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CHAPTER II
LITERATURE REVIEW
Definition of Ferrocement/Ferrogrout
As the material ferrocement was used for a long time in boat building and
similar allied structures rather than in structural applications, a rigorous engineering
definition of ferrocement was not followed. Within ACI Committee 549, a
considerable discussion on its definition eoled and it was agreed to group together
arious aailable definitions from man! sources to come up with a concise and
accurate definition that ma! be acceptable to the engineering profession. "ome
definitions considered b! the committee are presented here.
#igg $%9&'( has discussed the problem of definition in detail. )e pointed out
that according to the American #ureau of "hipping it is*
+A thin, highl! reinforced shell of concrete in which the steelreinforcement is distributed widel! throughout the concrete, so that the
material under stress acts approimatel! as a homogenous material.
-he strength properties of the material are to be determined b! testing a
significant number of samples....
Although at first glance, the aboe definition seems an acceptable one, it
brought about a number of /uestions on the words italicised therein, which ma! hae
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different meanings of ferrocement to different people. #igg went on to discuss arious
aspects of ferrocement, suggests arious wa!s of defining it, such as a composite
material and points out how the aailable engineering approach for composites of fiber
reinforced concrete ma! be used to come up with a definition of ferrocement.
As a two0component composite, made up of reinforcement and mortar $matri(,
#e1u2lado $%9&'( defined it in terms of the ratio of the surface area of reinforcement
to the olume of, the composite. In this manner, ferrocement is separated from the
conentional reinforced concrete. "omewhat arbitraril!, he assigned the specific
surface greater than 3cm3cm to ferrocement which then behaes more or less as a
homogenous material. 6ess than 3cm3cmis considered reinforced concrete.
"hah $%974( in discussing different materials of construction, defined
ferrocement in a manner similar to #e1u2lado. )e called it a composite made with
mortar and a fine diameter continuous mesh as reinforcement, with which has higher
bond due to its smaller si1e and a larger surface area per unit olume of mortar.
Accordingl!, this ratio ma! be as mush as ten times that which is obsered in
conentional reinforced concrete8 this results in failure of ferrocement in tension b! the
actual brea2ing of wire mesh and a much higher crac2ing strength in the matri.
As a composite, certain characteristics of ferrocement ma! thus be summarised
as follows*
a. "ince the wire mesh $reinforcement( is much stronger in tension compared to
the matri $mortar(, the role of the matri is to properl! hold the mesh in place,
to gie a proper protection and to transfer stresses b! means of ade/uate bond.
b. Compression strength of this composite is generall! a function of the matri
$mortar( compressie strength, while the tensile strength is a function of the
mesh content and its properties.
c. It follows from $b( aboe that the stress0strain relationship of ferrocement in
tension ma! show either a complete elastic behaiour $up to fracture of
reinforcing mesh( or some inelasticit! depending upon the !ielding properties
of the mesh.
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d. "ince the properties of this composite are er! much a function of orientation of
the reinforcement, the material is generall! anisotropic and ma! be treated as
such in the theoretical anal!sis.
-he aboe discussion indicates the ariet! of approaches that hae been made
in a structural definition of ferrocement. It became apparent to the ACI Committee
549 that the first tas2 should be to define errocement as a construction material.
Accordingl!, the following definition was adopted*
:errocement is a t!pe of thin wall reinforced concrete commonl!
constructed of h!draulic cement mortar reinforced closel! spaced
la!ers of continuous and relatiel! small wire diameter mesh. ;esh
ma! be made of metallic or other suitable materials.:
-he aboe definition implies that although ferrocement is a form of reinforced
concrete, it is also a composite material. )ence the basic concepts underl!ing the
behaiour and mechanics of composites materials should be applicable to ferrocement.
History of Ferrocement/Ferrogrout
-he use of ferrocement was first started as earl! as in %'4'. It too2 the form of
a rowing boat constructed b!
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errocement gained wide acceptance onl! in the earl! %9&=s in @nited
ingdom, ?ew Bealand, and Australia. In %9&5, an American0owned ferrocement
!acht built in ?ew Bealand, the %&m Awahnee, circumnaigated the world twice
without serious problems, although it encountered seeral mishaps.
?eri built a small storehouse of ferrocement in %947 which was
approimatel! %=.7m 3%.m. -his was the first time ferrocement concept in the
applications to building. 6ater he coered the swimming pool at the Italian ?aal
Academ! with a %5m0diameter dome and then the famous -urin hibition )all D a
roof s!stem spanning 9%m. In both cases, ferrocement sered as permanent forms for
the structural s!stem including the main support ribs.
In %95', the technolog! then spread to Eussia with the construction of a
number of structures. amples of these were a ferrocement ault of %7.=m spans in
one of the metro stations in 6eningrad and the interior of a hall coered with
ferrocement elements.
-he more recent ferrocement structures include the "!dne! Fpera )ouse, built
in %97. errocement tiles were used as surfacing on the aults of the Fpera )ouse, a
maGor arts centre in "!dne!. "imilar beautiful buildings and mos/ue were built in
India and Indonesia using ferrocement.
Advntges of Ferrocement/Ferrogrout
errocement is particularl! suited to deeloping countries for the following
reasons*
Its basic raw materials are aailable in most countries.
It can be fabricated into almost an! shape to meet the needs of the user8
traditional designs can be reproduced and often improed.
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or properl! fabricated, it is more durable than most woods and cheaper than
imported steel, and it can be used as a substitute for these materials in man!
applications.
-he s2ills re/uired for ferrocement construction are /uic2l! ac/uired, andinclude man! s2ills traditional in deeloping countries. errocement
construction does not need hea! plant or machiner!8 it is labour intensie.
#eing labour intensie, it is relatiel! inepensie in deeloping countries.
cept for sophisticated and highl! stressed designs, as those for deepwater
essels, a trained superisor can achiee the re/uisite amount of /ualit! control
using fairl! uns2illed labour for fabrication.
In case of damage, it can be repaired easil!.
-he beaut! of ferrocement was that it could appear in an! shapes. Fnl!
imagination could limit the forms and shapes of this beautiful and cheap material.
urther uns2illed labour could be emplo!ed to construct the structure. -he material
and labour re/uired are plentiful in the deeloping countries, especiall! in rural areas.
-hese factors ma2e it a er! appropriate material for national deelopments.
Constituent !teri"s
errocement can be diided into two main components* the matri and the
reinforcement.
!tri#
-he matri is a h!draulic cement binder, which ma! contain fine aggregates
and admitures to control shrin2age and set time, and increase its corrosion resistance.
-he binder is itself a composite material consisting of a h!drated cement paste and an
inert filler material.
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Cement
-he cement commonl! used is >ortland cement possibl! blended with
po11olan. -he cement should compl! with A"-; C %5=0'5a, A"-; C 5950'5, or an
e/uialent standard. -he cement should be fresh, of uniform consistenc! and free of
lumps and foreign matter. It should be stored under dr! conditions and for a short
duration as possible. Cement factors are normall! higher in ferrocement than in
reinforced concrete.
;ineral admitures, such as fl! ash, silica fumes or blast furnace slag ma! be
used to maintain a high olume fraction of fine filler material. iller material is
usuall! well0graded sand and this classifies the binder material as a mortar. "ince the
matri represents approimatel! oer 95H of the resulting ferrocement olume, its
ph!sical properties and microstructure, which depend upon the chemical composition
of the cement, the nature of the inert filler, the water0cement ratio and the curing
regime, hae a great influence on the final properties of the product.
Eice )us2 Ash $E)A( cement can be economicall! used as partial replacement
of cement in mortar mies. When E)A does not eceed 5H b! weight of the
blended cement, the compressie strength at 3' da!s is similar to that of -!pe I
>ortland Cement ;ortar.
-he reaction of >ortland cement and water results in formation of hardened
cement paste. -he ranges of mi proportions recommended for common ferrocement
applications are sand0cement ratio b! weight, %.5 to 3.5, and water0cement ratio b!
weight, =.5 to =.5. ineness modulus of sand, water0cement ratio and sand0cement
ratio should be determined from trial batches to insure a mi that can infiltrate
$encapsulate( the mesh and deelop a strong and dense matri. Water reducing
admitures ma! be used to enhance mi plasticit! and retard initial set, as with
conentional concretes. -he behaiour of mortar is similar to that of plain concrete.
-he maGor distinction is the si1e of the aggregate used. In general a good /ualit!
mortar is stronger and more durable than good /ualit! concrete8 howeer, their basic
response to the enironment is essentiall! the same.
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Fine Aggregtes
?ormal weight fine aggregate $sand( is the most common aggregate used in
ferrocement. It should be clean, hard, strong, and free of organic impurities and
deleterious substances and relatiel! free of silt and cla!. It should be inert with
respect to other materials used and of suitable t!pe with respect to strength, densit!,
shrin2age and durabilit! of the mortar made with it. rading of the sand is to be such
that a mortar of specified proportions is produced with a uniform distribution of the
aggregate, which will hae a high densit! and good wor2abilit! and which will wor2
into position without segregation and without use of a high water content. -he
fineness of the sand should be such that %==H of it passes standard siee ?o. '. -able
3.% gies some guideline on desirable grading.
T$"e %&'( )uide"ine on desir$"e snd grding
*ieve *i+e Percent Pssing
?o. ' '=0%==
?o. %& 5=0'5
?o. = 350&=
?o. 5= %=0=?o. %== 30%=
Admi#ture
Chemical admitures used in ferrocement sere one of the following four
purposes* water reduction, which increases strength and reduces permeabilit!8 air
entrainment, which increases resistance to free1ing and thawing8 and suppression of
reaction between galanised reinforcement and cement.
Reinforcement
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-he reinforcement of ferrocement is commonl! in the form of la!ers of
continuous mesh fabricated from an assembl! of continuous single strands filaments.
"pecific mesh t!pes include woen and welded mesh, epanded metal lath and
perforated sheet products. -here is a wide ariet! in mesh dimensions, as well as in
the amounts, si1es and properties of the materials used.
Wire !es,
Wire mesh is one of the essential components of ferrocement. Jifferent t!pes
of wire meshes are aailable almost eer!where. -hese generall! consist of thin wires,
either woen or welded into a mesh, but the main re/uirement is that it must be easil!
handled and, if necessar!, fleible enough to be bent around sharp corners. -he
function of the wire mesh and reinforcing rod in the first instance is to act as a lath
proiding 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 be able to withstand. A structure is subGected to great deal of pounding,
twisting and bending during its lifetime resulting in crac2s and fractures unless
sufficient steel reinforcement is introduced to absorb these stresses. -he degree to
which this fracturing of the structure is reduced depends on the concentration and
dimensions of the embedded reinforcement. -he mechanical behaiour of ferrocement
is highl! dependent upon the t!pe, /uantit!, orientation and strength properties of the
mesh and reinforcing rod. igure 3.% shows the common t!pe of wire mesh used in
ferrocement industr!.
-he ACI committee 549 on errocement concluded that the definition of
ferrocement could not be limited to steel reinforcing onl!. -he ACI definition of
ferrocement included the statement +;esh ma! be made of metallic material or other
suitable materials. -his definition allows bamboo mesh and mesh made of other
materials to be used for ferrocement structures.
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centre thus acting as a main reinforcing component wire mesh in highl! stressed
structures, for eample boat, barges, tubular sections, and others.
"teel rods of different 2inds are used in ferrocement construction. -heir
strength, surface finish, protectie coating and si1e affect their performance as
reinforcing members of the composite. In general, mild steel rods are used for both
longitudinal and transerse directions. In some cases high tensile rods and prestressed
wires and strands are used. Eod si1e aries from 4.3=mm to 9.5mm whereas &.5mm
is the most common. errocement panels with longitudinal and transerse rods of this
si1e are about 35mm. A combination of different rod si1es can be used with smaller
diameter rod in the transerse direction.
*u$stitute !teri"s
"ome of the substitute materials include bamboo mesh and bamboo s2eletal
reinforcement. Chembi and ?imit!ongs2ul $%9'9( inestigated the use of bamboo
mesh to replace steel wire mesh in ferrocement water tan2. A bamboo cement tan2 of
&mcapacities was constructed in %9'. -he tan2 was 2ept alternatiel! full and
empt! of water to simulate actual field condition and was monitored regularl!. After 5
!ears, the! found that the tan2 has not shown structural defects. #amboo
reinforcement =. m from the top of the tan2 was inestigated and found in good
condition.
;eanwhile, Ken2ateshwarlu and EaG $%9'9( inestigated the use of bamboo to
replace s2eletal steel in ferrocement roofing elements. "labs reinforced with bamboo
strips as s2eletal reinforcement and chic2en wire mesh were subGected to
monotonicall! increasing uniforml! distributed load to stud! the load deflection
behaiour and to determine its sericeabilit! limit $spandeflection(. -he inestigation
showed that b! using bamboo, the cost of roofing elements comes to about 5=H of
reinforced concrete and 7=H of ferrocement elements. -he slabs can be prefabricated
in the factor! or can be produced at the site manuall!. -he sericeabilit! limit was
suggested as %5= and it was obsered, that at deflections up to %=mm, no crac2ing
occurred. )ence, roofing elements can be produced up to a maimum span of %.5m
and can be used in multiples to coer longer span.
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t,er !teri"s
Wter
Water used in the miing is to be fresh and free from an! organic and harmful
solution, which will lead to deterioration in the properties of the mortar. "alt water is
not acceptable but chlorinated drin2ing water can be used. >otable water is fit for use
as miing water as well as for curing ferrocement structures.
Coting
In general, ferrocement structures need no protection unless the! are subGected
to strong chemical attac2 that might damage the structural integrit! of their
components. A plastered surface can ta2e a good paint coating. In terrestrial
structures, ordinar! paint is applied on the surface to enhance the appearance. ;arine
structures need protection against corrosion and in!l and epo! coatings were found
to be the most successful organic coatings.
Pro-erties
errocement, often regarded as Gust another form of reinforced concrete, is
/uite uni/ue with respect to material behaiour and suitabilit! for structural
applications. errocement possesses a degree of toughness, ductilit!, durabilit!,
strength and crac2 resistance that it is considerabl! greater than that found in other
forms of concrete construction. -hese properties are achieed in structures with a
thic2ness that is generall! less than 35mm, a dimension that is nearl! unthin2able in
other forms of concrete construction, and a clear improement oer conentional
reinforced concrete. "ome of the properties of ferrocement such as tension,
compression, fleure, shear, fatigue, impact and fire resistance, durabilit!, corrosion,
and water retaining capacit! had been inestigated and are listed as below.
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Tensi"e 0e,viour
@nli2e reinforced concrete, tensile behaiour of ferrocement is considerabl!
different. -his is mainl! because the reinforcement is spaced closer and uniforml!
than in reinforced concrete and its smaller diameter results in a larger specific surface
area. -his in turn affects crac2ing behaiour $finer and more number of crac2s( in
ferrocement.
?aaman and "hahs $%974( wor2 indicated that the stress leel at which the
first crac2 appeared and the crac2 spacing were a function of the specific surface of
reinforcement. -he ultimate load of the ferrocement specimen was the same as the
load carr!ing capacit! of the reinforcement in that direction. -his should be epected
since the load is carried b! the reinforcement itself after the mortar is crac2ed.
Al0?our! and )u/ $%9''( had proposed epressions for predicting the first
crac2 strength and modulus of elasticit! of ferrocement in the uncrac2ed and crac2ed
range. It was found that the first crac2 strength of ferrocement in tension might be
predicted on the basis of the strain at the limit of proportionalit! of mortar and the
uncrac2ed modulus of ferrocement. -he modulus of elasticit! of ferrocement in the
crac2ed range could be predicted on the basis of the behaiour of an e/uialent
composite model aligned wires. #e!ond first crac2, the crac2 formation mechanism in
ferrocement in the crac2ed range is related to the matri0wire interfacial bond.
Com-ression *trengt,
-he high compressie strength of mortar contributes primaril! to the
compressie strength of the ferrocement composite. Although the reinforcement ma!
hae some influence on the compressie strength, but this is limited to certain t!pes of
reinforcement. or eample, the use of welded wire mesh would increase compressie
strength due to the lateral restraint proided b! the welded transerse wires, while the
heagonal mesh or epanded metal ma! wea2en the composite due to longitudinal
splitting.
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ameswara Eao and amasundra $%9'&( inestigated the stress0strain cure
and >oissons ratio of ferrocement in aial compression. It was found that the specific
surface is the onl! factor, which controls the behaiour of ferrocement in aial
compression. /uations deeloped for predicting the increase in strength, strain and
modulus of elasticit! b! regression anal!sis were used to generate the stress0strain
cure of ferrocement under aial compression. -he! hae found that ferrocement
behaes linearl! up to 5=0&=H of the ultimate strength in compression8 be!ond this
limit the behaiour becomes non0linear. -he alue of ultimate strength, strain at
ultimate strength and Loungs modulus increase with increasing of specific surface
area.
F"e#ur" *trengt,
In some application, ferrocement ma! be subGected to fleural stress. In such
cases, one must consider the method and manner in which its behaiour in fleure ma!
be predicted. ?eedless to sa! that compared an aerage reinforced concrete beam
$which is generall! under0reinforced(, the ferrocement beams due to seeral la!ers of
wire mesh tend to be oer reinforced. It is therefore important to insure that indeed
ferrocement will not fail similarl! to an oer0reinforced concrete beam. Anal!tical and
eperimental ealuations were reported b!
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*,er
Ken2ata rishna and #asa ouda $%9''( performed testing on ferrocement
beams with different olume fraction of reinforcement in transerse shear. It was
found that the shear strength depends upon mortar, strength of wire mesh, olume
fraction and shear span. -heoretical epressions were deeloped for predicting the
shear strength at first crac2 and collapse of ferrocement beams with different t!pe of
wire meshes namel! heagonal, woen and welded.
Ftigue Resistnce
atigue strength pla!s an important role in restricting the use of ferrocement in
structures subGected to such a loading as in bridges. -he fatigue strength of the wire,
as tested in air, is the primar! factor affecting fatigue of the composite. #alaguru et al
$%977( inestigated the fleural fatigue properties of ferrocement beams reinforced
with s/uare woen and welded meshes. -heir finding is the relationship between the
stress range in the outermost la!er of steel mesh and the number of c!cles to failure.
"ingh et al. $%9'&( inestigated the influence of the reinforcement on the
fatigue behaiour of ferrocement. -he! conducted fatigue tests on ferrocement slabs
with different t!pes of mesh reinforcement, stud!ing the effect of the si1e of wire,
galanising of the wire and placing of wire mesh in la!ers to the fatigue strength of
ferrocement. "amples of the wires were also fatigue0tested in air and a relationship is
deeloped between the fatigue strength of each t!pe in air and in the composite. It was
found that the fatigues of the wire in air and in ferrocement are related. ;ost fatigue
failures occurred b! fracture of the wires and the range of repeated stress in the wires
gae the greatest on the fatigue strength of ferrocement.
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Im-ct Resistnce
Impact strength is a useful parameter in applications related to offshore
structures and boats. Eeports attesting the faourable characteristics of ferrocement in
collisions inoling boats with each other or with roc2s are numerous. -he main
attributes include resistance to disintegration, localisation of damage, and ease of
repair. )oweer, due to eperimental compleit! associated with measurement of
impact resistance, little /uantitatie or comparatie data eist.
Impact strength was defined as the energ! absorbed b! the specimens when
struc2 b! a swinging pendulum dropped from a constant height. -he damage was
measured b! the relatie flow of water through the specimen surface for a fied energ!
absorbed which is &==lb0in $&&.72?0mm(.
"hah and e! $%973( tested 9in3$5&35mm3( and Min $%3mm( thic2
ferrocement slabs using an impact tester. rom the test, it indicated that the higher the
specific surface of the meshes and the higher the strength of the mesh, the lower the
damage due to impact loading.
Fire Resistnce
A problem uni/ue to ferrocement is potentiall! poor fire resistance because of
the inherent thinness of its structural form and the abnormall! low coer gien to the
reinforcement.
#asanbul et al. $%9'9( studied the fire resistance of ferrocement load bearing
sandwich panels. -he fire resistance of the ferrocement wall was found to be
encouraging for designers of ferrocement buildings. -hough the thin shell nature of
ferrocement has raised /uestions about its fire resistance, it was found that ferrocement
retains much of the load bearing /ualities of reinforced concrete. Its heat transmission
/ualities are not as good as those of reinforced concrete, which would be Gust under
four hours, but this latter consideration is more dependent on the mass of the wall.
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6imited problems of spalling of the front face sheets occurred during the earl! portion
of the test but this spalling was not seere enough to cause serious structural damage
during the period in which the wall satisfied the A"-; 0%%9 performance criteria.
Dur$i"ity
When ferrocement is eposed to aggressie enironment, its successful
performance depends to a great etent on its durabilit! against the enironment than on
its strength properties. -he eternal causes ma! be ph!sical, chemical or mechanical.
-he! ma! be due to weathering, occurrence of etreme temperatures, abrasion,
electrol!tic action, and attac2 b! natural and industrial li/uids and gases. -he etent of
damage produced b! these agents depends largel! on the /ualit! of the mortar,
although under etreme conditions an! unprotected mortar will deteriorate. -he
internal causes are al2ali0aggregate reaction, olume changes due to the differences in
thermal properties of aggregate and cement paste, and aboe all the permeabilit! of
mortar. -he permeabilit! of mortar largel! determines the ulnerabilit! of the mortar
to eternal agencies, so that in order to be durable the mortar must be relatiel!
imperious.
Although the measures re/uired to insure durabilit! in reinforced concrete also
appl! to ferrocement, three other factors which affect durabilit! are uni/ue to
ferrocement. irst, the coer is small and conse/uentl! it is relatiel! eas! for
corrosie li/uids to reach the reinforcement. "econd, the surface area of the
reinforcement is unusuall! high, so the area of contact oer which corrosion reactions
can ta2e place, and the resulting rate of corrosion, are potentiall! high. -hird, although
man! forms of reinforcement used in ferrocement are galani1ed to preent corrosion,
the 1inc coating can hae certain aderse effects bubble generation. All three factors
hae ar!ing importance depending on the nature of the eposure condition. )oweer,
in spite of these uni/ue effects, there is no report of serious corrosion of ferrocement
not associated with poor plastering or poor matri compaction. -o insure ade/uate
durabilit! in most applications, a full! compacted matri is necessar!. A protectie
coating ma! also be desirable.
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Corrosion
Corrosion is the deterioration of metals or allo! due to interaction with its
surroundings. -he most common eample of corrosion is the rusting of steel.
Corrosion is normall! a fairl! slow but comple process8 howeer, due to presence of
certain conditions, it ma! occur er! rapidl!. ;an! of these can occur in ferrocement
and aoiding them is one of the biggest problems. All ferrocement marine structures,
b! irtue of their marine enironment are liable to corrosion attac2. -he danger of
corrosion is enhanced in ferrocement b! the etreme thinness of the coer of mortar
oer the steel reinforcement. -he corrosion process is often difficult to recognise until
etensie deterioration has occurred. -he seerit! of the attac2 on structure will
depend basicall! on how well it has been designed and built, the materials used and
what happens to it when in and out of use.
Wter 1or Li2uid3 Retining C-city
Another special propert! to be noted is that of water retention when application
of ferrocement is considered in li/uid storage tan2s. -he important aspect here is
small crac2 widths so that lea2age ma! be minimal. "hah and ?aaman $%977(
indicated that crac2 widths in ferrocement for the same steel stress are smaller than in
reinforced concrete b! order of magnitude. -his ma2ing it a better choice on material
for water retaining structures. -ests were conducted on c!lindrical essels with
internal water pressure to inestigate this impact. -he results showed that the crac2
width in ferrocement is much smaller than allowable. ?aaman and "abins $%97'( also
proided some recommendations on using ferrocement for water tan2s.
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Construction Procedure
errocement construction unli2e other sophisticated engineering construction
re/uires minimum of s2illed labour, utilises readil! aailable materials and most of the
tools for construction are intended for conentional concrete construction. -he s2ills
for ferrocement construction techni/ues are easil! ac/uired and re/uisite /ualit!
control can be achieed using fairl! uns2illed labour for the fabrication under the
superision of a s2illed foreman.
-here are seeral means of producing ferrocement. All methods re/uire high0
leel /ualit! control criteria to achiee the complete encapsulation of seeral la!ers of
reinforcing mesh b! a well0compacted mortar of concrete matri with a minimum of
entrapped air. -he most appropriate fabrication techni/ue depends on the nature of the
particular ferrocement application8 the aailabilit! of miing, handling and placing
machiner!8 and s2ill and cost of aailable labour.
-he four maGor steps in ferrocement construction are*
>lacement of wire mesh in proper position,
;ortar miing,
;ortar application, and
Curing.
-he obGectie of all construction methods is to thoroughl! encapsulate a
la!ered mesh s!stem with a plastic >ortland cement matri. -he mortar must be
thoroughl! compacted during placing to ensure the absence of oids around
reinforcement and in the corners of an! framewor2. errocement structures are to be
properl! cured once the mortar has ta2en its first set $which occur to 4 hours after
mortar application(. -he set mortar or concrete is to be 2ept wet for a period
dependent on the t!pe of cement used and the ambient conditions.
%&4 A--"ictions
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Housing A--"ictions
errocement has found widespread applications in housing particularl! in
roofs, floors, slabs and walls. errocement is considered as a suitable housing
technolog! for deeloping countries attested b! the increasing number of easil! built
and comfortable ferrocement houses. errocement houses utilising local materials
such as wood, bamboo or bush stic2s as e/uialent steel replacement hae been
constructed in #angladesh, Indonesia and >apua ?ew uinea.
>recast ferrocement elements hae been used in India, the >hilippines,
;ala!sia, #ra1il, >apua ?ew uinea, Kene1uela and the >acific for roofs, wall panels
and fences. In "ri 6an2a, a ferrocement house resistant to c!clones has also been
deeloped and constructed. A p!ramidal dome oer a temple in India and numerous
spherical domes for mos/ues in Indonesia hae been constructed with ferrocement.
-he choice was dictated b! low self0weight, aoidance of formwor2 and aailabilit! of
uns2illed labour. igure 3.3 shows one of the eamples of the houses built using
ferrocement structures.
Figure %&%( A ty-ic" ferrocement ,ouse
!rine A--"ictions
errocement has been adapted to traditional boat designs in #angladesh, China,
India, Indonesia and -hailand due to timber shortages. In China, &== ferrocement
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boat0manufacturing units produce annual capacit! of &==,=== to 7==,=== tonnages.
errocement boats are diided into four categories according to usage* farming boats,
fishing boats, transport boats and wor2ing boats.
In countries li2e )ong ong, orea, India, ;ala!sia, >hilippines, "ri 6an2a
and -hailand, ferrocement boats generall! conform to western standards. In )ong
ong, India and "ri 6an2a, most of the ferrocement crafts constructed are used as
mechanised fishing trawlers while in orea, as fishing boats. In addition, the
"outheast Asian isheries Jeelopment Centre, >hilippines, has used ferrocement
tan2s for prawn brood stoc2 and ferrocement buo!s for a floatation s!stem in the
culture of green mussels. -his is the first large0scale use of ferrocement for these
purposes.
In Africa, ferrocement boat!ards hae been successfull! established in en!a,
"udan and ;alawi. -he boat!ards are now self0supporting under the management of
local staff trained b! the consultants. -he obGectie of these boat!ards is to proide
rural fisherman opportunities to eplore the fishable grounds to increase their income.
igure 3. shows a ferrocement boat under constructions8 meanwhile igure 3.4 shows
a t!pical ferrocement boat.
Figure %&5( A ferrocement $ot under constructions
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Figure %&6( A ty-ic" ferrocement $ot
Agricu"ture A--"ictions
Agriculture proides the necessar! resource for economic growth in
deeloping countries. -he use of ferrocement technolog! can contribute towards
soling some of the production and storage problems of agricultural produce.
errocement has been used for grain storage bins in -hailand, India and #angladesh to
reduce losses from attac2 b! birds, insects, rodents and moulds.
-hailo, a conical ferrocement bin8 was designed and first constructed at the
Asian Institute of -echnolog! $AI-(, #ang2o2, -hailand. "torage capacities range
from % to %= tons. -his bin has proed to be structurall! sound and construction has
proided ade/uate protection to the produce against rodent, insect and bird attac2s.
-he bin costs well within the means of the farmers. #esides, this t!pe of silo also can
hold up to 5=== gallons $33.7m( of drin2ing water.
In thiopia, underground pits are the traditional method of grain storage. It has
been found that when the traditional pit is lined with ferrocement and proided with an
improed airtight lid, a hermetic and waterproof storage chamber can be achieed.
Wter nd *nittion A--"ictions
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errocement can be effectiel! used for arious water suppl! structures li2e
well casings for shallow wells, water tan2s, sedimentation tan2s, slow sand filters and
for sanitation facilities li2e septic tan2s, serice modules and sanitar! bowls. "ome
findings indicated that ferrocement tan2s are less epensie than steel or fibreglass
tan2s. -he reasons wh! ferrocement is cheaper are*
errocement is an feasible material for the construction of water storage
leibilit! of shape, freedom from corrosion, possibilit! of hot storage, relatie
lac2 of maintenance, and ductile mode of failure are important adantages of
ferrocement oer other materials
errocement tan2s re/uire less energ! to produce than steel tan2s.
errocement water tan2s of 3= to 3=== gallons $=.=9 to 9m( capacit! are mass0
produced in India. #amboo0cement well casings hae been built in Indonesia to
preent contamination of the water.
!isce""neous A--"ictions
errocement is proing to be a technolog! that can respond to the dierse
economic, social and cultural needs of man. errocement has been used to strengthen
older structures, a medium for sculpture and for man! other t!pes of structures.
errocement as a medium for sculpture proes its ersatilit! and the unlimited
dimension to which it can be used. errocement in art is an eciting deelopment and
it open new hori1ons. igure 3.5 shows a t!pical sculpture made from ferrocement.
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Figure %&7( A ty-ic" ferrocement scu"-ture
@niersiti -e2nologi ;ala!sia $@-;(, "2udai, ;ala!sia also gained some
eperiences in constructing the prefabricated and landscaping obGects. -he obGects
done b! ;ohd. Warid )ussin, Abdul Eahman ;ohd. "am, and the staff from
"tructural and ;aterial 6aborator!, acult! of Ciil ngineering are*
arden and outdoor furniture
Jecoratie mushroom
ascia
"idewal2 slab
"un "creenshade
errocement canoe
"ome of these obGects are still well in condition and can be found within the
area of the laborator!. igure 3.& shows the ferrocement obGects in @-;.
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( *uns,de nd irrigtion cn" "ining $( Cnoe
c( C,irs nd t$"e d( !us,room
Figure %&8( *ome of ferrocement o$9ects t,t cn $e found in UT!
Conc"usion
errocement has gained widespread use and acceptance, particularl! in
deeloping countries and has alread! attained worldwide popularit! in almost all 2inds
of applications* marine, housing, water resources and sanitation, grain and water
storage, biogas structures, and for repair and strengthening of structures. Widespread
use of ferrocement is eident in countries li2e China, Eussia, India, Cuba, "outh ast
Asia and others.
-here are seeral reasons for its widespread use. Fn the construction side, it
can be fabricated into almost an! shape, s2ill needed for the construction can be easil!
ac/uired, hea! plant and machiner! is not re/uired and eas! to repair. ;eanwhile, on
the material side, ferrocement possesses a degree of toughness, ductilit!, durabilit!,
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strength and crac2 resistance that is considerabl! greater than that found in other forms
of concrete construction.
)oweer, there are still areas of applications where ferrocement is not widel!
used, such as structural components, li2e main beam, column, etc. -his ma! be due to
insufficient understanding on the behaiour of ferrocement. )ence, more researches
still hae to be done. -his present research will contribute to the enrichment of
information and understanding on this subGect.
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