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Introduction
Concrete is the most important element for construction industry. The
reason concrete made is to give any shape to build man made environment.
The chemical properties of concrete are water, cement, gravel, sand and air.
The basic procedure to make customary concrete is mixing sand, cement,
gravel (gravel is made by putting larger rock into rock crusher that crushes the
rock to specific sizes) and accede to dry with air, this progression called
cement hydration procedure. If we turn back to history, concrete has been
using since 12,000,000 BC. Concrete is basically man made stone, that can
shaped in any form to construct environment. Concrete is indeed the most
used man-made material in the world, nearly three tons used once a year for
each man, woman and child. Twice as much concrete is used around the
world than the total of all other building materials, as well as wood, steel,
plastic and aluminum. None of these further resources can substitute concrete
in terms of effectiveness, price and performance for most purposes. Though
all properties of concrete coming from nature, but still it has some impact on
environment when it is exposed to environment. That environmental exposure
condition might be mild, moderate, severe, very-severe or extreme level.

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Types of concrete
There are a lot of different kinds of concrete, below mentioned are some of
the few major concrete types that are widely used in construction industry.
1. Dry Ready Mix
This type usually comes in a bag containing all necessary components in it
except for water. It is usually used in Home Improvement stores and repairs.
If you follow the manufacturer’s instructions, this type of concrete is nearly
foolproof meaning it is most suitable for indoor repairs and improvements.
This mix has proven to be the most expensive compared to others even
though for small projects, ready mix can be more cost effective.
2. Ready Mix
This type of concrete is harder to find compared to dry ready mix. As the
name suggest it is ready to use meaning it already has water added to it.
Mostly kept in a trailer with a rotating drum that mixes the concrete as you go.
This type of concrete is much more expensive compared to the one above as
it may cost you other small expenses such as transportatio0n costs etc.
Even though it may sound convenient, it can have its disadvantages such as
you must buy a car, which can mix this, concrete and transport it.
Above are sample pictures of Dry Ready mix concrete from different
manufacturing companies.

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3. Bulk Dry Materials
This type of concrete is the best option for large projects. It involves you
buying your own bulk material and mixing it yourself. You can manage the
strength of the concrete. Bare in mind there is a cost of delivery of the bulk
material.
4. Transit Mix
Highly used by contractors. It comes premixed and ready to use. It is time
saving as you can do one large pour at once.
Properties Of Concrete
When water and cement are mixed together, a chemic process of hydration
takes place and the concrete takes about 2hours to change from plastic to
solid.
As curing continues, concrete continues to strengthen, as most of its strength
has been proven practically to come from the curing environment.
In the first 10 days, the concrete shouldn’t be allowed to dry-out. As the
chemical reaction takes place, heat is given off, sometimes known as ‘’Heat of
Hydration”

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Uses of concrete
We can separate concrete by its usage. There are few categories we can
define based on concrete use, such as: Cast-in-place concretes, decorative
purpose, making fiber cement, making green roof, building design, white
topping.
For heavy construction, concrete also very popular. For instance bridge,
culvert, high-rising building etc.
Various kind of concrete made shape used for decorative purpose.
Concrete used for heavy construction, like we can see in the picture.

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Different uses we can find:
 Getting the strong structure.
 Concrete has sound blocking ability
 Resists insects
 Resists disaster
This is house in USA showing that during the Tornado
How it sustain.

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Environmental Impacts of concrete
Concrete is made with four basic components, those are water, cement,
gravel, sand. All the components we can find from nature without effecting
environment less, but the making of cement do bring some harm to the
environment; let’s look at what are those impacts:
 Need huge amount of natural energy
Kilning process of cement actually need lots of natural energy, that is basically
bad for our environment. A single cement kiln can burn more than a million
tires (vehicle tire) a year. Yet we need coals to produce faster and better
quality of cement.
Remedy: The waste fuel, used motors oil, cleansing solution, scrap tires can
be used to save the energy.

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 CO2 Discharge:
During the making of cement, there are two different kinds of carbon dioxide
(CO2) emissions. One is burning fossil fuel to operate the kiln. Approximately
3/4 ton of CO2 discharges per ton of cement. The chemical process of
limestone into lime in the cement kiln also produces CO2 with the chemical
formula, (CaCO3 + heat = CaO + CO2). Combining these two sources, for
every ton of cement produced, 1.25 tons of CO2 is released into the
atmosphere where CO2 will bring harm to the Ozone layer.
Remedy: To reduce the CO2, we can use agriculture waste, natural gas,
beside that we can use waste limestone to react less to produce CO2.
 Other Air Emission:
Beside CO2, throughout the making process of concrete it generates
considerable quantities of air-pollutant. It produces lots of dust majority of
which results from the cement production handling raw materials, grinding
cement clinker, and packaging list goes on. This dust is hazardous for human
health.

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Remedy: This part actually very hard to get rid of, but some measure can be
taken, like those labors are working at site, the can wear mask, so that those
dust can’t get in to their lungs.
 Water Pollution:
For washing gravel to reuse or first time have to use pond water, otherwise
river. This washing method also include equipment cleaning is often
discharged into setting ponds or rivers where the solids can settle out. Those
solid most of the time will remain inside the water and capable to damage the
eco-system underwater.
Remedy: Source pond can be man-made, so that without interrupting the
eco-system, the cleaning procedure can be accomplished.

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 Solid Waste:
We can’t just overlook the solid waste of concrete after any construction.
There will always have solid waste remain, when construction is done and if
the solid is not remove from the site of the construction, then it might cause
damage to the eco-system by the surrounded area. Most of the time concrete
is responsible for the solid waste.
Remedy: Recycle process is the best solution to dispose of solid materials.
As soon as construction finishes, we can recycle them and clean the site.