Advance Concrete technology topic

1. Waste Material Based Concrete

2. What is waste material based
Concrete?
• A concrete that made using agro, urban and
industrial waste.
• They may be used as binder material, as
partial replacement of conventional Portland
cement or directly as aggregates in their
natural or processed states.

3. Waste Material Based Concrete
• Three types of wastes
• Organic Waste
• Inorganic Waste (Urban Waste)
• Industrial Waste

4. Organic Waste
• It is Plant originated namely saw dust, coconut pith,
rice husk, wheat husk, groundnut husk, etc.
• Rice Husk:
• Produced in rice mills each tonne of paddy produces
about 200 Kg of husk.
• Its bulk density is only 100 to 150 kg/cum.

5. Rice Husk
• It used as an aggregate for making light weight
concrete which is mainly suitable for making precast
blocks and slabs for walls and partitions.
• The ground reactive rice husk ash can be blended with
OPC to produce satisfactory hydraulic acid resistance
cements.
• More resistance to acid environment.
• When mixed with sand and lime in suitable proportions
with an appropriate quantity of water can be used to
cast bricks having density 1400-1600 kg/cum. And
compressive strength of 5-6 Mpa with water
absorption is 15-20%.

6. Inorganic Waste (Urban Waste)
• The inorganic wastes which are hard, particularly, the demolition waste
such as broken concrete, broken bricks and crushed glass can used to
produce concretes of requisite strength and durability.
• Broken or Recycled Concrete:
• Recycled concrete is the simply the old concrete that has been removed
from buildings, foundations, pavements and other structures and crushed
to the specified size.
• Recycled aggregate is used in production of concrete.
• This kind of concrete widely accepted for pavements, base and sub-base
courses and to some extend for foundation purpose.
• The lean concrete produced using recycled aggregate resulted in a saving
the cost of construction up to 30%.

7. Broken Brick Aggregate Concrete:
• It is obtained as rejected over burnt or damaged
bricks in brick works and at construction sites.
• It is used in concrete for foundation in light buildings,
flooring and walkways.
• Broken brick aggregate may also be used in
lightweight reinforced concrete floors.

8. Industrial Wastes
• Blast Furnace Slag:
• Produced during large quantities during production of iron &
steel.
• The granulated slag can be used in the manufacture of slag
cement.
• Blast furnace slag cements contain slag up to 60%, hence
there is considerable reduction in the rate of heat evolution
and a significant increase in the resistance to chemical attack.

9. Coal Ash from Power Station
• The main by-product is fly ash or pulverized fuel ash.
• Its proportion is generally limited to 30% in situation where
early strength is important.
• The low rate of heat evolution makes fly ash useful in mass
concrete.
• The fly ash concrete has resistance to sulphate attack.
• On the other hand fly ash reduces the the rate of
development of strength and increases drying shrinkage and
creep strains.

10. Industrial Wastes
• Red Mud Aggregate:
• It is by product of resulting from the production of
alumina from bauxite by bayer’s process is known as
red mud.
• Concrete made with this aggregate have more
compressive, tensile and flexural strengths than
gravel.

11. Silica-fume Concrete
• It is a by product of the reduction of high purity quartz with
coal in electric arc furnaces in the production of ferro-silicon
metal.
• It is efficient pozzolanic material.
• It suitable for high water cement ratio about 0.55 and higher.
• 1Kg of Silica Fume can replace 3 to 4 Kg of cement in concrete
without changing the compressive strength of aggregate.
• Ultra high strength concrete (80 to 125 MPa) is now possible
for field placeable concrete with silica-fume additive.
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