MATEC Web of Conferences 138, 01024 (2017) DOI: 10.1051/matecconf/201713801024 EACEF 2017

Mechanical properties of different bamboo species

Dinie Awalluddin1, Mohd Azreen Mohd Ariffin1,2*, Mohd Hanim Osman1,2, Mohd Warid Hussin1, Mohamed A. Ismail3, Han-Seung Lee4, and Nor Hasanah Abdul Shukor Lim1. 1Faculty of Civil Engineering, Universiti Teknologi Malaysia, 81310 UTM Johor Bahru, Johor, Malaysia. 2Forensic Engineering Centre, Institute for Smart Infrastructure Innovative Construction, Faculty of Civil Engineering, Universiti Teknologi Malaysia, 81310 UTM Johor Bahru, Johor, Malaysia 3Department of Civil and Construction Engineering, Faculty of Engineering and Science, Curtin University Sarawak, CDT 250, Miri 98009, Sarawak, Malaysia. 4Department of Architectural Engineering, Hanyang University, 1271 Sa 3-dong, Sangrok-gu, Ansan 426-791, Korea.

Abstract. Bamboo is a rapid renewable plant that has a fast growth rate as compared to trees, which increases its suitability to be used as a sustainable source for wood industry, especially in construction works. Due to the lack of understanding on bamboo properties, the utilization of bamboo in construction has always been neglected. This paper presents an investigation on the mechanical properties of four species of treated bamboos that are available in Malaysia, which include Bambusa Vulgaris, Dendrocalamus Asper, Schizostachyum Grande, and Gigantochloa Scortechinii. A mechanical testing was carried out in various parts along the culm of these bamboo species in order to examine the differences of their compressive strength and tensile strength. The strength development and moisture content of these bamboo species were also monitored at a five-month interval. The results showed that Bambusa Vulgaris, Dendrocalamus Asper, and Gigantochloa Scortechinii possess excellent mechanical properties in compression and tensile strength, which indicate a good quality to be used as a construction material. As bamboo offers promising advantages, thus, it is suitable to be used as a substitute in place of structural timber in construction, which indirectly facilitates the preservation of the global environment.

1 Introduction

Being classified as a grass member of a larger grass family [1], bamboo can be easily found in tropical and some temperate areas of the world. ______* Corresponding author: [email protected]

© The Authors, published by EDP Sciences. This is an open access article distributed under the terms of the Creative Commons Attribution License 4.0 (http://creativecommons.org/licenses/by/4.0/). MATEC Web of Conferences 138, 01024 (2017) DOI: 10.1051/matecconf/201713801024 EACEF 2017

Bamboo has a nature form comprising a cylindrical pole with jointed stem known as a culm. There are over 1500 identified bamboo species in the world [2]. As one of the fastest growing plants, bamboo can reach a full height ranging from 15-30m in a period of two to four months [3]. All bamboo species has a similar anatomy, which consists of nodes, internodes, and diaphragm as shown in Figure 1. Each species can be identified according to their root system, in which there are three known root systems including, sympodial, monopodial, and amphodial [4]. The thickness of a bamboo decreases along the height of the culm, while the fibres density increases from the bamboo culm’s inner wall to outer wall.

Fig.1 Bamboo anatomy Bamboo forest has a higher harvest cycle, with up to four times of carbon density per hectare in comparison to spruce forest [5]. This means that bamboo can be harvested in a short period of time, in addition to having a high rate of carbon absorption as compared to timber. Recently, there is a growing interest in using bamboo as a construction material, in place of timber. In China, contractors have utilized bamboo as scaffoldings, while in Bali, bamboo is used to construct a Green School [6], where all structural components of the building is sourced from a local bamboo supplier. In contrast, in other developing country, the utilization of bamboo as a construction material is scarce, even with an abundance of bamboo source available. Lack of study concerning the mechanical properties of bamboo is known to be one of the factors that is associated with a low utilization of bamboo in construction. The ability and capacity of bamboo to withstand the force applied onto it is very important. The strength and moisture content of the bamboo are among the most important factors, which determine both ability and capacity of full bamboo culm. Bamboo with a moisture content of 15% or lower tends to have good mechanical properties and is less vulnerable to fungus attack [7]. In determining the strength of bamboo, 12% of moisture content in air-dry condition has been regarded as a standard and reference [8]. In terms of

2 MATEC Web of Conferences 138, 01024 (2017) DOI: 10.1051/matecconf/201713801024 EACEF 2017

Bamboo has a nature form comprising a cylindrical pole with jointed stem known as a culm. uablt t aes acco to seces a ae aes t s estmate that a uteate There are over 1500 identified bamboo species in the world [2]. As one of the fastest growing bamboo has a es le o aomatel eas t s stoe aoatel hle a plants, bamboo can reach a full height ranging from 15-30m in a period of two to four months teate bamboo ll hae a much loe es le [3]. All bamboo species has a similar anatomy, which consists of nodes, internodes, and he steth o bamboos also ees o ae aes a seces hch etemes the diaphragm as shown in Figure 1. Each species can be identified according to their root sutablt to be use costucto he the each matut ae o aou eas system, in which there are three known root systems including, sympodial, monopodial, and matut bamboos ossess a otmum steth a ae sutable to be use o heaut amphodial [4]. The thickness of a bamboo decreases along the height of the culm, while the alcatos t has also bee ou that bamboos’ comesse steth ceases alo the fibres density increases from the bamboo culm’s inner wall to outer wall. heht ato to ceas comesse steth om the e at to the oute at o the culm – he am o ths eseach s to estate o the mechacal oetes o eet seces o local bamboos hs eseach s a at o a eemetal o hch ocuses o the ossblt o utl bamboo as a costucto mateal

2 Materials and methods

2.1 Preparation of the bamboo hee ae ou bamboo seces ole ths eseach hch ae souce om ea alasa hose ou bamboo seces clue Dendrocalamus Asper Bambusa Vulgaris Schizostachyum Grande a Gigantochloa Scortechinii hese ou bamboo seces ee selecte a let to o about thee ees utl the colou o the bamboos tue ellosh om the oal colou he ee subseuetl teate b us boc ac oe to cease the uablt a ablt aast uus attac ue shos a le o elle bamboos athee o to mechacal test

Fig.1 Bamboo anatomy Bamboo forest has a higher harvest cycle, with up to four times of carbon density per hectare in comparison to spruce forest [5]. This means that bamboo can be harvested in a short period of time, in addition to having a high rate of carbon absorption as compared to timber. Recently, there is a growing interest in using bamboo as a construction material, in place of timber. In China, contractors have utilized bamboo as scaffoldings, while in Bali, bamboo is used to construct a Green School [6], where all structural components of the building is sourced from a local bamboo supplier. In contrast, in other developing country, the utilization of bamboo as a construction material is scarce, even with an abundance of Fig.2 ou bamboo seces bamboo source available. Lack of study concerning the mechanical properties of bamboo is known to be one of the factors that is associated with a low utilization of bamboo in construction. 2.2 Mechanical testing The ability and capacity of bamboo to withstand the force applied onto it is very ll bamboo seces ee cut to small samles hch the samles ee tae om the important. The strength and moisture content of the bamboo are among the most important teoe o the bamboo culm hee tests hae bee ole ths eseach clu factors, which determine both ability and capacity of full bamboo culm. Bamboo with a comesso tesle a mostue cotet accoace th at moisture content of 15% or lower tends to have good mechanical properties and is less ll secmes ee cut om the bottom mle a to ats o the bamboo a mae vulnerable to fungus attack [7]. In determining the strength of bamboo, 12% of moisture th lettes a esectel o comesso test a tesle tests all secme content in air-dry condition has been regarded as a standard and reference [8]. In terms of th ee oes ee selecte he oute amete o the bamboo secme to be use o

3 MATEC Web of Conferences 138, 01024 (2017) DOI: 10.1051/matecconf/201713801024 EACEF 2017

omsso s as mas om o oos os o o sa aa am as o a a ss o bamboo m as mas om o os saa b a a ao am o sm omsso s as a o b s a sa s a sms o o bamboo ss s a osa a o mms as so amm oa o a sm as o b s a aa o

Fig 3. amboo sm omsso s s sa s a

o omo o omsso s sma sams a mso o mm mm as so a a mma om each bamboo species’ specimen o o mos o s sams bs a o a o a o os o o a amo o mos o a b o a o sams aa a as o

Fig 4. ms o mos o s

4 MATEC Web of Conferences 138, 01024 (2017) DOI: 10.1051/matecconf/201713801024 EACEF 2017

omsso s as mas om o oos os o o sa aa ana ensie senh es as escibe in a iecs ha specimens am as o a a ss o bamboo m as mas om sho be c ino a ‘dogbone’ shape. The specimens in this study ee c aia om he o os saa b a a ao am o sm omsso s cm a in oe o poce a ‘dogbone’ shape o he specimens ee c an pepae as a o b s a sa s a sms o o bamboo paae o bamboo’s ibe For testing the specimens’ tensile strength, a 0.01mm/s oa as ss s a osa a o mms as so amm oa appie aa he sep o he ension es hich as aane paae o bamboo’s o a sm as o b s a aa o ain is shon in ie

Fig 5. ensie senh es sep

3 Results and discussions Fig 3. amboo sm omsso s s sa s a 3.1 Compression test and moisture content o omo o omsso s sma sams a mso o mm mm ompessie senh an moise conen o bamboo specimens ae epoe in abe as so a a mma om each bamboo species’ specimen he senh o each bamboo species’ specimen as ese a a iemonh inea in oe o o mos o s sams bs o eemine he senh eeopmen o he bamboo a o a o a o os o o a amo o mos o a b o a o sams Table 1 ompessie senh an moise conen o bamboo aa a as o pecies a eae eae eae eae ompessie oise ompessie oise enh s onen enh h onen onh onh mm mm enocaams op spe ie oom ambsa ais op ie oom ianochoa op coechinii ie oom Fig 4. ms o mos o s chiosachm op ane ie oom

5 MATEC Web of Conferences 138, 01024 (2017) DOI: 10.1051/matecconf/201713801024 EACEF 2017

s reported in Table 1, the aerage compressie strength o bamboo as obsered to be high at the top part o all bamboo species, olloed by middle, and lastly, bottom part. The dierent alues signiy the dierent specimen locations here the specimens ere cut. pecimens taen near the culm’s base ere slightly ea and older than the specimens that ere taen ar rom the culm’s base. The dierence in this property is attributed to the presence o big ascular bundles that are present in bamboos. ascular bundles are responsible or transporting all the nutrients rom culm’s base during the lie o bamboos. These ascular bundles hae indirectly resulted in a loer ibre content at the culm’s base as compared the top part o the culm.

100

80

60

40

20

0 BOTTOM MIDDLE TOP DA BV GS SG

Fig 6. The dierence compressie strength at bottom, middle and top.

ter a iemonth interal, a second compression test as conducted. The result shoed a similar trend, hereby the top part o the culm possesses a high compressie strength as compared to middle and bottom parts. n moisture content test, ater a iemonth interal, the moisture content o bamboo specimens ell. This resulted in a higher compressie strength o the specimens as compared to one month old specimens. The moisture content o the specimens ell gradually, as all the specimens ere ept in an air drying storage. s presented in Table 1, the moisture content of all four bamboo species’ specimens ranges rom 1. to the loest moisture content, 1.01, hich is to percent short rom the desired optimum moisture content, 1.00.

Fig 7. ertical crac and end bearing ailure o specimen ater compression test

6 MATEC Web of Conferences 138, 01024 (2017) DOI: 10.1051/matecconf/201713801024 EACEF 2017

s reported in Table 1, the aerage compressie strength o bamboo as obsered to be isual inspecion on e specimens afer compression es also reeale muliple cracs high at the top part o all bamboo species, olloed by middle, and lastly, bottom part. The ic eenuall le o splis as iniiual specimens’ secions bucle ese erical dierent alues signiy the dierent specimen locations here the specimens ere cut. cracs are son in igure rom is figure i is e eien a bamboos i airrie pecimens taen near the culm’s base ere slightly ea and older than the specimens that culms eperience brile failure ere taen ar rom the culm’s base. The dierence in this property is attributed to the presence o big ascular bundles that are present in bamboos. ascular bundles are 3.2 Tensile test responsible or transporting all the nutrients rom culm’s base during the lie o bamboos. These ascular bundles hae indirectly resulted in a loer ibre content at the culm’s base as ensile sreng es parallel o bamboo’s grain as carrie ou in e same coniion as compared the top part o the culm. compressie sreng es ere e specimens use a unergone o air ring e resul of e ensile es is son in able able sos e ensile sreng of Dendrocalamus Asper species e aerage sreng of Dendrocalamus Asper species is sligl loer a e mile par of e bamboo ile e sreng a e op an boom pars are almos eual 100 i recore reaings of an mm respeciel Table 2: ensile sreng of Dendracalamus Asper 80 ar ample rea mm ensile reng erage ensile 60 mm reng mm 40 op 20 0 ile BOTTOM MIDDLE TOP DA BV GS SG oom Fig 6. The dierence compressie strength at bottom, middle and top.

ter a iemonth interal, a second compression test as conducted. The result shoed able sos e ensile sreng of Bambusa Vulgaris species ic recore a a similar trend, hereby the top part o the culm possesses a high compressie strength as sreng of aboe mm across all pars of e bamboo consiere in is su e compared to middle and bottom parts. n moisture content test, ater a iemonth interal, resuls so a Bambusa Vulgaris eibis an almos similar ensile sreng as the moisture content o bamboo specimens ell. This resulted in a higher compressie strength Dendrocalamus Asper with bamboo’s top, middle, and bottom parts recorded readings of, o the specimens as compared to one month old specimens. The moisture content o the an mm respeciel specimens ell gradually, as all the specimens ere ept in an air drying storage. s presented in Table 1, the moisture content of all four bamboo species’ specimens ranges rom 1. Table 3. ensile sreng of Bambusa Vulgaris to the loest moisture content, 1.01, hich is to percent short rom the desired optimum ar ample rea mm ensile reng erage ensile moisture content, 1.00. mm reng mm op ile oom

or Gigantochloa Scortechinii e recore reaings of ensile sreng for op mile an boom pars of bamboo are belo mm e iges sreng a e op par of e bamboo recore a reaing of mm ile e boom par recore a reaing of Fig 7. ertical crac and end bearing ailure o specimen ater compression test

7 MATEC Web of Conferences 138, 01024 (2017) DOI: 10.1051/matecconf/201713801024 EACEF 2017

mm eanwhile, middle part of the bamboo recorded a slightl lower reading than the bottom and top parts, with a reading of mm oweer, the difference is not significant he tensile strength of Gigantochloa Scortechinii species is shown in able Table 4. ensile strength of Gigantochloa Scortechinii art ample rea mm ensile trength erage ensile mm trength mm op iddle ottom

astl, able shows the tensile strength of Schizostachyum Grande species he top part of this species shows the highest tensile strength reading as compared to its middle and bottom parts’ readings oweer, in comparison to other three bamboo species, Schizostachyum Grande shows the lowest recorded readings of tensile strength Table 5 ensile strength of Schizostachyum Grande art ample rea mm ensile trength erage ensile mm trength mm op iddle ottom

igre shows failres of specimens taen from tensile test ost of the specimens eperienced similar mode of failre, which comprised of the combination of tension and shear parallel to grain his mode of failre is different as compared to timber, which has ras and nots that case it to withstand less stress throgh the length of stal

8 MATEC Web of Conferences 138, 01024 (2017) DOI: 10.1051/matecconf/201713801024 EACEF 2017

mm eanwhile, middle part of the bamboo recorded a slightl lower reading than the bottom and top parts, with a reading of mm oweer, the difference is not significant he tensile strength of Gigantochloa Scortechinii species is shown in able Table 4. ensile strength of Gigantochloa Scortechinii art ample rea mm ensile trength erage ensile mm trength mm op iddle ottom Fig 8. de aire n ensie seiens ased n reis resear indings as s a gd errane in sreng reries as ared er aerias s as d and see ae ss e astl, able shows the tensile strength of Schizostachyum Grande species he top arisn sreng reries sre d see and a a ssesses part of this species shows the highest tensile strength reading as compared to its middle and iger ressie and ensie srengs en ared i sre d er en bottom parts’ readings oweer, in comparison to other three bamboo species, ared i see Schizostachyum Grande shows the lowest recorded readings of tensile strength Table 6. arisn sreng reries a i er aerias Table 5 ensile strength of Schizostachyum Grande art ample rea mm ensile trength erage ensile aerias ressie reng ensie reng asi ds mm trength r ied reng mm op re d ee iddle reaed a asa garis ottom 4 Conclusions igre shows failres of specimens taen from tensile test ost of the specimens e resen sd indiaes a a as a rising enia e sed as a nsrin eperienced similar mode of failre, which comprised of the combination of tension and aeria e indings as indiae a e iiain a sd e raied ide shear parallel to grain his mode of failre is different as compared to timber, which has n e sd ressin ensie and isre nen ess ere nded es r ras and nots that case it to withstand less stress throgh the length of stal a seies’ ability and capability ing a ien inera e ressie sreng a a seies ad inreased de degraded isre nen n addiin a a seies eiied a gd errane in ensie sreng es r e era res eania esing Dendrocalamus Asper and Bambusa Vulgaris seies endred e iges ressin and ssess e iges ensie sreng ed Gigantochloa Scortechinii and Schizostachyum Grande seies s e eeriena ress reeaed a a as a gd errane in sreng reries

is resear as sred a asi siene resear rgra rg esear niersi ran i e nding r e inisr ig dain and niersii engi aasia is resear as as sred e aina esear ndain rea i e nding r e inisr iene and re anning

9 MATEC Web of Conferences 138, 01024 (2017) DOI: 10.1051/matecconf/201713801024 EACEF 2017

ats is t pss ti tst atitd t ts ndin ntitis ic a alld t sac nda t b caid t

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