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| Materials
of Construction : |
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| Concrete : |
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Concrete is a construction material that consists,
in its most common form, of Portland cement, construction
aggregate and water.Concrete does not solidify
from drying after mixing and placement; the water
reacts with the cement in a chemical process known
as hydration. This water is absorbed by the cement,
which hardens, bonding the other components together
and eventually creating a stone-like material.Concrete
is used more than any other man made material
on the planet. It is used to make pavements, building
structures, foundations, motorways/roads, overpasses,
parking structures, brick/block walls and footings
for gates, fences and poles.
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| Wood : |
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Wood is derived from woody plants, notably trees
but also shrubs. Wood from the latter is only
produced in small sizes, reducing the diversity
of uses.In its most common meaning, "wood"
is the secondary xylem of a woody plant, but this
is an approximation only: in the wider sense,
wood may refer to other materials and tissues
with comparable properties. Wood is a heterogeneous,
hygroscopic, cellular and anisotropic material.
Wood has been used for millennia for many purposes,
being many things to many people. One of its primary
uses is as fuel. It is also used as a material,
for making artworks, boats, buildings, furniture,
ships, tools, weapons, and more. Wood has been
an important construction material since humans
began building shelters, and remains in common
use today. Construction wood is commonly known
as lumber in North America and timber elsewhere.
Wood may be broken down and reconstituted into
chipboard, engineered wood, hardboard, medium-density
fibreboard (MDF), oriented strand board (OSB),
paper or used to make other synthetic substances.
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| Rock(Stone) : |
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The mining of rocks for their metal ore content
has been one of the most important factors of
human advancement. Humanity's advancement has
been decided by the kind of metals available from
the rocks of a region. The prehistory of civilization
is classified into the stone age, iron age, and
bronze age. Rocks have been and continue to be
used to construct buildings and infrastructure.A
rock is a naturally occurring aggregate of minerals
and/or mineraloids. Rocks are classified by mineral
and chemical composition, by the texture of the
constituent particles and by the processes that
formed them. These indicators separate rocks into
igneous, sedimentary and metamorphic. They may
also be classified according to grain size, in
the case of conglomerates and breccias or in the
case of individual stones.
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| Steel : |
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Steel is a metal alloy whose major component is iron, with
carbon content between 0.02% and 1.7% by weight. Carbon is
the most cost effective alloying material for iron, but many
other alloying elements are also used. Carbon and other elements
act as a hardening agent, preventing dislocations in the iron
atom crystal lattice from sliding past one another. Varying
the amount of alloying elements and their distribution in
the steel controls qualities such as the hardness, elasticity,
ductility, and tensile strength of the resulting steel. Steel
with increased carbon content can be made harder and stronger
than iron, but is also more brittle. The maximum solubility
of carbon in iron is 1.7% by weight, occurring at 1130°
Celsius; higher concentrations of carbon or lower temperatures
will produce cementite which will reduce the material's strength.
Alloys with higher carbon content than this are known as cast
iron because of their lower melting point. Steel is also to
be distinguished from wrought iron with little or no carbon,
usually less than 0.035%. It is common today to talk about
'the iron and steel industry' as if it were a single thing;
it is today, but historically they were separate products.
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| Glass : |
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Glass is a uniform
material of arguable phase, usually produced when the viscous
molten material cools very rapidly to below its glass transition
temperature, without sufficient time for a regular crystal
lattice to form. The most familiar form of glass is the Silica-based
material used for household objects such as light bulbs and
windows.Glass is a biologically inactive material that can
be formed into smooth and impervious surfaces. Glass is brittle
and will break into sharp shards. These properties can be
modified or changed with the addition of other compounds or
heat treatment.
The most obvious characteristic of ordinary glass is that
it is transparent to visible light (not all glassy materials
are). This transparency is due to an absence of electronic
transition states in the range of visible light, and because
ordinary glass is homogeneous on all length scales greater
than about a wavelength of visible light. Glasses used for
making optical devices are categorized using a six-digit glass
code, or alternatively a letter-number code from the Schott
Glass catalogue. For example, BK7 is a low-dispersion borosilicate
crown glass, and SF10 is a high-dispersion dense flint glass.
The glasses are arranged by composition, refractive index,
and Abbe number.
Glass is sometimes created naturally from volcanic magma.
This glass is called obsidian, and is usually black with
impurities. Obsidian is a raw material for flintknappers,
who have used it to make extremely sharp knives since the
stone age. Collecting obsidian from national parks and other
locations may be prohibited by law in some countries, but
the same toolmaking techniques can be applied to industrially-made
glass.
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| Drywall : |
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Drywall, also
commonly known as gypsum board, plasterboard , or rock lath,
and sheetrock is a common manufactured building material used
globally for the finish construction of interior walls and
ceilings.A drywall panel is made of a paper liner wrapped
around an inner core made primarily from gypsum plaster, the
semi-hydrous form of calcium sulphate (CaSO4.½ H2O).
The plaster is mixed with fiber, foaming agent, various additives
that increase mildew and fire resistance, and water and is
then formed by sandwiching a core of wet gypsum between two
sheets of heavy paper or fiberglass mats. When the core sets
and is dried, the sandwich becomes rigid and strong. |
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| Straw-bale construction : |
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Straw-bale construction
is a building method that uses straw bales as structural elements,
insulation, or both. It is commonly used in natural building.
It has advantages over some conventional building system because
of its cost and easy availability, and its high insulation
value.
Straw bales offer excellent insulation. At R 2.7 per inch,
an eighteen-inch wide bale equals R-48. One California study
indicated that such a "super-insulated" straw
bale home could save as much as 75% of heating and cooling
costs! This translates to direct dollar savings for the
homeowner, and a corresponding reduction in the use of fossil
fuels and CO2 emissions.Construction costs can also be reduced
when building with straw bales. They are cheap to buy and
easy to build with. Stacked like huge bricks, straw bale
wall systems can be erected quickly without much building
experience and few power tools. In a "barn-raising"
type party, it's common for all the straw bale walls in
a modest size structure to be erected in a single day.Building
with bales can also cut down on cutting down trees by reducing
lumber used in typical "stick frame" construction.
Straw is available wherever grain crops are grown, and is
annually renewable. In fact, it's considered an agricultural
waste product, and in many parts of the world is simply
burned in the fields. The millions of tons which go up in
smoke every year cause a great deal of air pollution. It
makes sense to bale this nuisance, and turn it into an energy-efficient
resource.Those concerned with indoor air quality also appreciate
straw bale buildings for their "breathability."
A non-toxic product itself, bales allow a gradual transfer
of air through the wall, bringing fresh air into your living
environment, especially when combined with a natural plaster.
And you can forget about neighborhood noise, too. Straw
bales are so sound proof, one Nebraska pioneer family was
found playing cards in their kitchen, oblivious to the roar
of a tornado which had just blown through the town.
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| Adobe : |
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Adobe is a natural
building material composed of sand, sandy clay and straw or
other organic materials, which is shaped into bricks using
wooden frames and dried in the sun. It is similar to cob and
mudbrick. Adobe structures are extremely durable and account
for the oldest extant buildings on the planet. Adobe buildings
also offer significant advantages in hot, dry climates; they
remain cooler as adobe stores and releases heat very slowly.
Buildings made of sun-dried earth are common in the Middle
East, North Africa, and in Spain, but adobe had been in
use by indigenous peoples of the Americas in the Southwestern
United States, Mesoamerica, and the Andean region of South
America for several thousand years, although often substantial
amounts of stone are used in the walls of Pueblo buildings.
This method of brickmaking was imported to Spain in the
16th century by Spaniards who had traveled to Mexico and
Peru.
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| Brick : |
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Brick is an
artificial stone made by forming clay into rectangular blocks
which are hardened, either by burning in a kiln or sometimes,
in warm countries, by sun-drying.Bricks are used for building
and pavement. In the USA, brick pavement was found incapable
of withstanding heavy traffic, but it is coming back into
use as a method of traffic calming or as a decorative surface
in pedestrian precincts.
Bricks are also used in the metallurgy and glass industries
for lining furnaces. They have various uses, especially
refractory bricks such as silica, magnesia, chamotte and
neutral (chromomagnesite) refractory bricks. This type of
brick must have good thermal shock resistance, refractoriness
under load, high melting point, and satisfactory porosity.
There is a large refractory brick industry, especially in
the United Kingdom, Japan and the U.S.A..
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| Rammed earth : |
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Rammed earth
construction, also known as pisé de terre or simply
pisé, is an age-old building method that has seen a
revival in recent years as people seek low-impact building
materials and natural building methods. Traditionally, rammed
earth buildings are common in arid regions where wood is in
scarce supply.
Walls are constructed from a mixture of earth that has
suitable proportions of sand, gravel and clay sometimes
with an added stabilizer. Traditional stabilizers such as
lime or animal blood were used to stabilise the material,
but cement has been the stabilizer of choice for modern
times.In modern variations of the method the rammed earth
walls are constructed on top of conventional footings or
a reinforced concrete base, sometimes with extra ground
insulation from a horizontal layer of styrofoam. Some builders
also add coloured oxides or other items such as bottles
or pieces of timber to add variety to the structure.
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| Ferrocement : |
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Ferrocement
is both a method and a material used in building or sculpture
with cement, sand, water and wire or mesh material - often
called the thin shell. Thin shell ferrocement offers strength
and economy and has a broad range of applications which include
home building, creating sculptures, or building boats and
ships.
The desired shape is built from a multi-layered construction
of chicken wire, and if needed reinforced with steel wire
or steel bars. Over this finished framework, an appropriate
mixture of cement, sand and water is spread out. During hardening,
the ferrocement is kept moist, to ensure the cement is able
to set and harden. |
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| Aggregate : |
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Aggregate is
the component of a composite material used to resist compressive
stress. For efficient filling, aggregate should be much smaller
than the finished item, but have a wide variety of sizes.
In most cases, the ideal finished piece would be 100% aggregate.
A given application's most desirable quality is usually most
prominent in the aggregate itself; all the aggregate lacks
is the ability to flow on a small scale, and form attachments
between particles. The matrix is specifically chosen to serve
this role, but its abilities should not be abused. |
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| Slipform stone : |
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A reinforced
concrete wall with stone facing in which stones and mortar
are built up in courses within reusable slipforms. It is a
cross between traditional mortared stone wall and a veneered
stone wall. Short forms, up to 60 cm high, are placed on both
sides of the wall to serve as a guide for the stone work.
You place stones inside the forms with the good faces against
the form work and pour concrete in behind the rocks. Rebar
is added for strength, to make a wall that is approximately
half concrete and rebar and half stonework. The wall can be
faced with stone on one side or both sides. With slipforms
it is easy for a novice to build free-standing stone walls. |
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| Asphalt : |
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Asphalt is a
sticky, black and highly viscous liquid or semi-solid that
is present in most crude petroleums and in some natural deposits.
Asphalt is composed almost entirely of bitumen. There is some
disagreement amongst chemists regarding the structure of asphalt,
but it is most commonly modeled as a colloid, with asphaltenes
as the dispersed phase and maltenes as the continuous phase.There
are two forms commonly used in construction: rolled asphalt
and mastic asphalt. Rolled asphalt is one of the forms of
road surfacing material known collectively as blacktop; another
form is the macadam, including both tar and bituminous macadams.
The terms asphalt and tarmac tend to be used interchangeably
in common usage, although they are distinct products. |
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| Structural insulated panel : |
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Structural insulated
panels, SIPs, are a composite building material. They consist
of a sandwich of two layers of structural board with an insulating
layer of foam in between. The board is usually Oriented Strand
Board and the foam either polystyrene foam or polyurethane
foam.SIPs allow the application of an internal and external
structural skin and thermal insulation to a building in one
stage, offering efficiency benefits. They are commonly used
in conjunction with modern timber framed buildings. |
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