Cellular Light

CELLULAR LIGHT-WEIGHT CONCRETE (CLC).

AGARWAL PRATHEEK SHRAWAN KUMAR

(08GE1A0102)

Department of Civil Engineering

BHASKAR ENGINEERING COLLEGE

(Affiliated to Jawaharlal Nehru Technological University, Hyderabad, A.P)

Yenkapally, P.O. Himayathnagar, Moinabad, Hyderabad – 500 075

2012

1

CELLULAR LIGHT-WEIGHT CONCRETE (CLC)

TECHNICAL SEMINAR Report Submitted in partial

Fulfillment Of the requirements for the award of degree of

BACHELOR OF TECHNOLOGY

IN

CIVIL ENGINEERING

BY

AGARWAL PRATHEEK SHRAWAN KUMAR

(08GE1A0102)



(Affiliated to Jawaharlal Nehru Technological University, Hyderabad, A.P.)

Yenkapally, P.O. Himayathnagar, Moinabad, Hyderabad -500 075

2012

2


(Affiliated to Jawaharlal Nehru Technological University, Hyderabad)

Yenkapally, P.O. Himayathnagar, Moinabad, Hyderabad-500 075


CERTIFICATE

Date: 10 TH MARCH 2012

This is to certify that the TECHNICAL SEMINAR entitled CELLULAR LIGHT-WEIGHT CONCRETE (CLC) is a bonafide work carried out By AGARWAL PRATHEEK SHRAWAN KUMAR (08GE1A0102) in partial fulfillment of the requirements for the award of degree of BACHELOR OF TECHNOLOGY in CIVIL ENGINEERING by the Jawaharlal Nehru Technological University, Hyderabad during the academic year 2011-2012

The results embodied in this report have not been submitted to any other University or Institution for award of any degree or diploma.

Smt. RAGHAVA RANI

Head of dept.

3

External Examiner

ACKNOWLEDGEMENT

The satisfaction that accompanies the successful completion of my task would be incomplete without a mention people, who made it possible and whose guidance and encouragement crown all the efforts with success. We would like to express our deep sense of gratitude and extend our best wishes to all people, who guided, inspired and motivated us during this project and given us immense pleasure to acknowledge their cooperation.

We express our deep sense of gratitude to honorable principal Dr.APPALRAO NAIDU, for his valuable guidance.

We are deeply indebted to Smt.RAGHAVA RANI, Head of the Department (CIVIL) for his valuable suggestions and encouragement during the period of mini project.

We would like to thank the faculty members, Department of CIVIL, for the timely help and assistance for the successful completion of this mini project.

Finally we deem it a great pleasure to thank our beloved parents, friends and class mates for their valuable support in course of this mini project.

PRATHEEK AGARWAL SHRAWAN

(08GE1A0102)

4

INDEX

ABSTRACT ------------------------------------------------------------------------------------------------------------ 6

CELLULAR LIGHT WEIGHT CONCRETE ---------------------------------------------------------------------------- 7

DESCRIPTION ----------------------------------------------------------------------------------------------- 7

PERFORMANCE SUMMARY ---------------------------------------------------------------------------------------- 8

Appearance ------------------------------------------------------------------------------------------------- 8

Structural Capability --------------------------------------------------------------------------------------- 8

Durability and moisture resistance ---------------------------------------------------------------------- 9

Toxicity and Breath-ability -------------------------------------------------------------------------------- 9

Applicability ---------------------------------------------------------------------------------------------------------- 10

PRESENTATION HARD COPY ------------------------------------------------------------------------------ ATTACHED

5

ABSTRACT

Cellular Lightweight Concrete (CLC) is one of the recent emerging

technology in making concrete. By using this type of concrete, there

are so many advantages when compared to the normal conventional

concrete. This presentation is mainly focused on making cellular light

weight concrete based on fly ash. Therefore, fly ash based CLC is

considered as environment friendly sustainable material produced

with least energy demand. The presentation also include the

advantages and other benefits of the cellular lightweight concrete in

future construction.

6

Cellular Light-weight Concrete (CLC)

Description

Cellular Lightweight Concrete (CLC) is produced by the mixing of sand, fly-ash cement foam

and water in requisite proportion in ready mix plant or ordinary concrete mixer. The mixed slurry is

then poured into moulds of pre-cast blocks / structural components / assembled form-work of

building elements or over flat roofs for thermal insulation as per I. S.: 6598. It is essentially aircured,

thus can be produced at project site, utilizing equipment and moulds normally in use for conventional

concrete.

The foam is produced with the help of a Foam Generator by using a foaming agent. The foam

contains isolated air bubbles, which creates million of unconnected tiny voids/cells in the mix

resulting in lighter weight of concrete. CLC can be produced in wide range of controlled densities from

400 kg/m3 to 1,800 kg/m3. The density recommended is 1.000kg/m3 (oven-dried) for blocks and

1.200 kg/ m3 to produce prefab elements and walls cast in-situ. CLC has moderate embodied energy

content and performs very well as thermal insulation. Blocks are made to very exacting dimensions

and are usually laid in thin-bed mortar that is applied with a toothed trowel, although more

conventional thick-bed mortar can be used. CLC has a long life and does not produce toxic gases after

it has been put in place. It offers a substantial material savings as little cement and no gravel is used.

7

PERFORMANCE SUMMARY

Appearance

Cellular Light-weight Concrete is very light coloured. The addition of foam into the concrete

mixture creates millions of tiny voids or cells in the material, hence the name cellular concrete.

Although there is no direct path for water to pass through the material, an appropriate coating is

required to prevent water penetrating into the CLC material. The quality of CLC production can be

controlled accurately at the project site, just like Concrete. The surface finish depend upon the

formwork and moulds used during casting.

Structural Capability

CLC, like conventional concrete ages well, increasing its strength by as much as 50% (!)

between 28 and 90 days after pouring, As long as CLC draws humidity from the atmosphere it will

keep on increasing its mechanical properties. Curing takes place within the same period as

conventional concrete. If cast in the evening, the concrete it could be demoulded the next morning.

Curing can be speeded up by heat, steam or chemical (accelerators). CLC is an excellent and

competitive material for low -rise, load-bearing construction and outside walls as well as partitioning

work in multi –storeyed blocks. Thermal properties Air is known to be the best insulation material

available. Air voids, if smaller than 2mm each, consequently increase thermal insulation substantially.

Normal aggregate concrete has a specific thermal conductivity (Lambda) of 2.1 W/mK, compared to

0.405 only for 1200kg/m3 cellular concrete. To offer identical thermal insulation as a 100 mm thick

CLC wall, the equivalent thickness of dense concrete wall would have to be more than 5 times thicker

(i.e. 500 mm) and ten times heavier. Sound insulationDue to its high sound insulating properties it is

used as a sound barrier between suspended structural floors, where its light weight and strength is a

added advantage. Fire and vermin resistanceFire rating of cellular concrete is far superior to that of

brickwork or dense concrete. Just a 100 mm thick wall of 1200 kg/m3 CLC, offers a fire endurance

(heat transmission) of three hours. Moreover, there are no dangerous fumes or spread of fire as

experienced with plywood partitions having rigid (styropore, urethane) insulation material - often the

reason for loss of life of entrapped individuals due to toxic fumes during fires. CLC does not harbour or

encourage vermin.

8

Durability and moisture resistance

CLC, like conventional concrete ages well, increasing its strength by as much as 50% (!)

between 28 and 90 days after pouring, As long as CLC draws humidity from the atmosphere it will

keep on increasing its mechanical properties. As a consequence of closed cellular structure of the

material, the water absorption of CLC is lower, being in the range of 5% to 12%, depending on density.

But it may require a surface protection to resist moisture penetration, affects of very harsh climatic

conditions. Reinforced slabs were produced for tests in CLC of densities between 1000-1400 kg/m3,

where the non-protected reinforcement was covered with 25 mm of cellular concrete. After four

months, tests confirmed there was no corrosion on the 1200 kg/m3 specimen.

Toxicity and Breath-ability

Our protein-hydrolisation based foaming agent warrants high stability of the foam,

successfully withstanding the manifold forces occurring when mixing, conveying (pump-able), casting

and during the hydration process. The foam causes no chemical reaction in the concrete but merely

serves as wrapping material for the air entrapped. It produces no toxic fumes or emission over its

lifetime. Store-life of the foaming agent is guaranteed to be at least 24 months when adhered to

instructions (before its integration into the concrete mixtures). However, CLC is a concrete product,

and similar precautions should be taken as when handling and cutting concrete products. Personal

protective equipment (such as gloves, eye wear, respiratory masks) is required during cutting due to

the fine dust that is produced by concrete products. Sustainability (environmental impacts)

In view the use of flyash 33% (an environment polluting industrial waste) being a major

ingredient of CLC, CLC and this being a good substitute of ordinary clay bricks (which use high energy

and precious agricultural topsoil) the Govt. of India has given special import duty concessions for

specialized equipment. Its low density, good thermal and sound insulation and long life make it a

good choice as a construction material. Buildability, availability and cost This lightweight concrete has

higher consistency due to absence of coarse aggregate (gravel) and a ball bearing effect of the foam

on the concrete is of great advantage for it flows by itself into the moulds and shuttering and any

cavities, thereby doing away with the necessity of compaction or vibration.

CLC is an air-cured lightweight concrete that can be produced at project site, utilizing

equipment and molds normally in use for conventional concrete. Utilizing, the most traditional mixers

and very successful truck mixers to produce cellular concrete, by installing and integrating a foam

9

generator, into the existing concrete or prefab plants, with little investment and maintaining the

production procedures being followed. However, a full range of stationary and mobile equipmentto

produce and precisely dose the foam, through a conveying system feeding sand and cement to a

mixer, with highly effective horizontally operating screw and integrated concrete pump, could be

sourced and setup to increase productivity.

Applicability

The wide range in densities and consequently their different thermal and structural properties make

CLC equally suitable for use: -

• As reinforced load-bearing in-situ walls and roofs in Low Rise Buildings.

• 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.

• Non load-bearing internal or external walls in High Rise Buildings.

• Thermal Insulation of building roofs and walls & roofs of cold storage.

10

PRESENTATION

HARD COPY

11

Documents

Cellular Light