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LASSENITE SR POZZOLAN
   
Lassenite SR Overview
The
term pozzolan is derived from the ancient term Pozzolana, which
refers to a volcanic ash (finely divided siliceous and aluminous
material) found on the slopes of Mt. Vesuvius, adjacent to the
small town of Pozzouli near the bay of Naples.
The
Romans discovered that certain finely divided siliceous and
aluminous materials when mixed with lime, produced cements having
hydraulic properties, and up until two centuries ago these
mixtures were the only cements that possessed the properties of
hardening under water. The durability of natural pozzolan was
proven in the construction of the Roman Empire buildings such as
the Coliseum and the Aqueducts, which are still standing 23
centuries later. Earlier structures have been found in what was
Mesopotamia, still intact now 40 centuries old, as well as,
Alumina Silicate cast material found in the Mediterranean Sea,
have withstood centuries of salt-water attack.
The
concrete bunkers in Iraq (old Mesopotamia) that could not be
destroyed in the “91 Gulf War were built using natural pozzolan
from Italy. In the United States the use of pozzolan with Portland
cement concentrates dates back to 1910 in the construction of the
Los Angeles Aqueduct. Other early examples of the use of imported
pozzolan include the construction of the San Francisco Bay Bridge
Piers and the Friant Dam.
Lassenite-SR is a natural siliceous (amorphous) mineral, made from
the layers of diatoms and volcanic tuffs of Northern California's
Cascade Range. Lassenite Type N Pozzolan conforms to
ASTM C-618, Federal Specifications #SS-C-1960/5 and
CSA-CAN-A266-3M (Canadian) specifications for Type N (Natural)
Pozzolan and meets specification requirements of the NRC for use
on Nuclear Reactor Program, California Department of Water
Resources, Corp of Engineers, U.S. Water and Power Resources
Services, Cal Trans, Pacific Gas and Electric; Idaho Power and
Arizona Public Service for hydraulic structures and power plants;
Bechtel Corporation for hydraulic structures; municipalities for
waste water treatment and transportation facilities.
Advantages of Lassenite SR Pozzolan:
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Strongly Resists Sulfate and Corrosive Attack
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Improves Durability and Rebar Seal
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Excellent Pumpability and Finishability
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Curtails Efflorescence
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Low Permeability
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Reduces Segregation and Bleeding
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Compatible with All Admixtures
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Low Heat of Hydration
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Increased Strength
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Lighter Weight Slurries
Lassenite SR Testimonials
“A suitable pozzolan used in appropriate amounts substantially
increases resistance of concretes to sulfate attack…….Most
effective are the pozzolan’s high in opal.”
Raymond E. Davis, Director,
Engineering Materials Laboratory, University of California,
Berkeley
“Those that are high in opal, such as diatomaceous earths and
opaline shales, are much more effective than those high in glass,
such as pumicites and fly ashes.”
Raymond E. Davis, Director,
Engineering Materials Laboratory,
University of California, Berkeley
“From the results of many laboratory investigations and of field
applications of pozzolans, it can be concluded that the addition
of suitable pozzolanic materials in appropriate amounts to
Portland cement concrete would be of benefit in nearly all types
of construction. The effectiveness in improving workability,
reducing bleeding and segregation, and in lessening the cracking
tendency of concrete would indicate that these materials should be
used far more widely than they are at present.”
Milos Polvika, Professor of
Civil Engineering,
University of California, Berkeley
“Workability was the biggest advantage of using pozzolan. It really
aided the pumping. I’ve never seen such a workable mix as this
one.”
Dave Schmidt, Laboratory
Chief, Bureau of Reclamation
Pacheco Tunnel Project
“Another important benefit of using pozzolan was that we got
significantly less shrinkage cracking than we would have using a
straight cement mix. This is due to the low heat of hydration.” |
