WHAT
IS FERROCEMENT?
Ferrocement is a form of reinforced concrete using closely spaced multiple layers of mesh and/or small diameter rods completely infiltrated with, or encapsulated in, mortar.
•
In 1940
Pier Luigi Nervy, an Italian engineer, architect and contractor, used
ferrocement first for the construction of aircraft hangars, boats and buildings
and a variety of other structures.
•
It is a
very durable, cheap and versatile material.
Highly versatile form of reinforced concrete.
It’s a type of thin reinforced concrete construction, in which large
amount of small dia wire meshes uniformly through out the cross section.
Mesh may be metal or suitable material.
Instead of concrete Portland cement mortar is used.
Strength depends on two factors quality of sand/cement mortar mix and
quantity of reinforcing materials used.
COSTITUENTS
OF FERROCEMENT
- Cement
- Fine Aggregate
- Water
- Admixture
- Mortar Mix
- Reinforcing mesh
- Skeletal Steel
- Coating
- Cement: The cement should be fresh, of uniform consistency and free of lumps and foreign matter.
- Fine Aggregates: Normal weight fine aggregate clean, hard, and strong, free of organic impurities and deleterious substances and relatively free of silt and clay.
- Water: Potable water is fit for use as mixing water as well as for curing ferrocement structures.
- Admixture : Chemical admixtures used in ferrocement serve purposes OF water reduction, with strength and reduces permeability; air entrainment, which increases resistance to freezing and thawing; and suppression of reaction between galvanized reinforcement and cement
- Reinforcing mesh: The function of the reinforcing wire mesh in the first instance is to act as a lath providing the form and to support the mortar in its green state.
- Skeletal Steel :Skeletal steel is generally used for making the framework of the structure upon which layers of mesh are laid
- Coating :vinyl and epoxy coatings were found to be the most successful organic coatings
CONSTRUCTION
•
The
desired shape using ferrocement may be built from a multi-layered construction
of chicken wire or other steel mesh.
•
Over
this finished framework, an appropriate mixture of cement, sand and water is
spread out
•
A
considerable amount of time may be necessary for the material to fully cure and
reach its final strength
CHALLENGES
•
MORTAR
MIXING: The mortar must be dense
and compact. A general mix is 1 part cement, 2 parts sand. Water is added
roughly 0.4 parts water by weight
•
MORTAR
APPLICATION: Fingers and trowels
are used for mortar placement in the mesh structure. Mortar guns are not
recommended
•
CURING. It should be kept moist at least 7 days and
protected from the sun and wind.
COMPOSITE PROPERTIES
•
Ferro cement has very high tensile strength- to
weight ratio and a superior cracking behavior
•
Low w/c
ratio produces an impermeable structures
•
Ferro cement structures have high durability,
less shrinkage, and low weight.
FERROCEMENT COMPOSITES
HAVE:
•
Thickness 6 to 50 millimeters
•
Steel cover 1.5 to 5 millimeters
•
Ultimate tensile strength up to 34 MPa
•
Allowable tensile stress up to 10 MPa
•
Modulus of rupture up to 55MPa
•
Compressive strength up to 28 to 69MPa
ADVANTAGES
•
Its basic raw materials are readily available in
most countries.
•
It can be fabricated into any desired shape.
•
The skills for ferrocement construction can be
acquired easily.
•
Heavy
plants and machinery are not involved in ferrocement construction.
•
Being labor intensive, it is relatively
inexpensive in developing countries.
•
It is
widely used due to the low self weight, durability & versatility.
DISADVANTAGES
•
Structures made of it can be punctured by
collision with pointed objects.
•
Corrosion of the reinforcing materials due to
the incomplete coverage of metal by mortar.
•
Large no
of labors required
•
It is difficult to fasten to ferrocement with
bolts, screws, welding and nail etc...
•
Tying rods and mesh together is especially
tedious and time consumin
APPLICATIONS
•
HOUSING:Ferrocement houses utilizing
local materials such as wood, bamboo or bush sticks as equivalent steel
replacement have been constructed in Bangladesh
& Indonesia
•
MARINE :Ferro cement can be effectively
used for various water supply structures like well casings for shallow wells,
water tanks, sedimentation tanks, slow sand filters and for sanitation
facilities like septic tanks, service modules and sanitary bowls
• RURAL
ENERGY: In Thailand and India, biogas digesters and biogas
holders have been constructed with ferrocement which lead to a considerable
cost reduction.
•
Miscellaneous Applications: Ferro cement
is proving to be a technology that can respond to the diverse economic, social
and cultural needs of man.
Recent Applications
•
Residential
and Public Buildings.
•
Industrial
Structures.
•
Agricultural
structures.
•
Transportation
Structures.
•
Cost Effectiveness of
Ferro-cement Structures
•
The type
of economic system.
•
Type of
applications.
•
Relative
cost of labor.
•
Capital
and local tradition of construction procedure.
•
Doesn’t
need heavy plant or machinery.
•
Low cost
of construction materials.
WORKS CARRIED OUT
AL AMEEN
COLLEGE
 |
LEELA PALACE
•
Al-Ameen
College, Bangalore
•
Leela Palace Bangalore
•
Sai Super Specialty
Hospital, Whitefield, Bangalore
•
Kolkata Commercial Plaza,
Kamaraj Road, Bangalore
•
Dome Residence for I.
K Hospital,
•
Alipur
Sai temple, Kanakapura Road.
CONCLUSION
•
Ferro-cement come into wide spread use only in
the last two decades and still in its infancy.
•
Sufficient design information is available and
adequate field experience has been acquired to enable safe design and
construction of Ferro-cement structures.
•
Whether it can economically compete with
alternate materials depends on the type and location of application.
•
However, innovative structures in
different parts of the world have clearly indicated the unique, unmatched
properties of this material and therefore the vast potential waiting to be
explored
REFERENCES
•
www.appropedia.org/Original:Ferrocement_Applications_in_Developing_Countries_9"
•
Ferrocement
and Laminated
Cementitious Composites by Antoine E. Naaman
Cementitious Composites by Antoine E. Naaman
•
www.concure.com
•
www.fasiformsystem.com
•
www.smithconcretenc.com
•
www.wikipedia.com
•
Journal
of Ferrocement ISSN 0125-1759 CODEN JOFEDZ.
•
Book
Review of Ferro-cement and Laminated Cementatious by Batson.G (2000).
•
Economical
Construction Techniques for Walls by P.K Adlakha.
•
Ferro-cement
Application in the Developing Countries by M.Nervi.
•
Www,
forintek.ca/acessed 12th Feb2007.
•
www,Architectureforhumsnity.com/acessed
10th Feb2007
Yes, It's a challenging work for civil engineers. But this information are helpful to civil engineer at construction time. They are easily understand their work or their flow and apply it.
ReplyDeleteconcrete reinforcing
Construction is always a challenge for engineers to work in any condition,going through your views many of them can be solved easily.
ReplyDeleteCement mortar mix