Post on 10-Jan-2023
VISVESVARAYA TECHNOLOGICAL UNIVERSITY
Jnana Sangama, Belagavi, Karnataka-590 014
A PROJECT REPORT ON
“Investigation On Flexural Behaviour of
Ferrocement Panels”
Project report submitted in partial fulfilment of the requirement for
the award of the degree of
BACHELOR OF ENGINEERING
IN
CIVIL ENGINEERING
Submitted by
LEON CHARLES USN:1NH14CV056
C PRASANNA KUMAR USN: lNH15CV031
RAJATH K R USN:1NH16CV088
ROSHAN KUMAR SAH USN:1NH16CV133
Under the guidance of
Dr. NATCHIMUTHU SUBRAMANI
ASSOCIATE PROFESSOR
NEW HORIZON COLLEGE OF ENGINEERING DEPARTMENT OF CIVIL ENGINEERING
BANGALORE-560 103
Outer Ring Road, Kadubeesanahalli, Bellandur Post, Near Marathalli,
Bengaluru-560103.
Department of Civil Engineering
Certificate
Certified that the project work entitled “Investigation On Flexural
Behaviour of Ferrocement Panel” is a bona fide work carried out by LEON
CHARLES, USN:1NH14CV056, PRASANNA KUMAR USN:1NH15CV031, RAJATH
KR USN:1NH16CV088 and ROSHAN KUMAR SAH USN:1NH16CV133 in partial
fulfilment for the award of Bachelor of Engineering in Civil Engineering of the
Visvesvaraya Technological University, Belagavi during the year 2019-2020. It
is certified that all correction/suggestion indicated for internal assessment have
been incorporated in the report deposited in the department library. The project
report has been approved as it satisfied the academic requirement in respect of the
project work for the said degree.
Signature of the Guide Signature of the HOD Signature of the Principal Dr. NATCHIMUTHU SUBRAMANI
Dr. NIRANJAN P S Dr. MANJUNATHA
Associate professor Prof. and HoD-CIVIL Principal
Dept. of Civil Engineering. Dept. of Civil Engineering. NHCE
External Viva
Examiner Signature with date
ACKNOWLEDGEMENT
The satisfaction and euphoria that accompany the successful completion of any task would
be impossible without the mention of the people who made it possible, whose constant
guidance and encouragement crowned our efforts with success.
We express our sincere thanks to Dr. MOHAN MANGHANI, Chairman of New Horizon
College of Engineering for providing necessary infrastructure and creating good environment.
We would express our great thanks to Dr. MANJUNATHA, Principal of New Horizon
College of Engineering, outer ring road Marathahalli, Bengaluru -560103 for granting us
permission to undertake the VTU prescribed project.
We express our deep sense of gratitude and thanks to Head of Civil Engineering Department,
Dr. NIRANJAN P.S, for providing necessary facilities and encouraging us to make this
project grand success.
We express our gratitude to Dr. N SUBRAMANI Associate Professor, our project guide, for
constantly monitoring the development of the project and setting up precise deadlines. His
valuable suggestions were the motivating factors in completing the work.
We fell with a great pleasure to express our deep of gratitude and profound thanks to staff
members of the Department of Civil Engineering Their valuable guidance in both field and
office work helped us to complete the project within the prescribed time.
Finally, we express our sincere thanks to lab instructors who helped us in the camp to complete
the camp successful and all our friends for their kind co-operation and help for the successful
completion of the project.
LEON CHARLES
(1NH14CV056)
C. PRASANNA KUMAR
(1NH15CV031)
RAJATH K R
(1NH16CV088)
ROSHAN KUMAR SAH
(1NH16CV133)
Abstract Ferrocement is a cementitious thin wall based on the solid structure of reinforced
cement mortar with mesh layers of wire of relatively small diameter. Mesh can
be made of metal or other saturated material. It is generally suitable for thin-
walled structural elements because uniform distribution and dispersion of
reinforcement provide high tensile strength for optimal fracture resistance,
weight ratio, ductility and impact resistance. In this project, we have studied the
structural behaviour of ferrocement panel when a constant load of 10KN, 15KN
and 20KN is been applied on the ferrocement panels with varying thickness of
25mm, 30mm, 35mm and 40mm and varying mesh reinforcement single, double
and triple layers. In this study we came to conclusion that deflection decreases
with the increase in mesh reinforcement layers for varying thickness of
ferrocement panels.
Ferrocement has been widely used for the past two decades and is still in its
infancy. Adequate design information is discussed and sufficient investigation is
obtained to enable the safe design and construction of Ferrocement structures. It
can compete economically with alternative materials depends on the type and
location of the application.
However, innovative structures in different parts of the world clearly point to the
unique and unmatched properties of this material and therefore, great potential is
being explored.
CONTENTS Abstract
List of Figures
List of Tables
1 Introduction .............................................................................................................................. 1
1.1 Introduction ....................................................................................................................... 1
1.2 FERROCEMENT INGRADIENTS ............................................................................................ 2
1.2.1 A. Matrix .................................................................................................................... 2
1.2.2 B. REINFORCEMENT FOR FERROCEMENT .................................................................... 5
1.2.3 C. PROPERTIES OF FERROCEMNT COMPOSITE .......................................................... 10
1.3 Advantages and Disadvantages of Ferrocement ............................................................... 11
1.4 Construction Methods ..................................................................................................... 12
1.5 APPLICATIONS OF FERROCEMENT IN CONSTRUCTION ...................................................... 16
1.6 Ferrocement Usage .......................................................................................................... 22
1.6.1 Bhalerao bungalow, Bhugaon near Pune .................................................................. 22
1.6.2 House in Jabalpur: .................................................................................................... 25
1.6.3 Foot bridges in Sri Lanka ........................................................................................... 26
1.6.4 FORMATIONS SECONDARY ROOFING SLABS ............................................................. 26
2 OBJECTIVE OF STUDY ............................................................................................................... 29
3 LITERATURE REVIEW ................................................................................................................ 29
3.1 LITERATURE REVIEW ........................................................................................................ 29
3.2 STUDIES FROM ASIA......................................................................................................... 31
3.3 STUDIES FROM EUROPE ................................................................................................... 40
3.4 STUDIES FROM USA ......................................................................................................... 41
3.5 Summary of the literature review .................................................................................... 44
4 MECHANICAL PROPERTIES OF FERROCEMENT ......................................................................... 46
4.1 Introduction ..................................................................................................................... 46
4.2 Behaviour in compression ................................................................................................ 46
4.3 Behaviour in tension ........................................................................................................ 47
4.4 Elastic Range .................................................................................................................... 47
4.5 Cracked range .................................................................................................................. 47
4.6 Yeild range ....................................................................................................................... 48
4.7 Behaviour in various stages .............................................................................................. 48
4.8 Cracking behaviour .......................................................................................................... 49
4.9 BEHAVIOUR IN FLEXURE................................................................................................... 50
4.10 Pre-cracking or elastic range ............................................................................................ 51
4.11 Post tracking Range.......................................................................................................... 53
4.12 Simplified equations ........................................................................................................ 55
4.13 PREDICTION OF CRACK WIDTH ......................................................................................... 55
4.13.1 Uniaxial tensile members ......................................................................................... 55
4.13.2 Flexural members..................................................................................................... 56
4.14 IMPACT AND FATIGUE BEHAVIOUR .................................................................................. 57
5 METHODOLOGY ...................................................................................................................... 58
5.1 Introduction ..................................................................................................................... 58
5.2 MATERIAL USED, DESIGN AND CONSTRUCTION ............................................................... 58
5.3 SPECIFICATION OF MATERIALS ......................................................................................... 61
5.4 LOADING PATERN AND PARAMETER STUDY ..................................................................... 62
6 CONCLUSION ........................................................................................................................... 70
7 REFRENCES .............................................................................................................................. 72
LST OF FIGURES
Figure 1. Reinforcing mesh ...................................................................................................6
Figure 2. Hexagonal wire mesh .............................................................................................7
Figure 3. Welded wire mesh ..................................................................................................8
Figure 4. Woven mesh ...........................................................................................................9
Figure 5. Press fill method used on circular tank .................................................................. 14
Figure 6. Lay-up technique .................................................................................................. 15
Figure 7.Bhalerao bungalow, Bhugaon near Pune ................................................................ 24
Figure 8. House in Jabalpur ................................................................................................. 25
Figure 9. Ferrocement secondary roofing slab ..................................................................... 27
Figure 10. Distribution of strains, stressed and forces for the uncracked section of the beam51
Figure 11. Distribution of strains, stress and forces for the cracked section of the beam ....... 53
Figure 12. Properties and types of constituents materials used in ferrocement construction .. 60
Figure 13. Constant load of 10KN varying slab thickness with varying mesh reinforcement 63
Figure 14. Constant load of 15KN varying slab thickness with varying mesh reinforcement 64
Figure 15. Constant load of 20KN varying slab thickness with varying mesh reinforcement 65
Figure 16. Varying load on constant thickness on the slab - 25 mm ..................................... 66
Figure 17. Varying load on constant thickness on the slab - 30 mm ..................................... 67
Figure 18. Varying load on constant thickness on the slab - 35 mm ..................................... 68
Figure 19. Varying load on constant thickness on the slab - 40 mm ..................................... 69
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1 Introduction 1.1 Introduction
Plain concrete has low tensile strength, ductility and resistance to crack
propagation. Before applying any load, the material contains micro cracks
because of the inherent microstructure and volumetric changes during its
fabrication. These defects result in a brittle failure of the material under pressure,
compared to its compressive strength. In reinforced concretes, the concrete
suffers from extensive rupture, although the failure of the composite is due to the
elastic nature of the reinforcement. In the past, work pressure was relatively low.
As a result, the cracks in reinforced concrete members are small and therefore
very small. The current trend toward more economic models, however, has been
pressured for higher work pressures. Due to the high crack width and deflection
that can damage the appearance of the structure, the steel corrosion weakens the
member and damages the non-structural members. Service efficiency standards
are more important than strength considerations. Concrete technician has faced
the problem of improving the inherent weakening properties of concrete to meet
the needs of the designer. Repair improves the performance and performance of
good structures, restores and enhances its strength, provides water tightness and
prevents aggressive environments for steel surface durability. Corrosion of
reinforced concrete cement structures mainly occurs in reinforcement in slabs,
beams and strips, where the cover is not well supplied. Good quality materials
should be found to overcome such problem. Promoting the discovery of new
materials in place of partially reinforced concrete. It is under such circumstances
that fermentation, among other things, emerges. The reinforcement of the
ferrocement consists of several layers of relatively fine wire mesh filled with or
without steel bars in the center. Cement mortar is used to fill gaps between
meshes and provide reinforcement cover.
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Ferrocement is a major use in developing countries, where successful field
applications have been seen with excellent physical properties and low theoretical
basis. The robust mechanism in ferrocement improves many engineering
properties of brittle mortars, such as brittle, tensile and flexible strength, ductility
and impact resistance, but also benefits in terms of manufacturing products and
components. Ferrocement uses a thin structural element and a great cement
mortar with a thickness of 10-25mm; Coarse aggregates cannot be used; And the
reinforcement consists of one or more layers of steel wire weld mesh with
continuous short diameter. It does not require skilled labor for casting and works
only with little or no formwork. In ferrocement, the cement matrix does not
detonate because the cracking force is carried to the surface by wire mesh
reinforcement. Subsequently, it is not surprising that the field of ferrocement
applications and the study of its properties have received widespread attention.
1.2 FERROCEMENT INGRADIENTS
1.2.1 A. Matrix
Ferrocement matrix is usually a cement mortar, consisting of cement, sand, water
and additives. Depending on the structure used in the matrix, high compressive
strength, defectiveness and hardness, resistance to chemical attack, low
shrinkage, and work efficiency, the following requirements must be met. Most of
the features available in relation to the properties of mortar used in ferrocement
are based on the observation and practical evaluation of ferrocement applications,
with some help from solid technology knowledge. From a concrete technology
perspective, the main factors that affect the properties of mortar are:
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1. Water / Cement Ratio
2. Sand / cement ratio.
3. Graduation, size, and maximum size of aggregates.
4. Quality, age and type of cement.
5. Admixtures
6. Curing condition.
7. Mixing, placing and compaction of Mortar.
Limitations of the above factors are influenced by the mortar requirements, which
depend on the use of fermentation. In marine structures, civil engineering
structures usually require more restrictions. In most applications, high strength
and low shrinkage are required and therefore low water: cement ratio, between
0.35 and 0.55, should be used. The work capacity should be high and therefore a
sufficient compromise should be made to increase the amount of water to take
into account the decrease in strength. Rich cement mortar is required to give
compressive strength between 35 and 50 N / mm2
1.Cement
Typical Portland cement is used in the manufacture of mortar. Cement should be
fresh and free of stains.
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2. Aggregates
A common-weight fine is the most commonly used in total ferrocement. The
gravels consist of fine graded fine aggregates that pass through a 2.34 mm sieve;
And a salt-free source is recommended, and should be chosen from river-beds,
and free from organic or other harmful substances, and relatively free from silt
and soil. To ensure proper penetration (ACI Committee 549R-97) good stability
and compaction is achieved using well-graded, rounded, natural sand. The
moisture content of the aggregate should be considered in the calculation of water
required.
3. Water
The mixture should be fresh, clean and drinkable.
4. Matrix Mix Proportions
The composite ratio of mortar for fermentation is weight-to-sand / cement ratio,
weight 1 and 2.5 and water-cement ratio, 0.30 to 0.5. The amount of water used
should be less favorable for compatibility. This is usually accomplished using a
well-graded, rounded, natural sand with a maximum top size of one-third of the
smallest openings in the reinforcement system to ensure optimal entry. Sand
travel through a 1.16 mm sieve has yielded satisfactory results in many practical
applications. If the mixture does not prevent the complete entry of the mesh, the
mixture should be as solid as possible. Generally, the slope of a fresh mortar
should not exceed 2 inches (50 mm). For most applications, the compressive
strength of a 75-by-28-day cylinder with a 150-mm wet-cylinder should not be
less than 35 MPa.
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1.2.2 B. REINFORCEMENT FOR FERROCEMENT
Different types of meshes are available in almost every country in the world. Two
important reinforcement parameters are commonly used in classifying
ferrocement and the volume of reinforcement is defined differently; This is the
amount of reinforcement per unit volume of ferrocement. The specific surface of
the reinforcement is the total bonded area of the reinforcement per composite unit
volume. The following are the main types of wire mesh currently used: hexagonal
wire mesh, welded wire mesh, woven wire mesh, extended metal mesh, and
three-dimensional mesh.
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1. REINFORCING MESH
Wire mesh is an essential component of Ferrocement. Different types of wire
mesh are available. These generally consist of thin wires either woven or welded
into a mesh, but the main requirement is that it must be easily handled and if
necessary, flexible enough to bent around sharp corners. The function of the wire
mesh and the reinforcing rods in the first instance is to act as a lath providing the
form and to support the mortar in its green state. In the hardened state its function
is to absorb the tensile stresses on the structure which the mortar, on its own,
would not have been able to withstand. The mechanical behavior of Ferrocement
is highly dependent upon the type, quality, orientation, and strength properties of
the mesh.
Figure 1. Reinforcing Mesh
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2. HEXAGONAL WIRE MESH
This mesh is commonly known as chicken wire mesh and is fabricated from cold
drawn wire which is generally woven into hexagonal patterns. The diameter of
the wire is 0.5 mm to 1 mm. the mesh openings vary from 10 mm to 25mm.
standard galvanized meshes, galvanized after weaving are adequate.
Figure 2. Hexagonal Wire Mesh
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3. WELDED WIRE MESH
Eighteen- or nineteen-gauge wire, spaced half an inch apart are normally used in
this mesh. These wires are made of low to medium tensile strength steel and are
much stiffer than hexagonal wire mesh. However, in welded mesh the possibility
of weak spots at intersections resulting from inadequate welding during the
manufacture of mesh may occur.
Figure 3. Welded Wire Mesh
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4. WOVEN MESH
In this type of mesh shown in fig, the wires are simply woven into the desired
grid size and have no welding at the intersections. The mesh wires are not
perfectly straight and a certain amount of waviness exits. One of the difficulties
encountered is that it is difficult to hold in position but when stretched, it readily
conforms to the desired curves.
Figure 4. Woven Mesh
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5. EXPANDED METAL MESH
It is formed by cutting a thin sheet of expanding metal to produce diamond shape
openings. The manufacturing process is less labor intensive than the method used
for manufacturing hexagonal wire mesh or welded mesh.
6. SKELETEL STEEL
Skeletal steel as the name implies is generally used for making the frame work
of the structure upon which layers of mesh are laid. It is generally desirable to
provide skeletal steel to take care of tensile forces and provide wire mesh
reinforcement to ensure crack control. As Ferrocement elements are generally
cast in thin sections of about 15 to 30 mm thick, the size of the bars should be
around 6 to 10 mm.
1.2.3 C. PROPERTIES OF FERROCEMNT COMPOSITE
1. The wire diameter is 0.5 to 2 millimeters.
2. The mesh size is 6 to 35 millimeters open.
3. Maximum 8% volume fraction in both directions.
4. The thickness is 6 to 50 millimeters.
5. Mesh covers 1.5 to 5 millimeters.
6. Ultimate tensile strength up to 34 MPa.
7. Allowable tensile strength up to 10 MPa.
8. Breakdown modulus up to 55 MPa.
9. Compressive strength from 28 to 69 MPa.
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1.3 Advantages and Disadvantages of Ferrocement
Advantages of Ferrocement:
It has got a higher ratio of tensile strength to weight and superior cracking
behavior compared to R.C.C. They comprise of thin elements and light
structures hence; they are lighter in weight.
Can be casted in any desired shape and size for wide ranges of uses.
It provides better resistance to fire, earthquake, and corrosion than
traditional materials, such as wood, adobe and stone masonry in residential
construction.
The materials are relatively inexpensive, and can usually be obtained
locally.
Only a few simple hand tools are needed to build uncomplicated structures.
Repairs in Ferrocement structure are usually easy and inexpensive which
means it has low maintenance cost.
It is easy to handle.
Ferrocement saves 20% cost and materials.
There’s reduction in cost economy and speed, both can be achieved.
It has less thermal conductivity as compared to RCC.
Raw materials are available in most of the countries.
Labor is not required to be very experienced.
Precast members can be suitably manufactured by using this type of
concrete
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Disadvantages of Ferrocement:
Excessive shrinkage occurs due to higher cement content. Thus, it requires
constant curing for a
It is prone to corrosion of wire mesh due to incomplete coverage of steel
by mortar
Ferrocement is labor intensive and hence not a good choice where the labor
costs are high.
As Ferrocement construction are usually thin structures, buckling is
another factor that needs to be
Being thin Ferrocement members, they have poor impact resistance.
Structures made of by Ferrocement can be punctured by forceful collision
with pointed objects.
They have low shear strength and low ductility.
Ferrocement are susceptible to stress rupture failure.
It is hard to do welding, drilling, nailing, screwing etc. properly in
Ferrocement construction.
1.4 Construction Methods
The preparation process is important for the manufacture of ferrocement. Since
the iron elements are very thin on the order of 10-25 mm, care is taken to keep
the cover to a minimum of 3 mm.
Construction Methods and Applications: Construction process is important for
Ferrocement construction. Since the Ferrocement elements are very thin in the
order of 10-25 mm; considerable care is to be taken.
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1. ARMATURE SYSTEM
The armature system is a framework of tied reinforcing bars to which layers of
reinforcing mesh is attached on each side. Mortar is then applied from one side
and forced through the mesh layers towards the other side. The skeletal steel can
assume any shape. Diameter of the steel bars depend on the size of the structure.
Skeletal steel is cut to specified lengths, bent to the proper profile, and tied in
proper sequence. The required numbers of layers of mesh are tied to each side
of the skeletal steel frame.
2. CLOSED MOLD SYSTEM
The mortar is applied from one side through several layers of mesh or mesh and
rod combinations that have been stapled or otherwise held in position against the
surface of a closed mold. The mold may remain as a permanent part of the
finished Ferrocement structure. If removed, treatment with release agents may be
needed. The use of the closed-mold system represented it tends to eliminate the
use of rods or bars.
3. PRESS FILLS METHOD
In Ferrocement construction, mortar plastering and penetration on to the mesh
plays a crucial role. The mortar is usually applying in the mesh reinforcement
either by hand or shot through a spray gun device in order to get a homogeneous
mixture of ingredients and produce almost a fabric of mesh coated and well
packed with mortar.
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4. LAY- UP TECHNIQUE
Lay-up technique which involves placing the mesh in the mortar rather than the
mortar in the mesh; and successive layers of mesh are placed in layers of freshly
sprayed, or manually placed, mortar. To assure that mesh layers do not pop out,
a thin mortar cover layer is placed first and allowed to set, but not dry completely,
prior to application of a second mortar layer and the first mesh layers. This first
layer of mortar cover is generally about 3 mm. A major advantage of the lay-up
technique is that each layer of mesh is placed under full visual contact any gap in
the mortar is immediately apparent and instantly corrected.
Figure 6. Lay-up Technique
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1.5 APPLICATIONS OF FERROCEMENT IN CONSTRUCTION
1. Housing and other Industrial and commercial.
Low cost dwelling house
Strengthening reinforced concrete element.
Strengthening masonry element.
2. Marine
3. Agricultural
4. Anti-corrosive Membrane treatment
5. Tank container & silos
6. Floor & Roof
7. Waterproofing
8. Manhole cover
9. Wall cupboard
10. Ferrocement duct
11. Chemical resistant treatment
12. Rural Application
13. Elevation Treatment
14. Soil stabilization
15. Pipes
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16. Sewer lines
17. Bridge
18. Foot Bridge
19. Sulphate resistant cement saving
20. Precast Ferrocement structure
21. Fire resistant structure
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1. HOUSING:
a. Low cost dwelling house
b. The good properties of Ferrocement e.g. high tensile strength/ weight ratio,
unskilled worker requirement, roofs with less dead lead make it an interesting
solution for a housing propose.
c. There are good properties of Ferrocement against.
Cyclic loading
Lateral displacement
Resistance to earthquake loading.
d. Strengthening of structural element
e. Ferrocement is a best alternative for retrofit recent studies use this material
as a retrofit for beams, column, beam column connection and give better result.
f. Strengthening reinforced concrete element
Ferrocement is applicable to provide extra confinement to achieve good axial
capacity of column without considering the grade of concrete.
g. Strengthening masonry element.
h. On other hand Ferro cement is also applicable for strengthening masonry
column with Ferrocement jacketing same as above mentioned in RCC column,
in masonry column by using Ferrocement also improve the crack behavior and
compressive strength of masonry column.
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2. MARINE:
Marine structure such as Boat, trawler, Barges, floating docs can be constructed
with a help of Ferrocement and give better result than steel and wood and a good
resistance of atmosphere.
3. AGRICULTURAL:
The plates that are construct with a help of Ferrocement can be used for:
Construction of canal.
Gates over dam
Cross-drainage work
Aqua-duct
Penstocks etc.
Ferrocement lining is good against abrasion.
4. ANTI CORROSIVE MEMBRANE TREATMENT:
A Ferro cement consist anti-corrosive membrane treatment hence no other
treatment is required for protection against corrosion.
5. TANK CONTAINER AND SILOS:
Every type of tank e.g. overhead, underground or at ground level can be
manufactured with the help of Ferrocement and give a satisfactory service.
6. FLOOR AND ROOF:
We can construct floor & roof various type of building e.g. residence, factories,
office, sheds etc.
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7. WATER PROFFING:
By using Ferrocement membrane technique we can construct water proofing.
8. MANHOLE COVER:
Heavy duty and light duty manhole cover be constructed and are superior and
durable than conventional once.
9. WALL CUPBOARD:
It consists no. of small holes in rectangular form with or without shutter used to
store office record, factory material etc.
10. FERROCEMENT DUCT:
Ferro Cement ducts are suitable for circulation of cool or hot air.
11. CHEMICAL RESISTANT TREATMENT:
An overly of epoxy, bitumen, polyurethane, chlorinated rubber, lead lining and
glass fiber will be an ideal chemical resistant treatment
12. RURAL APPLICATION:
Ferrocement is applicable in rural areas for construction of cattle sheds, silos for
storage of food grains. Low costs houses, community centers, well lining, goober
gas plant, lavatory block, water storage tank etc.
13. ELEVATION TREATMENT:
Elevation treatment e.g. fins, projection curved, folded and hollow, sun shed to
the building have been provided with advantages.
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14.FIRE RESISTANT STRUCTURE:
It can resist fire upon 7500 for a period of 48 hours.
15. SOIL STABLIZATION:
Ferrocement can be used for increase bearing capacity of soil for foundation of
building, bridge, dams etc.
16.PIPES:
There is corrosion problem using steel and iron pipes instead of these wire
Ferrocement pipes overcome the problem of corrosion.
17. SEWER LINES:
Ferrocement in sewer line is necessary same as pipes.
18. BRIDGE:
As per know Ferro cement is crack resistance and corrosion resistance and
applicable to make girder plates.
19. FOOT BRIDGE:
Foot bridge with Ferrocement girder, decking, railing and roof is better than RCC
and steel
20. SULPHATE RESISTANT CEMENT SAVING:
During conventional concrete curing by using sulphate resistant Ferrocement
lining very cost effective and structure is safe against sulphate attack.
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21. PRE-CAST FERROCEMENT STRUCTURE:
Pre-cast Ferrocement structure are in light weight as compared with RCC and
sometime pre stressed concrete structure, considerably reduce the cost hence
Ferrocement is most appropriate in pre-cast industry.
1.6 Ferrocement Usage
1.6.1 Bhalerao bungalow, Bhugaon near Pune
Owner Mr. Bhalerao decided to construct a Farm House at Bhugaon near Pune.
Its plan was made by the Architects. It is designed as single storied house with
sloping roof. The roof area is totally about 500 m2. In Plan the walls are either
radial lines or arcs of the circles of different diameters and canters. Ridge line of
sloping roof is also an arc. Steel Structure or RCC structure proved to be costlier
and also more difficult. The Only best solution for the roof worked out as with
Ferrocement. Roof and also walls were designed and are being done with double
layer and Thermopolis layer in between. (Courtesy: Ferrocement Society, Pune)
Initial Design:
a) RCC Alternative: In the Plan the building is a segment of a circle. Initially
it was thought to be done in RCC. However, cost of shuttering for roof was going
too high due to its circular shape and slopes. Due to slopes and curvature it would
have been very difficult to provide shuttering in exact form. It is practically
impossible to make line of the shuttering. Normally concreting of the sloping slab
is difficult as vibrating the concrete is difficult. So many times such slab leaks if
proper water-proofing treatment is not provided. So this idea was discarded.
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b) Structural Steel Alternative: Then it was thought to be done with steel
structure. For steel structure it was possible to bend the sections with exact radius
on bending machines. Then fabrication and erection works could have been done.
However, this would require bending machines on site with sufficient Electric
Supply which is only possible with Gen set of more capacity. Cost of this whole
thing was going high. Besides roofing with Precoated or similar sheeting was not
possible. So it was thought to be done with Bison Panels (Saw dust and Cement
composite). Then these panels were to be covered with decorative Shingles. This
system has certain short comings. Obviously costing was one of them and also
water proofing was main concern. Repairing if needed would have been a big
headache. Also this would require false ceiling work from bottom to have soffit
plain.
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c) Ferrocement Alternative: Project Consultant was well aware of
Ferrocement technology. So, he suggested and convinced the Owners and
Architects about use of Ferrocement. Then the Ferrocement alternative was
considered. It can overcome all the problems that were coming in RCC or steel
structure. It was simpler, maintaining shape and dimensions was possible, leak-
proof structure was easily possible, it is light weight than RCC, decorating the
roof was with tiles etc. is easily possible, making changes during construction is
also possible. Then it was decided to go for Ferrocement Structure
Figure 7.Bhalerao bungalow, Bhugaon near Pune
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1.6.2 House in Jabalpur:
Project details:
Name of the project: ‘Sumati Greens’
Location of project: Village Nigri – 25 kms. From Jabalpur on NH.7
Built up area: Ground floor: 120 m2 and First floor: 145 m2
Year of completion: December 2012
This farmhouse building as shown in fig rises up like a flower and attracts hordes
of travelers who cannot stop themselves from pausing in their tracks curiously to
have a closer look at this building
Figure 8. House in Jabalpur
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1.6.3 Foot bridges in Sri Lanka
National Engineering Research and Development Centre of Sri Lanka have built
footbridges and tested also. This research was focused on the application and
development of Ferrocement technology to construct cost effective foot bridges.
The first phase of the study focused up to 20’.0” clear spans foot bridges for the
pedestrians. The T-shaped section was selected for the bridge members. Section
and the steel members and mesh layers were optimized by using FEM analysis.
Also, the Model Code of Ferro Cement Design was referred. In the second phase
of the study clear span extended up to 30’.0” and for three wheels and motorcycle
users. Pre-stressed Ferrocement made 30’.0” long beam was designed as bridge
member. T-shape section was selected using FEM analysis as done in the first
phase of the study. Load tests were carried out for bridge beams to check the
strength in longitudinal and lateral directions. Pilot projects were done in both
cases to check the performance.
1.6.4 FORMATIONS SECONDARY ROOFING SLABS
In tropical countries, secondary roofing slabs are installed on the roof top of the
buildings to insulate against intense heat. In Singapore these slabs consist
typically of 1500 mm x 600 mm x 50 mm precast cellular concrete slabs
containing a centrally placed layer of galvanized welded wire mesh of 50 mm
square grid and 3.25 mm diameter. The slabs were assembled side by side; each
being supported on 150 mm x 150 mm x 225 mm precast hollow blocks placed
on the top of the structural roof to provide as air gap of 225 mm. The cellular
concrete mix has a sand: cement ratio of 2.2 with a density of about 1500 kg/m3.
These slabs pose a problem of severe cracking even before they are transported
and erected in place. Although the presence of cracks may not be critical with
respect to strength requirements, they are undesirable from a durability point of
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view. Consequently, there is a need to replace such slabs at least once every 10
years.
A study was carried out at National University of Singapore to examine the
current design with the intention of improving durability of the slabs. A
Ferrocement design of 30 mm thickness with two layers of galvanized fine wire
mesh of 25 mm square grid and 1.6 mm wire diameter separated by a layer of
skeletal steel of galvanized welded wire mesh of 150 mm square grid and 3.3 mm
diameter, as shown in the given figure, was found to be adequate. Because of the
reduced thickness, the dead weight of the Ferrocement slabs remains
approximately the same as that of the cellular concrete slabs
Figure 9. Ferrocement Secondary Roofing Slab
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The functionality of such slabs was investigated by carrying out flexural tests,
patch load tests and shrinkage measurements on specimens. It was found that the
slabs could be subjected to design service load of 1.8kN patch load, two days
after casting without cracking. The slabs also registered low long-term shrinkage
of about 400 microns. The effects of weathering and thermal fluctuations were
also studied. Slabs subjected to alternate wetting and drying test don not show
any deterioration in first scarce or ultimate strengths. Cyclic compression test to
simulate the effect of thermal stresses due to heating in the day and cooling at
night did not affect the strength significantly. Comparison in terms of production
costs shows the Ferrocement slabs to be slightly more expensive than the cellular
slabs. However, it is expected that with Ferrocement slabs the frequency of
replacements will be reduced. The cost can be reduced through increasing
productivity by demolding them in the shortest possible time, minimizing the
controlled curing period and installation on site at the earliest time with less
number of spoils during transportation and erection. The reliability study
indicates that the Ferrocement slabs used were safe against ultimate failure one
day after casting when subjected to both dead and live loads and in the case of
first cracks with respect to dead load alone. In another study the durability of the
Ferrocement secondary rooting slabs was investigated with respect to service life-
cycle in relation to the actual load range that a typical slab would experience. The
results show that the slabs have good fatigue properties within the stress range
considered.
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2 OBJECTIVE OF STUDY
1. Study includes investigation of Ferrocement panel by varying different
thickness and different layers of reinforcement for the constant application
of loading.
2. Effective of number of mesh layers on the flexural strength of slab panels.
3. To examine the effective span to depth ratio.
4. Effective deflection to reinforcement ratio.
3 LITERATURE REVIEW 3.1 LITERATURE REVIEW
Ferrocement is a highly versatile reinforced composite material made of cement
mortar and wire mesh membranes, forming a rigid structural structure with high
strength to weight ratio. (ACI 549R-97, 1997), as defined by the ACI Committee,
is a type of "thin-walled reinforced concrete, usually reinforced with hydraulic
cement mortar continuous and layers of small diameter wire mesh". Due to its
excellent strength, fracture resistance and impact resistance, ferrocement has
been used as a roofing or floor element for housing units to build boats, water
tanks, marine structures and grain silos. Most of this strength arises from
curvature and rebellion. Size can, therefore, travel long distances with low-cost
support.
Unlike other sophisticated structures, ferrocement construction requires less
skilled labor and the use of available local materials. Proper care must be taken
to control the quality of construction; Otherwise, thin shell fermentation can
disrupt the manufacturing purpose. To utilize the potential of ferrocement as a
building material, a proper understanding of the material behavior under different
conditions is required. (Paramasivam et al., 2004).
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The most important advantages of ferrocement are that it can be fabricated into
almost any desired shape to meet the need of the user. It is being extensively used
in developing countries like India, Indonesia and Sri Lanka for (a) Housing
applications (b) Marine application (c) Agricultural application (d) Rural energy
application (e) Water and Sanitation application and (f) Repair and maintenance
applications (Mansur et al. 1987, Paramasivam et al. 1990, Ganesan , 1994 ).
For high-pressure structures such as boats, barrages, steel bars with wire mesh
are considered part of the reinforcement, providing structural strength and
rigidity, but wire mesh is the main reinforcement in most earthquake structures.
Is considered as. The reinforcement network must be securely welded or fastened
so that it stays in its original position during the application of the mortar (ACI
549R-97 1997, Swamy 1984). In highly reinforced structures, the steel rod and
mesh must be fitted with sufficient penetration of the mortar, leading to zero free
dense material.
In order to obtain good quality hardened mortar, mortar must be placed and
deposited by proper curing in the appropriate environment during the early stages
of rough weather (Andal et al., 2003). The purpose of curing is to keep the mortar
saturated with the hydration products of the cement until enough water is filled
in the fresh cement paste.
Ferrocement is ideally suited for thin-walled structures. In addition, many other
uses of ferrocement are used worldwide as a building material. These include
sunscreen and sandwich wall panels for high-rise buildings (Mansour 1987,
Paramasivam 1990). Ferrocement has been widely used in the repair and
maintenance of a recent building (Romualdi 1987, Lorns 1987).
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3.2 STUDIES FROM ASIA
In the early 1940s, Pier Luigi Nervi (ACI 549R-97, 1997) revived the concept of
the original Ferrocement. After World War I, Nervy demonstrated the use of
fermentation as a boat building material. The International Fermentation
Information Center (IFIC) at the Asian Institute of Technology was established
in 1976 in Bangkok, Thailand. Ferrocement is now widely used in the production
of structural elements in repair and maintenance work (Romualdi, 1987).
Mansur and Paramasivam (1986) conducted experimental and analytical
research on the flexural behaviour of the Ferrocement element to study the
behavior and ultimate strength of the tube. A method based on the concept of
plastic analysis that predicts the last moment potential of Ferrocement is
proposed and is in good agreement with experimental values. From the study, it
was determined that the moment of first cracking and the first moment were
increased with an increase in the matrix grade and volume fraction of the steel.
They conclude that the higher volume fraction of steel provides more effective
control over the width of the crack.
Walkus (1986) attempted to determine the parameters for testing the material of
ferrocement to define the characteristics of the structure and type of equipment
used to test and measure equipment for determining deformation and fracture.
Atsushi Shirai and Yoshihiko Obama (1988) conducted an experimental study
to investigate the flexible behavior and effectiveness of ferrocement through the
use of polymer. From their study, they found that the first crack load, the final
load and the crack resistance increased, and the increase in the number of
fractures and the increase in the number of fractures were largely controlled by
the addition of polymers. Effective resistance is also increased by the use of
polymer modified mortar.
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Karunakar Rao and Jagannadha Rao (1988) proposed a theory for calculating
the final moment of Ferrocement structural elements based on the experimental
evidence of crack patterns, fractures and propagation.
Desai et al. (1988) proposed a bilateral method for estimating deflection and one
and two methods for crack formation and the final moments of ferrocement
elements. These methods are found to give a satisfactory agreement with the test
data.
Ganesan and Suresh Kumar (1988) conducted an experimental study to study
the effect of discrete small steel fibers on the strength and behavior of
Ferrocement structural elements of channel cross-section. The results indicate
that the addition of steel fiber increases the strength and energy absorption
efficiency of Ferrocement elements.
Desai and Desai (1988) have developed and tested various forms of Ferrocement
roofing elements to examine the compatibility and load-carrying capacity of low-
cost homes. The study concluded that in all embodiments, the folded shape
Ferrocement elements exhibit high viscosity and last minute efficiency.
Furthermore, the Ferrocement fold-plate element is proven to cost 15 to 25% less
than the asbestos cement sheet.
Lohtia et al. (1988) conducted an experimental study on the linear behavior of
ferrous slabs. They observed that the cracks of the Ferrocement slab were very
different than those of the RCC slab. In Ferrocement slabs, the fractures are very
fine and distributed over a larger area than in the case of RCC slabs. In addition,
the Ferrocement slab has been found to have greater expansion and higher reserve
strength than the RCC slab.
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Rao and Rao (1988) conducted a research to develop an acceptable and rational
method for calculating the last moment of resistivity of Ferrocement channel
units. Their study indicated that the analysis of the crack pattern and deflection
gave an insight into the dynamics of the moment of resistance of the Ferrocement
channel unit.
Ganeshan et al. (1988) conducted an experimental study on the development
and proof testing of ferrocement roofing systems. Development and evidence
testing of the composite roof I floor system consists of partially pre-fabricated
ferrocement trough units and in situ concrete toppings. The purpose of the tests
is to study the simple behavior of a partially pre-fabricated ferrous trough unit as
an individual element and as a composite element in site concrete. The results
showed that the structural behavior of the ferrocement trough units, as well as the
composite units, was very satisfactory.
Naman (1989) conducted a study on the different levels of technology used in
ferrocement housing products. The study indicated that the typical household
needs were filled with approximately fifteen standard panel configurations. Box-
shaped panels for walls and lintels were considered, while U-shaped panels were
considered for floors and ceilings.
Vijay Raj (1990) conducted an experimental and theoretical study to assess the
structural behavior of large span bamboo ferrocement elements for floor and
ceiling purposes. The study concluded that large span bamboo ferrocement slabs
should have a thickness of 40mm to meet the requirements of the roof and floor
elements of reinforced buildings. Further, he concludes that the cost of bamboo
ferrocement slabs is only 70% of ferrocement slabs.
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Mathews et al. (1991) conducted an analytical and experimental investigation of
cracking loading, ultimate load, deflection, crack spacing, and crack width of a
bolo ferrocement roofing system. Test results confirm that the system has
sufficient strength, rigidity, and other service efficiency requirements for
residential applications. The estimated theoretical values are in good agreement
with the experimental values.
Desai et al. (1992) conducted an experimental study to study the first crack
strength and the breakdown modulus of light fiber reinforced ferrocement. From
the study, they found that the volume fraction of the steel fiber controls the
modulus of the rupture and the first crack strength of the ferrocement elements.
He also developed an equation for estimating the first crack strength and slit
modulus.
Well AI-Rifi and Arslan Hassan (1994) conducted an experimental and
theoretical study on the behavior of ferrocement one-way bending elements.
Elements of different sizes and widths were selected to study their relative
feasibility for adoption on small-sized residential roofs. As a result of the
investigation, it is believed that the unilateral bending element undergoes large
deflection before failure and is the main cause of reinforcement. Additionally,
they found that as the flange width increases, the final load capacity decreases,
but the ratio of the final load capacity of the first tube load increases as the pulsing
length increases.
Mathews et al. (1994) conducted a study on the planning aspects of ribbed
ferrocement elements for low-cost homes, taking into account the principles of
modular coordination. The study concludes that the manufacturing process can
be simplified by using modular coordination and a general manufacturing plant;
Massive production for elements is easily achieved.
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Ganeshan and Suresh Kumar (1994) conducted an experimental investigation
on the moment probability of fibrous ferrocement members. The main objective
of this study was to determine the effect of randomly oriented microfluidic steel
fibers on the strength and behavior of ferrocement elements. The results indicate
that the addition of steel fiber greatly enhances the moment efficiency of
ferrocement flexural elements. In this study a method for estimating the moment
capacity of an element is proposed.
Hossain et al. (1997) conducted a study to develop an analytical model for the
flexibility and tensile behavior of ferrocement plates in the pre- and post-cracking
stages. From the study, they established that two-way ferrocement slabs can carry
10% -30% more weight than one-way slabs.
Mansur et al. (2000) conducted flexural tests to rapidly evaluate the flexural
strength on thin-walled ferrocement structural T, transverse T and symmetric I-
sections and accelerate the design charts for structural sections. They developed
specific design maps and suggested the existence of considerable flexibility for
thin-walled pandas, stating that rigorous plastic analysis must be applied to assess
their last-minute capabilities.
AI-Kubaisy and Mohd Zamin Jumaat (2000) conducted a study on the flexible
behavior of reinforced concrete slabs with ferrous tension zone covers. The
percentage of wire mesh reinforcement in the ferrocement cover layer, the
thickness of the ferrocement layer and the type of connection between the
fibrocement layer and the RCC slab. The results showed that the use of
ferrocement cover increases the final flexural load and first crack load and
reduces the width and spacing of the crack.
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Shesu (2000) conducted an experimental study on fermented limited reinforced
concrete beams. Their study concluded that imprisonment by the ferrocement
shell improves the moment-carrying capacity by about 9 to 15% and also
increases the moment of the first crack.
Ratish Kumar and Rao (2000) conducted an experimental study to study the
stress-strain behavior of ferrocement confined reinforced = concrete (FCRC)
under axial compression by changing the specific surface factor and constraint
index. The study concluded that the improvement of ductility for a given restraint
index is proportional to the specific surface factor of ferrocement
Mansur et al. (2001) conducted an investigation to find the shear strength of the
ferrocement structural section. The study concluded that flexural fractures occur
initially despite span / depth ratio but cracking and ultimate load decrease when
the span / depth ratio decreases.
Imam et al. (2002) conducted a study to simulate the deflection and stress
behavior of different types of roofing elements through finite element methods.
From the investigation, they conclude that the numerical results match the
experimental results. The main stress sections are low in the shell element and it
is the most economical shape as the roofing element.
Vijaya and Hedge (2003) conducted an experimental study on the ferrocement
of concrete beams made of brick butt and recycled concrete aggregates. Their
study has shown that ferrocement leads to a significant increase in beam stiffness,
strength and ductility.
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Andal et al. (2003) conducted a study on the ductility and impact resistance of
cured ferrocement samples in seawater and normal water. They found that
seawater samples showed reduced strength in ductility and effectiveness due to
the infiltration of seawater into ferrocement elements.
Jagannathan et al. (2003) studied the suitability of polymeric nets as a substitute
for reinforcement in ferrocement flexural elements. The four-layered polymeric
mesh reinforcement ferrocement element meets the IS requirements as the
number of mesh layers increases with lower deflection, higher youth modulus,
comparable flexural strength and crack width.
Veerappa Reddy (2003) conducted a study on the industrial production of new
ferrocement elements. The industrial production of ferrocement elements, such
as ferrous and septic tanks, pre-designed modular community toilets and
undersized length classes emphasized for longer periods are described in this
study.
Ramesh et al. (2003) conducted experimental research on the behavior of hybrid
ferro-fiber concrete under axial compression. A variety of parameters reinforce
the specification of a specific surface factor, fiber reinforced concrete. The results
indicated that the combined strength of ferrocement and fiber improved the final
strength, the stress of the final strength and the ductility of the reinforced
concrete. The correction is proportional to the specific surface of the
reinforcement.
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Jagannathan and Sundararajan (2004) conducted an experimental and
theoretical research to study the simple behavior of reinforced ferrocement slabs
with 3-5-layer polymer mesh as an alternative form of reinforcement. From the
study, it has been observed that polymer mesh reinforced ferrocement slabs
exhibit the same linear elastic behavior up to the first crack load.
Paramasivam et al. (2004) conducted detailed research on the origin, suitability
and application of ferrocement mixtures. The authors discuss the R&D work done
on ferrocement element and sunscreen, secondary roof slabs, water tanks, and
repair equipment in the construction industry. The key features of the design,
fabrication, and performance of some applications of ferrocement structural
elements are highlighted.
Bhaskar Desai et al (2004) conducted an experimental investigation on the
flexible behavior of a super plasticizer which partially replaced the silica fume
ferrocement elements in the cement, variable with the depth ratio and the number
of shear layers. 10% silica fume can be taken as the optimal dosage form to give
maximum compressive strength in place of cement, dividing the modulus of
tensile strength and elasticity. It is also found that the ultimate flexural strength
increases with shear span / depth (A / 0) ratio and the silica fume increases by
10% for the number of wire mesh layers.
Hago et al. (2005) conducted an experimental study on the final and service
behavior of ferrocement roof slab panels. The objective of the study was to
determine the final and service behavior of the ferrocement roof slab panels. The
use of monolithic shallow edge ferrocement beams with panels has significantly
improved the serviceability and final behavior of the panels, regardless of the
number of steel fibers.
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Andal et al. (2005) conducted an experimental study on the behavior of
ferrocement flexural members with polymer-modified mortars. The main
objective of this study was to determine the flexural strength of ferrocement
element of size I 000mm x 200 mm x 25 mm with cement sand mortar 1: 1 and
water-cement ratio 0.3. The variants used in the study were different volume
fraction of reinforcement, different percentage of SBR polymer, and different
percentage of recon 3S fiber. This study gave 12.5% SBR latex and 3% volume
fraction high fall overhead by cement weight.
Prem Paul Bansal and others. (2006) conducted an experimental study on the
effect of various bonding agents on the strength of retrofitted beams using
ferrocement laminates. A study was conducted to determine the retrofitting effect
of the beam using ferrocement laminates bonded with cement solution, epoxy
and shear connectors. The study concluded that there was a significant increase
in the third point loading crack width, increased crack spacing, large deflection
and ductility ratio at all samples.
Prakash and Patil (2007) conducted an experimental study on the effect of silica
fume addition on the strength properties of fibrous ferrocement using round steel
fibers. The study shows that fibrous ferrocement is a combination of ferrocement
n and fiber reinforced concrete, which shows significant improvements in
mechanical properties such as toughness and impact resistance. It also exhibits
overall high compressive, tensile, and impact strength
Prem Pal Bansal et al (2007) conducted a study on shear reduction, in which the
RC beam was initially stressed at the pre-set percentage of the retrofitted secure
load using ferrocement. To increase the strength of the beam in both shear and
flexibility, the wire mesh is placed at an angle of 45 45 from the longitudinal axis
of the beam. The study concluded that the safe load bearing capacity of
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rectangular RC elements made of ferrocement laminate increases significantly
with the mesh at 45 at.
Patil and Prakash (2007) conducted experimental research on the inclusion of
silica smoke on the strength properties of fibrous ferrocement using round steel
fibers. The addition of round steel fibers in the ferrocement mixture has shown
significant improvements in some mechanical properties, such as toughness and
impact resistance.
Liegood Atual et al. (2007) studied microstructural analysis with different
combinations of wire mesh reinforcement. Panels of different combinations were
tested for flexibility under identical distributed loads, and its deflection and
fracture patterns were studied
3.3 STUDIES FROM EUROPE
Ferrocement as a roof has been used successfully for many years European and
South American countries. Large ferrocement roofs were built in Italy.
Onet and Maguire (1993) attempted to study the linear behavior of ferrocement
beams under long-term loading. Their results suggest that long-term deflections
affect the behavior of the beam more than instantaneously.
Maton (1995) conducted a study on the design and testing of the ferrocement
roof element. This study proposes operational steps for the development of
common roofing element and equipment required for small-scale production.
Gurdev Singh and Guang Jing Jiang (1995) conducted a study on the rational
evaluation of flexible fatigue properties of ferrocement for reliable design. A
study based on the stress-life (S-N) plot and a new method based on the
likelihood-stress-life (P-SN) for the design of flexible fatigue properties of
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ferrocement. The study concluded that the rectangular pressure distribution is
relatively more reliable and economical for estimating stress when designing
ferrocement against fatigue using the P - S - N relation of the air tested wire.
Ramesh and Vickridge (1996) attempted to develop a computer program FA
OFFERS to predict the last moment of ferrocement in elasticity. The study
demonstrates that the FA Offers program is in good agreement with the
experimental values and is easy to use.
Nedwell and Nakasa (1999) conducted an experimental study of high-
performance ferrocement. The results show that stainless steel and silica fume
improve the first crack load, increase the number of cracks and reduce the width
of the crack m in addition to cost-effectiveness.
Pankaj et al. (2007) conducted a study on the mechanical behavior of
ferrocement composite-numerical simulations. The authors propose an
anisotropic elastoplastic model to simulate the mechanical behavior of the
ferrocement plates. The study shows that the mortar ferrocement layer model
works best with orthotropic ferrous layer. It was also determined that the same
set of physical properties could be used to simulate the behavior of the
ferrocement plates outside the aircraft load as well as the loading on the aircraft.
3.4 STUDIES FROM USA
Naumann and Homerich (1986) proposed a general methodology for the
analysis and design of ferrocement flexural elements. The proposed method and
the developed design chart are very simple and can be used to estimate the
flexible resistance of the ferrocement element.
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Balaguru et al. (1990) proposed an analytical model to study the flexibility of
the ferrocement flexural element. The study concluded that the type of
reinforcement distribution and the ratio of reinforcement to some extent affect
not only plasticity but also increased flexibility in the thin section. The literature
suggests that ferrocement elements of various shapes can be used as roofs in
developing countries.
Honey et al. (2004) conducted experimental and analytical research on the
composite beams of ferrocement concrete. Different types of beams with
different types of mesh are tested for failure in the two-point loading system. The
study concluded that the proposed composite beam has good ductility, cracking
strength and ultimate efficiency.
In this thesis, an attempt has been made to obtain a proper ferrocement
component. Hence a brief review of optimization techniques. The following is a
literature review of studies conducted on the optimization of ferrocement
elements and reinforced cement concrete elements:
There have been many investigations into various optimization techniques to
optimize the fabrication cost of different sizes of ferrocement elements and the
design of reinforced concrete structures (Rajeev et al., 1998).
Goldberg (1989) introduces the genetic algorithm (GO) approach to engineering
optimization. It has important applications in structural optimization problems.
This approach has been used by many researchers to optimize the shape and
cross-section of structural elements.
Rajeev and Krishnamurthy (1992) extend the application of GA in discrete
design variables to optimize the minimum weight of steel trusses as buckling
strength in the form of deflection and deflection.
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Shyam Prakash, Rajiv and Mathews (1995) conducted an analytical study to
obtain the optimal design method for Ribbed ferrocement Roof / Floor Elements
using GA. The variables to be considered are cross-sectional shape and
descriptions of reinforcement.
The study concluded that the GA-based design optimization method provides
methods for real-time modeling that leads to rational solutions.
Kalyanimay Deb (2004) published a book on the introduction of genetic
algorithms. The author recognizes that the simplest genetic algorithm is an
optimization technique that relies on analogy with nature, and a simple analogy
can be made with the mathematical problem, which consists of several
parameters. These parameters can replace the chromosome in the mathematical
similarity of a real chemical sequence. The author suggests the steps and
operation of simple genetic algorithms.
Govindaraj and Ramasamy (2006) published a paper on the optimal design of
reinforced concrete rectangular columns using genetic algorithms. Their study
concludes that the optimal design model using GA provides practical practical
design considerations such as width and depth of column sections, such as
predefined discrete variations, detail and reinforcement bar detail. He proposed a
new optimization method that is less complex in mathematics.
Pranab Agarwal and Anne M. Raich (2006) conducted a study on the design
and optimization of steel trusses using GA parallel computing and human-
computer interactions. The authors conducted a study on hybrid structural design
and optimization method, which combines the strength of GA to develop optimal
truss systems. GA’s application for the design and optimization of the truss
system supports conceptual
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Castillo and Lima (2007) performed an analytical study on the cost optimization
of lattice reinforced joist slabs using genetic algorithms with fixed variables. The
results indicate that the GA method is a viable optimization tool for solving the
cost optimization problem for lattice reinforced joist slabs.
3.5 Summary of the literature review
From the review of the literature, the following points have been identified,
1. There have been a large number of studies in the past on the strength and
behavior of Ferrocement elements subject to stress, compression and flexibility.
2. In most of these studies, small-scale sampling models have been used in
research. Only a few attempts on large scale or prototype elements have been
considered. However, it can be observed that it is appropriate to consider the
structural elements of the model to demonstrate the actual behavior of the
structural elements.
3. An attempt has been made to obtain the relationship between the final load
and the specific surface of the ferrocement with variables such as strength
parameters such as first crack load and volume load.
4. In all previous research the fine aggregates used for making Ferrocement
mortar are simple river sand. However, as river sand becomes more scarce,
alternatives to river sand can be explored for the optimal cost of ferrocement
elements.
5. In the past, an attempt has been made to rely entirely on the laboratory
facilities, strength, and rigidity of the total dimensions of the Ferrocement
flexural elements.
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6. No attempt has been made to obtain the optimum cross-sectional shape of
the Ferrocement elements with respect to (a) flexibility (b). strength (b) deflection
(c) cracking and (d) cost.
7. Previous efforts have been limited to studies on the power and behavior of
individual subjects. However, investigations into the joint action of the elements
have not been reported. It would have made more sense if it had been studied. On
the strength and behavior of a roof or floor structure consisting of several
elements.
8. The matrix of Ferrocement n consists of cement, fine aggregates and
water. No attempt has been made to improve the properties of ordinary cement
mortars through a special process such as polymerization, which improves the
overall properties of many engineering properties such as tensile strength,
fracture toughness and tensile strength.
9. In previous studies, the combined effects of optimum cross-section and
polymer modification on prototype ferrocement elements have not been
maintained
From the comments above, that effort can be observed
1. Optimization of Ferrocement structural elements
2. Effect of polymer modification on the strength, hardness, fracture behavior
and ductility of Ferrocement elements
3. There is no mixed effect on the above.
There is therefore a gap in current knowledge that suggests there is research to
fill the above gap.
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4 MECHANICAL PROPERTIES OF
FERROCEMENT 4.1 Introduction
During the late sixties and seventies, considerable amount of research has been
conducted on the mechanical properties of ferrocement the information presented
in this section is based on these extensive studies the discussion primarily deals
with ferrocement reinforced with welded or woven square
4.2 Behavior in compression
It is reasonable to expect that the behavior in compression will be generally
similar to that of cement mortar modified by the presence of reinforcement
increases in the ultimate strain due to confining effect and increase the
compressive strength are possible.
On the basis of the test of Atcheson and Alexander, Sabnis and naaman concluded
that whereas welded wire mesh increases the compressive strength hexagonal or
expanded metal may not be very effective due to possible longitudinal spreading
of the composite. the experimental results of pama showed that under
compression, the ultimate compressive strength is lower than that of an
equivalent pure mortar.
Desayi and Joshi investigated the ultimate strength in compression of
ferrocement wall elements. They found that some of the conventional formula
for reinforced concrete gave good predictions.
While the role of the reinforcement in modifying the compression characteristics
of ferrocement cannot be underestimated in view of several variables related to
the reinforcement, it might be provincial to adopt a lower bound approach foe
47 | P a g e
design and analysis, considering the characteristics of the plain mortar and by
considering the peak and ultimate strains to be 3.5 x 10^-3 respectively.
4.3 Behavior in tension
Ideally, ferrocement acts as a homogeneous material in the elastic range and the
stress of the composite material is obtained from the laws of the mixture when a
ferrocement specimen is subjected to increasing tensile load, three stages of
behavior are observed these stages are classified according to the width of cracks
as described by walkus and are shown in table experimental studies on the
behavior of ferrocement specimens in tension show a typical stress strain curve
as shown. A brief description of the stress strain curve of ferrocement at different
stress levels are described as follows.
4.4 Elastic Range
The stress curve is essentially linear in this stage there is no evidence of any crack
formation even when observed under magnificent the limit of elasticity o
ferrocement is also higher than that of the unreinforced concrete.
With a further increase in stress, ferrocement becomes quasi elastic the micro
cracks are invisible to the naked eye and are difficult to observe even when
optical instruments are used these two stages linearly elastic and quasi elastic
constitute the practical elastic working range of ferrocement
4.5 Cracked range
These stage can be termed as the multiple cracking stage. theoretically, these
stages start with the occurrence of the first crack in the matrix and continuous up
to the point where the wire meshes starts to yield in the range of loading, the
number of cracks keeps increasing with an increase in tensile stress of strain.
However, the crack width increases with very small amount the increase in strain
48 | P a g e
which occur under larger load is distributed through a greater number of cracks,
instead of widening the existing cracks. The cracks are very fine in the stage and
it has been observed to a function of the specific surface of the reinforcement.
4.6 Yield range
As a load increased, the process of crack winding continuous at a uniform rate
the maximum number of cracks that are going to develop have already developed
before this stage increases in mortar strain is caused by increases in width of
cracks. Composite action between the mortar and reinforcement concrete
continuous up to the attainment of crack width about 100 microns and thereafter,
the reinforcement carries all the tensile forces.
4.7 Behavior in various stages
In the elastic stage, the stress strain relationship can be defined using a single
elastic constant, namely the young’s modulus of the ferrocement composite. The
modulus of the ferrocement, which will be the function of the module of mortar
and reinforcement and their relative volume fractions can be expressed as
During the multiple cracking stage, the contribution of mortar to the stiffness of
the composite decreases progressively hence, the stiffness of the composite and
the slope of the stress strain curve, decrease from an upper bond value represented
by equation to a lower bound value in which the contribution from mortar
becomes zero the lower bound value of modulus of elasticity can be obtained by
simple substituting zero for Em in equation
49 | P a g e
4.8 Cracking behavior
It has been observed that everything else the higher the volume of reinforcement
and smaller the diameter of wires, the larger the extent of multiple cracking stage
the larger the number of the cracks developed in the same gaugage length the
smaller the final crack spacing and the smaller the crack width a parameter which
is found critical in determining the cracking behavior is a specific surface of
reinforcement which is defined as the lateral surface of the reinforcement per unit
volume of the composite. It shows the plot of composite stress at first crack verus
the specific surface of reinforcement. It can be seen from the composite stress at
first cracking increase with increasing value of specific surface. naaman has
proposed an empirical formula for the first cracking strength
In the multiple cracking stages, with the increase of load more cracks will be
formed and the crack spacing will decrease till a limiting stage is reached after
which no further cracks will appear. Naaman and shah observed that the average
cracks spacing at failure, decreased with the increasing specific surface of the
reinforcement for ferrocement with woven and welded square meshes.
In their tests on ferrocement pipes, geuerra et al observed that for the same stress
in the reinforcement, average crack width in ferrocement is considerably smaller
than the crack widths in reinforced concrete.
The high value of the specific surface for ferrocement (which typically 10 times
that for reinforced concrete), and the close spacing of the transverse
reinforcements results in closer spacing of the cracks.
50 | P a g e
4.9 BEHAVIOUR IN FLEXURE
The behavior of ferrocement in flexure can be studied using a typical load-
deflection curve. As in the case of tension behavior, the load-deflection curve can
be divided into three regions or stages, post-cracking stage and post-yielding
stage. The entire discussion presented in this section is based on the following
assumptions.
1) Plane sections remain plane and perpendicular to the neutral axis strains in
mortar and reinforcement or directly proportional to their distances from the
neutral axis.
2) The behaviour of reinforcement is elastic-perfectly plastic
3) Tensile strength of mortar is neglected in flexural strength calculations of
cracked beams
4) Maximum usable compression fibre strain is 0.003mm/mm.
5) For the strength calculation at ultimate load, and parabolic stress strain
distribution of mortar can be approximated to a rectangular distribution using the
procedure given by ACI code
51 | P a g e
4.10 Pre-cracking or elastic range
Ferrocement has the highest stiffness in the stage. In this stage mortar contribute
to both compressive and tensile resistance of the ferrocement composite. The
strength and stiffness of the beam can be calculated using the classical bending
theory.
Figure 10. Distribution of strains, stressed and forces for the uncracked section
of the beam
Referring to Fig. 5, the resisting moment of the cross section, can be written as.
M=1
6𝑏ℎ2𝑓𝑟 + ∑ 𝐴𝑠𝑖𝑓𝑠𝑖𝑗𝑑𝑖
𝑚𝑖=1
52 | P a g e
Where Cm is the total compressive force in mortar
Tm is the total tensile force in mortar
h is the thickness.
Asi is the total area of the i-th layer of reinforcement.
fsi in the stress in the i-th layer of reinforcement.
Jdi is the lever arm of the ith layer of reinforcement, measured from neutral axis
m is the number of layers of reinforcement.
Cm=1
4𝑏ℎ𝑓𝑚
where is the width of beam is the mortar stress in the extreme compression or
tension fibre Substituting equation.
M=1
6𝑏ℎ2𝑓𝑟 + ∑ 𝐴𝑠𝑖𝑓𝑠𝑖𝑗𝑑𝑖
𝑚𝑖=1
Equation (7) can be used to calculate the moment of resistance of the section up
to the where find tensile crack occurs.
For calculating the moment at first cracking, Mcr substitute for fin equation where
is the modulus of rupture of mortar.
M=1
6𝑏ℎ2𝑓𝑟 + ∑ 𝐴𝑠𝑖𝑓𝑠𝑖𝑗𝑑𝑖
𝑚𝑖=1
53 | P a g e
4.11 Post tracking Range.
This range starts with the occurrence of first crack and extends up to the point
where the extreme tension fibre of reinforcement starts yielding.
After cracking, the tensile force contribution of mortar is negligible compared to
the contribution of reinforcement and hence Tm can be assumed to be zero.
Figure 11. Distribution of strains, stress and forces for the cracked section of the beam
Referring to Fig (6), the neutral axis depth (c), of the cracked section can be
calculated by using the force equilibrium equation,
54 | P a g e
𝑏𝑐
2𝑓𝑚 = ∑ 𝐴𝑠𝑖𝑓𝑠𝑖
We have,
𝑓𝑚 = 𝐸𝑚𝜀𝑒
𝑓𝑠 = 𝐸𝑅𝜀𝑠𝑖
𝑠𝑐
𝑠𝑠𝑖=
𝑒
(𝑑𝑖−𝑒) n=
𝐸𝑟
𝐸𝑚
using the above equation, equation (8) can be rewritten as,
𝑏𝑐
2𝑓𝑚 = 𝑛 ∑ 𝐴𝑠𝑖(𝑑𝑖 − 𝑐)
The resisting moment M is,
𝑀 =𝑏𝑐2
3𝑓𝑚 + ∑ 𝐴𝑠𝑖𝑓𝑠𝑖(𝑑𝑖 − 𝑐)2
Equation (10) can also be written in a form convenient to calculate the stresses in
mortar and reinforcement as follows:
𝑓𝑚 =𝑀
𝐼𝑐𝑟𝑐
𝑓𝑠𝑖 =𝑚
𝐼𝑐𝑟
(𝑑𝑖 − 𝑐)𝑛
where equation is the moment of inertia of the cracked section, calculated using
the following
𝐼𝑐𝑟 =𝑏𝑐2
3+ ∑ 𝑛𝐴𝑠𝑖 (𝑑𝑖 − 𝑐)2
55 | P a g e
The above equations (9) to (13) are useful in the design calculations in the post
cracking, pro yielding stage of loading.
4.12 Simplified equations
The equation (7a) can be simplified as follows:
Assuming that the wire meshes are continuously distributed throughout the
sections, Volume fraction,
𝑉𝑅𝐿 =∑ 𝐴𝑠𝑖
𝑏ℎ
Then 𝑀𝑐𝑟 given by equation (7) can be written as,
𝑀𝑐𝑟 =1
6𝑏ℎ2𝑓𝑟[1 + (𝑛 − 1)𝑉𝑅𝐿
where n is the modulus ratio 𝐸𝑅/𝐸𝑛.
Also moment of inertia of the uncracked section, can be written as.
𝐼𝑔 =1
12𝑏ℎ2[1 + (𝑛 − 1)𝑉𝑅𝐿
4.13 PREDICTION OF CRACK WIDTH
4.13.1 Uniaxial tensile members
Based on the experimental results, the following empirical formula equations
were proposed by Naaman for predicting the width of the crack.
When stress in steel 𝑓𝑠 is less than yield strength and in any case less than
400Mpa,he considered two situations.
(1) 𝑓𝑠 < 345𝑆𝑅𝐿
56 | P a g e
𝑊𝑚𝑎𝑥 =3500
𝐸𝑅
Where 𝑓𝑠 is in Mpa,
𝑆𝑅𝐿 is in c𝑚2/𝑐𝑚3
𝑊𝑚𝑎𝑥𝑖𝑠 𝑡ℎ𝑒 𝑐𝑟𝑎𝑐𝑘 𝑤𝑖𝑑𝑡ℎ 𝑖𝑛 mm 𝑎𝑛𝑑
𝐸𝑅 𝑖𝑠 𝑖𝑛 𝑀𝑝𝑎
(2)for 𝑓𝑠 > 345𝑆𝑅𝐿
𝑊𝑚𝑎𝑥 =20
𝐸𝑅[175 + 3.169(𝑓𝑠 − 345𝑆𝑅𝐿)]
4.13.2 Flexural members
The average width of the cracks was expressed as a function of strain at the
tension face and the spacing of transverse wires.
𝑊𝑎𝑣 = 𝑠𝛽𝜀𝑠
where
E, is the strain in the outermost layer of steel.
s is the mesh opening size.
where c is the depth of neutral axis calculation using elastic crack section
analysis d'mart is the depth measured to the extreme tension Iayer.
𝑓𝑠 =𝑀
𝐼𝑐𝑟
(𝑑𝑚𝑎𝑥 − 𝑐)
𝜖𝑠 =𝑓𝑠
𝐸𝑟
57 | P a g e
4.14 IMPACT AND FATIGUE BEHAVIOUR
In comparison with unreinforced mortar, ferrocement has a high impact
absorption capacity. Studies on the behaviour of ferrocement subjected to impact
loading have been reported by Shah and Key [10]. They found that impact
behaviour of ferrocement was considerably influenced by the reinforcement
characteristics. Impact resistance and reduction in impact damage improved with
increasing specific surface and ultimate strength of reinforcement. For the same
volume of reinforcement, increase in specific surface increases the impact
strength.
For equal value of reinforcement percentage, welded-wire meshes offer the
highest impact resistance. In comparison, the specimens reinforced with chicken
wire mesh off the lowest impact resistance. Woven mesh reinforcements provide
impact strength lugha than the chicken wire meshes but lower than welded wire
meshes.
Fatigue failure of ferrocement flexural specimens is governed by the tensile
fatigue properties of the mesh, just as for reinforced and pre stressed concrete
beams. Based on regression analysis of the experimental data, proposed the
following aqua relating the fatigue failure with the stress in steel.
𝑓𝑠𝑟 = 1051 − 137𝑙𝑜𝑔10𝑁𝑓
where fu-stress range in the outermost layer of steel in MPa.
N- number of cycles to failure.
58 | P a g e
5 METHODOLOGY 5.1 Introduction
In this study the ferrocement panel will be studied for varying thickness of about
25mm, 30mm, 35mm and 40mm and maintain a constant loading of 10KN, 15KN
and 20KN we studied the defecation parameter for performance analysis for each
ferrocement slab panels.
5.2 MATERIAL USED, DESIGN AND CONSTRUCTION
The properties and types of constituent material used in ferrocement construction
are shown in table 1. Although meshes of glass and vegetable fibers have been
used, the most common form involved steel and it is this type that is described in
this paper. The cement mortar matrix should be designed for appropriate strength
and maximum denseness and impermeability, with sufficient workability to
minimize voids. The use of sharp fine grade sand as aggregate together with
ordinary Portland cement is generally adequate, despite the low covers employed.
This is due to the comparatively high cement content in the mortar matrix.
The strength of the ferrocement composite made with varying steel content, types
of mesh, wire size, mesh size and number of layers have been investigated and
reported previously. Design guidelines, adequate for most applications, have
been published. These include recommendations concerning surface area per unit
volume of mesh reinforcement, cover, ultimate strength in flexure and
serviceability requirements of cracking. However, no particular deflection
limitations are recommended as most ferrocement members and structures are
thin and very flexible and their design is very likely to be controlled by design
criteria rather than deflection. Stresses in flexural members may also be checked
at service loads.
59 | P a g e
Several means are used in the construction of ferrocement but all methods seek
to achieve the complete infiltration of several layers of reinforcing mesh by a
well compacted mortar matrix with a minimum of entrapped air. The choice of
the most appropriate construction technique depends on the nature of the
particular ferrocement applications, the availability of mixing, handling and
placing machinery, and the skill and cost of available labor. After compaction,
proper curing is essential to develop the desired properties of the mortar matrix.
60 | P a g e
Figure 12. PROPERTIES AND TYPES OF CONSTITUENTS MATERIALS
USED IN FERROCEMENT CONSTRUCTION
61 | P a g e
5.3 SPECIFICATION OF MATERIALS
We have assumed the following,
Slab dimensions
Length – 1000millimetre
Breath – 1000millimetre
Thickness – 25 to 40millimetre
Mesh diameter: 1.5mm
Square mesh will be used as reinforcement
Volume factor = 6%
Yield strength = 400 N/mm2
Ultimate tensile strength = 500 N/mm2
Skeleton/Steel Bar
Diameter = 6mm
Void size = 150mm
Yield strength = 30 N/mm2
Compressive strength of mortar is 30 N/mm2
Ultimate tensile strength = 500 N/mm2
Mortar Composition
Cement- OPC = 43 grade cement
Sand = 1:3 by weight
W/C ratio = 0.5 by weight
62 | P a g e
5.4 LOADING PATERN AND PARAMETER STUDY
LOAD APPLIED 10 KN
Thickness of
Slab (mm)
One Layer of
Mesh
Reinforcement
Two Layer of
Mesh
Reinforcement
Three Layer of
Mesh
Reinforcement
25mm 39.2 mm 31.2 mm 22.2 mm
30mm 42.6 mm 32.8 mm 26.4 mm
35mm 46.2 mm 33.4 mm 28.9 mm
40mm 47.1 mm 34.45 mm 30.12 mm
LOAD APPLIED 15 KN
Thickness of
Slab (mm)
One Layer of
Mesh
Reinforcement
Two Layer of
Mesh
Reinforcement
Three Layer of
Mesh
Reinforcement
25mm 41.2 mm 32.3 mm 24.6 mm
30mm 43.6 mm 34.2 mm 26.4 mm
35mm 47.2 mm 36.2 mm 28.6 mm
40mm 49.25 mm 34.4 mm 32.1 mm
LOAD APPLIED 20 KN
Thickness of
Slab (mm)
One Layer of
Mesh
Reinforcement
Two Layer of
Mesh
Reinforcement
Three Layer of
Mesh
Reinforcement
25mm 42.6 mm 33.4 mm 26.1 mm
30mm 44.5 mm 35.6 mm 29.4 mm
35mm 48.6 mm 37.3 mm 31.12 mm
40mm 50.08 mm 35.41 mm 34.6 mm
Table 1. LOADING PATTERN AND PARAMETER STUDY
63 | P a g e
Figure 13. CONSTAL LOAD OF 10KN VARYING SLAB THICKNESS WITH VARYING MESH REINFORCEMENT
A constant load of 10KN is been applied on a Ferrocement slab with slab
thickness being 25 mm, 30 mm, 35 mm and 40 mm, along with varying meshes
used as reinforcement in single, double and three layers and the when the load
was applied the slab was found to have the deflections as above shown on the
graph.
39.2
42.6
46.247.1
31.2
32.8 33.434.42
22.2
26.4
28.930.12
0
5
10
15
20
25
30
35
40
45
50
20 25 30 35 40 45
DE
FL
EC
TIO
N
FO
R P
OIN
T L
OA
D A
PP
LIE
D
THICKNESS OF SLAB
CONSTAL LOAD OF 10KN VARYING SLAB THICKNESS WITH
VARYING MESH REINFORCEMENT
SINGLE LAYER OF MESH REINFORCEMENT DOUBLE LAYER OF MESH REINFORCEMENT
THREE LAYER OF MESH REINFORCEMENT
64 | P a g e
Figure 14. CONSTAL LOAD OF 15KN VARYING SLAB THICKNESS WITH VARYING MESH REINFORCEMENT
A constant load of 15KN is been applied on a Ferrocement slab with slab
thickness being 25 mm, 30 mm, 35 mm and 40 mm, along with varying meshes
used as reinforcement in single, double and three layers and the when the load
was applied the slab was found to have the deflections as above shown on the
graph.
41.2
43.6
47.249.25
32.334.2
36.234.4
24.6
28.6 27.78 32.1
0
10
20
30
40
50
60
20 25 30 35 40 45
DE
FL
EC
TIO
N
FO
R P
OIN
T L
OA
D A
PP
LIE
D
THICKNESS OF SLAB
CONSTAL LOAD OF 15KN VARYING SLAB THICKNESS WITH
VARYING MESH REINFORCEMENT
SINGLE LAYER OF MESH REINFORCEMENT DOUBLE LAYER OF MESH REINFORCEMENT
THREE LAYER OF MESH REINFORCEMENT
65 | P a g e
Figure 15. CONSTAL LOAD OF 20KN VARYING SLAB THICKNESS WITH VARYING MESH REINFORCEMENT
A constant load of 15KN is been applied on a Ferrocement slab with slab
thickness being 25 mm, 30 mm, 35 mm and 40 mm, along with varying meshes
used as reinforcement in single, double and three layers and the when the load
was applied the slab was found to have the deflections as above shown on the
graph.
42.6
44.5
48.650.08
33.4
35.637.3
35.41
26.1
29.431.12
34.6
0
10
20
30
40
50
60
20 25 30 35 40 45
DE
FL
EC
TIO
N
FO
R P
OIN
T L
OA
D A
PP
LIE
D
THICKNESS OF SLAB
CONSTAL LOAD OF 20KN VARYING SLAB THICKNESS WITH
VARYING MESH REINFORCEMENT
SINGLE LAYER OF MESH REINFORCEMENT DOUBLE LAYER OF MESH REINFORCEMENT
THREE LAYER OF MESH REINFORCEMENT
66 | P a g e
Figure 16. VARYING LOAD ON CONSTANT THICKNESS ON THE SLAB - 25 mm
When the thickness of the slab was kept as constant about 25mm with varying
loads of 10KN, 15KN and 20KN along with varying meshes used as
reinforcement in single, double and three layers and when the load was applied
the slab was found to have deflections as above shown on the graph.
39.2
41.242.6
31.232.3
33.4
22.2
24.6
26.1
0
5
10
15
20
25
30
35
40
45
0 5 10 15 20 25DE
FL
EC
TIO
N
FO
R
PO
INT
LO
AD
AP
PL
IED
VARYING LOAD
VARYING LOAD ON CONSTANT THICKNESS ON THE SLAB - 25mm
SINGLE LAYER MESH REINFORCEMENT OF 25 MM THICKNESS
DOUBLE LAYER MESH REINFORCEMENT OF 25 MM THICKNESS
TRIPLE LAYER MESH REINFORCEMENT OF 25 MM THICKNESS
67 | P a g e
Figure 17. VARYING LOAD ON CONSTANT THICKNESS ON THE SLAB - 30 mm
When the thickness of the slab was kept as constant about 30mm with varying
loads of 10KN, 15KN and 20KN along with varying meshes used as
reinforcement in single, double and three layers and when the load was applied
the slab was found to have deflections as above shown on the graph.
42.643.6
44.5
32.834.2
35.6
26.4
28.629.4
0
5
10
15
20
25
30
35
40
45
50
5 10 15 20 25
DE
FL
EC
TIO
N
FO
R P
OIN
T L
OA
D A
PP
LIE
D
VARYING LOAD
VARYING LOAD ON CONSTANT THICKNESS ON THE SLAB - 30mm
SINGLE LAYER MESH REINFORCEMENT OF 30MM THICKNESS
DOUBLE LAYER MESH REINFORCEMENT OF 30MM THICKNESS
TRIPLE LAYER MESH REINFORCEMENT OF 30 MM THICKNESS
68 | P a g e
Figure 18. VARYING LOAD ON CONSTANT THICKNESS ON THE SLAB - 35 mm
When the thickness of the slab was kept as constant about 35mm with varying
loads of 10KN, 15KN and 20KN along with varying meshes used as
reinforcement in single, double and three layers and when the load was applied
the slab was found to have deflections as above shown on the graph.
46.247.2
48.6
33.4
36.237.3
28.9 29.7831.12
0
10
20
30
40
50
60
5 10 15 20 25
DE
FL
EC
TIO
N
FO
R P
OIN
T L
OA
D A
PP
LIE
D
VARYING LOAD
VARYING LOAD ON CONSTANT THICKNESS ON THE SLAB - 35mm
SINGLE LAYER MESH REINFORCEMENT OF 35MM THICKNESS
DOUBLE LAYER MESH REINFORCEMENT OF 35MM THICKNESS
TRIPLE LAYER MESH REINFORCEMENT OF 35 MM THICKNESS
69 | P a g e
Figure 19. VARYING LOAD ON CONSTANT THICKNESS ON THE SLAB - 40 mm
When the thickness of the slab was kept as constant about 40mm with varying
loads of 10KN, 15KN and 20KN along with varying meshes used as
reinforcement in single, double and three layers and when the load was applied
the slab was found to have deflections as above shown on the graph.
47.1
49.2550.08
34.42 34.435.41
30.12
32.1
34.6
0
10
20
30
40
50
60
5 10 15 20 25
DE
FL
EC
TIO
N
FO
R P
OIN
T L
OA
D A
PP
LIE
D
VARYING LOAD
VARYING LOAD ON CONSTANT THICKNESS ON THE SLAB - 40mm
SINGLE LAYER MESH REINFORCEMENT OF 40 MM THICKNESS
DOUBLE LAYER MESH REINFORCEMENT OF 40MM THICKNESS
TRIPLE LAYER MESH REINFORCEMENT OF 40MM THICKNESS
70 | P a g e
6 CONCLUSION
For 25mm thickness ferrocement slab panel of constant loading of 10KN
if the layer of reinforcement if increased from one layer to two layers then
deflection is decreased about 20.4% and when increased from two layer to
three layer the deflection is decreased about 28.84%
For 30mm thickness ferrocement slab panel of constant loading of 10KN
if the layer of reinforcement if increased from one layer to two layers then
deflection is decreased about 23% and when increased from two layer to
three layer the deflection is decreased about 19.51%
For 35mm thickness ferrocement slab panel of constant loading of 10KN
if the layer of reinforcement if increased from one layer to two layers then
deflection is decreased about 27.70% and when increased from two layer
to three layer the deflection is decreased about 13.47%
For 40mm thickness ferrocement slab panel of constant loading of 10KN
if the layer of reinforcement if increased from one layer to two layers then
deflection is decreased about 26.85% and when increased from two layer
to three layer the deflection is decreased about 12.5%
The load is being increased in in an increment of 5% from 10KN and an
increment of 33.33% from 15KN and we have seen the deflection is
decreased in the increase in the layer of mesh reinforcement.
In India, Ferrocement is often used because the structures made from it are
more resistant to earthquakes. It has many uses, including sculpture and
prefabricated building blocks.
Ferrocement has been widely used for the past two decades and is still in
its infancy.
71 | P a g e
Adequate design information is available and sufficient field experience is
obtained to enable the safe design and construction of Ferrocement
structures.
Whether or not it can compete economically with alternative materials
depends on the type and location of the application.
72 | P a g e
7 REFRENCES 1. Nathan, G.K. and Paramasivam, P., (1974). Mechanical Properties of
Ferrocement Proc. First Australian Conference on Engineering Materials,
Sydney, 309-331.
2. Paramasivam, P. and Sri Ravindrarajah, R. (1988) Effects of Arrangements
of Reinforcements on Mechanical Properties of Ferrocement. ACI
Structural Journal 85: 1, 3-11.
3. Ong, K.C.G., Paramasivam, P. and Lim, C.T.E. (1992). Flexural
Strengthening of Reinforced Concrete Beams Using Ferrocement
Laminates. Journal of Ferrocement 22:4, 331-342
4. Lee, S.L., Tam, C.T., Paramasivam, P., Das Gupta, N.C., Sri
Ravindrarajah, R. and Mansur, M.A (1988). Ferrocement: Ideas Tested at
the University of Singapore. Concrete International: Design and
Construction 5:11, 12-14.
5. Naaman, A.E and Shah, S.P. Evaluation of ferrocement in some structural
applications Proceedings IAHS Symposium, Atlanta, 1976, n. 1069-1085.
6. Desayi, P and Ganesan N. Performance of the ferrocement roof an
Experimental low-cost House, proceedings of the Asia-Pacific
symposium, University of Roorkee, April 23-25.
7. ACI Committee. 549, State of the Art-report on Ferrocement, Concrete
International. August, 1982, pp.13-38.
8. New Reinforced Concrete, Ed. R.N. Swamy, VOL2, Concrete Technology
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