/ . ~:? XXX IAHS World Congress on Housing •J -· .

VOLUME· Z Edited by: Oktay Ural - Vitor Abrantes - ARt6nio T adeu

I HOUSING CONSTRUCTION

An Interdisciplinary Task

/

I

~ost Organization

Jniversity of Coimbra- Faculty of Sciences and Technology )epartment of Civil Engineering - Constructions Laboratory Portugal

..

\

---- - · -·-- - --- ··----· · - - -- -- -- - ·· ·- - · ·-

. f I

~- rt l ., .,

\

-, · .J'· ·

l~·lit'irunmenttlltti '\u.\htinable Coll. .. tructiun

Acknowledgements

The authnr~ arl' grateful to the University of Malaya for the financial assistance under ··vuto.: F ' ~dlcllll' and to rhe Ministry of Sdcnce, Technology and Environment. Government of.VIalays ia f.,r the generous J"inancial assistance under the Industrial grant scheme. without ,,·hil:h ihi ~ 'ill\h W<Jtt!J not have been possible .

Reference~

Ill Ahmad 1-ladri Haris and Wan Faizal Anwar. ··EqiC'rienas in conducting resecm·h on piln1 grid <'II Jinc•cted Solar plwtowJ/taic systems i11 Malaysia " . TNBR Internal cornnntnil·;tlton. Ku;lla Lumpur. Malaysi:1.~00I .

111 Boer. 1-:arl \V .. Ath·ances in Solar Energy : All Annual l?e1 ·ic•w r1( Resea rch and

/)e, ·•·l"flll l< "lll Vol ume I~- American Solar Energy Soci.:ty. USA. I \!98.

1-' I Bower. Ward . "Phmm•oltaic hidustry-propO.\"£•cl ClwllgcsjiJr !lw /9(}9 Natio11al F:lectrical <'!Ide )i11· I'\ · AI'JIIicatiull.l' ... Twenty Sixth IEEE Photo voltaic Spel·ialists Conference­Jl)l)7 . lnstitut.: of Electrical and Electronics Engineers. Inc .. USA. 1997

I~ J Chua S<•o Hoon "Pho/0 mltaic applicathms in Sii1gapore". 13 .Arch Dissertation (Unpublisht•t)) National University of Singapore. Singapore. 1998.

I) I Gn:J.?n. Joanta. Renell'ahle Ent'I:~Y Systems in Smllltcasl t\xia . Penn Well Publishing Company. Tulsa. Oklahoma. 1996.

l(,jlshika\\'a N .. M. Kanai. and I. Hide. " Del't!lopm£'111 o(huilt!ing-integmted PV modules

uxing color solar cells for mrious exterior walls", Twenty Sixth IEEE Photovoltaic Spel·ialists Conference-1997. Institute of Electrical and Electronics Engineers. Inc., USA. 19lJ7.

[71 Lim. Bill B. P .. Solar Energy Application in tire Tropics. Reidel Publishing Company, Holland. i'li-:3 .

[Hj Randall Tlmmas. "Pito!ol'ulwics ant! Archilecture". Spun press. London, 200 I

19] Rannels. James E .. "Markel impact l!( a large scale PV huiltling.s program", Twenty · Sixth IEEE Plwtovoltak Specialists Conferencc:-1997. Institute of Electrical and

Electronics Engineers . Inc .: USA. 1997·.

II Ol RaP. S. P .. Rest?an:h Report 9/83: Dynamic Thermal Performance of Buildings under

the Sin:.:atN•rc· Climlll£'. National University of Singapore. 1995.

Ill I Sayigh. :\ . .. \ . ;\1.. Nene11 ·ablt· £ne1;~y: E.ne1~r.:_,. 1~/flcient ·v. l'olic_,. tllllltlte Enriro11me111, \\ 'prJd R,·llc'\1 abk Energ~ Congress Y. Elsevier Science Ltd .. Florence. Italy. llJ98 .

II~ I Y"u Shi.iun. and Yang H1'ngxing. " 711e Potential l:'let'lrie"itr Generating Capacity of /Ill ' \ · in 1/oJt,!j J..."ong". Twenty Sixth IEEE Photovoltaic Spc·cialists Conference-1997. lll,titull' "t' Ekt·tril·al and Eh:ctrunics Enginc.:rs. lnl'.. USA. Jl)1J7 .

X'l'

.. :

Affordable Housing Production: The lntluence of Traditional Construction !VIatcrials

Adcrcmi \'. Adcycmi and Stephen 0. Ojo

Department uf Bnildin)! Ohaf~mi · .-\woluwu University. lk-lk. Nig,·ria

e-mail: yaJcycmi ~' ' o:~.uik .-:du.ng : ",_j< •<"'' Iiii i i fco _ ,.,h, . n ~

Henry i\. Och:yink:r

Dcparlmcot of Qu<llllily Surv~ying Oh:~kmi t\wolowo University. 11\' · lk. Nigcri:1.

c-m:~il: ho<kyink:~(q1 o:~uik . ~du . ng

Ohthosipu I. Fnghenlc

Dl·p:lrtmcnt of Building Osun Stall! Ct>llcg~ ofT~chnolugy. ba-Okc. Nig,•ria .

Ke~ words: affordable housing prodttc!_ion. sustainahk housing technology. conventional construction materials. traditional construction materials. l'Ost reduction .

Abstract An aspect of the problems of sustainable housing tl'dllll>lngy in Nigeria like many other developing countries of the world is th.: escalating ct~st of l·onvt?lllionalmaterials input to construction. These tml!erials are not wholly prouuced locally. often in short supply. involves importation and hence: not atToruablc: tn the poor masses. One of tht~ paths to sllstainahh: housing technology appears Ill be production of affordable ht~using using tradition;d t:lmstruction matc:rials whil·h an: adjuugt?d to be cht?apcr and in ahumlant supply locally. C'lll11pamtive construction c·ost analysis between the usc of '"n,·entional m1d traditional materials was therefore perfornll·d on existing h•w·i nc<H IIl' building in anl·statl' in the tnwn of lle-lfe. Nigeria. The n:sull shnwnl that the c t~sl nf '"'" amlthrct? bedrt~omunits reulll"l'd by 12.5% and 15.-l~'lr r.:spel·tivdy when cen1cnt stahili1.cd earth hlol·k was used for tlw walll·onstruction. Jeep haruwood Sl'l'lillll for lintels . palm kernel shells ( KJ.?rndrat.zo) fnr flt>nr finish anu \\'()l)d l':ISClllt?nl windliW as l'l'JliilL'l' lllCnl fpr gla~s IOU\'I'l'S . It was reCllllllllendcll that the ;~pplication uf thcst? lt~c:lily "'urc·l·d materials he standarditt?d a11d hacked up by large scak pwdtll'tion so that prospect in: h<~llll' "'''llc'rs . IHlusing cooperative·>

anJ private dcvclopt?rs.can huy at allt~rdabk pric'cs.

•

•·II• .. u . ,/1,, _.,. Oollti .Jf:,\ ,. ,i iUI/Jll! (.,tJIU'Jf'llC/IOH

1 Introduction

Inadequate housing provision is a common phenomenon in many developing countrtes~ the world. In Nigeria with a population of about 120 million people and rapid urbaniza~ population growth in the urban centers and supply of housing stock have inadv .. rt•A•t!

assumed the dimension of a one sided race. While the population densities in urban continue to surge astronomically. the rate of increase in housing delivery by governmentS

' [local, state and federal]. private developers and individuals lags behind demand. A wide range of problems contributing to the near collapse of housing programmes in the country have been identified by researchers from dilrerent viewpoints. Some of these views include inconsisterK·y in government policy [ 1 ); lack of adequate data relating to housing and non­implementation of habitat recommendations [2); non· consideration of gender issues in housing programmes [3]: inadequate housing finance market [4]; inappropriate project management :';. practices [51 and non-development of traditional construction materials to reduce cost [6, 7, 8]. · Research effons into traditional construction materials are predicated on the assumption that locally sourced materials are cheaper and hence serve as good replacement for expensive conventional materials . To this end, a number of potential construction materials ranging from various species of timber to some agricultural wastes and residues have been investigated and found suitable in terms of strength and durability. However, the cost implication of using these traditional materials as replacement for conventional materials is usually not given.' This paper therefore has as its objective to evaluate the cost implications · of replacing conventional construction materials with traditional construction materials in . the drive towards affordable and sustainable housing technology.

2 Research Methodology

Cenain authors, Basavaragjaiah and Raju [9] have indicated that in the analysis or a traditional house, the three principal components of a construction made up of walls, roof. doors and windows are responsible for about 75% of the total cost of the building. To reduce cost and accelerate construction therefore, durable and cheaper materials of construction are required for these three components in addition to optimum structural shape. In order to meet the requirement of optimum structural shape, ·prototype rectangular bungalow buildings on Moremi low-income housing estate in lle-lfe, Osun State, Nigeria were selected for this research. The estate was constructed by Osun State Property Development Corporation -­(OSPDC) with conventional construction materials. The objective of constructing the estate ·:.~. was to provide low cost houses at atTordable tenement rate to low income earners. The estate is ;.l; made up of two building typologies; two and three bedroom bungalows (fig. I and 2). The -"¥ · buildings were constructed with concrete base and traditional strip foundation on which sandcrete ~' hollow blockwalls were raised. The roof comprises of corrugated roofing sheets on hard wood * truss (fig.3). For construction cost reduction evaluation; possible substitutes tor conventional i.'· construction materials were compiled based on plethora of research findings on traditional i construction materials. The possible substitutes and those applied in this research are shown in * table I. The cement stabilised hollow eanh hlocks used as replacement for sandcrete hollow ·f,. blocks were those with optimum mix of 4~ and 20% cement and water content respectively ·4~

'If: with a compressive strength of 2.12 N/mm2 at 28 days. The Nigerian Standard Organisation [I OJ. specified a strength of 2.10 N/mm2 at 28 days for sandcrete hollow blocks. To determine construction cost of both conventional and traditional construction materials on the two building typologies. the following procedure were followed :

i. Taking off of quantities · ii. Abstracting

iii. Billing of quantities

82X

'* t~f

*: .,::

-~~ :'?t'

XXX fAllS - World Cotr.~ress 011 Hou.vitrg- Hou.~itrg Ccm .,oucriotr-t\n/mc•rclil cip~ .

The billing of quantit:es was performed in accordance with the prevailing materials'~· •

;~nd labour rates in lle-lfe around January. 2000. ·

sOx1SOmm tintJQr cross \1011 pur\ins at 1050 crs '· soxsomm timber nogg ings a~ 600mm crs.

infill blocks --, II r1200x1200mm asbestos ceiling nailed to SOxSO

~~ 1 1

mm hard wood

1SOX150mm reinforced conc.lintel

bedroom

.<f'.eo'/WhMD1 ::.4. ,.IWif\4*4·1 II

8 nos mm louvre blades adjustable louvered glass Wtndow in 50x15Umm

. u-==----4SJJ ~--.

Earth f 111 ing ·

.hard wood frame

0· 2~ill ce me nt screeding 100 mm concretQ floor slab 300mm hardcore

'-----450 x1 50mm cone. foundation

Source: Field Surwy (2000)

Figure I: A section showing typical use of conventional building materi<lls

3 Results and Discussion

The results of the billing of quantities at each stage of construction using the conventional materials and traditional materials are shown comparatively in Tables 2 and 3 for the tWO· hedroom and three-bedroom typologies respectively. In the substructure. a saving of 8.331h­was obtained for the two-bedroom bungalow und 8.23% for the three-bedroom bungalow. The substructure works quantified includes e': cavation, hard-core filling, lateritic filling . concrete work and blockwalling. The use of traditional construction materials was only possible in the blockwalling of strip foundation where cement stabilized earth brick was ,;ubstituted for concrete block. The use of cement stabilised earth brick for the foundation work gave 41.67% savings over the use of sandcrete block for this operation. In the construction of the superstructure the operations quantilicd are block walling. inswllatinn of screen wall. lintels (concreting. reinforcement and formwork). hard wood door ami window frames, roof frames. rooting sheets and concrete roof ridge. The opcrutions that showed appreciable reductions in cost were block walling with 41 .67% reduction in both typologies and lintels with a staggering 80% to 80.9% reduction in the respective typologies. TI1c truditional material substituted in the blockwalling of the superstructure was the same as that of tlw substructure. The substitution of traditional constntction materials in the superstructure gave a reduction of26.04% in the two-bedroom typology and 30.55% in the thcee-bcdroomtypology.

""""

Tahlc I: Possible Substitution of Traditional Construction Materials for Conventional

Walls ! Sandcrete block i Burnt bricks, stabilized earth I Stabilisen earth blocks brick/block , saw dust -crete block

Lintels I In-situ concrete with Deep h~rdwood section I Deep hardwood i reinforcing steel bars section (lvfahogany)

Flooo I Mass in-situ concrete Clay block Mass in-situ concrete

Floor finish I Cement sand mortar Palm kernel shell ' kernel - Palm kernel shell razzo' ' kernelrazzo'

Ceilin~ i Asbestos sheets I 1-lardboards, fibrous core bamboo

Asbestos sheet

Doors j Plywood flush doors Plywood flush doors Plywood flush doors

Windows I Glass - louvre Wood casement Wood casement

Roof I Corrugated Iron sheet Clay slates, fibre reinforced Corrugated iron sheet concrete tile

Source: Field Sun·ey 2000

The operations considered for the finishes wen! rendering and plastering of walls, floor finish . window glazing, door fixing and locks , ceiling, woodwork painting and polishing and wall painting. However, traditional materials were substituted for floor finish and window glazing only. Palm kernel shells otherwise referred to as kernelrazzo was substituted for floor finish . This finish was devised in the Department of Building, Obafemi Awolowo University, Jle-lle as part of the ongoing research into traditional construction materials. This finish was found to compete favourably with the conventional terrazzo both in strength . and durability [II]. The use of this material gave 34.47% ami 32.67% reduction for the two-bedroom and the three-bedroom typologies respectively. Wood casement windows were substituted for glass louvres and this gave a saving of 31.20% in the two-bedroom typology and 43.03'k- in the three-bedroom typology. The overall percentage reduction for finishes was 7.43-K. The operations considered under services were plumbing.fixtures and electrical installations. No traditional materials were found suitable for these items and hence no reduction in the cost was obtained for this element of work. The situation is the same for the preliminaries. For all the substitutions made, it was found that a two-bedroom typology would cost 12.59% less when traditional construction material is used than the conventional construction materials. Similar reduction for three bedroom typology was found to be 15.44%.

830 -------

,;,

.£... it ·:.·.

• • • • • • . . .. . u

" " ' '" \,..vnx'c"·' 1111 nuu.H II~ - · nou.Hng L tJIIStrJICtltnr -;Aillnlertlisciplillclr,V Task

Table 2: Comparative cost of conventional and Traditional Construction Materials

' ..... ey : Components/ 1 Operations

Exhibiting Cost ! R~oduction '""J.'Prelnninarics ifOllO

Substructures I ISJOSS Block Work

3 Sup~rstruclurc 244,195 Blockwork Lintel

.J Finishes 203,802 Floorin~ Window

· (Glazing) 1 110,900

5. Services

i

0.00

167, 8.\5 I I 15.250 I .36,ooo

180.6.\ I i ·lh.900 3.1,500 1 1.520 30.064

188.665 I ' 2l ,b83 11.917

7. 100 3,220

80.·100 37,584

33,600 10,320

110.900 I O.Oil

Source: Field Survey, 2000: US$/ = 110 Naira

rc:entage Reduction

0.

8.33 41.67

26.04 41.67 80.00 7.43 35.47 31.20

0.00

Table 3: Comparative Cost of Conventional and Traditional Construction Materials

Key Elemerits/ · ( onventional 1\fatcriafs TrR<Htlonal Materials Red_uction -~rc:entage

Operations l':o~ or C~orKey Co~ or Co~ or inC~ Reduction

1 Exhibiting Cost Elements Operations Elements Key

, Reduction Open•lions

I.· Prelim maries 4.500 4,500 0.00 0.00

! 2. Substructures 215,715 197,965 8.23

, Block Work 46,600 24,850 17,7~0 41.67

3 Supcrstmcture 296,225 205,705 30.55

I Bloekwork 126,000 73,500 52,500 41.67

Lintel 46,980 8,960 38,020 80.93

-1 Finishes 268, 128 248,108

Flooring 42,000 28,280 13,720 7.47

Window 14,640 8,340 6,300 32.67 43.03

(Glazing) 110,900 110,900 0.00

0.00 5. Services

·Total 895,468 137.T78 IJ8.290 "15.44

_<;:ost1Savin2s

Source: Field SIIIW,I' 2000

4 Conclusions and Recommendations

'

Cost analysis has shown that traditional construction materials have high potentials in reducing the construction cost of low-income houses. This is more evident in the construction

831

,

•

•

';!;

Erll'it¥111/ll<'rtl a11d Sttslainah/e Com·rrucliwJ :' '~ --~ ~ · :'t- :;~

of the superstructure where between 26% and 31% reduction in cost is obtained. Specific,~(~~

construction operations leading to substuntiul cost reduction are in the use of cemeni~-­stabilized earth for wall, deep hardwood section for lintel, palm kernel shell floor finish'·~1fi[ and wood casement windows in place of glass louvres. llf:' Concerted efforts must be made to reduce to the bearest minimum. the use of cement and ·~ reinforcing bars in low income housing for the purpose of reducing cost. The local production M these two materials are inadequate and currently being supplemented hy importation which is expensive. Even the quantity of cement being produced IO<.:ally depends wholly on impurtation of gypsum a major ingredient inthc .nwnufac.:turc of c.:,·mcnt. This i~ the re[tson why the pricc of locally manufactured cement t:o111pet.:s favourahly ll'ith the imported one. An aspect of the problems of low-income housing production in the country is non-use of materi:~l production plants. It is therefore· n:commended that the use of these traditional materials be standardized and large production plants crcatt:d r,1r thc IIHtnufacture of these materials. The materials can then be sold to prmpective home own.:rs. developers and housing cooperatives. The traditional materials introdured in this work do not in any way impair quality and aesthetic of the building .

References

[I] Godwin. J. -.The .House in Nigeria - Keynote add res~. Protcedings of a National Symposium on the f:louse in Nigeria. lle-lfe. Nigt:ria 1997.

(21 Onibokun. A.- ()rbanHousing in Nigeria. NISER. lbadan 1990.

[31 Oruwari. Y.- The Ro.liJjfWomen in Housing· Finance: A Case Study of Port - Harcourt, Nigeria : Proceedi:ng~ pf the 5th International Research Conference on Housing, Montrcai. Can:ada'J992.: · ... .:·

[41 Fcdcrai .Ministry ofyY~~k/ind ·Housi~g- Nwional Housing Policyfor Nigaia, Federal

,, Government of Nig~,riai La~~s, Nigeria )991 . :~:.

[5] Wahab; K.A.- Thek~tfimalis(lt. ioh of Cor. · lst~ticrion Resources for Housing Investment ·::\\· in Nigeria. in Jourmil ofEnv.i.ronmentaLOe~ign in West Africa, Vol.l'( 1983). pg. 1-10. ·~

. . . ·. . ·'. · : . . . :, , [ 6 j Okpala. D.C. -Rice Husk-Ash . ( RHA) as Partial R'eplacement of Cement in Concrete, -~

Proceedings of the Annual Conference of the Nigerian Society of Engineers, Port - . Han:ourt. Nigeria 1987.

(7] Ajibola. K.: Falade, F. - DC:ter,mination pf Som·e Structural 'P.roperties r~f'A.frican Oil Palm Timber. ·(Eiaies Guineensis), in lfe Journal of Technology. Vol. I, No.2 ( 1989), 'i. pag. 24 - 29. · · · · · · ·~* .. · .... . .

[ 8] Adeyemi . A. Y. -An j,;ve.ftfgmit};, ii11o tlilf .5)tfwbi,lity (if Coc,om(l Shell.;. as Aggregate in . - i-~ · Concrete Production. in lfe Journal of En.vironmenial' Design a~1d M'anag_cmeill, Vol.l 1 St

·&. Nos I & :! ( 2Q00). pag. 17 - 26. · ~ -"('

!lJI Rasn,·;,rajaiah. B.S.: Raju. N.K. - Ecoll£"1lic r>£;Iigll 'PfLoll'·lllcorll£' f!ousi11g Systems; Proceedings of the lntcrnatioti;d ConfcrcnL·c on Low Income Hmtsing. B<ig_kok, Thailand. 1977 . · · .:>:

I I 01 !'Jig~rian St_andard ?rganisation- Drqfi Code t!(Pmctice.for Sa11dcrt'1e Blocks. Federal . ~ M111tstry nt Industnes. Lagos 1975. ~ ·

[Ill Olateju. B. - lmwvatil·£' 8uildi11g Jl4tllerio/s: At'Piicatioll for Cooriemtit•e Hottsillg 1f Det ·elopllll'llt i11 Nigeria. Proceedings of. the National Workshop on Housing ::: Cooperatives for Nigeria: lle-lfe. Nigeria 1990. :i

,.",

EcomateriHis in Construction: Confection of Recycled Concrete with Rubbles

C. l'vl. B. Montoya

Espccializcd Consu:.1ction Architect and Prnkssor National University of Colomhia. Medellin

.:-mail : mhcdnya2000@yallll\l .(t>lll

J:..:cy words: recycled arids. concrete with rubble

Ahstrnct Thi~ nrticle shows the statements which . have led us to search about Ecomaterials and ,pcciully concrete made of residues from construction or rubbles. It also shows a proposal "hich has been made by the group of research on Sustainable Construction and Technological \lanagcment- CONGET- about the conventional technical rules in order to determine the , d,~orption percentages in recycled ari9s. runhermore. the results ot>tained ahout resistance '" d'fort of the compression at differe.nt ages .in recycled concrete mixtures and their c ~>lllpnrison with a conventional concrere· frmn natural aggregates an: shown, as well as its l'l'liiHIIlliCai feasibility tO the academic. ind' SC.ientitiC COillmUnity.

. ~ : .·.

Introduction

Tiler..: is approached the investigation of a r~tyckd materjal. which implementatilll) is feasible lc~· lmically aJlU fit)anci .ally for the confection of optimal concrete one. studying in turn. the lllc·thodology adapt~d to deteni1ine the J}ercetitages of absorption of the recycled a rids roming lit' the generation of solid resi~ues in the con~ii'uclion.

::··~: . · ~

. 2 ·•· .. · .. .. j·t.istiflcation !· ' ·.· :: • .

l'ill· l· itit:~ are b•>rn. are .:onstntcted and transfunn. s~Jll~ of them are destn1yed. Inside the process • •t' transformation and growth that experience these c) ties. many of the Cllnstnu:tions arc rcfom1cd ' •r dcmolish~u . .<JS result of-these two activ.i~ies. the~ tlpj?:ears the genemtion of high quantities of ' ''lid rl·~iuues C;IJ_i1ing Of the COnStl'UCticln, which We ~vfll ~all fp(effeC(S of U 1110re agile reading ruhhlt:s. These rubbles not alone are · genermed in the reforms or demolitions. also they arc pn lt.luced in the new constntctions .. the quantities are really worrying. so ;tc·..:ording to inform<~tion 11 t. the Empres;~s Varias of Medellin. in thi!f·cfty a~ ~n~luted about 6 100 daily tons of rubbles. I >f \\:hich Only lhCre lS h;td record Of a tina] SUit;ibh!: diS{Xll\iii011 Of:!) 'i'r, the remaining pcrO.:Cntag<! '' taken to throw out clandestine. gully mid edge's ·of til_e. ·roads.·

.....