CEMENT
- Cement is mostly used as a binding agent
in concrete, which is used to build
houses, roads, schools, hospitals, dams,
ports, and other types of buildings, as
well as floors, stairs, driveways, pool
decks, and other things like tables,
sculptures, and bookcases.
- The term cement derives from the Latin
word "caementum", which meant "stone
chippings".
HISTORY OF CEMENT
- Ancient Greece and Rome – the
materials used were lime and a volcanic
ash. The volcanic ash used was mined
near what is now the city of Pozzuoli,
Italy, was particularly rich in essential
aluminosilicate minerals, giving rise to
the classic pozzolana cement of the
Roman era. To this day the term
pozzolana, or pozzolan, refers either to
the cement itself or to any finely divided
aluminosilicate that reacts with lime in
water to form cement.
- 1756 - hydraulic lime was first developed
by John Smeaton when he was called in
to erect the Eddystone Lighthouse off the
coast of Plymouth, Devon, England.
- 1800 - Around 1800, a new kind of
material was developed in both England
and France. This material was made by
burning certain types of rock -
specifically, nodules of limestone that
had a high clay content. This process
resulted in a substance that could be
used in building construction, and it was
similar in some ways to the natural
cement that had been developed earlier.
Shortly after this, in the United States,
another material was developed using a
similar process but with a different kind
of rock - a naturally occurring substance
called "cement rock" was burned to
create the material. Both of these new
materials were significant developments
in the construction industry, and they
helped to pave the way for the
development of modern cement.
- 1824 – The invention of Portland cement
is usually credited to Joseph Aspdin, who
lived in Leeds, Yorkshire, England. Aspdin
developed this new type of cement in
1824 by combining limestone and clay in
a laboratory using a synthetic process. He
obtained a patent for this material and
named it Portland cement, possibly
because when the cement hardened it
had a similar appearance to Portland
stone, which is a specific kind of
limestone used in building construction
in England. Aspdin's invention of
Portland cement was a significant
development for the construction
industry, and it paved the way for the
development of modern cement-based
building materials.
- 20th Century – manufacture of cement
spread worldwide
- 2019 – China and India became the world
leaders in cement production followed
by Vietnam, United States, and Egypt.
COMPOSITION OF CEMENT
• Limestone
- Limestone is the primary component of
cement and is the source of calcium
oxide (CaO). Calcium oxide is a key
ingredient that provides the cement with
its binding properties. Limestone is
typically quarried and crushed into small
pieces before being mixed with other
components.
• Clay
