The most widely used material for construction is Concrete for all-important structural components of a building ( Footings, columns, beams, and slabs) and the walls which are made of bricks and plaster. The main ingredients in concrete, mortar, and plaster are cement, Aggregates sand, water, steel reinforcement, etc.
CEMENT :
Cement is a water-based binder used to bind other building materials together. It is used in the production of mortar and concrete during the construction process. The reason cement is one of the most common construction ingredients among others is its ability to hold the structure together.
Types of Cement used in house construction:
Cement used for building are basically of three types:
Ordinary Portland Cement (OPC): A combination of clinker and gypsum.
Portland Slag Cement (PSC): A combination of good quality blast furnace slag (from the iron and steel industry) with clinker (which makes OPC) and gypsum.
Portland Pozzolana Cement (PPC): A combination of fly-ash (from thermal power plants) with clinker and gypsum.
Ideal cement for house construction:
The best cement for house construction is blended cement-like PSC and PPC. But please note that good quality blended cement-like PSC and PPC will take more time to set. However, the final strength after 28 days will be much more.
Features of good quality cement:
Reduced water requirement.
Improved workability.
Less permeable to moisture.
Improved resistance to acids and chlorides.
Reduced heat of hydration.
Easier to finish.
Reduced shrinkage.
Reduced leaching problems because it is low on free lime.
Selecting the right cement for your house:
It is very important that you use only a reputed brand of cement. Good brands of cement may cost 3 to 5% more but offer quality, consistency, and reliability as well as 10 to 20% greater strength characteristics. Cement accounts for a mere 14 to 16% of the total expenditure on your home. So, using cheaper cement gives you little overall savings but a greater risk to the strength of your building.
The right way of using cement in construction:
The cement must be added to the concrete and mortar in a precise, consistent manner. improper water-cement ratios cause lower strengths, shorter design life, and lower durability.
The current Market rate of Cement per bag various from INR 350 to 400.
MANUFACTURED SAND:
Manufactured sand also called M-sand is being promoted by the government as a cheaper alternative to natural sand because of the scarcity of good quality natural sand. Experts vouch that manufactured sand is not only a viable alternative to natural sand but superior in many ways. Mortars and concrete using M-sand as fine aggregate are superior when compared to those using natural sand. The ready-mix concrete manufacturers are already using manufactured sand.
Advantages of manufactured sand:
The appropriate quality of rock suitable for construction can be used for manufactured sand;
There is no clay content in M-sand;
M-sand is scientifically graded to comply with BIS specifications;
Customizing the different grades depending upon the need of construction ensures consistent quality throughout the construction cycle.
M-sand is half the price of natural sand.
There are few reputed Manufacturers who make the M sand had classified into three grade 1. Concrete Sand (Price Varies from INR 900-950/ Ton) 2. Masonry Sand (Prices varies from INR 1000-1050) 3. Plastering Sand (Prices Caries from INR 1400-1500/ Ton)
AGGREGATES (Coarse and Fine)
Technically, known as coarse aggregates, stone chips are a major ingredient of concrete, giving it strength and solidity. The quality of concrete depends very much on the characteristics of aggregates used.
Features of good quality aggregates:
Stone chips should be angular or round, not flat or flaky.
They should not contain marks or layers of any other color.
They should be free from mud and other impurities, which are harmful to concrete. It is advisable to wash the stone chips before mixing to make it free from dust, dirt, and mud.
They should be well-graded, which means these should contain sizes from 5mm to 20mm in proper proportion so that voids are minimal.
Selecting the right aggregates for house construction:
Aggregates should be well-graded and should contain sizes from 5mm to 20mm in proper proportion so that voids are minimal. This will make strong and durable concrete.
Aggregates prices various from 25-28/ Cuft
REINFORCING STEEL:
Reinforcing steel contributes to the tensile strength of concrete. Concrete has low tensile, but high compressive strength. The tensile deficiency is compensated by reinforcing the concrete mass through the insertion of plain or twisted mild steel bars.
Features of good quality steel:
Steel bars/rods should be reasonably clean and free of rust.
Bars that cannot be easily bent manually or mechanically should be rejected.
Optimum length bars must be chosen to reduce wastage in cutting.
To avoid laps, shorter bars must not be accepted.
Welded lengths of bars should not be accepted.
Selecting the right steel for your house construction:
Both branded and unbranded bars are available. It is wise to buy good brands like JSW, Indus, During construction, ensure that size and the type of steel reinforcement used is exactly as per the engineering design specifications.
Construction steel (TMT) Prices various from 45000-5500/Ton
WATER:
Tips in using water:
You must use only potable water in quality concrete production.
Brackish or salty water must never be used.
Contaminated water will produce concrete and mortars with a lower durability, erratic set characteristics, and inconsistent colour.
BRICKS
For most of the buildings two types of Bricks are used:
Red soil bricks - the size is 9"x4.5"x3". They may be wire-cut or table molded
Cement blocks - the sizes vary. They are of two types: Hollow blocks or solid blocks (Hollow blocks are preferable but nowadays they are not easily available)
Fly ash bricks - are used as an alternative to the regular bricks or cement blocks as they are lighter in weight.
With Hollow and solid cement bricks, you can complete wall construction faster than normal red bricks.
Features of good bricks for construction:
They should show uniform texture and color.
When broken, they must not leave lumps and grit.
Ensure that bricks are not made from saline clay.
Look for proper and uniform burning.
Selecting bricks for house construction:
Bricks may be purchased directly from the brickfields located close to your area to get it at a lower cost. Keep samples for conformity to ordered quality.
Good quality bricks prices various from INR 7-9 /Nos
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