Weather United States of America, Kansas City United States of America, Kansas City +8°C

Home Building | Home Improvement | Intereior Design | Kitchen Designs | House Plans

Home Building Ideas

Raw Material for Cement Concrete

Raw Material for Cement Concrete
July 16
07:19 2014
Cement Concrete cement concrete Raw Material for Cement Concrete Raw Material for Cement Concrete

Cement Concrete

The following points should be kept in mind while collecting raw materials for cement concrete in work.

Cement

Cement is the most important raw material used in of a building. You can ensure the quality of ‘Cement’ with following guidelines.

  • Cement should be factory manufactured of a reputed brand and it should not be from plant manufactured.
  • Cement bag bears date of manufacturing
  • One cement bag has 50 Kg. weights
  • Cement bags are not hand stitched
  • Consignment must have identification mark on the package
  • Cement is packed in bags of synthetic jute or polypropylene bags
  • Factory manufactured instead of plant manufactured
  • Bears manufacturer’s name or his trade mark , grade and type of cement
  • Not older than six weeks from the date of manufacturing
  • It should be stored in moisture proof store on pukka platform
  • Not partially set due to moisture or have small lumps in bags
  • Not pressed or have lumps due to high pressure of stack, having more than 10 to 12 bags
  • The bags are not torn by side and stitched later on.

Fine Aggregates

Fine aggregate/ coarse sand consists of natural sand, crushed stone sand or crushed gravel stone dust. The quality of the sand has more impact on the strength of the structure in spite of the quantity of the cement used.

  • If there is more silt in coarse sand, the strength of cement mortar is reduced from 1%to30%.
  • If you take best quality coarse sand, it will give maximum strength. You can ensure the quality of Fine aggregate with following guidelines.
  • It should be hard, durable chemically inert, clean and free from organic matter, not containing any appreciable amount of clay balls or pellets and other harmful impurities i. e. alkaline, salt, mica, decayed vegetation, lumps etc.
  • It should be passed through I. S. Sieve 4.75 MM. It should have the finest modulus 2.50 to 3.50 and silt contents should not be more than 4%. Coarse sand should be either river sand or pit sand; or combination of the two.
  • It should be obtained from Badarpur Sand or Stone dust obtained by crushing hard stones or gravel. It should also be obtained from river bed such as Tajewala, Dadupur sand.
  • The sand particle should be coarser and have minimum silt contents. The silt contents should not be more than 4%.
  • It should be according to the size/specification and free from mud, clay, organic matter and other foreign matters.

Coarse Aggregates

Coarse Aggregate or bazri consists of natural occurring stones (crushed, uncrushed or broken). The quality of the Coarse Aggregate or bazri has more impact on the strength of the structure in spite of the quantity of the cement used.

  • If you take best quality coarse sand, it will give maximum strength. You can ensure the quality of Coarse Aggregate with following guidelines.
  • It should be hard, strong, dense, durable, and clean.
  • It must be free from veins, adherent coatings and injurious amounts of disintegrated pieces, alkali, vegetable matter and other deleterious substances.
  • It should be roughly cubical in shape. Flaky pieces should be avoided. It should confirm to IS: 2383(I).
  • The coarse aggregate is clean, hard, non porous, free from lumps of clay and vegetable matter.
  • Water absorption of aggregate is not more than 10 % of its weight after 24 hours immersion in water.
  • Angular and roughly cubicle particles are ideal. River gravels make the best coarse aggregate.
  • Aggregate is chemically inert material.
  • The maximum quantity of deleterious materials should not be more than 5% of the weight of the aggregate when determined in accordance with IS: 2386(I).

Water

Water is one of the most important elements in construction but people still ignore quality aspect of this element. The water is required for preparation of mortar, mixing of cement concrete and for curing work etc. during construction work. The quality and quantity of water has much effect on the strength of mortar and cement concrete in construction work.

It has been observed that certain common impurities in water affect the quality of mortar or concrete. Many times in spite of using best material i.e. cement, coarse sand, coarse aggregate etc. in cement concrete, required results are not achieved. Most of Engineers/Contractors think that there is something wrong in cement, but they do not consider quality of water being used.

  • The water used for mixing and curing should be clean and free from injurious quantities of alkalis, acid, oils, salt, sugar, organic materials, vegetable growth and other substances that may be deleterious to bricks, stone, concrete or steel.
  • Potable water is generally considered satisfactory for mixing.
  • The PH value of water should be not less than 6.
  • Salty water should not be used in any case since it will destroy the steel.
  • Presence of salt in water such as Calcium Chloride, Iron Salts, inorganic salts and sodium etc. are so dangerous that they reduce initial strength of concrete and in some cases no strength can be achieved. There is rusting problem in steel provided in RCC.
  • Presence of acid, alkali, industrial waste, sanitary sewage and water with sugar also reduce the strength of concrete.
  • Presence of silt or suspended particle in water has adverse effect on strength of concrete.
  • Presence of oil such as linseed oil, vegetable oil or mineral oil in water above 2 % reduces the strength of concrete up to 25%.
  • Presence of algae/vegetable growth in water used for mixing in cement concrete reduce of the strength of concrete considerably and also reduce the bond between cement paste and aggregate.

More from Building Construction

0 Comments

No Comments Yet!

There are no comments at the moment, do you want to add one?

Write a comment

Write a Comment

Your email address will not be published.
Required fields are marked *

Translation


 Edit Translation

Advertisement

Subscribe to the Newsletter

Get latest posts and updates from Homeey.com
Name
Email *
error: Content is protected !!