| 1 |
Enhances
Concrete Workability: (Click Here to know
more…): The “ball-bearing”
effect of fly ash particles creates a lubricating action when concrete
is in its plastic state. This creates benefits in: |
| (i)
|
Ease
of Pumping
|
Pumping
requires less energy and longer pumping distances are possible.
|
| (ii)
|
Improved
Finishing
|
Sharp,
clear architectural definition is easier to achieve, with less worry
about in-place integrity. |
| (iii)
|
Reduced
Bleeding
|
Fewer
bleed channels decrease permeability and chemical attack. Bleed
streaking is reduced for architectural finishes. |
| (iv)
|
Reduced
Segregation
|
Reduced
Segregation
|
| 2
|
Increasing
Concrete
Performance: In its hardened state, fly ash
creates additional benefits for concrete, including:
|
| (i)
|
Higher
Strength
|
Fly
ash continues to combine with free lime, increasing compressive
strength over time. |
Click Here to
know more… |
| (ii)
|
Decreased
Permeability
|
Increased
density and long term pozzolanic action of fly ash, which ties up free
lime, results in fewer bleed channels and decreases permeability
|
Click Here to
know more |
| (iii)
|
Increased
Durability
|
Dense
fly ash concrete helps keep aggressive compounds on the surface, where
destructive action is lessened. Fly ash concrete is also more resistant
to attack by sulfate, mild acid, soft (lime hungry) water, and
seawater. |
Click Here to
know more |
| (iv)
|
Reduced
Sulfate Attack
|
Fly
ash ties up free lime that can combine with sulfates to create
destructive expansion. |
Click Here to
know more |
| (v)
|
Reduced
Corrosion |
By
decreasing concrete permeability, fly ash can reduce the rate of
ingress of water, corrosive chemicals and oxygen — thus
protecting steel reinforcement from corrosion and its subsequent
expansive result. |
.
|
| (v)
|
Reduced
Efflorescence
|
Fly
ash chemically binds free lime and salts that can create efflorescence,
and dense concrete holds efflorescence producing compounds on the
inside. |
Click Here to
know more |
| (vi)
|
Reduced
Shrinkage
|
The
largest contributor to drying shrinkage is water content. The
lubricating action of fly ash reduces water content and drying
shrinkage. |
.
|
| (vii)
|
Reduced
Heat of Hydration
|
The
pozzolanic reaction between fly ash and lime generates less heat,
resulting in reduced thermal cracking when fly ash is used to reduce
portland cement. |
Click Here
to know more |
| (viii)
|
Reduced
Alkali Silica Reactivity
|
Fly
ash combines with alkalis from cement that might otherwise combine with
silica from aggregates, causing destructive expansion.
|
Click Here to know more |
| (ix) |
Increased Resistance to Freezing
and Thawing
|
Click Here to know more |
|
3
|
Environmental
Benefits:
|
| (i)
|
Conserves
natural resources |
Using
recovered fly ash conserves natural resources by eliminating the need
to produce new raw materials. . |
| (ii)
|
Conserved
Landfill Space
|
Conserving
landfill space by utilizing fly ash is an obvious environmental
benefit. Just 1 ton of
fly ash use avoids landfill requirement corresponding to 455 days of
solid waste produced by an average American.
|
| (iii)
|
Reduces
greenhouse gas emission |
Fly
ash use can also significantly
decrease greenhouse gas emissions. When fly ash is used to replace
cement, it reduces the need for cement production —
a highly energy-intensive process that also creates significant amounts
of greenhouse gases.
Reducing cement production reduces greenhouse gas emissions on almost a
ton for ton basis. Production
of one ton of cement emits about one ton of carbon dioxide. In many
circumstances, a ton of fly ash can be used to displace a ton of cement.
Experts estimate that cement
production accounts for about 5 percent of carbon dioxide emissions
from human sources. If all of the fly ash generated in the United States
each year were used to replace cement in producing concrete, the
reduction in carbon dioxide released because of decreased cement
production would be equivalent to eliminating 25 percent of the
world’s motor vehicles. . |
