Cements Flashcards
is a type of cement that is used as the binding agent in concrete. It is made by heating limestone and clay to high temperatures in a kiln.
portland cement
when was Portland cement invented and by who
invented in 1824 by Englishman Joseph Aspdin and patented in 1825.
where did the name portland cement come from
The name comes from its similarity to the stone quarried on the Isle of Portland, Dorset, England.
Portland cement is one of the most widely used high-carbon cement in use today because it has a large amount of silica that makes up __% of its weight
13%
major reason why portland cement is so widely used.
its low heat of hydration
The limestone version of portland is called
“caliche”
the clay version of portland cement is called
“portland”
The raw material that is commonly used in the manufacturing of portland cement mainly consists of
lime, silica, alumina and iron oxide
Two types of materials are necessary for the production of portland cement
one rich in calcium calcareous, such as limestone, chalk, etc., and one rich in silica (argillaceous) such as clay.
known as cement rock, found in New
Jersey and the Lehigh district of
Pennsylvania.
argillaceous limestone
Usual products for general construction. There are other types of
this cement, such as white, which contains less ferric oxide, oil-well cement, quick-setting cement, and others for special uses.
TYPE I - REGULAR PORTLAND CEMENTS
Use where moderate heat of hydration is required or for general
concrete construction exposed o moderate sulfate action. The
heat evolved from these cements should not exceed 295 and 335
1/g after 7 and 28 days respectively
TYPE II - MODERATE HEAT OF HARDENING AND SULFATE RESISTING PORTLAND CEMENTS
Made from raw materials with a lime- to-silica ratio higher than
that of Type I cement and are ground finer than Type I cements.
They contain a higher proportion of tricalcium silicate (CS) than
regular portland cements.
TYPE III - HIGH EARLY STRENGTH (HES)
contain a lower percentage of tricalcium silicate (C3S) and
tricalcium aluminate (C3A), thus lowering the heat evolution.
TYPE IV - LOW HEAT PORTLAND CEMENT
composition or processing resist sulfates better than other four
types. It is used when high sulfate resistance is required.
TYPE V - SULFATE RESISTING
PORTLAND CEMENTS
a special cement which has air bubbles introduced in the
cement or concrete that provides the space for expansion of
minute droplets of waters in the concrete due to freezing and
thawing and protects from cracks and damage of concrete
AIR ENTRAINMENT
a material which is not cementitious in itself but becomes admixture with lime. It is with the
same strength with the Portland cement. Its
advantage is that it resists the corrosive action
of saline solutions and seawater much better.
pozzolans
manufactured by fusing a mixture of limestone and bauxite. It is characterized by a very rapid rate of development of strength and superior resistance to seawater and sulfate-bearing water.
high alumina cements
silica-filled, chemically setting silicate cements withstand all concen- trations of inorganic acids except hydrofluoric. They are not suitable at pH values above or in the presence of crystal-forming systems.
silicate cements
- homogeneous plasticized filled sulfur ingots possessing low coefficients of expansion.
- are resistant to nonoxidizing acids and salts but should not be used in the presence of alkalies, oils, greases, or solvents.
sulfur cements