned, tough, compact grained, uniform texture
Should be free from cracks, flaws, cavities, veins and patches of soft or loose materials
Above plinth level: lime or cement mortar
Water logged site or in basements: hydraulic lime or cement mortar with surkhi
All stones should be laid upon their natural bed
Proper bond should be maintained
Facing and the backing should be well bound by through stones
Toothing should not be allowed
Joints should not be too smooth to loose friction
Bed joints should not be dresses hollow
Vertical joints should be staggered as far as possible
Stones should be well wetted before use
Masonry should not be subjected to tensile stresses
Exposed joints should be properly pointed
Entire work should be well cured

12 of 35

Classification

Based upon

the degree of refinement used in shaping the stone
Finishing adopted
Arrangement of the stone in construction

Rubble
Ashlar

13 of 35

Rubble Masonry

Uncoursed

Poorest form; stones used are directly from quarry

Random

Slightly superior from above; stones used are hammer or chisel-dressed; not suitably shaped or finished

Coursed

Adopted in the construction of buildings, piers
Based upon the dressing and finishing: first class, second class and third class

Dry

Similar to ordinary rubble masonry without mortar

14 of 35

Ashlar Masonry

Built from carefully dressed stones with accurate bedding and jointing

Ashlar Fine

All are fine tooled, on all bed and side joints and faces are rendered perfectly true to the pattern desired

Ashlar Rough tooled

Exposed faces generally have a fine dressed chisel drafting all round the edges

Ashlar Rock, rustic or quarry faced

Same as above but exposed faces of face stones between the chisel drafting are left rough

Ashlar Chamfered

Edges around the exposed faces of the stone are beveled off at an angle of 45⁰ for depth of 25mm or more

Ashlar Facing

Faces of stones are rough tooled and chamfered and the stones are provided in face work only

15 of 35

Stone selection

Situation	Type of stone
For face work of building	Marble, granite and close-grained sand stone
For curved or ornamental works	Soft sand stone and marble
For masonry work in industrial town exposed to smoke and chemical fume	Granite, compact sand stone and quatrzite
For road metal	Basalt and coarse grained granite
For railway ballast	Sand stone, granite and quartzite
For pavings, door sills and steps	Marble, Slates and sand stone
For bridges, piers, docks and other marine structures	Fine grained granite and gneisses
For fire resistant masonry	Compact sand stone

16 of 35

Safe permissible load

Type of stone masonry	Safe permissible stress in kN/m²
Ashlar masonry in 1:3 cement mortar Using granite stone Using sand stone	1600 1100
Ashlar masonry in 1:6 cement mortar Using granite stone Using sand stone	1300 900
Ashlar masonry in lime mortar Using granite stone Using sand stone	1100 800
Course rubble masonry in 1:3 cement mortar Using granite stone Using sand stone	1200 1000
Course rubble masonry in 1:6 cement mortar Using granite stone Using sand stone	1000 800
Course rubble masonry in lime mortar Using granite stone Using sand stone	900 700
Random rubble masonry in 1:3 cement mortar	700 to 1000
Random rubble masonry in 1:6 cement mortar	500 to 600
Random rubble masonry in lime mortar	400 to 500

17 of 35

Brick Masonry

18 of 35

Elevation of a Masonry wall

19 of 35

Brick types

Traditional

L: 21-25cm; W: 10-13cm; H: 7.5cm
Commonly adopted size: 23x11.4x7.6cm

Modular

Standard size: 20x10x10cm
Actual dimension: 19x9x9

Nominal thickness of wall

Thickness of the wall to be considered in evaluating the quantity of brickwork in estimates

23cm for traditional bricks
20cm for modular bricks

20 of 35

Brick portions

21 of 35

General principles observed

First class bricks should be used
Thoroughly soaked in clear water

While using with mud or fat lime mortar, it should not be soaked

Laid on a full bed of mortar and slightly pressed
Joints properly flushed and filled with mortar
No brick-bats to be used
Specified mortar of good quality be used and thickness of joints not to exceed 13mm

No part of the wall should rise more than 100cm than the rest
Plastering after 28days of brick work
Finished masonry should be kept wet for at least seven days
Toothed end should be left at the end of the wall, if length needs to be increased at some time in future
18mm wide expansion joints after every 30-45m length of wall

22 of 35

Bonds

Bricks can be arranged in a variety of patterns giving rise to “BONDS”
Essential to eliminate continuous vertical joints → strength to masonry

23 of 35

Bond: Types

Most common

English
Flemish

Single
Double

Others

Stretching; Heading; Garden wall; Facing; Raking; Dutch; English cross; Zig-Zag; Silverlock’s

24 of 35

Type of “Bonds” for brick work

25 of 35

Others

Tee-junction

Formed when two walls meet each other at right angle

Bonds in Piers

Type of bond depends upon shape of the pier and individual choice
Most common are English and Double Flemish

Squint junction

Formed when two walls meet at an angle other than right angle without forming a “quoin”
May be in English or Flemish Bond

Squint quoins

Formed when two walls meet at an angle other than right angle forming a “quoin”

Obtuse
Acute

26 of 35

Others

27 of 35

Tools for brick-layer

Hammer
Line and Pins
Brick Axe
Spirit level
Plumb rule
Mason’s square
Trowel
2’ and 4’ rule

28 of 35

Retaining wall

Wall built to resist pressure of liquid, earth filling, sand or other granular material filled behind after it is built
Required in construction of hill roads, dams, abutments and wings walls of bridges
Depending upon the requirements and site conditions, retaining walls may be built in

Dry stone; stone; brick; plain cement concrete and reinforced concrete cement

29 of 35

Design of retaining walls

Thrust from the backing wall tends to overturn the wall or causes it to slide
Thrust depends upon

Cohesion of soil; dryness of the material; manner in which the material is filled etc.,

Calculation of thrust is important to ascertain the design of the walls

30 of 35

Case1: Calculation of earth pressure

Horizontal pressure per sq m at a depth ‘h’ below the leveled top

w: weight of filling (kg/m3)
f: angle of repose of the soil

Total horizontal pressure (P) at a depth of (h) meter per meter length of wall

Acting at h/3 meter from the base

31 of 35

Case2: Calculation of earth pressure

Retaining wall is at an angle a^o to the horizontal

Lateral earth pressure
Acting parallel to the wall

Total pressure at depth of h meter per meter length of the wall is

32 of 35

Strength of Brick Masonry

Depends upon

Type and strength of bricks
Mix of mortar
Size and shape of masonry construction

33 of 35

Basic compressive stresses for masonry

Mortar	Mix proportions (parts by vol)					Hardening time	Basic compressive stress
Mortar	Cement	Lime	Lime-Puzzolana	Puzzolana	Sand	Hardening time	35	70	105	140	175	210
Cement	1	0-.025	-	-	3	7	3.5	7.0	10.5	12.5	14.5	16.5
Cement	1	0.5	-	-	4.5	14	3.5	7.0	10.0	11.5	13.0	14.5
Cement Lime	1	1	-	-	6	14	3.5	7.0	8.5	11.0	12.0	13.0
Cement Lime	1	2	-	-	9	14	3.5	5.5	8.5	10.0	11.0	12.0
Cement	1	-	-	-	6	14	3.5	5.5	7.0	10.0	9.0	12.0
Lime-Puzzolana	-	-	1	-	1.5	14	3.5	5.5	7.0	10.0	9.0	12.0
Cement Lime	1	3	-	-	12	14	3.5	5.0	7.0	8.0	9.0	10.0
Hydraulic Lime	-	1	-	-	2	14	2.5	5.0	5.5	8.0	6.5	10.0
Lime Puzzolana	-	1	-	1	2	14	2.5	5.0	5.5	8.0	6.5	10.0
Lime	-	1	-	-	3	28	2.5	4.0	5.5	6.0	6.5	7.0

34 of 35

Defects in brick masonry

Sulphate attack

Sulphate in brick reacts with alumina in cement and hydraulic lime → increase in volume of mortar → chipping and spalling of bricks and formation of cracks

Crystallisation of salts from brick

When bricks contain excessive soluble salts which gets deposited on the surface → efflorescence

Corrosion of embedded iron or steel

Iron gets corroded, metal expands and crack the brickwork

Shrinkage in drying

Swells with moisture and shrinks when dry → cracks in the masonry joints

35 of 35

Reinforced brick work

Brick work strengthened by introduction of mild steel flats, hoop iron, expanded mesh or bars
Capable of resisting both compressive as well as tensile and shear stress
Extensively used in seismic areas
Use first class bricks and rich and dense cement mortar
Should be effectively bedded and surrounded with mortar cover of 15-25cm