A Brief description on Light weight Construction Materials and Production of foamed concrete.

1. LIGHT WEIGHT CONSTRUCTION
MATERIALS
UNIT-1
LECTURE - 3
Brig. S.K. Sharma (Retd.)
Pro Vice Chancellor and Professor
Department of Civil Engineering,
The Northcap University, Gurgaon
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2. 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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3. 1. CONCRETE MIX PROPORTIONS
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)
PRODUCTION OF FOAMED CONCRETE
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4. 2.Typical mix proportions for Foamed concretes
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5. 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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6. 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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7. 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. 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, 03:25
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9. Thank You
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