I                            h                                                                                            ...
1 U.S. DEPART&NT      Of: AG’R%.ULTUPE               ” ’                                 /I.. L1:         .‘:+p, ”_.,     ...
BAMBOO AS A BUILDING       MATERIAL                                                   F.’ A. McClure’                     ...
;’ ,;,-            ‘$%is publi$@..kas             ”                                           originally prepared and publ...
*                                                                                                                         ...
-*                  ,,   “’                                                                     ’                         ...
.                                Parts          of a Hdug’e for                      Which                       Ba?nb&   ...
& ting).         No dostly.machines,                only simple.:                                                         ...
I                               .    *                                                                               *    ...
7      --‘.I--‘-    .   .1            are     attached,          they    provide                a suitable       base     ...
*Pipes       and Troughs                                                          (fig,     19).        In Japan,         ...
Bamboo            Reinfoxement                   df       ConcreteI.            _              .                   Publish...
_ :                   , !                                                                                                 ...
Mclure f.a., bamboo as a building material
Mclure f.a., bamboo as a building material
Mclure f.a., bamboo as a building material
Mclure f.a., bamboo as a building material
Mclure f.a., bamboo as a building material
Mclure f.a., bamboo as a building material
Mclure f.a., bamboo as a building material
Mclure f.a., bamboo as a building material
Mclure f.a., bamboo as a building material
Mclure f.a., bamboo as a building material
Mclure f.a., bamboo as a building material
Mclure f.a., bamboo as a building material
Mclure f.a., bamboo as a building material
Mclure f.a., bamboo as a building material
Mclure f.a., bamboo as a building material
Mclure f.a., bamboo as a building material
Mclure f.a., bamboo as a building material
Mclure f.a., bamboo as a building material
Mclure f.a., bamboo as a building material
Mclure f.a., bamboo as a building material
Mclure f.a., bamboo as a building material
Mclure f.a., bamboo as a building material
Mclure f.a., bamboo as a building material
Mclure f.a., bamboo as a building material
Mclure f.a., bamboo as a building material
Mclure f.a., bamboo as a building material
Mclure f.a., bamboo as a building material
Mclure f.a., bamboo as a building material
Mclure f.a., bamboo as a building material
Mclure f.a., bamboo as a building material
Mclure f.a., bamboo as a building material
Mclure f.a., bamboo as a building material
Mclure f.a., bamboo as a building material
Mclure f.a., bamboo as a building material
Mclure f.a., bamboo as a building material
Mclure f.a., bamboo as a building material
Mclure f.a., bamboo as a building material
Mclure f.a., bamboo as a building material
Mclure f.a., bamboo as a building material
Mclure f.a., bamboo as a building material
Mclure f.a., bamboo as a building material
Mclure f.a., bamboo as a building material
Mclure f.a., bamboo as a building material
Mclure f.a., bamboo as a building material
Mclure f.a., bamboo as a building material
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Mclure f.a., bamboo as a building material

  1. 1. I h ..r .._ , _ MlCROFl&E n ,REFERENCE . . % -:LtyAte ” 0 *i4 A project / df i Vol’u.pteei%‘iA Asia’ ? ’ s 1 8 t . . rz * 3, ’ 41::.,. c > . * ”. oo as a Rulldlna Material.a I-+ . ,. ,- # . .* I byi F.A. McClureo, ,. n , _1 (I 1 Published by: t /. ‘Office of International Acfairs < , US Department of Housing and Urban Development, " . . Washington, -DC 20410 USA - B ." .: .i. -. , ., = &per copies are $7. in the USA, $14 overseas. Ask‘ .. for accession number PB;+188, when ordering. I _I “, I I/ - 5 mi : -- -Available from.: _ I i .* . ,, * <. L,+$- z National TechnicailInformationService ,,.: , ~ * IL %. 5285 PortRoyal Ro/ad. k r CSpringfield, VA 22161 USA ~ _. . i r. i ? A -microfiche edition of .this book is.availab.le +l-?ree. to se.rious group/s in developing count,rie=s~~~~. " i; * Micro.fiche;available /from: ~ 1: -.-. .% Office of International Affairs : US De$artment of/.Hous-ing and. Urban Development: i DC-2b410. USA pi ~ .y “- j i _.-- .._* I, e Washi/ngton, I _ " -,p+ J:T,j,f ;. -r , > 1 , ,g .-" . $:* Reproduction Oaf this mXcrofiche.document in any d *" . --. .$:: -- form is subject to theYsame restrictions as those .* i, i _ of the original document; m.j "3, .. 1 *-. : *y ,,:- : - :, I Y .. -- 7 : . -7 " 1 iw., 1 -_ , e s il 1 / :,_ * : *c I . / a _ I & y ,i * r.,* 1 ) -), :i r * ./.._-.-- - ii. * ., . ‘ /(,.
  2. 2. 1 U.S. DEPART&NT Of: AG’R%.ULTUPE ” ’ /I.. L1: .‘:+p, ”_., . .FOREIG&N AGkl.CUL,T(JEAL SERViCE‘,z _’ ” . I :-;:;,. :_ - L .- . a - I- .~ a ,. ‘_ _.<, ._ _ ‘.& _ k’ ‘, ( . Reprinted by . .I , -.<;: - . “‘?,< “f’ DEPARTMENT 0~ H~.uSING’AND URBAN~DEVELOPMENT ;‘i‘_I ‘2 7’ =.:, OFFIC~~OaF”INTE~~~TlO~~L AFFAIRS -‘Wi:iGn&n, D. C. 26410 9
  3. 3. BAMBOO AS A BUILDING MATERIAL F.’ A. McClure’ 5% formerly L Field Service doi&ultant c I Foreign Agricultqal Service : / presently Research’Associate i’n Botany ~ Smithsoniap Institutioq , a ,’‘I .- .. ,/’ - Q /’ , wForeign?Agric&urG S&vi& -’ , ’;1 .; .: .,.. :; .. ,“’ ited States Department of ‘hLg?icClture Renr&.ed J&, .‘i983 -
  4. 4. ;’ ,;,- ‘$%is publi$@..kas ” originally prepared and published at.,t..&&&&est of the6;:; ; - Department of Hous$g and Urban Development U. S. D.ep.&rtment __ , y,, .%f Agriculture under -the Point Four those active15 ._ !_ - ; ‘engaged or interested~ in 4he: use of bamboo. -_ TC .iz’mn+’ DTI ayhalmtive A.u:*cy uvr “4I “IYIUI-“-. - ----- ----_ -- .’ e - - ,“.. . of the flUD.st@f> .- -;-‘ . * . _ -,J, Servf ce, United States Department to ‘use $$hotograph b$ Hoard Dorsett. Edward ~- -;- m,-,~$ * Fi - ph of th@@orodja *house in” the,centr& Celebes, II R the”fr&g@ec~;, it- was‘ ori&nally published ~$,&vid Fair- , - World GrimaRouad &y Do&,’ and pern$sston to reproduce &Tby Scribners.. I-l. E,“.‘d‘lehn,,,Vice-~irector,‘:‘~ngineerfng Experi- ’ i’- South &$&a,~ granted, permission , ’ ‘.; &-&&t,te e&nsfvelv’fromms -- a----- - - * bullet&’ B&boo-&&&&ment...of Portland Ce-ment s r ~Condrete Structires.. I&&l C. Pet&prepared @ g’line drawings t&t;beaf MS i J’.+,, $1 .-I i _’ (, 8 ., .-.
  5. 5. * , . n ’ , ,., CONTENTS - r i I 1 Page _. Introduction*“. . . . . . -, . . . . . . . . P . . . 1 Parts of a House for Which.Bdmboos Are Suitable %.1 . . . . . . . .‘. :. . . Fo,nndation . ,. . . “_. . ,. . . . . . . . . . . Frame . . . . . . . . . .. , . . . . . . . . . .> * ,, Floors . . . . . , . . . . . . . . . . . . . ; 8 Walls, Partitibns ,I keilings . . . . . . . Doors and Windows . ..-. . . . . . f .“. . .., ‘, .Roof...................:.. Pipes and Troughs. . . . . . .. . . . . . .‘, Ba’mboo Reinforc.ement of Concrete . . . ~ . Geographical Distribution of Bamboos . .-u7 ,‘, * Differences Among Species . . . . . . . ; . 31 .’ i:. P ,’ f .. 32 -’ Some jBamboos Used in Housing .-, : . . . .-s - . 2. Shortcomings of Bamboo and, How to i- I) Overcome Th-em . . . . . .:. ./. . . ?. , .h . :. cariable Dimensions . . . . . . “.. ,/ . . .‘, ., Uneven Surfaces . . . . . . . . . .. . . . . . “._ _ i . Extreme Fis sibility . . . . . . . . . . . ~2 Low Durability . . . . .I. . . . . ‘1 m . i ,‘a . P P-reservation . . . ,i . . . .. . . . ‘. .‘. . . . . . 41 I ‘3 / _’ Skiil. Requirements ” : . . . , . . . .’ . . . . . ‘43 B’ - Tool Requirements ‘. .‘. . .’ . . . . . . . . .. :- ” .,?4’ Differentia-tion~dEvaluat&ff-Bf,~Species / c 46, -./ ‘Q 1 e .I - ‘Z . d Collecting Specimens for Identif’cation . 47 * C’,; ‘! ! 50 !i .., .’ .<.A-, Selected References . ‘. . .’ . . . . . ; . . . . q < : /, i . i
  6. 6. -* ,, “’ ’ have amply de*m,onStrated its claim to a spe-_.-_--- cial place in their evdryddy life. As technic& cooperation continues to single out species wit’ outstanding‘ utility, 7 and $0 te them more ‘widel’y, along with the old and the ‘new techniques _. essential to their practical use, the lot of people will defi- ’ ties in spare time for sale or -exchange at I _ ,,c s the market. .-- oped to- a. point where bamboo’s multifo If techhiques.of large-scale, mechinized j utiljzation can be be velopedy,as., for example,, ‘. in’th‘e,manufa6turb (If high-quality papers ‘and * rayon‘new industrij es ar&.%ncrgase~$l national. income m&y be be&u .ght .tg underdeveloped ;. L , ‘- areas. Ii. &with the 3se 1 prospects in view bility to -h&an needs ;:it.?r;as few -i- +Ldasone~of +eJ&%- .L.: t% pliint’kin~dom. In-the OFcident It&g the”Point Four pro-.. . . ! s,f ” as well‘as,,the Orient, ‘the ,peoples ‘, in whose ;i^, .I_ ,.!,,‘...> ., -- : .-. I ._ I. _(’ , . ._ ..,,, _ .,f ‘._d /~ ‘- “i /. - ‘. ’ ,: ,! ” i ”
  7. 7. . Parts of a Hdug’e for Which Ba?nb& Are Suitable ,a : - I Bamboo may;be used perior knowledge of, and devotion to, the+ parts’ of-a house.‘except principles of functional design w,ith an chimney. Under most awareness of the possibilities. of bamboo L as a building material of strength and bamboo’:is actually beauty. Being an artist as well as an ar- , bujlding materials, such as woo P cfment, galvanized iron, and pa chitect, he will appreciate the aesthetic ‘1 yccording ‘to their relative qualities of bamboo and its versatility as ‘, i . ability, and cost. they have been demonstrated in each area ,, ,: The use of bamboo either as a primary, where its use has been lifted to a high plane. 1 secondary, or occasional source of building Given the right inspiration, the opportunity material is common only in areas ‘where , to travel and tb study the best examples of suitable bamboos ‘grow in suffitient abund- the use of bamboo in building construction, . -. ~ ante. Importance of bamboo in any given and the cooperation of persons who know the bamboos and thb techniques of using ‘_,,,. !‘, larea ~ usually is de+&mined .chiefly by the economic level of the common people and them, he will be ab e to synthesize the .’ B other, more best features of bamboo with the! technical improvements sug- ested by his Western * ,: &background in func i ional design-and so ” achieved with barn produce for each c ltural area a series .of’ j ony pf design and a designs and plans hat will be a credit to the architecture of,1 our age. 0.. Bamboo has several characteristics that make it a suitable and economical building material for house construction, 1---Java-, and-Malaysia,- &m&owmployedY ----?--as-well as-for-the scaffolding ;iig. 1) that i --- / -varchitecturally~ in ways ihat are distinctive facilitates such construction: and basically artistic. Cohen indirectly . alludes to,,this r’ecognitiorr’bf bamboo’s 1. ,The natural un,its, or culmsi, as .special virtues: “The principal post’ in a they are called, ar’e of a size and shape Japcnese house‘ characterizes”the house I that make handling, storing,.and process;g with regard to quality and construction. ‘/both convenient and ecohomi’eal. d ‘Therro’of members ar’e trussed to the post, 2. The culms have a characteristic and enable a properlySonstructed house to phys+al-structure that g&s them a high stand up to earthquakes and tremors. ‘The ‘strength-weight ratio. They ar&,.round or‘ ‘.--.% writer has seen many houses in which the nearly so in cross section, and u&ally , - principal- post is of stout bamboo, .or in ‘_ hollow, with rigid cross walls strategically : ‘; _ i.. which a stout timber post is..given more placed to preventcollapse on bending. , 1 ’ character by being faied witpbamboo. Iy - Within the culm walls the strong; hard - It is my expectation that an architect : tis.sue.s~ of high tensile strength are most I will pr,qsentlyeappear who combines a su- (‘. highly concentrated near the surface. In 0 thi; position they can function most effi- 62 .. ciently, both in giving ‘mechanical strength / ’ y W. E. Cohen. Utilization of Bamboo and in forming a firm, ‘resistant shell, I i 1 in.Japan, p. 1. Commonwealth of Australia, 3. The substance and grain.of barn- : ‘Scientific and Industrial Research Organi- boo, culms make them easy to divide by zation. South.heiboufpe, Au.s$ra.lia. April hand”*into shorter pieces (by sawing or 1 1 l’cr47,. -. (by split- ’ - I (7,: .2 : % - I -’ 9,.‘!i f .:‘s,?.I . ,,&v,%;A*..i“,J. -i, I_ ., - - -1
  8. 8. & ting). No dostly.machines, only simple.: . L tools: are ,.required. ,, P attaohed to hardwoods,.-‘-: 4’. .. The natural surface of most ba,m-‘,,OI,:.$ ,, >j. boos is clean, hard, and smooth, with an ‘* ,,I I?. ,. , attF&tive color when the culms are prop- .; erlycmatured tin?d seasoned. ” 5. Bamboos have little*waste, and no : certain ciriumstahces, 1 . ,f bamboo posts ‘j $nstead of a conventional foundation for . :‘I : ‘low-co&f ‘houses may be seen in -both hem-!”‘, ‘, ” p: ,. ispheres’ (fig. 2). Wriless they are treated ‘with somkreffective fungicidal’preservative, - lection of materials for tl?e ’ of structural elements, the: ., ,’ .; ” last more-than two or three years onythem:,~, * These tip cuts nlayF,e used in ,;’ mn/daioni and tye roof : P. is-the’ part of ‘:.
  9. 9. I . * * i’, I’ )I 1/ Spacing specifitatidns must be worked out In the Far East loc&lly for the bndividuaP species of bamboo ’ . for lashings are commenly’ and the si’ze of culmQ&sed. * more rarely from rattan. The flodr *dovering may be made bf’small bamboos’ yieid bT+ittle wh’ole culms, stri-ps , or bamboo boards made. or the bark of’certain’ * by opening and flattening out-whole culms . _ be use’s for lashings. (figs. 8, 9, and lo).” When’the.floor’%onsists r : iron wire, mmost’of it of-bamboo boards, jt is gengrally,fastened down My the ube of thin strips of bamboo empirical;kn&l- secured to the supporting members byboo.craftsmen in variqus cdun’i thongs, w.ire jashings, or small nlils, accord- = the ;most highly recommended l‘ng to local preference and the materials selection and us’e of avail- available (fig. 6, B). c j Howeyer, a resourceful per- 2 experience in building ma’y Walls, Partitions ,,.‘2eilingZ &uggest sound .and useful mod- The construction ,of bamboo wa.115 is’sub- conventional procedures. ject to infinite variation, depending on*the strength required.(for resistance to natural ‘forces such as hurricanes and earthquakes), ^ .) the protection desired from rain and ordinary ,’ wind.s,/and the need ‘for light and ventilation. Eithe ‘whole cu-lms or.longiLdinal halves j : ~ may 6’ e used, and they may be applied in # i / . eith.er horizontal or vertical array, They ‘function more effectively, however, when walls ir;ade of conventional stone, rammed earth, or adobe bricks. : Another form of wall construction,‘per- .haps more widely used, ;s known in Peru
  10. 10. 7 --‘.I--‘- . .1 are attached, they provide a suitable base If window openings are provided, they may-be framed with b$mboo or%ood. windows ace left unglazed and unscreened. Closure m,a:r be provided i&the form of a ’ 00 mattilg or palm-leaf thatch. Win- ported by a light framework of bamboo. pales. In the..Philippine Is la.nds , and .generally in the Far East, where suitable bamboos are plentiful, the partitions and even the outer generally considered unhealthful. Actually, the closing of houses at night’is justifiable on other, more realistic, ground: ‘it prevents the entrance of mosquitoes, rats, bats, and other unwelcome visitors. Permanent wind Because of their high strength-weighf ratio, bamboos are used to excellent advan- tage for stru~tt~ral..eIenients in roof con- struction (fig. 6, A). In designingthe r&$; <account must be taken of the nature -and ’ ‘weight of the roof coverming to (be used, ‘<. whether it be grass or palmleaf-thatch, halved bamboo culms (fig: lq), bamboo.. split from larger culms. Bamboo matting kitchen fife. Edward Beckwith’s photograph’of.the ’ ,, Q-in-central Cele,bes (see ,-:: - ’ frontispiece) IS another striking illustra-‘ j tion of.the,use ‘of bamboo in roof architec- ’ ourou, Pierre. &es’ Paysans du Delta Tonkinois .. Publ’ica’tions de 1’Ecole ’ airchild, The World Grows
  11. 11. *Pipes and Troughs (fig, 19). In Japan, closed’-pipe water.sys- .* The culms of certain bamboos, w-ith terns are ‘constructed of bamboo but it is diaphragms removed,” serve admirably very difficult to make the joints leakproof, ition+of pipes and tro hs. Underground drainage may’be effected halves of bamboo ‘cu’ms Y by means of bamboo pipes of simple con- - 0 very satisfactory eave troughs. Where structron. T.he steps in preparing the bam- boo for such.use,,ar!k. (1) halving the culms, i (2) removing th&d&p”hragms from one half a barrel- 6r cistern for to-make the lower..‘section of the drain pipe, Where rainfall is heavy-, they-are (3) cutting notches in the edge of the other the ‘water from the roof to, half to permit the free entrance of water, * in order to ‘avoid excessive (4) treating the two halves with preser’va- tive (5- to lo-percent pentachlorophenol *in light oil), (5) placing them together again . in their original relation, and (6) binding ‘. them together with wire: S’ch drains may be .extended to ,any length by lacing the L smaller tip end of one pipe &to the larger basal end of the succeeding onerr, To be suited for the uses just &scribed, - the bamboo culms should have a dia&e-$,er .., with the,diaphr!rgms *removed make suitabl;.‘ large enough‘to give therequired carry&g ( ‘_ .-.I:$:.: .:: .Lcohduits for bringing whter for domeT$e use ccipacity, and the walls should be thick eno&&, ’ ’ -fyy’t_s_l. sour cq i to tile hou~~-b~‘&v~<y~ to prevent collapse under use. :f$“+~‘.. . ---=--- v ‘Ii:;... ., ; j- 1,I ,-.
  12. 12. Bamboo Reinfoxement df ConcreteI. _ . Published references to the use of bam- readily available information on the subject boo in reinforcing cement concrete strut- is to be found in the report of a serie’s of ,- . ,>,.-tures or parts thereof indicate that the prac- experiments carried out by and under the’ tice has been followed to some extent locally, di’rection of Profes,sor H. E. Glenn: Two !. for some d.ecadkat least, in the’Far East - important sections of this report are quoted - j (China, Japan,, and the Philippine Islands). here,‘in entirety:?/ ,. * During the 1930’s several, experiments were . /: carrPed.out in Europe, pariicularly in Ger- q H. E. Glenn. Bamboo Reinforcement 7: ,:,- many and Italykto,test the ‘performance of ’ of Portland Cement Concrete Structures, - - cement concrete beams reinforced with bam- pp. 123-127. Clemson College Engineering : I. boo.;‘-‘: ’ .- - Experiment Station. Bul.’ 4. Clemson, S. C. 0: ’ The most recent. comprehensive, and May 1950.,: ,. I;// . I’ .,;/A ,,l <.:- ‘. .- . ‘; ” ._ I i Summary of Conclusions ‘ ,i i I Fr,oni Results of Tests. on,r7 ‘,-._ ,,, , Bamboo Reinforced Concrete Beams 2!,:.I ,‘,. I. .* Below is given’s sum me-+nLthe conclusions as indicated from the.:,. : _.. ..,: ,’ results,of‘tests on the various beams included in this study. +;--. P’ 1. Bamboo r,einforcement’iikdncrete beams-does not prevent the * ._‘. failure of txe’concrkte by crao,king at loads materially,%n excess of 1,. -. those. to be excected fr&n:an unreinforced member having the same *I. ‘3. d&e& ions, ,Tz*’ .:c ,, 2’ ,t ‘S< “ 2. Bamboo reinforcement in concrete beams does increase the:’ load ca&ify of the m,ember at ultimate dailure considerably above that: .-- ,. _ -,A to be ekpected from an unreinforced member having ti,e same dimensions. /.C’ .. . 3. =I’& load capadity.oh’ba&boo reinforced concrete bgams increased 3 /-‘,, .- . I’ . /- “b ,, ’ I: with increasingper’centages’ of the bamboo reinforcement up to an opti- ..i. mum valae; I,i I,I 4,) ‘This opt&urn ;alue -occurs when Yhe’cross-sectiona! area of the : IS I., --~ -ldngitudinal bamboo-_ reixifoicement, -.. was from three to four percent of !! -II _, ‘.S , %mcross-Laectional’area OX the concrete jn the member. --&-. j fl, ,’ -. r’,r,‘ze-: $. The load required td cause the failure of concrete beams rein-’ ~1/ > ‘3, r forced with bamboo was from four to.fiv,e times greater than that. re- ,.‘Y ‘“% ’ quired for concrete,members hav-$rg’equal dimensions and.wkhno re----.- mm--m-;---. ~- 7. /, .. . : I inforcement. ,. .7: .; 6. Concrete beams with fongitudinal ba.mboo reinforc;ment may be :’ ..’ :,. <_, 4 :I .; , .,.A I afely loads from two to three times greater than ‘.. . : a.c -. concrete members having the same dimensions and T j _’ b u ‘i’- ,( 4 I ; .<’I ,,; i % - &rns reinforced .with.unseasoned bamboo show .’ ’ . . -. . d capacities than do equal sections reinforced with ! ‘% _” ,‘, 0. ,,Z’ a_ bamboo. This statement w>as valid so long as’ the i .’.., 1% 8 ‘- -. %,’ o had not dried out andseasoned while encased in thg II /’ . , /, / ;: :: concrete’when the load was apbljed: ,’ When unseasoned untreated bafnboo was used as ‘the longitudinal; ,’ ,’ 11,dL~ , ( thei,
  13. 13. _ : , ! _ - I ; r ., i -_ f .I , .. _-. - ~ i " _i 1 .I *- .? ,- , . ( -7.( -- j 5 J /1; -. ,L - absorption of moisture from the wet concrete, andthis swelling-action$b - : often caused longitudinal cracks in the iconcrete, thereby lowering the load capaiity ofthe~members. These SW& cracks were more likely to I ” . occur in members, where the percentage of bamboo reinforcement was -/ high. This ter$ency was lessened by the use of hjgh early strength con-‘! ,, ,y’<;, 3. ; * * .drete. ‘i : The load,‘capacities of concrete members reinforced with barn- ’ 3., boo vary with the dimensions of the members. & * : 2 10. The unit stress in the longitudinal bamboo reinforcem,ent in concrete $rnembers decreased with increasing percentages of reinforce- -3 -__... -* ~. ~ment. 11. The ultimate tensile strength of the bamboo in bamboo r-einforced ‘; i ooricrete members was not affected by changes ip the cross-sectional- . .. ” area of the members so long as the ratio of bre3dth to depth was con- /- stant’but was ‘dependent upon the ‘amount of bamboo used for reinforce- . -. .a.- ment. *,$8 . D .J;‘, , 3 4,-i. . jsj&g _,.. . ,l.&’ Members having the percentage of bamboo reinfbrce- >” ___I.- -; __.- tment(bet&.en three and four are capable of producing tensile r _-----’ ., -. stresses in the.bamboo,of from 8:OOO to 10,000 pounds per square inch. 13. In designing concrete members reinforced with bamboo, a safe tensile stress for the bamboo of from 5,000 to 6,000 pounds per square’ j I ._ ---. , 2 .inch may: be used. 14. concrete members reinforced. with seasoned bamboo treated with a brush coat of asphalt emulsion developed greater load capacities ,’ ;i’ 1 than did equal sections in which the bamboo reinforcement was seasoned ’ i .’ untreated a,r unseasoned bamboo. I/ / 15; When soaspned bamboo treated with a brush coat of asljhalt _ emulT$on was useil,‘as the longitudinal reinforcement in concrete mem- - bers,/there was some tendency for.the concrete to develop-swell cracks; * .,‘: i I -. .: _ ‘especially when t,he per,centage of bamboo reinforce’ment was high, 2” ,,E . 16. Care should be exercised when using asphalt emulsion as a waterproofing agent on seasoned bamboo as an excess of theemulsion x 1i on the outer’perimeter of the cul’m might act as a lubricant to materi- L, /,i -‘. ., ally lessen the bond between the concrete and bamboo. 1 .. -- - : 1,,, / l?. Concrete members reinforced with unseasoned sections of barn- I .,i’ ; ‘h !> - b/oo culms, which had been split along their horizontal axes, appeared i .--?~, ;i , ,’ $o develop great$r’loa,d capacities than. did equal sections iii which the > . , i a -5 - P. ‘-. .,reinforcement consisted of.unsea’soned whole.culms. .,.! 18. Concrete members reinforced with seasoned sections of bam- n:-, ._. ,_ /boo culms,;‘whi,ch had beeri‘split along their 1. : t 1. with a brudh’coat of asphalt 2 !. -8 1 load cap’acities than did/equal sections in whish the . -* 1I : I split sey’tions !of seasoned J.. ‘: . .m > 19; When, split’sect&ns. 1_ .I ‘. .,,, were,used as/the reinforcement_iii-& concrete beam, ‘longitudinal cracks, , ,: apeeared in-the conc$ete due ‘b the swelling action of the bamboo. : it cracking-of t,hem,cozcrete was pf~s-ufficient.Yinten,sityias. to virtually ‘. the load capacitie’s of the members. . - ‘- ._ ~~.-,~ , i c <O. 3~ When unseasoned bamboo was used as the reinfo>cqment in a 11; . ,;’ : :‘. _-’ .7 concrete member, the bam,boo sdason;ed and shrank over’s peri,od of % ..- time while encased in the c0ncr.et.e. This seasoning action of the bam- boo materially lowere’d the effective bond between’the bamboo’and con- L’ Crete with’s resultantle i o : ,. ..s-- 21. Increasing the - <; ,: _.. ‘_ z.’ ,, . _ ; . f I I ,I : ., - "

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