House Construction from conception to completion – II

After learning about the binding material, cement, let’s move ahead towards the other important construction ingredients.

SAND:

Together with cement, sand is another important material in preparation of mortars and concrete. It is therefore important to understand the quality check parameters of this ingredient. The right quality of sand is significant in the durability and performance of the concrete/mortar mixture.

The ideal sand:

Generally, the river sand is considered ideal for construction. However, the practice being environmentally unsafe, companies avoid using river sand and prefer filter sand and manufactured sand over it.

Features of good quality sand:

  • Clear, angular and hard
  • Free from clay, mica, and soft, flaky material
  • Graded – mix of fine, medium and coarse sand
  • Free from contaminants
  • Moisture content should not exceed 7%

Selecting the right sand:

Filter sand is treated to make it better by washing off all the dust particles with water. The different consistency of sand is used for different purposes. For RCC slabs, rough sand can be used whereas for plastering work, it is advisable to use fine sand. Generally, sand should not be sticky when held in hand.

Manufactured sand:

The government is promoting the use of manufactured sand, also known as M-sand,  as it is a cheaper alternative to natural sand. Moreover, construction experts vouch that manufactured sand is superior in many ways. It is observed that mortars and concrete made using M-sand as a fine aggregate are superior as compared to natural sand mixtures. Therefor ready-mix concrete manufacturers are using manufactured sand for better quality product.

Advantages of manufactured sand:

  • No clay content
  • Scientifically graded to comply BIS specifications
  • Consistent quality is assured by customizing different grades as required
  • Cost effective

Sand being a significantly important material in construction work must be chosen and used with proper knowledge.

House Construction from conception to completion – I

“Whatever good things we build end up building us.” – Jim Rohn.

A building is much more than the individual parts that go into it. A quality home allows people to be in the comfort of knowing that their abode is made especially for them, and their needs. The quality of your home, to a large extent, determines the quality of the life of people dwelling in it. And hence, it is important to understand what goes into the construction of your house.

People constructing houses can never be sure of the quality of the materials that the contractor brings to site which eventually impacts the overall construction considerably. The most important structural components of a building construction are the columns-beams-slabs made of concrete and the walls which are made of bricks and plaster.

To help you understand the process from conception to completion, German Plast brings to you another series of articles on the features of the good quality building materials.

CEMENT:

Cement is the binding agent that holds the other ingredients together and therefore plays the most important role in providing strength and durability to any structure. It is used to make concrete for slabs, foundations, beams, columns, and mortar for brickwork, plastering, and flooring.

Types of Cement used in house construction:

  • Ordinary Portland cement (OPC) which is a combination of clinker and gypsum.
  • Portland Slag Cement (PSC) which is a combination of good quality blast furnace slag with clinker and gypsum.
  • Portland Pozzolana Cement (PPC) which is a combination of fly-ash with clinker and gypsum.

Although the blended cement like PSC and PPC take more time to set, they are considered the best cement for house construction. The final strength after 28 days is much more.

Intrinsically, it is difficult to decide upon the quality of any cement since the process of manufacturing is more or less the same for the most. However, there are certain features which distinguish a good quality of cement from the average one.

Features of good quality cement:

  • Reduced water requirement.
  • Improved workability.
  • Less permeable to moisture.
  • Improved resistance to acids and chlorides.
  • The reduced heat of hydration.
  • Easier to finish.
  • Reduced shrinkage.
  • Reduced leaching problems because it is low on free lime.

The color of cement has no relation to the strength characteristics. There is a common myth that darker color cement gives better strength. On the contrary, workers tend to add more sand in the darker color cement than the prescribed ratio which affects the mortar consistency and can cause problems.

The right way of using cement in construction:

Cement must be added to the concrete and mortar in a precise, consistent manner. Too little or too much cement in concrete and improper water-cement ratios results in lower strengths, shorter design life, and lower durability.

Selecting the right cement:

Cement accounts for around 12 to 18% of the total construction cost. Well established brands of cement offer quality, consistency, and durability and also greater strength characteristics. Hence, it is important to use good quality cement.

Cement being the most important ingredient; it is always desirable to use the best cement in constructions. Therefore, the properties of good cement must be considered and examined. Suitable tests can also be performed to ensure the quality of the cement.