Structural clay products (Conventional & Fly ash bricks)

1. Prepared by –:
Ashish Makwana
1

2.  Introduction
 Brick earth
 Field-testing of brick
 Characteristics (first class brick); it’s test for quality
 Fly-ash & it’s constituents
 How is fly-ash disposed of?
 Applications of fly-ash
 Advantages & disadvantages of fly-ash
 Material use for Fly-ash brick
 References
CONTENTS
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3. INTRODUCTION
A brick is a block or a single unit of
a ceramic material used in masonry construction.
Typically bricks are stacked together or laid
as brickwork using various kinds of mortar to hold
the bricks together and make a permanent
structure.
3
Source: http://en.wikipedia.org/wiki/Brick

4. INTRODUCTION (Cont’d)
Bricks are typically produced in common or standard sizes
in bulk quantities.
They have been regarded as one of the longest lasting and
strongest building materials used throughout history.
4
Source: “Engineering Materials” by R. K. Rajput, S. Chand & Company Ltd.
1 2
3Clay brick

5. CONSTITUENTS OF BRICK EARTH
Brick earth - disintegration of igneous rocks.
• Potash felspars,
• Orthoclase,
• microcline
Mainly responsible for yielding clay minerals in the earth –
A good brick earth should be such that it can be easily
molded & dried without cracking and warping.
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6. CHEMICAL COMPOSITION OF
BRICK EARTH
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Ingredient % by weight
Alumina or clay 20-30 per cent by weight
Silica or sand 35-50 per cent by weight.
Silt 20-25 per cent by weight.
The total content of clay and silt may preferably be not less
than 50.
Remaining ingredients such as Iron oxide, Magnesia (MgO),
Lime (CaO), Sodium potash is 1-2 percent by weight.

7. HARMFUL INGREDIENTS IN BRICK EARTH
Excess of lime
Iron pyrites
Pebbles
Organic matter
Alkalis ( MgO, K2O )
Salts
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8. FIELD-TESTING OF BRICK
Consistency test
Test for molding properties
Test for deformation and shrinkage on burning
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9. FIELD-TESTING OF BRICK (Cont’d)
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• The consistency test is performed to know the proportions
of clay and sand in the soil to be used for brick earth so
that the soil can be modified, if required.
Consistency test
• The main object of performing this test is to fix the soil and
water ratio so that the bricks can be included with sharp
and well formed edges.
Test for molding properties
• The primary purpose of performing this test is to know the
shrinkage and deformation on the burning of bricks,
molded and dried out of the soil under test, so that any
shortcoming in the composition of soil can be detected and
corrected for achieving a satisfactory result.
Test for deformation and shrinkage on burning

10. MANUFACTURE OF BRICKS
Step-1
Preparation
of clay
Step-2
Moulding of
bricks
Step-3
Drying of
bricks
Step-4
Burning of
bricks.
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11. MANUFACTURE OF BRICKS (Cont’d)
• Selection of site and unsoiling
• Digging and cleaning
• Weathering and blending
• Tempering
Step-1 Preparation of clay
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12. MANUFACTURE OF BRICKS (Cont’d)
Step-2 Moulding of bricks
• (i) Ground moulding
• (ii) Table molding
1. Hand moulding
• (i) Plastic method
• (ii) Dry process method
2. Machine moulding
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13. MANUFACTURE OF BRICKS (Cont’d)
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Ground molding
A molded brick lying over the pallet board
Source: “Engineering Materials” by R. K. Rajput, S. Chand & Company Ltd.
1 2
3

14. MANUFACTURE OF BRICKS (Cont’d)
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Table molding
Source: “Engineering Materials” by R. K. Rajput, S. Chand & Company Ltd.

15. MANUFACTURE OF BRICKS (Cont’d)
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• I Natural drying
• Ii Artificial drying
Step-3 Drying of bricks
Natural drying of bricks

16. • I Clamp or open kilns
• II Intermittent kilns
• III Continuous kilns
•  Bull's trench kiln
•  Hoffman's kiln
•  Tunnel kiln
Step-4 Burning of bricks
MANUFACTURE OF BRICKS (Cont’d)
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17. CLAMP/OPEN KILNS
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open kilns

18. BULL’S TRENCH KILN
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1 2
3
4

19. HOFFMAN’S KILN CLAY BRICK PROCESS
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1 2 3
4 5 6
7 8 9
Source: http://www.youtube.com/watch?v=mIwHxA-YJfs

20. 20
Video
HOFFMAN’S KILN CLAY BRICK PROCESS

21. TUNNEL KILN FOR BRICK
FIRING PROCESS
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1 2 3
4 5 6
7 8
9Source: http://www.youtube.com/watch?v=wZrY87ez8zk

22. 22
Video
TUNNEL KILN FOR BRICK
FIRING PROCESS

23. AUTOMATIC BRICK FACTORY TO
MANUFACTURE CLAY BRICKS
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Video

24. CHARACTERISTICS OF
A FIRST CLASS BRICK
A first class brick is Well burnt & regular in shape.
Edges are a sham and well defined.
It is sufficiently hard and sound.
Its surface is smooth, clean & free from cracks.
A fractured surface shows a uniform compact structure.
Water absorption shall not be more than one sixth of its
weight of water when kept immersed for sixteen hours.
When soaked in water for 24 hours and dried in the shade does
not show efflorescence. 24

25. It should not break when dropped from a height of I to 2 meters.
It has a specific gravity of 1.8.
It is so hard that no mark can be produced on it with fingernails.
It has a minimum crushing strength of 10.5 N/mm2.
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• For flooring and walling purposes.
• As ballast for R.C. Work.
• Shaped bricks are used in carvings, arches and
copings.
Use of a first class brick
CHARACTERISTICS OF
A FIRST CLASS BRICK

26. FIRST CLASS BRICK TEST FOR
QUALITY BASED
Water absorption test
Compressive strength test
Efflorescence test
Structure test
Shape and size test
Soundness test
Hardness test
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27. FIRST CLASS BRICK TEST FOR
QUALITY BASED
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Water absorption test
 First weighed dry
 Then immersed in water for 16 hours
 Weighed again
 difference in weight indicates the amount of water
absorbed by the brick. > NOT 20%
Compressive strength test
 Immersed in water for 24 hours.
 The frog of the brick is filled flush with 1: 3 mortar & the
brick are stored for 24 hours followed by three days
immersion period.
 Placed between the plates of the compression testing
machine.
𝐂𝐨𝐦𝐩𝐫𝐞𝐬𝐬𝐢𝐯𝐞 𝐬𝐭𝐫𝐞𝐧𝐠𝐭𝐡 =
𝐌𝐚𝐱𝐢𝐦𝐮𝐦 𝐥𝐨𝐚𝐝 𝐚𝐭 𝐟𝐚𝐢𝐥𝐮𝐫𝐞
𝐥𝐨𝐚𝐝𝐞𝐝 𝐚𝐫𝐞𝐚 𝐨𝐟 𝐛𝐫𝐢𝐜𝐤
Type equation here.

28. 28
Compressive strength test (Cont’d)
Efflorescence test
 The soluble salts cause efflorescence on the surface of
bricks.
 For getting it’s value specimen immersed in water for 24
hours. It is then taken out and allowed to dry in shade.
compressive strength of common building
bricks
not less than 3.5 N/mm2
Bricks of high quality strength less than 14 N/mm2
white deposits cover efflorescence
about 10% slight
about 50% moderate
more than 50% heavy and it is considered as serious

29. 29
Structures test
 A specimen brick is broken and its structure is examined.
It should be homogeneous, compact and free from any
defects, e.g., lumps, holes, etc.
Shape and size test
 Twenty bricks of standard size (190 mm x 90 mm x 90
mm) are randomly selected and stacked lengthwise,
along the width and along the height.
 For good quality bricks, the results should be within the
following permissible limits:
Length 3680 mm to 3920 mm
Width 1740 mm to 1860 mm
Height 1740 mm to 1860 mm

30. 30
Soundness test
 This test is performed by striking two specimen bricks
with each other; the bricks should not break and a clear
ringing sound should be produced.
Hardness test
 This test is conducted by making a scratch on brick
surface with the help of a fingernail; if no impression is
left on the surface, the brick is treated to be sufficiently
hard.

31. FLY-ASH
The fly-ash is the residue from the combustion of
pulverized coal collected by the mechanical or
electrostatic separators from the flue gases of
thermal power plants.
The fly-ash obtained from electrostatic precipitators is
finer than Portland cement.
It consists mainly of spherical glassy particles
ranging from I to 150 µm in diameter, of which the
bulk passes through a 45-µm sieve.
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32. CONSTITUENTS OF FLY-ASH
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Constituents Amount in %
Silicon dioxide (Si02) 30 to 60%
Aluminium oxide (Al203) 15 to 30%
Unburnt fuel (carbon) up to 30%
Calcium oxide (CaO) 0.1 to 7%
Magnesium oxide (MgO) small amounts
sulfur trioxide (SO3) smaller amounts

33. HOW IS FLY-ASH DISPOSED OF?
• Here the fly-ash is triggered into an overhead silo or a
bunker at the plant pneumatically. The use of mechanical
means (e.g. Screw conveyors etc.) for the removal of fly-
ash is restored to only if the quantity of flash to he handled
is small.
Dry system
• In this system of disposal of fly-ash, the fly-ash is mixed
with water and sluiced to the settling ponds or dumping
areas near the plant. The system, however, will work
satisfactorily if the following conditions are satisfied:
• (i) The water supply is available continuously;
• (ii) Large areas of wasteland for ponding are available: and
(iii) The filled up ponds are emptied regularly.
Wet system
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34. APPLICATIONS OF FLY-ASH IN THE
CONSTRUCTION INDUSTRY
The fly-ash may
be used in
concrete as an
admixture or
in-part
replacement of
cement.
Cellular
concrete blocks
Fly-ash building
bricks
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35. ADVANTAGES OF FLY-ASH
Fly Ash improves concrete workability and lowers
water demand.
Fly Ash generally exhibit less bleeding and
segregation.
Sulfate and Alkali Aggregate Resistance.
Fly Ash has a lower heat of hydration.
Fly Ash generally reduces the permeability and
adsorption of concrete.
Fly Ash is economical.
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36. DISADVANTAGES OF FLY-ASH
All fly ashes can not be used in structural concrete
Replacement level depends on fly ash properties
Requires a good facility for testing
Requires good quality control at the site
Requires good curing for minimum 10-14 days
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37. MATERIAL USE FOR FLY-ASH BRICK
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Fly-ash C-class (from Dahej) Kheda dust
Lime
Water
+

38. Automatic plant of Fly-ash brick
(Madhav Brick)
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1 2
3 4
Fly-ash brick

39. REFERENCES
“Engineering Materials” by R. K. Rajput, S. Chand & Company
Ltd.
http://en.wikipedia.org/wiki/Brick
building/LECTURE/SHARING/first_class/B.Material%20Technolog
y/M.%20Technology-6.pdf
http://www.uotechnology.edu.iq/dep
• http://www.youtube.com/watch?v=5F_7CbhpfEU
Automatic brick factory to manufacture clay bricks.flv
• http://www.youtube.com/watch?v=wZrY87ez8zk
Tunnel Kiln for brick firing process
• http://www.youtube.com/watch?v=N5abXsF8ZPM
Fireclay Tile Manufacturing Process
• http://www.youtube.com/watch?v=mIwHxA-YJfs
Hofmann kiln.clay brick machine,mud brick
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40. THANK YOU
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