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1. General Seminar On
CELLULAR LIGHTWEIGHT CONCRETE
By
KISHORE KUMAR PUNNA
20265A0112
DEPARTMENT OF CIVIL ENGINEERING
MAHATMA GANDHI INSTITUTE OF TECHNOLOGY (A)
(Affiliated to Jawaharlal Nehru Technological University, Hyderabad)
Approved by AICTE, New Delhi
Sponsored by Chaitanya Bharathi Educational Society
Gandipet , Hyderabad – 500 075
www.mgit.ac.in

2. CONTENTS
• Abstract
• Introduction
• Density Range
• Manfacturing Process
• Advantages Of Cellular Lightweight Concrete
• Strength
• Application
• Conclusion
• References

3. ABSTRACT
Now-a-days there are so many technologies involved in the recent development of concrete.
Of these, Cellular Lightweight Concrete (CLC) is one of the recent emerging technology in
making concrete. By using this type of concrete, we have found so many advantages when
compared to the normal conventional concrete. This study mainly focused on making
cellular light weight concrete based on fly ash. Fly ash is considered as one of the waste
industrial product that cannot be easily disposed. It solves the problem of disposal of fly ash
and at the same time it reduces the cost of the construction. Therefore, fly ash based CLC is
considered as environment friendly sustainable material produced with least energy
demand.
The density is considerably reduced by using fly ash based cellular lightweight concrete
than normal concrete and at the same time, the strength is not affected by appropriate design
mix. When we use this type of concrete we achieve large volume by less amount of
concrete. The manufacturing process of this type of concrete does not involve any high cost
techniques. Manufacturing process of CLC is similar to normal concrete and in this
additionally foam generating machine is used. We are committed to expanding and sharing
the knowledge, experience and techniques of cellular light weight concrete, and to
promoting its ever wider use.

4. INTRODUCTION
Fly Ash Based Cellular Light Weight Concrete
• It is a version of lightweight concrete that is produced like normal concrete under ambient
conditions. It is produced by initially making a slurry of Cement +Sand + Fly Ash (constituting 26% -
34 % content) + water.
• A cellular concrete is a lightweight product consisting of Portland cement, cement-silica, cement-
pozzolan, lime-pozzolan, lime-silica pastes or pastes containing blends of these gradients and having
homogeneous void or cell structure, attained with gas-forming chemicals of foaming agents.
• Fly Ash as a new additional constituent in its manufacture. Fly ash can constitutes more than 25%
(ranging between 26% to 33%) of the solid material constituents of CLC mixes for different density
outputs.

6. • Fly-ash- a nuisance waste product from thermal power plants - as an over 25 %
constituent material. This CLC can be produced in a density range of 400 kg/m3 to 1,800
kg/m3, with high insulation value and a 28-day cube crushing strength of up-to 275 kg/cm2.
• It is not only found a productive use of a waste industrial product, but incorporation of fly
ash also saves nearly 40% on cement content, otherwise needed for the corresponding
Cement and Sand only mixes, thereby also leading to substantial reduction in the cost of
manufacture.
• Normally the density of the cellular light weight concrete ranges from 400 kg/m3 to 1,800
kg/m3
• Cellular Light Weight Concrete based housing is fire proof, termite proof, thermally
insulated, sound proof, environment friendly.

8. DENSITY RANGE
This Cellular Lightweight Concrete (CLC) can be produced in a wide range of densities from 400
kg/m3 to 1,800 kg/m3 to suit different applications: -
• The lower densities of 400 –600 kg/m3 are ideal for thermal insulation applications. CLC’s fire,
termite, water-proof-ness, termite-resistance, very low water absorption and environment
friendliness. This range is also used in laying sound insulating layer over structural slabs of
intermediate floors in high-class hotels and institution buildings to minimize transmission of noise
between lower and upper floors. It can also be used as a filling in depressions in bathrooms or other
floors due to up-stand beams etc. It make a far superior alternative to the commonly used
Thermocole, glass wool, woodwool etc.

9. • The medium density range 800-1000 kg/m3 is utilized for making pre- cast blocks for non-load-bearing
walling masonry in framed structures. The size of blocks for the party/external walls may be 500x250x200 mm
and the internal partition blocks may be 500x250x100 mm nominal size, although any desired size as per
requirements, may be produced.
• The high density range from 1200kg/m3 (Crushing strength 65 kg/cm2) to 1800 kg/m3 (Crushing strength 250
kg/cm2) is structural grade material utilized for:-
(a)In-situ casting of structural (load-bearing) walls and roofs of low rise individual or group housing schemes./
(b) Manufacture of reinforced structural cladding or partitioning panels.
(c) Making pre-cast blocks (500x250x200/100 mm) for load- bearing walling masonry for
low rise buildings.

10. MANFACTURING
PROCESS
The manufacturing process of
cellular light weight concrete
involves the following steps:

11. (a) Providing a mixture of slurry of Cement, Sand, Fly Ash and water.
(b) Pouring the mixture into a form or mold of the intended
concrete product.
(c) curing the poured mixture.
(d) demolding the concrete product and
(e) utilizing the concrete product.
• In this process, first the wet mix slurry consists of fly ash, cement, sand and water is
either poured or pumped into assembled moulds of blocks or formwork of reinforced
structural elements or poured onto flat roofs for thermal insulation or for filling of voids.
• The second way is to introduce gas or foam to the concrete mix to produce cellular
lightweight concrete.
• The foam produced using Foam Generator is stable for a time duration far beyond the
final setting time of Cement, thereby creating permanent voids in the finally hardened
mass thus imparting lightness.

12. • The entrapped air bubbles are very fine in size and segregated from each other, because of
which the water absorption of the material is less.
• The foam imparts free flowing characteristics to this slurry due to ball bearing effect of foam
bubbles, enabling it to easily flow into all corners. It levels and compacts in the moulds/forms by
itself, without requiring any kind of external vibration or compaction.

13. ADVANTAGES OF CELLULAR LIGHTWEIGHT
CONCRETE
• CLC being the typical concrete, it keeps gaining strength with time, so long as some moisture is
available in the surroundings. It is therefore as weatherproof, termite resistant, fireproof and durable
as any other concrete.
• Cellular Lightweight Concrete is an environment friendly sustainable material produced with least
energy demand.
• Moreover CLC consumes a waste industrial product - Fly Ash - as one of its basic constituent
materials thereby helping to reduce environmental pollution.
• It substitutes use of burnt clay bricks, which are wasting precious agricultural soil and need energy
for baking and kiln smoke vitiate the atmosphere.
• Thinner walls in the case of CLC result in higher Carpet/Plinth area ratio (106% to 107%) in
comparison to brick alternative.

14. • Cellular light weight concrete, even in the structural grade densities, is nearly three times
thermally more efficient than brick or mud walls. Therefore even thinner walls of CLC are
better thermal comfort than single bricks/ dense concrete block walls.
• Being industrialized system the speed of construction is very fast and the work can be
executed mostly with the help of unskilled labour.
• Production of CLC is cheaper than normal concrete since fly ash, available free constitutes
over 25% of its raw material contents.
• Better strength to weight ratio .
• Reduction of dead load resulting in saving of steel & cement and reduction in foundation size.
• Better Acoustics and thermal insulation (Air conditioning requirement is considerably
reduced).
• Saving in consumption of mortar and Higher Fire Rating.
• Resistance to fungus, vermin and rot .

15. STRENGTH
•The 28 day compressive
strength of cellular light weight
concrete varies from 18 Mpa to
20 Mpa depending upon the
density of the mix.
•The flexural strength of is, in
general, between 1/5 and 1/3 of
the compressive strength.
•CLC can be produced in a
density range of 400 kg/m3 to
1,800 kg/m3, with high
insulation value and a 28-day
cube crushing strength of up-to
275 kg/cm2.

16. APPLICATIONS
The wide range in densities and consequently their different thermal and structural properties, make
CLC equally suitable for use: -
1.As reinforced load-bearing in-situ walls and roofs in Low Rise Buildings.
2.Even block-work (made from pre-cast blocks produced at the project site or obtained from a pre-
casting plant) can also be used for load-bearing low rise constructions.
3. Non load-bearing internal or external walls in High Rise Buildings.
4.Thermal Insulation of building roofs and walls & roofs of cold storage.
5.Filling of depressions in Toilets, floors etc.

17. CONCLUSION
The deliberations above conclusively establish, that air cured fly-ash based Cellular light-weight
concrete to be a far superior alternative to factory made aerated concrete or manmade light-weight
aggregate blocks. This CLC is even a better alternative to ordinary clay bricks for walling masonry.
The long term stability at low temperatures and potential corrosive effects on cellular light weight
concrete must be completely understood. The influence of admixtures and aggregates on strength of
CLC is of particular interest and is currently being investigated. Moreover, CLC has other diverse
applications and properties, some of which cannot be offered by the conventional alternatives Above
all, it is an environment friendly and energy efficient material, which is the need of the day. It is
therefore, no surprise that more and more builders are progressively opting for this material in their
constructions.

18. REFERENCES
• Dhengare, Sagar W., Ajay L. Dandge, and H. R. Nikhade. "Cellular Lightweight
Concrete." Journal of Advance Research in Mechanical & Civil Engineering 2.4 (2015): 19-22.
• Bhandari, P. S., and Dr KM Tajne. "Cellular Lightweight Concrete Using Fly Ash." International
Journal of Innovative Research in Science, Engineering and Technology (An ISO 3297: 2007
Certified Organization) Vol 3 (2014).
• Virendra sahu,Pallavi Dandwate and Bhushan Bakalkar. “Study On Cellular Lighteight Concrete.”
International Journal Of Trend In Reasearch and Development,Volume 5(6).

19. THANK YOU