Preetham Builders one of the Best Builders in Madurai are developing Gated Community Luxury villas and flats.

This gated community ” BRINDAVAN HOMES ” is being developed in Kochadai Madurai, a fast developing area in Madurai.

This gated community ” BRINDAVAN HOMES ” contains both apartments, flats, Individual Bungalows and Villas.

Individual bungalowas are for sale in Brindavan Homes.

Villas are for sale in Brindavan Homes.

Flats are for sale in Brindavan Homes.

 

With abundant water supply and green environments this gated community ” BRINDAVAN HOMES ” with individual buildings and Bungalows present a Resort like feelings.

Numerous Building materials are required for construction. Basic materials being fine aggregates, Coarse aggregates, cement, steel and bricks.

Suitability of various types of cement:

Selection of cement based on suitability for various concreting environment is important for durability considerations of structures. Thus, making wise choice of cement type for particular construction site, prevents structure from deteriorating and saves much repair and rehabilitation cost later. Following are the suitability of various cements for different environmental conditions:

i) 33 grade OPC:

It is used for normal grade of concrete upto M-20, plastering, flooring, grouting of cable ducts in PSC works etc. The fineness should be between 225 and 280.

ii) 43 grade OPC:

  • It is the most widely used general purpose cement. For concrete grades upto M-30, precast elements.
  • For marine structures but C3A should be between 5 – 8%.

iii) 53 grade OPC:

  • For concrete grade higher than M-30, PSC works, bridge, roads, multi-storied buildings etc.
  • For use in cold weather concreting.
  • For marine structures but C3A should be between 5 – 8%.

iv) Portland Slag Cement (PSC)

It is OPC + granulated slag cement. It gives low heat of hydration. The slag should be more than 50%and upto 70%. It is used for;

  • Marine and off shore structures- very high chloride and sulphate resistant.
  • Sewage disposal treatments works
  • Water treatment plants
  • Constructions which are expected to be attacked by dissolved chlorides and sulphate ions.
  • Should be mainly used for all future structures.

v) Portland Pozzolana Cement:

IS:1489(part-I ) -1991 (using flyash). It gives low heat of hydration and reduces the leaching of calcium hydroxide. This cement should be used only after proper evaluation. This should be tested as per IS:1489 (Pt I) – 1991. It is used for:

  • hydraulic structures-dams, retaining walls
  • Marine structures
  • Mass concrete works- like bridge footings
  • under aggressive conditions
  • Masonry mortar and plastering.

let us see Fine aggregates.

Aggregate most of which pass through 4.75 mm IS sieve is known as fine aggregate. Fine aggregate shall consists of natural sand, crushed stone sand, crushed gravel sand stone dust or arable dust, fly ash and broken brick (burnt clay). It shall be hard, durable, chemically inert, clean and free from adherent coatings, organic matter etc. and shall not contain any appreciable amount of clay balls or pellets and harmful impurities e.g. iron pyrites, alkalies, salts, coal, mica, shale or similar laminated materials in such form or in such quantities as to cause corrosion of metal or affect adversely the strength, the durability or the appearance of mortar, plaster or concrete.

The sum of the percentages of all deleterious material shall not exceed 5%. Fine aggregate must be checked for organic impurities such as decayed vegetation humps, coal dust etc.

1. Silt Content Test of Sand:

The maximum quantity of silt in sand shall not exceed 8%. Fine aggregate containing more than allowable percentage of silt shall be washed so as to bring the silt content within allowable limits.

Deleterious materials in sand: Sand shall not contain any harmful impurities such as iron, pyrites, alaklies, salts, coal or other organic impurities, mica, shale or similar laminated materials, soft fragments, sea shale in such form or in such quantities as to affect adversely the hardening, strength or durability of the mortar. The maximum quantities of clay, fine silt, fine dust and organic impurities in the sand / marble dust shall not exceed the following limits:

(a) Clay, fine silt and fine dust when determined in accordance within not more than 5% by mass in IS 2386 (Part-II), natural sand or crushed gravel sand and crushed stone sand.

(b) Organic impurities when determined in colour of the liquid shall be lighter in lighter in accordance with IS 2386 (Part –II) than that specified in the code.

SILT CONTENT TEST FOR SAND

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Silt content test

The permissible silt content in sand (fine aggregate) must not exceed the values as specified in the standards. However, this method can only be used for natural sand, it should not be used for crushed rock sand.

The apparatus required for this test is only 250 ml glass measuring cylinder.

The silt content determination by volume is done in the following manner:

  1. The glass cylinder is filled with salt-water solution (concentration of the solution will teaspoon full of common salt for every 570 ml) upto 50 ml mark.
  1. Add sand until the level of the sand is upto 100 ml mark.
  2. Add further salt-water solution till 150 ml mark is reached.
  3. Place the palm on the mouth of the glass cylinder and shake it vigorously.
  4. Place the cylinder on hard levelled surface and tap it all round so that sand is leveled.
  5. Wait for three hours for silt to settle on top of sand.
  6. Measure the thickness of the silt layer and the height of the sand. The silt content can be calculated as follows:

Silt (%) by volume = [(Thickness of silt layer/ Height of sand + Silt) x 100 %]

If silt content by weight exceeds 3% then washing of sand is necessary. After conducting few tests, a co-relation can be developed for silt layer thicknesses at various intervals of time. The silt content at 10 minutes can be fixed as inspection criteria.

3. BULKING OF SAND

When sand is damp, the water coating on the surface of each sand particle causes separation of particles from one another due to surface tension. This causes sand to bulk. Bulked sand occupies more volume and hence if volumetric measuring is done while proportioning it, bulking correction is necessary.

The bulking test is done as follows:

  1. The sand is filled, in loose condition in a box of measured height (H cm).
  2. The box is then flooded with water and rodding is done to make the sand settle and consolidate. Care should be taken that sand does not overflow during the flooding and compaction.
  3. The sand is then leveled in the box and the drop in height is measured (h cm).
  4. Bulking is calculated as: Bulking % = h/H x 100%

Dry sand occupies the same volume as fully saturated sand. The bulking will vary from load to load and day to day depending on the fineness of sand and its surface moisture content. It is there-fore, very essential to make bulking corrections by checking the actual bulking of sand proposed to be used by volumetric batching for mortar or concrete.

Jalli:

Concrete is a mixture of cementious material, aggregates and water. Aggregate is a inert filler in concrete  which accounts for 60 – 80% of concrete weight. Aggregate is called coarse aggregate if the aggregate size is more than 4.75mm.

The aggregate strength is decided upon by shape and texture of aggregates, gradation, moisture content and its specific gravity.

Surface texture is the pattern and relative roughness or smoothness of the aggregate particle. Surface texture is important in developing the bond between the aggregate  and cement.

A rough surface develops a strong bond.