Fly ash, a principal byproduct of coal burning power plants, is
an industrial waste product containing large amounts of silica,
alumina and small amount of unburned carbon, which pollutes
This fly ash has real disposal problems, and should hence be
utilized effectively for various purposes.
Fly ash, being primarily pozzolanic, can actually replace a
percentage of the Portland cement, to produce a stronger, more
durable and more environment friendly concrete.
The cement production process releases a lot of carbon-di-
oxide in atmosphere, which is the primary green house gas that
causes global warming.
Hence replacement of a considerable portion of cement by fly
ash, can make a major contribution toward solving the global
ASH PRODUCTION IN INDIA
YEAR ASH PRODUCED IN MILLION TONES ASH USED IN MILLION TONES
2006-07 116 24.80
2007-08 123 27.15
2008-09 130 29.68
2009-10 138 32.21
2010-11 145 34.74
2011-12 154 38.00
2012-13 163 42.50
PROJECTED VALUE OF FLY ASH UTILISATION
2013-14 173 48.00
ASH WITH PORTLAND CEMENT
Fly ash can be used with Portland Cement Concrete as a cement
extender to enhance the performance of the concrete. Some of the
resulting benefits are:
• Higher Ultimate Strength
• Increased Durability,
• Improved Workability
• Reduced Bleeding
• Increased Resistance To Sulfate Attack
• Reduced Shrinkage
FLY ASH BRICKS
Fly ash possesses both ceramic as well as pozollanic properties
and therefore can be utilized in a unique way for manufacturing
This proves to be very useful for building construction.
These bricks produced by the new process are superior in
quality as they offer higher cold crushing strength and smooth,
S.NO FEATURES NORMAL CLAY
FLY ASH BRICKS
1 BINDING LIGHT DENSE
2 COLOUR VARY UNIFORM
3 SHAPE IRREGULAR UNIFORM
4 WEIGHT MORE LESS
35 KGS/SQ.CM 100 KGS/SQ.CM
Reduces excavation of clay.
Low cost of brick as compared to clay brick as same
Number of bricks required per unit volume of construction
Less consumption of mortar.
Less number of joints in case of blocks.
Plastering is not required if it required
FLY ASH FOR ROAD
Fly ash can be used for construction of road and embankment.
This utilization has many advantages over conventional
• Saves top soil which otherwise is conventionally used .
• Avoids creation of low lying areas (by excavation of soil to be
used for construction of embankments) .
• Avoids recurring expenditure on excavation of soil from one
place for construction and filling up of low lying areas thus
• Does not deprive the nation of the agricultural produce that
would be grown on the top soil which otherwise would have
been used for embankment construction.
• Reduces the demand of land for disposal/deposition of fly ash
that otherwise would not have been used for construction of
embankment. Good Compaction .
• Free draining ( Less interruption due to raining ).
• Light in weight ( can be used in weak sub – grade )
The superior benefits of PFA as a fill material come from its
lower density when compared to soils. PFA has a density of
1.5Mg/m3 compared to around 2Mg/m3 for soils.
The benefits of PFA as a fill material include:
• Reduced settlement in poor underlying soils.
• Lightweight and therefore leads to savings in materials and
haulage costs. For example, there is approximately a 25%
reduction in lorry movements
FLY ASH AS FILL MATERIAL
• Increased stability as its self-supporting properties provide stable
conditions for shallow trenches and other excavations
• Immediate and increasing strength. For example, field tests on
existing embankments have demonstrated the positive strength
gain and long-term stability of PFA. In addition, PFA will absorb
water and therefore is not easily saturated, allowing construction
work to continue in bad weather conditions
• No internal settlement
• Soil stabilization is the alteration of soil properties to improve
the engineering performance of soils.
• Modification of soil properties is the temporary enhancement
of subgrade stability to expedite construction.
• Stabilization can increase the shear strength of a soil and/or
control the shrink-swell properties of a soil, thus improving the
load-bearing capacity of a sub-grade to support pavements and
• Stabilization can be used to treat a wide range of sub-grade
materials from expansive clays to granular materials.
Let Us Harness A Billion Dollar
Resource That Has Been Wasted