Ferrocement is a thin layer of cement mortar reinforced with closely spaced layers of wire mesh. It has a higher ratio of steel to cement than conventional concrete. Ferrocement is stronger and more flexible than concrete alone. It can be manufactured through various techniques like hand plastering, semi-mechanized processes, centrifuging, and guniting. Ferrocement has high strength, ductility, impact resistance, and is lightweight and durable. Its applications include water tanks, boat building, manhole covers, pipes, and prefabricated structures.

1. DEFINITION
• Ferrocement is a type of thin wall reinforced
of hydraulic
concrete commonly constructed
cement mortar reinforced with closely spaced
layers of continuous and relatively small size wire
mesh. The mesh may be made of metallic or other
suitable materials.”
- ACI Committee

2. FERRO-CEMENT
In 1943 Pier Luigi Nervi tested and
presented in his paper, a new structural
elements, an extremely thin plate of
concrete made layers of small diameter
wire mess and cement mortar with sand
used as binder.
Ferrocement differs from conventional
concrete in that there is a higher ratio of
steel to cement mortar.

3. FERRO-CEMENT
• Ferrocement has many properties of steel and yet it will not rust.
Although it looks and feels like concrete it can flex without cracking.
• By altering the steel/cement ratio we actually produce a material,
which is superior to either steel or cement separately.

4. MATERIAL USED IN FERROCEMENT
1.CEMENT MORTAR
2.REINFORCEMENT
A. Skeleton Steel
B. Wire Mesh

5. CEMENT MORTAR
• Ordinary portland cement and fine aggregate matrix is used
• Particle size of sand should not more than 2.36mm and less than
1.18mm
• More than 2.36mm particle can make the mortar porous and particles
less than 1.18mm requires more water to impermeable structure.
• Sand occupies 60 to 75% of the volume of the mortar

6. SKELETON STEEL
• The skeleton steel frame is made conforming exactly to shape of
the structure and the geometry
• The steel rods is spaced at 70 to 100 mm apart and diameter may
vary from 3 to 8 mm
• This is used for holding the wire mesh in shape of the structure and
position
• In case where higher stresses may occur, the mild steel bars are
used.

7. WIRE MESH
• The wire mesh consists of galvanized wire spaced at 6 to 20 mm centre to
centre and 0.5 to 1.5 mm diameter
• The wire mesh may be of the shape as welded wire mesh or square
woven wire mesh, Hexagonal wire or mesh expanded metal etc
• The yield strength of plain wires used in fabric should no be more than
415 MPa and 500 MPa for deformed wires.
• The steel content may vary between 300 kg to 500 kg per cubic metre of
mortar.

8. WIRE MESH
Hexagonal and Welded Wire Woven Wire Mess

9. TECHNIQUES OF MANUFACTURING
1. Hand plastering
2. Semi mechanised process
3. By centrifuging
4. Guniting

10. HAND PLASTERING
• In this method the control thickness is difficult and the minimum
thickness of section that can be casted works out to be 2cms.
• The strength obtained by this system will be lower compared to
other methods
• Units can be cast by this process and used in situations where for
other improved methods do not exist.
• These units can be used for pipes , storage structures and
gasholder unit

11. SEMI MECHANISED PROCESS
• This system is termed as semi-mechanised because the mould can
be rotated to facilitate dashing of mortar
• The uniformity of this system is also better than the earlier system
• Better compaction can be obtained by means of a straight edge
pressed against the inner mould in this method
• Local, un-skilled people can handle this process

12. CENTRIFUGING METHOD
• Centrifuging process is adopted for the fabrication of concrete
cylindrical units
• Because of good compaction the ferrocement pipe cast by
centrifuging can be used as pressure pipes

13. GUNITING
• The process of geniting can be adopted for applying the mortar to
the wire mesh system.
• This appears to be suitable process or mass production of
ferrocement prefabricated units.
• If This process applies with experienced gunman, it can give
compacted and uniform surface

14. PROPERTIES OF FERRO-CEMENT
• High tensile strength and stiffness
• Better impact and punching shear resistance
• Undergo large deformation before cracking or high deflection
• Low weight
• Low w/c ratio produces impermeable structures
• It is very durable, cheap and versatile material

15. ADVANTAGES
• High ductility
• High resistance to cracking width
• Ability to undergo large deflection
• Improved impact resistance and toughness

16. ADVANTAGES
• Good fire resistance
• Good impermeability
• Low strength to weight ratio
• Low maintenance costs

17. DISADVANTAGES
• Hard to do welding
• Binding mesh and rod along can be time consuming.
• Number of labour will be higher
• There is excessive shrinkage due to higher cement content
• Constant curing isneeded for a period of 7 days to avoid any
shrinkage cracks.

18. APPLICATIONS OF FERRO-CEMENT
• Ferro cement can be used for casting domestic overhead tanks.
These tanks will be cheaper than any other type of material tanks
• Ferro cement tanks can be used in villages as gas holding
• This material has been used widely for boat building in U.S. U.K.,
and New Zealand
• Thus the use of ferro cement manhole covers is becoming very
popular

19. APPLICATIONS OF FERRO-CEMENT
• Pre-fabricated roof units
• For the production of pressure pipes
• For casting curved benches for gardens, parks, and open cinema
theatre

20. THANK YOU