low cost materials for building and construction

8/3/2019 Low Cost Materials for Building and Construction

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June 2011 Journal of Sustainable Development and Environmental Protection Volume 1 Number 1

87

LOW COST MATERIALS FOR BUILDING AND CONSTRUCTION:A CASE STUDY OF RICE HUSK

Opara Patrick NnamdiBuilding Materials Research And Development Center

Ebonyi State University Abakaliki.

AbstractNigeria has for many years been over dependent on conventional and imported buildingmaterials which are rather costly and beyond the affordability of the common man. Thebuilding industry in Nigeria is encapsulated with shortage of affordable building andconstruction materials. People have difficulties building houses of their own because thecosts of building materials are astronomically high. A look inward reveal that Nigeria has agood number of agro-allied wastes, industrial wastes and mineral deposits such as rice husk,saw dust, coconut fiber, palm kernel fibre, marble dust, caicium cabonate to mention but a

few. Rice husk is produced in many parts of Nigeria such as Abakaliki, Afikpo, Ogoja, Ikepe,Lafiaji, Badeji, Pategi, Sokoto, Birnin Kebbi, Abeoukuta, Benin and Delta regions. Rice huskdumps are mountainously available in alarming proportion in Abakaliki and othercommunities. The rice husk dumps contribute immensely to environmental pollution,degradation and hazards. The evacuation of rice dumps. From these communities requiresurgent attention. With an optimized ratio the researcher used Rice husk, marble dust, pulp,cement and water to produce ebonite roofing tiles. The researcher invented a chemicallocally made that can be used to treat rice husk and make it workable in the production ofroofing tiles. It cannot work except it is treated. Also burning the rice husk before use woulddestroy its water repellent qualities. The equipment used are vibrator, Italian vortex hydra

ferrar, pulverizing machine, oven, shovel and trowels, twenty four tests were carried out onthe tiles including fire endurance (30min) U-value (0.22w/m2lx), water absorption capacity(25%). Tensile strength (45/cm2) and modulus of rupture (0.99N/mm2). The test results weresatisfactory in accordance with Bs 1191, 6463 part 4 Bs 4550/ Bs 43359, Din 4202 andASTMC 204. The tile is cost effective, strong, maintenance free; resistant to corrosion, waterand heat, and it is not carcinogenic.

IntroductionThe study of low cost materials forbuilding and construction is an area ofhuman endeavour which collaboratesdirectly or indirectly to the socio culturaland socio economic setting of the peopleor community. The level of technologicaldevelopment determines the level ofsocial, economic and environmental

development. Nigeria for a long time, hasdepended on conventional buildingmaterials which are rather astronomicallycostly. The problem of over dependenceon conventional building materials can besolved by diverting our attention towardthe local sourcing of alternative materials

for building and construction. It was forthis reason that the Nigerian building androad research institute (NBRRI) wasestablished in 1978 (Ukot 1989). NBRRIlaid emphasis on the development ofsuitable local building materials from

mineral deposits and agro industrialwastes that are abundantly available atlittle or no cost. The waste materials that

are available in our environment includerice husk, saw dust, coconut fibre, palmkernel fibre, marble dust, stone dust tomention but a few. Rice husk for instanceis abundantly produced in many parts ofNigeria such as Abakaliki, Afikpo, Ogoja,Ikepe, Lafiagi, Badeji, Pategi, Sokoto,BirninKebi, Abeokuta, Benin and Delta

region. Rice husk dumps are increasing inalarming proportion at Abakaliki.Disposing and evacuating the rice dumpsis urgently necessary because of theimpending environmental hazards,degradation and pollution it posses to thepeople and the environs. In attempt todispose rice husk, most communities, setthe rice husk takes dumps on fire.Unfortunately a small heap of rice husktakes months to get burnt to ashes. Opara(1998) noted that rice husk burns to ashesat the temperature of 800oF. Even when

burnt to ashes, it is still an eyesore in thecommunities especially during the rainyseason. Rice husk dump on fire constitute


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serious environmental hazards especiallyduring the harmattan season when thedust devil and other manner of winds blow.It can set nearby buildings on fire. Somepeople are known to have died byunknowingly running into or stepping into

rice husk dumps on fire beneath thesurface.Rice husk can be used in the production ofroofing tiles. Okorie (1994) stated that theharvested rice kernel known as paddy isenclosed by the hull or husks otherwisecalled rice husk. To obtain the rice husk,the rice paddy is parboiled, dried andmilled to separate the rice from the husk.He also revealed that the rice huskcontains cuticule,a biological membranethat does not allow for easy.Onyemachi (1994) investigated the utility

of rice husk and its derivatives in thebuilding industry. In the said studyonyemachi subjected rice husk to varioustests to determine its chemicalcomposition and properties. In theprocess the liquid limit content of the ricehusk ash was established. Compressivestrength machine was used to determinethe strength of the rice husk concrete.Defeasibility test was also carried out todetermine the thermal conductivity of therice husk. Rice husk has some organicsubstance which makes it difficult to bind

effectively with cement. For this reasononyemachi converted husk into organicmaterial by burning it to ashes.

Parry (1985) reported that fibres whichhave the following properties areunsuitable for the production of buildingmaterials.

1. Stiff fibre2. Oily and greasily to touch3. Impregnated with cement-affecting

chemicals (e.g. sugar)4. Susceptible to large dimensional

changes when changing betweenwet and dry state.

In a study of partial displacement ofcement with rice husk in concreteelement, Ukpon (1991) revealed that ricehusk could be used in the construction ofconcrete elements. In the said study,Ukpon (1991) mixed cement, sand andburnt rice husk with water. He used themixture to make concrete cubes. Thecubes were subjected to some tests whichincluded compressive strength test, theresult of the test revealed that theconcrete cubes recorded adequatecompressive strength.

The permeability test showed that the rateof penetration of water into the concretewas low. Ukpon added that there wasreduction in the weight of the concretewhen the cube was compared with similarcubes produced from the mixture of

cement and sand without rice husk. Thestudy also noted that rice husk does notburn with flame and that the rate ofburning was very slow which indicatesthat rice husk is fire resistant. In the saidstudy, Ukpon did not give reasons why therice husk was burnt into ashes before use.The research was not aimed at theproduction of roofing sheets using ricehusk. Tests, such as resilence test andductility tests were not carried out.However, Ukpons study recorded

significant success.

In a similar study titled replacement ofcement with rice husk in concreteconstruction, Emenari, (1987) inOnyemachi (1994) converted rice huskinto rice husk ash and used it togetherwith sand and cement to produceconcrete cubes. At the end of the study,Emenari concluded that: the use of ricehusk in concrete construction reduced thecost of concrete elements. In his costanalysis, Emenari stated that, if a concreteindustry uses say 220, 000 bags of cementeach year at the cost of N11.00 a bag, the

cost is 2, 420, 000 Naira but with 15 percent replacement of clement with ricehusk ash, the cost reduces to 2, 057, 000Naira. The study revealed that rice huskreduces hydration on concrete andimproves resistance to attack by sulphatesoil. The study noted that rice husk lowersthe strength of concrete at the earlystages and increases the strength morerapidly at the latter stages of the concrete.Though the study involved rice husk, itwas not geared towards the production ofroofing sheet. No test was carried out onthe concrete cubes in relation to,permeability of the concrete element

formed.Fashoba (1994) also carried out a

research on rice husk in concreteelements. In the said study Fashobaadopted a method of partial replacementof cement with rice husk. The concretewas cured by the use of authoclave. Whilethe quantity of cement was kept constant,the rice husk ash was increased. Differentsamples with different mix ratios wereobtained. Fashoba used this method todetermine the mix at which the concretehad the highest strength. A comparism of


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the result of compressive strength testrevealed that there was no significantdifferences between the concreteproduced from cement, sand and ricehusk ash, and the concrete produced fromcement, sand and rice husk ash, and the

concrete produced from a cement andsand.In a search for a low cost materials forroad construction in Eastern Nigeria,Nwogu (1986) in Onyemachi (1984)reported that rice husk can be used toimprove the embarkment and sub-gradesof highways through marshy and waqterlogged areas where unstable laterite isecountered. The study did not indicatewhether any treatment was carried out onthe rice husk before use or not. Also, thestudy did not indicate whether any test

was carried out to determine theeffectiveness of rice husk as a roadconstruction material. Rice husk, in thesaid study was not used in the productionof corrugated roofing sheets.While Nwogu carried out a search on lowcost materials, Ojosu (1989) examined theacoustic properties of building materials

for building design. Ojosu revealed thatrice husk can be used with cement toproduce acoustic materials. In the saidstudy Ojosu assessed the following localmaterial: Rice husk, palm fibre, coconut

fibre and polystyrene foam. The studyreiterated that the lack of proper soundtreatment of various components in

functional enclosure led to excessivenoise and reverberation creating the

difficulty of speech communication. Ojosunoted that sound treatment is particularlyimportant in functional units such asauditoria, schools, concert halls, mosquesand cinema halls. The study also revealedthat rice husk can effectively be used in

the production of ceiling boards andsurface boards. While Ojosu concludedthat rice husk was converted to ash orused in its natural state. He did not statewhether the rice husk underwent anytreatment. Besides, the study was notgeared towards the production ofcorrugated roofing sheets. Also there wasno indication of any tests carried out onthe ceiling board.

Nevertheless, an investigation of soilamelioration with rice husk ash was

carried out by Madu (1986). The studyreported that rice husk ash can be used asa pozzolana in partial replacement ofcement for soil stabilization. Madu, in theinvestigation revealed that rice husk ashhas the advantage of increasing theresistance of cement stabilized soil tosulphate attacks. Also, the study revealedthat rice husk reduces the rate ofhardening of concrete elements. Maduadded that low strength development atthe early ages including high shrinkageeffects were observed. Though rice husk

was converted to rice husk ash, Madu didnot give any reason for the conversion. Notest result in relation to the permeability ofthe concrete element was reported.

Characteristics which Asbestos Sharewith Rice Husk as Roofing Tile Materials1. Fire ResistanceHornbostel (1991) revealed that Asbestosis fire resistant. He added that thoughAsbestos is fire resistant, it coulddeteriorate as a result of loss of water ofhydration at a very high temperature of752oF and above. At temperatures ofbetween 110oF and 1400oF all themolecules in Asbestos will evaporate andthe resultant effect is loss of strength andembritlement. However, for roofing andbuilding construction purposes the level of

fire resistance of Asbestos is veryadequate.In a study of partial displacement ofcement with rice husk in concreteelements Ukpon (1991) revealed that ricehusk does not burn with flame. He notedthat the rate at which rice husk burns is

very slow which indicates that rice husk isfire resistant.In an attempt to burn rice husk into ashesthe researcher discovered that rice huskis converted to ashes at the temperatureof 800oF. In addition to the report ofUkpon, Roger (1987) in a study ofchemical composition of rice huskrevealed that rice husk is fire resistant.The study showed that rice husk recordedzero percent Ignation loss.

2. Heat ResistanceIn a book titled construction materials,types and uses, Hornbostel (1991)reported that Asbestos is resistant to heat.He noted that asbestos roofing tiles havecooling effects on a building. Hornbostelalso recorded that Asbestos is a non-conductor. Naomicahi (1989) noted that


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rice husk can be used as a superiorsiliceous material for the manufacture ofcalcium silicate heat-insulating materialwith a good thermal durability of 1000oC.This indicates that rice husk is resistant toheat.

3. Resistance to Water Penetration,Corrosion and Chemical Attack.Hornbostel (1991) reiterated thatAsbestos is resistant to moisturepenetration. Hence Asbestos roofingsheet does not allow the passage of waterthrough it. He also noted that Asbestos isresistant to corrosion and chemicalattacks. In support of the fact that ricehusk is water resistant, Okorie (1988)reported that rice husk is coated withcuticle, a biological membrane which is

resistant to water passage. Madu (1986)established that rice husk ash increasesthe resistance of cement-stabilized soil to

sulphate attacks. Hence rice husk isresistant to corrosion and chemicalattacks.

4. Light WeightIn further investigation Hornbostel (1991)

stated that Asbestos is light in weight.Rice husk has been known to be very lightin weight. The weight of a building materialis a very important factor in constructionindustries. One of the biggest problems inthe construction industry today is how toreduce to the weight of concrete elementsand at the same time achieve a highstrength capacity.A comparism of the characteristics ofAsbestos and rice husk show that ricehusk compares favouably with asbestos asa roofing material hence, it is hoped that

the production of roofing tiles using ricehusk as a local raw material will compare

favourably with asbestos roofing sheets.

Production of Rice Husk Roofing TilesThe Materials used in the production ofrice husk roofing tiles include

a. Ordinary Portland cementb. Waste paperc. Filler (marble dust)d. Clean dry rice huske. Rice husk

f. Chemical for treating rice husk.Tools and Equipments Useda. Trowelb. Shovelc. Pulverizing machined. Vibrator-Italian vortex hydra

ferrarae. Small kitchen knife with pointed

end

Ratio of Mix: an optimized ratioappropriate to the production of a strongand durable roofing tile was used.

Method of Productiona. Treat the rice husk with a local

chemical invented by the researcher.b. Add clean water to a mixture of

granulated waste paper, clean ricehusk, portland cement and marbledust.

c. Mix thoroughly with trowel untilworkability is achieved.

d. With trowel, carry and place some quantity of themixture in the mould or batches.

e. Trowel, make well and level themixture to the thickness of the mouldgauge.

f. Vibrate the mixture for a period of 10minutes in the vortex hydra ferrara orany other local mould.

g. Strike out the tiles from the mouldsh. Cure in oven or sun dry.

Test ResultSample No: OMRC/81209AType of test Result RemarksParticle crystallography 2.05x10-16 Normal/goodAverage mass of particle (g) 0.98x10-3 Normal/goodAverage area of particle (mm2) 6.12x10-36 Normal/goodAverage No. of particles with the lowest energy 2.60x107 Normal/goodParticle disintegration pr m2 1.65Q Normal/goodAverage bond energy, E (lateral/angular) Normal/goodFailure mode Rough/ceased Normal/good

Surface texture 12.15 N/mm2

Normal/goodMean compressive strength (MCS) 022.w/m2k Normal/good


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U-value 0.22w/m2k Normal/goodFire endurance 30 mins Normal/goodAverage swelling thickness rate 6% Normal/goodWater absorption capacity 25% Normal/goodWater vapour permeability per 24 hours 0.85g/m2 Normal/goodWater vapour diffusion resistance 120, 000 Normal/good

Average modulus of rupture 0.99N/mm2 Normal/goodAverage thermal conductivity 1.56W/MoC Normal/goodTensile strength 45 KP/cm2Shore hardness 70 Normal/goodThermal stability +08oC to -20oC Normal/goodCoefficient of thermal conduction 0.005 Kcal/mhoC Normal/goodLinear coefficient of thermal expansion 1.5x10-5 grd-1 Normal/goodResistance to windblown fire and bright sunlight Stable ResistantResistance to acidulated water and aggressivemedia from industrial air pollution

Stable Resistant

Summary of ResultsThe results of the test sample weresatisfactory in accordance with BS 1191,6463: Part 4, Bs 4550/BS 43359, DIN 4102and ASTMC204

DiscussionMost researchers who worked on ricehusk had always used the process ofburning into rice husk arsh or boiling.From the result of the test it is observedthat treated rice husk is better in other to

retain its water appellant qualities whichare greatly needed in roof manufacturing.Rice husk has a water proof membrane, abiological cuticle that resists easypenetration of water or misture.

The most important qualities a roofingtile is suppose to have are

1) Its ability to resist waterpenetration

2) Its ability to resist fire3) Its tensile strength and meancompressive strength

4) Its u-value, modulus of rupture andthermal stability.

-A water absorbsion capacity of 25% isvery good

-Fire endurance of 30 mins isencouraging

-Tensile strength of 45kp/cm2 isnormal

-Mean compressive strength (MCS) of022w/m2k is normal

-The U-value of 0.22w/m2k is good-Average modulus of rupture of

0.99N/nm2 is good-Thermal stability of +08oc to -20c is

good and stableRice is in abundance in Nigeria. A gooduse should be made of rice husk foreconomic growth.

ConclusionJudging from the result of the tests carried

out, it can be concluded that rice husk inits natural state without burning intoarches can be used in the production ofcorrugated roofing tiles. Its advantagescannot be overemphasized

1) It is environmentally friendly

2) It is cost effective3) It is maintenance free4) It is water repellent, fire resistant

and light in weight5) It is resistant to wind and it is not

carcinogenic like asbestos roofingsheet.

RecommendationIt is recommended that

1) Rice husk be used to replaceasbestors in the production ofcorrugated roofing tiles to solve

carcinogenic problem ofasbestors.

2) Small scale rice husk roofing tileindustries be established in all riceproducing towns and cities inNigeria to help in solving theproblem of unemployment. This will

also solve the problem ofenvironmental pollution,


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degradation and hazards possedby rice husk dumps.

3) The government should encouragerice farmers through the provision

incentives such as soft loans, farmmachinery and appropriate

fertilizer.

Implication for Sustainable TechnologicalDevelopment and Commercialisation.The federal and State Governments shouldrealize that there is urgent need forreduction of prices of contemporarybuilding materials through themanufacture of local building materials.With the breakthrough in the sourcing of alocal material that can be used in theproduction of roofing tiles such as ricehusk, immediate action should be taken toestablish large or small scale industries toutilize rice husk dumps in the production

of roofing tiles.The establishment of rice husk roofing tileindustries will set in motion a giant stridein sustainable technological developmentin the country. . Rice husk is notcarcinogenic and has no infectionwhatsoever. Rice is an edible food. It willproject the image of Nigeriatechnologically to the outside world.Rice husk roofing tile industries, ifestablished will create an open door for

job opportunities for youth wishing tochoose career in the production of roofingtiles and maintenance of machines used inthe production of roofing tile. It will surelyreduce the unemployment and povertyrate in Nigeria.The production of rice husk roofing tile isthe most effective means of disposing ofthe rice husk dumps in rice producingcommunities thereby solving the problemof environmental degradation,environmental pollution and environmentalhazards caused by rice husk dumps in the

rice producing communities in Nigeria.The commercialization of this rice huskroofing tile is a direct ticket toward theachievement of the millennium goal andthe seven-point agenda of the presidenthis Excellency, Shehu MusaYaradua[late].Investors should utilize thisgolden opportunity to make shelteraccessible to the common Nigerian.

ReferencesAba, J.O (1997), Strenght of Concrete

Elements in Building:Unpublishedmanuscript, University of Jos.

Bolynn, C. C (1997), Production of rooftiles using Cocoanut fibre. AbujaNigeria bolyn Construction Ltd.

Emenari, O. (1987) Analysis of rice husk ascement replacement in ConcreteConstruction Unpublished MScThesis University of Nigeria Nsukka.

Fashoba Co. (1994) Partial replacement ofcement with rice husk in concreteelement Unpublished manuscript

Hornbostel, C. (1991) Constructionmaterials, types uses andapplication, New York: John Willeyand Sons Inc.

Naomichi, H (1989), Hydromthermalreactivity of rice husk ash and itsuse for calcium silicate products.American Concrete Abstract 17.

Nwogu, C. M (196) Search for a low costmaterial for road construction MScThesis University of Nigeria Nsukka.

Ojosu J.O (1988) Determination ofacoustic properties of somebuilding materials for buildingdesign (NBRRI Rep No. 9)

Okorie JU (1994) Agricultural Science forSenior Secondary Schools, OnitshaSumer education Publishers LTD.

Opara PN (2007) The Technology of ricehusk as a roofing material, Journalof Technology and education inNigeria Jotten vol 12 No. 1

Onyemachi, G.A (1994) utility of rice huskand its derivations in buildingindustry. Unpublished BSc MesuUniversity of Nigeria Nsukka.

Madu E.C (1986) Soil amelioration withburnt rise husk Msc ThesisUniversity of Nigeria Nsukka.

Parry, J.P. M. (1985. Fibre Concreteroofing. Gradley health: Parry andAssociates.

Ukot, U (1989) Building materials researchactivities at NBRRI. Ten years ofbuilding and road researchactivities in Nigeria Lagos.


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Ukpon A. O. (1991) Partial displacement ofcement with rice husk in concreteelement, unpublished manuscript.

Ukpon A,I *1991) Partial displacement ofCement with rice husk in concreteelement unpublished manuscriptUniversity of Jos.

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