 |
Fly Ash |
DMI Fly Ash is the only
locally produced Class "F" fly ash in California, providing the
highest value in
LEED™ points for sustainable concrete.
Fly Ash is a pozzolan that reacts with available lime in cement
providing more cementitious compounds
and is direct replacement for cement (*).
Performance
value in using Fly Ash in concrete: Fly Ash improves
workability,
durability, better
long term strengths, resistance to freeze/ thaw damage and
reduces permeability,
efflorescence,
shrinkage, thermal cracking,
alkali silica reaction
(ASR) and
sulfate attack in concrete.
Basically using fly ash makes better concrete that is more
economical and better for the environment.
Environmental value in using fly ash in
concrete: For every ton of fly ash used to replace
cement in concrete.
- Enough energy is saved
to provide electricity to an average American home for
24 days.
- The landfill space
conserved equals 455 days of solid waste produced by the
average American.
- The reduction in
CO2 emissions equals 2 months of emissions from an
automobile.
Making
LEED™
points with Fly Ash
- Use of fly ash is also a
means of making points in the increasingly important
LEED™ (Leadership in Energy and Environmental
Design) system of evaluating and rating
buildings, developed by the US Green Building Council (USGBC).
(references from USGBC website
(www.usgbc.org).
- Recycled content in
concrete products (Materials and Resources Credit 4).
The requirements of this credit are
for using materials with recycled content. One point is
awarded if the sum of the post-consumer recycled content
plus one-half of the pre-consumer recycled content
constitutes at least 10% of the total value of the
materials in the project. The value of the recycled
content of a material is the weight of the recycled
content in the item divided by the weight of all
materials in that item, and then multiplied by the total
cost of the item. Supplementary cementitious materials,
such as fly ash, silica fume, and slag cement are
considered pre-consumer. Furthermore, using recycled
concrete or slag instead of extracted aggregates would
qualify as post-consumer. Although most reinforcing bars
are manufactured from recycled steel, in
LEED™, reinforcing is
not considered part of concrete. Reinforcing material
should be considered as a separate item. This credit is
worth 1 point for the quantities quoted above and 2
points if the quantities are doubled to 20% combined
post-consumer plus one-half pre-consumer recycled
content. (references from PCA website
(www.cement.org).
* concrete mix designs
containing fly ash may very between 5%- 90% depending on the
application. Confirm concrete mix designs before using any
admixtures.
|
 |
 |
