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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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