Unit-1 Lecture 3 - Light Weight Construction Materials by Brig. S.K. Sharma

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UNIT-1LECTURE - 3

• LIGHT WEIGHT CONSTRUCTION MATERIALS

Brig. S.K. Sharma (Retd.) Pro Vice Chancellor
and Professor Department of Civil Engineering,
The Northcap University, Gurgaon
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INDEX

• PRODUCTION OF FOAMED CONCRETE
• CONCRETE MIX PROPORTIONS
• TABLE OF MIX PROPORTIONS FOR FOAMED CONCRETE
• WATER-CEMENT RATIO
• BATCHING OF MATERIALS
• FOAM GENERATION
• MIXING AND TRANSPORTATION
• PLACING OF FOAMED CONCRETE
• CURING OF FOAMED CONCRETE

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1. CONCRETE MIX PROPORTIONS
PRODUCTION OF FOAMED CONCRETE

• Based on current knowledge, the preliminary
  proportions of ingredients for typical foamed
  concretes are given in next slide. The guidelines
  in the table are intended to provide an idea of
  the possible proportions of the mix and resulting
  strength characteristics. These mix proportions
  are in no way restrictive and there can be
  numerous designs.
• Video Production from foam concrete blocks (CLC
  blocks) 

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2.Typical mix proportions for Foamed concretes
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3. WATER-CEMENT RATIO

• On an average, a water-to-cement ratio of 0.40 to
  0.45 is normally used. Additional water is added
  as a content of the foam, thereby bringing the
  total water-to-cement ratio up to the order of
  0.6.
• In general, when the amount of foam is increased,
  for lighter densities, the amount of water can
  therefore be decreased. However, the
  water-to-cement ratio should be kept as low as
  possible in order to avoid excessive shrinkage.
• Tests should be carried out on the mix so that
  the resulting foamed concrete will have a flow
  able, creamy consistency. Some properties of
  ingredients are
• Sand Clean washed sand of
  maximum nominal size of 0.75 mm
• Cement Ordinary Portland
  cement
• Foam generated 1 cub m/liter of a typical
  concentrate

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• 4. BATCHING OF MATERIALS Appropriate quantities
  of sand and cement are batched, and an amount of
  water required for the mix to be flow able is
  added and materials are mixed thoroughly in a
  mixing plant fitted with foam-generating plant
  and pumping units.
• 5. FOAM GENERATION Foam concentrate, also called
  foaming agent is poured into a container
  typically at one per cent of the container volume
  and the container is then filled with clean
  water, referred to as dosing water.

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• 6. MIXING AND TRANSPORTATION In case a
  ready-mixed concrete, agitator is used for
  mixing, all the raw materials are metered into
  the agitator (according to mix design
  specification) and with the agitator turning at a
  high speed, a predetermined batched volume of
  foam is introduced into the agitator.
• 7. PLACING OF FOAMED CONCRETE Properly designed
  foam concrete has a stable bubble structure and
  can be pumped to normal heights without loss of
  entrained air. Typically, foam concrete produced
  and delivered at the site can be pumped up to a
  height of 60m.

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• 8. CURING OF FOAMED CONCRETE The compressive
  strength of the foamed concrete can be
  significantly increased through an effective
  curing process. Moist curing is highly effective
  in increasing compressive strength. Some of the
  commonly used methods of curing are outlined
  below
• AIR CURING This is the simplest and most popular
  method of curing. It is slow, but acceptable as
  it enables a turn around of moulds every 24 hours
  on an average, depending on the ambient
  temperature.
• STEAM CURING In case of factory production a
  precast foamed- concrete panel or slab is cured
  by applying steam to the underside of the mould
  in order to develop an early strength and obtain
  a relatively fast turn-around of moulds.
• Video YouTube, Smart Bricks A new way to
  build, 0325

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• Thank You