PRESENTED BY
R.SATISH
D.SHOBAN BABU
T.SREEKANTH
B. TECH FINAL YEAR
CIVIL ENGINEERING
S V ENGINEERING COLLEGE
Introduction
Types of fly ash bricks
Raw materials required
Manufacturing Process
Advantages and Disadvantages
Conclusion
 Introduction
American civil engineer HENRY LIU announced the invention of a new
type of fly ash brick in 2007. Fly ash bricks are constructed at least
partially from the residue of burnt coal. Depending on the type of coal
that is burned, the resulting fly ash can take a number of different forms.
Some kinds of fly ash require a cementing agent, such as quicklime or
Portland-cement. Other types contain a large enough percentage of lime
that they are self setting, requiring only the addition of water to be turned
into fly ash bricks. Since the 1950s in places like the United Kingdom
(UK) and the 1970s in parts of Africa, houses and other structures have
been build with fly ash bricks.
 Types of fly ash bricks
i)FAL-G (fly ash-lime-gypsum) Bricks:
Fly ash-lime-gypsum bricks/blocks
technology has been developed
successfully by National Thermal Power
Corporation (NTPC). Bhanu International
and Ahmadabad Electricity Company
(AEC) for manufacturing bricks/blocks
which can replace burnt clay bricks as
walling material.
Fal-G bricks are made of a mixture of fly ash-lime gypsum or fly ash-cement-gypsum. In either
combination, Fal-G is a hydraulic cement, which means it sets and hardens in the presence of moisture,
on the lines of ordinary Portland cement, gaining strength progressively over ageing. Nearly 200 tonnes
of coal is used to sinter one million clay bricks, a process that generates over 350 tonnes of carbon
dioxide (CO2). The production process of World Bank has offered to buy 800,000 tonnes of CO2
reductions from utilization of Fly ash. Fal-G bricks eliminates harmful emissions of this scale.
 Clay-Fly ash Bricks
 Manufacturing process of clay fly ash bricks by manual
or extrusion process involves mixing of fly ash (60 %) with
clay of moderate plasticity.
 The green bricks are dried under ambient atmospheric
conditions or in shed to equilibrium moisture level of
below 3 percent.
 Dried bricks are fired in traditional brick kilns at 1000º ±
30º C with a soaking period of 5 – 7 hours at maturing
temperature.
 This technology has great potential to reduce not only
precious top soil and consumption of coal in making
clay bricks, but also requires minimum charges
inconventional existing set up at kiln sites and not very
much susceptible to quality of ash.
Clay-Fly ash bricks
 Fly ash – Sand lime Bricks
This processes involves homogeneous
mixing of raw materials (generally fly
ash, sand and lime), moulding of bricks
and then curing of the green bricks.
 In presence of moisture, fly ash reacts with lime at
ordinary temperature and forms a compound
possessing cementatious properties. After reactions
between lime and fly ash, calcium silicate hydrates
are produced which are responsible for the high
strength of the compound.
Fly ash – Sand lime Bricks
 Cold Bonded Lightweight Fly ash Bricks,
Blocks and Tiles
 The material can be produced in a variety of building
blocks, bricks and tiles, depending on local markets and
regulations. Keraton consists of cheap and ubiquitous raw
materials such as fly ash and / or other waste materials.
 These materials are mixed and a cold bonding agent is added.
The mixed raw material is cast in moulds, after which the moulds
are processed in a microwave oven for transportation to the
building site.
 The products can be applied as a lightweight material in the house building
industry and utility building A surface treatment or coating for coloring is possible
 Flux Bonded Fly ash Bricks Blocks and
Tiles
 For making of this type of blocks fly ash is mixed with less than 10 % plastic clay and a
few additives and tiles, bricks or blocks are pressed. These shapes are fired in the range of
900ºC to 1000ºC to make the final product. More than 85% of fly ash is used in the
process.
 The process is similar to the one in the conventional tile industry
 The process is based on the formation of low melting fluxes at the firing temperature,
which partly react with the fly ash and form a high temperature reactive glass binder
phase
 Raw Materials Required
The following are the RAW MATERIALS required for making of FLY ASH
bricks
 Lime
 Gypsum
 Stone dust
 Sand
 Water
Procurement Of Raw Material
And
Sand From Pits,Rivers,Seas etc.
 Manufacturing Process
 Brick Making Machine
o The machine consist the following
parts
 Brick making machine.
 Vibrator, hydraulic power pack
motor and Control panel
 Pan mixing machine with gear
box and motor
 Belt conveyer system
 Hydraulic pallot trolley
FULLY AUTOMATIC FLY ASH BRICK MAKING MACHINE
Manufacturing of fly ash bricks is done by Two Methods
as follows
Normal Method
62%
FLY
ASH
8%
LIME
5%
GYPSU
M
25%
SAND OR
QUARRY DUST
Profitable Method
20%
15%
5%
60%
FLY ASH
LIME
GYPSUM
SAND OR
QUARRY DUST
 Flow Chart Diagram pf Manufacturing of Fly ash
Bricks
Fly Ash, Gypsum, Lime, Sand
Transported To Wooden Racks
↓
↓↓↓↓
Kept as it is
Weighing
↓
for two days for setting
↓
Pan Mixer
Water Curing
↓
(7 to 20 days)
↓
Conveyor
Drying
↓
Fly Ash Brick Making Machine
(Hydraulic (or) Power Press)
(one or two days)
↓
Sorting and Testing
↓
Dispatch
 Comparison Between
Normal Clay Bricks And Fly Ash Bricks
NORMAL CLAY BRICK
Varying colour as per soil
FLYASH BRICK
Uniform pleasing colour like cement
Uneven shape as hand made
Uniform in shape and smooth in finish
Lightly bonded
Plastering required
Dense composition
No plastering required
Heavier in weight
Lighter in weight
Compressive strength is around
35 Kg/cm2
Compressive strength is around 100
Kg/cm2
More porous
Thermal conductivity
1.25 – 1.35 W/m2 ºC
Less porous
Thermal conductivity 0.90-1.05 W/m2 ºC
Water absorption 20-25%
Water absorption 6-12%
 Characteristics of Fly Ash Bricks

The standard size of the brick is 230mmx110mmx70mm.

The bricks are manufactured and tested as per IS 12894-2002.

Fly ash bricks are sound, compact and uniform in shape, size and colour. Smooth rectangular
faces of the bricks are accompanied with sharp and square corners.

They are free from visible cracks, warpage, flaws and organic matter.

Economical & environment friendly.

28% lighter than ordinary clay bricks.

Compressive strength: 7.5N/mm2 on an average.

Water absorption <8%.
 Advantages of fly ash bricks
Fly ash bricks has numerous advantages are as follows
 Appearance and Structural Capability
 Applicability
 Toxicity and Breath-ability
 Thermal properties
 Sustainability
 Sound insulation
 Buildability, availability and cost
 Durability and moisture resistance
 Technical Advantages
 Energy Efficient
 Fire resistant
 Sound Resistant
 Structurally sound
 Strong • Durable • Versatile
 Safe • Secure • Robust
 Economical
 Other Advantages
 Less wastage and breakages
 It can reduce 10% of water consumption.
 Reduce dead load on total Building Structure
 Compression strength improves by more than 15 %.
 Less mortar consumption in masonry & saving in plastering cost.
 Uniformly in shape and size.
 Disadvantages
× Manufacturing process involves strong health hazard for the labors.
× Its disposal require large quantities of land, water, and energy, its fine particles.
× Fly ash is one of the numerous substances that cause air, water and soil pollution.
× FA contains trace amounts of toxic metals (U, Th, Cr, Pb, Hg, Cd etc.), which may have
negative effect on human health and on plants.
 Technical Specifications
230 x 100 x 75 mm
(1) Fly Ash Brick Size Details :
[4 Inches ]
(2) Compressive Strength
(3) Water Absorption
(4) Efflorescence
(5) Density
75 to 150 kg/cm2
8-12 %
Nil
1700 Kg/m3
(6) Weight
:
:
:
:
:
230 x 100 x 100 mm
[ 6 Inches ]
230 x 150 x 80 mm
230 x 150 x 100 mm
230x100x75 mm ( Weight about 4.75 to 5.00 kgs.approx )
230x150x75 mm ( Weight about 2.75 to 3.00 kgs.approx )
(7) Load Bearing Capacity :
More than 25% as compare to clay bricks
(8) Composition
:
(9) Drying Shrinkage
:
Cement, Thermal Station Fly Ash ,Crushed Sand / Stone Dust And
Chemicals
Maximum Average drying test shrinkage 0.035-0.04 %
(10) Brick Colour
:
Gray / Dark gray
CONCLUSION