Experimental investigation on chemically treated bamboo reinforced ...wix-anyfile.s3.amazonaws.com/vShsBLlqQbmQUh3MS5qu_Experiment… · Experimental investigation on chemically treated

Construction and Building Materials 71 (2014) 610–617

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Construction and Building Materials

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Experimental investigation on chemically treated bambooreinforced concrete beams and columns

http://dx.doi.org/10.1016/j.conbuildmat.2014.09.0110950-0618/� 2014 Elsevier Ltd. All rights reserved.

⇑ Corresponding author.E-mail address: [email protected] (B. Nanda).

Atul Agarwal a, Bharadwaj Nanda b,⇑, Damodar Maity a

a Department of Civil Engineering, Indian Institute of Technology, Kharagpur, Indiab Department of Civil Engineering, Veer Surendra Sai University of Technology, Burla, India

h i g h l i g h t s

� Experiments are conducted to study feasibility of bamboo as reinforcement in concrete.� Varieties of adhesives are used for treatment of bamboo to study their effect on bond strength.� Tests are performed to reveal behavior of bamboo reinforced concrete members under loading.� These tests suggest that bamboo with proper treatment has potential to substitute steel as reinforcement.

a r t i c l e i n f o

Article history:Received 15 February 2014Received in revised form 31 August 2014Accepted 4 September 2014

Keywords:Bamboo reinforced concreteAlternate materialLow cost constructionBond strengthChemical treatmentUltimate strength

a b s t r a c t

Concrete is often reinforced with steel bars to negate its weak tension carrying capacity. However, due tohigher cost and non-renewability of steel, nowadays attempts are made to provide a low-cost sustainablealternative by using locally available material. The feasibility for usage of bamboo as reinforcement inconcrete is evaluated through a series of experimental investigations in the present study. First of all, ten-sile test of locally procured bamboo strips are conducted for evaluation of its ultimate strength and engi-neering properties. Varieties of adhesives such as Tapecrete P-151, Sikadur 32 Gel, Araldite and Anti CorrRC have been used for the treatment bamboo to study their effect on bond strength at the interface of thebamboo concrete composite. From the comparative study the most suitable adhesive has been selectedand used further to cast bamboo reinforced beams and columns. The axial compression and transverseloading tests are performed on plain, steel and bamboo reinforced columns to reveal the load carryingcapacity, lateral deflection, and failure mode pattern. Also, two-point load test is performed on beamsto study their behavior under bending. All these tests suggest that bamboo with proper treatment hasthe potential to substitute steel as reinforcement in beam and column members.

� 2014 Elsevier Ltd. All rights reserved.

1. Introduction

Concrete is the most widely used material in building construc-tion. It is very strong in compression but weak in tension. Due tothis, it is often reinforced with steel bars wherein these barsprovide the tensile strength to the concrete. But use of steel asreinforcing material has some disadvantage like higher cost andnon-renewability of steels. Apart from these, production of steelis responsible for a major source of greenhouse gas emission.Hence, attempts are being made by several researchers to providea low-cost sustainable alternative of steel by using locally availablematerial. In this regard, many researchers investigated the possi-bilities of using vegetable fibers materials as reinforcement in

concrete. The typical vegetable fibers materials which have beenstudied in the past includes, jute [1,2], coconut coir [3,4], sisal[5], babadua [6], date palm [7], raffia palms [8], bamboo [9,10],and bamboo fibers [11] etc. Although most of these studies yieldedgood results still bamboo has a clear advantage over other naturalreinforcing materials.

Bamboo is a fast growing wood like substance belongs to thegrass family Poaceae. It reaches its optimum strength in just threeto four years and attains the maturity in five years. The tensilestrength of bamboo is very high and for some of its species the ulti-mate tensile strength is same as the yield strength of mild steelwhile the strength to specific weight ratio is six times greater thanthat of steel. Like steel bars, bamboo can take both tension as wellas compression whereas many other vegetable reinforcing materi-als cannot carry compression loading. Furthermore, the energyrequired to produce one cubic meter per unit stress of bamboo is

A. Agarwal et al. / Construction and Building Materials 71 (2014) 610–617 611

50 times lower than the energy required by steel [12]. Due to theseproperties bamboo has drew the attention of many researchers foruse as reinforcement in concrete.

Mansur and Aziz [13] experimentally evaluated the feasibilityof using bamboo in the form of woven mesh as reinforcement incement mortar. This study indicated that inclusion of bamboomesh imparts considerable ductility and toughness to the mortar,and increases significantly its tensile, flexural and impactstrengths. Akeju and Falade [14] used bitumen and sand coatingon bamboo to reduce its water absorption capacity and used thisfor reinforcement of beam and column members. Ghavami [9]experimentally pointed out that, the ultimate load carrying capac-ity is increased four times for bamboo reinforced concrete (BRC)than unreinforced concrete. Further, the author found that, thebonding between bamboo and concrete is lower than that of steeland concrete which reduces the tension carrying capacity. Ghav-ami [12] presented a concise summary regarding structural appli-cations of bamboo as structural concrete elements includingbeams, shutters, frames and elements subjected to bending stress.Prasad et al. [15] used bamboo reinforced cement–sand mortarpanels for making low cost housing in hilly regions. Bitumencoated and sand sprayed bamboo-mats were used for constructionof wall and roof elements. Then, cement–sand plaster (1:6 mix)was applied on both faces with average thickness of 12 mm eachto impart strength to bear stresses under static and impact loadsto the structure. However, no load test was reported to understandthe composite behavior of the member. Maity et al. [16] proposedthe use of precast BRC wall panels as a replacement to mud andbrick walls for construction of low cost dwellings in rural areas.Durability analysis of bamboo carried out by Lima et al. [17] con-cluded that, even after 60 cycles of wetting and drying in calciumhydroxide and tap water did not result any variation of its tensilestrength and Young’s modulus which is an important factor satis-fied for its use as concrete reinforcement. Rahman et al. [10] eval-uated the performance of single and double BRC beams whereasSalau et al. [18] investigated structural strength of BRC columns.Terai and Minai [19] demonstrated that, the fracture behavior ofBRC beam can be evaluated by the existing formula of RCC beams.Yamaguchi et al. [20] studied the performance of BRC beams usingbamboo as main rebar and stirrups in carrying flexural loads.

From the past researches, the failure of BRC members isobserved mainly due to weak bond between bamboo and concrete.No literature is available which suggests the most suitable adhe-sive to be used for treatment of bamboo for increasing bondstrength between bamboo and concrete. The present investigationis focused to increase the bond strength at the interface of thebamboo concrete composite. With this objective, varieties of adhe-sives such as Tapecrete P-151, Sikadur 32 Gel, Araldite and AntiCorr RC have been used for treatment purpose. The bond strengthhas been compared by performing pull out test on bamboo rein-forced cylinders using different adhesives. The adhesive producingmaximum bond strength, has been further used for castingbamboo reinforced beams and columns. The axial compressionand flexural tests are performed on plain, steel and BRC membersto compare the lateral deflections, ultimate loads and failure modepatterns.

2. Experimental program

2.1. Selection and preparation of bamboo strips

The bamboo culms of locally available Muli Bamboo (Melocanna bambusoides)are procured considering the guidelines such as the samples procured are between3 and 5 years of age, having a brownish appearance, and samples which has beencut in winter season. Thereafter, bamboo strips of desired size are cut from thesebamboo culms by the lathe machine. The tensile tests are conducted on the bamboosample to determine bamboo’s ultimate strength and modulus of elasticity. For thispurpose, the specimens selected are air dried for over 30 days. The test is conducted

in a 60 ton (588.4 kN) universal testing machine (UTM) under a loading rate of1 mm/min. To improve the grip between specimen and the UTM, aluminum tabsare attached to both ends of the specimen.

For the reinforcement, the bamboo samples are treated in four stages. Firstlybamboo samples are soaked in water for 24 h. Then a coat of lime is applied on thesamples. Due to immersion the samples may absorb water up to 32% of its weight[21] therefore it is allowed to dry for 30 days. Next, these samples are treated withvarious adhesives as required turn by turn. Finally, a coat of dry sand is applied onthe samples to improve the bonding between bamboos and cement mortar.

2.2. Test methods

The current research primarily aims at conducting tests such as pull out test toevaluate bond strength between bamboo and concrete, axial load testing and trans-verse load testing on BRC columns and two point loading test on BRC beams. Theconcrete used for these studies are design mix of M20 grade, designed as per Indianstandards (IS 10262:2009). The Indian standard specifies (IS 456:2000) the charac-teristics compressive strength, Young’s modulus and flexure strength are given by20 N/mm2, 22361 N/mm2 and 3.13 N/mm2 respectively.

Comparison is made to measure the interfacial strength between the bambooand concrete block for varieties of adhesives through pull out tests. Three cylindersof diameter 100 mm and height 200 mm are cast for each adhesive arrangement(i.e. plain bamboo, Araldite, Araldite with binding wire, Tapecrete P-151, Anti CorrRC and Sikadur 32 Gel). Araldite is an epoxy based thermosetting adhesive withattributes like low shrinkage on curing and high creep resistance and offers a highdegree of adhesion to all the substrates except some low surface energy, untreatedplastics and elastomers. This adhesive has excellent resistance to water, oil andmany other solvents. Tapecrete P-151 is an acrylic based polymer modified cemen-titious coating system based on cross linked polymethyl methacrylate grafted tovinyl terminated nitrile rubber. This offers better shear strength, faster curing andbetter weather and water resistance. Sikadur 32-Gel is a liquid consistency, twocomponent-based selected and solvent free epoxy resins and it is used to improvethe bonding strength of treated bamboo with concrete. Finally, Anti Corr RC is apolyurethane based adhesive prepared from iso-cyanate resins as building blocks.This adhesive simultaneously improves the shear and peeling strength in bonding.

Bamboo strips are inserted into the concrete cylinders up to the mid-point i.e.100 mm. These specimens are demoulded after 24 h and then cured in water for28 days before conducting the test. The pull out test is undertaken in the same60 ton UTM used for tensile test of bamboo specimen. Axial compression test is per-formed on plain, steel and bamboo reinforced columns of dimension150 mm� 150 mm� 1000 mm. In total 24 concrete columns are casted whichincludes three columns each from (i) plain, (ii) 0.89% steel reinforcement, (iii) untreatedbamboo (with reinforcements of 3%, 5% and 8%) and (iv) treated bamboo reinforcedconcrete (with reinforcements of 3%, 5% and 8%). Similar to pull out test these speci-mens are also demoulded after 24 h and then cured for 28 days in water before con-ducting the test. Uniaxial compression machine of 300 ton (2942 kN) capacity isused for conducting these tests. The compression force is applied to the specimen ata rate of 20 kN/min. The test is performed till the column could resist the load.

From the uniaxial compression test it is observed that columns are failed byaxial splitting type cracks. Further, transverse loading test is conducted on theseset of columns to ascertain their strength, failure mode and deflection behaviorunder the applications of both axial as well as transverse load. For this purpose,15 columns of dimension same as that of axial compression test specimens arecasted. The casted columns included 3 for plain concrete, 3 for steel reinforced con-crete and 9 for treated bamboo with reinforcement percentage of 3%, 5% and 8% (i.e.3 specimens for each percentage).

First, a loading frame is fabricated which is shown in Fig. 1 for conducting thistest. Here, two bars are attached at the center of the column in order to hold the dialgages and to prevent sudden collapse of the columns under test. Constant axial loadof 10 kN is applied to the column through a hydraulic jack of 18 ton capacity. Then,gradually increasing transverse load under a loading rate of 2 kN/min is appliedthrough another jack of 10 ton capacity on one side of the beam as shown in the fig-ure. Behavior of the column is constantly monitored by the dial gauge during thetest. The test is ended when the column failed to resist any further load.

Finally a two point loading test is done on bamboo reinforced beams to studytheir strength and deflection behavior and failure patterns. In total 12 beams ofdimension 75 mm � 150 mm � 1000 mm are casted. These 12 beams include 3beams each for plain concrete, untreated bamboo, treated bamboo reinforcementand RCC beam. M20 grade design mix concrete is used for this purpose. 25 mm clearcover is provided for BRC beams. Two bamboo strips of area 70 mm2 each has beenprovided as reinforcement. Thus the percentage of the bamboo reinforcement pro-vided is becoming 1.49%. The RCC beam is reinforced with two 8 mm steel bars. Thebeams are cured in water for 28 days before conducting the test. The test is con-ducted using 10 ton (98.06 kN) proving ring with a least count of 149.1 N(15.2 kg) and a manual jack arrangement. Dial gauge is affixed at the center ofthe beam to measure its central deflection. Loading is applied manually with thehelp of iron rod which is used to rotate the jack. Fig. 2(a) shows the descriptive linediagram and Fig. 2(b) shows photographs of the test setup. The loading, deflectionand crack pattern are constantly monitored during the test which is ended whenthe beam fails to resist any further load.

L

Transverse Load

Constant Axial Load = 10kN

L/3

Shor

t C

olum

n

(a) Line diagram (b) Test setup

Fig. 1. Transverse loading test set up.

L

L/3P P

PP

(a) Line diagram

(b) Test setup

Fig. 2. Two point loading test set up for beams.

612 A. Agarwal et al. / Construction and Building Materials 71 (2014) 610–617

3. Results and discussions

The results of the tests conducted on the bamboo strips and BRCelements described in Section 2 are presented in this section. Basedon these results relevant discussions are provided.

3.1. Tensile test on bamboo strips

Tensile test is conducted on the locally procured bamboo stripsto understand the ultimate strength and elasticity parameters ofthe reinforcement. Total three specimens are tested for this

purpose. From literature review it is understood that bamboo ismore vulnerable for failure at the nodes. Due to this, all the threesamples considered for the study were having one node. The phys-ical dimensions of the samples and corresponding test results aregiven in Table 1. Measurements for width and thickness are doneat three different locations of the specimen and their average valueis considered for strength estimation. It is observed from the testthat, the samples are failed mostly at nodes due to splitting asshown in Fig. 3. From Table 1, the average tensile strength is calcu-lated as 185.93 N/mm2. The modulus of elasticity is calculated as24.46 GPa.

3.2. Pull out test results

As discussed in Section 2, a comparison is made among severaladhesives available to measure their performance in improving theinterfacial strength between the bamboo and concrete. In total 18cylinders are casted for the comparison purpose which includesthree cylinders for each adhesive arrangement, i.e., (i) plain bam-boo, (ii) Araldite, (iii) Araldite with binding wire, (iv) TapecreteP-151, (v) Anti Corr RC and (vi) Sikadur 32 Gel respectively. Bam-boo strips are inserted into the concrete cylinders to a depth of100 mm. The bond stress of the specimen is calculated using theequation sb ¼ F

SL, where F denotes the pulling out load, S denotesthe perimeter of the bamboo strip and L denotes the length ofbonded interface. The details of all 18 test cylinders and the testresults are shown in Table 2.

From these tabulated results, it is found that the average bondstrength between the bamboo and concrete is highest for Sikadur32 gel. Hence, this adhesive is selected for all further studies. It isfound from the test that, most of the specimens failed due to slip-page of bamboo strips from the concrete cylinders as shown inFig. 4. However, in few cases, it is also observed that bamboo sam-ples have broken during the slippage despite of the fact that thetensile strength of the bamboo sample is much higher than themaximum bond stress obtained between bamboo strips and con-crete. This may be due to possible non alignment of the samplesin the testing machine leading to unnecessary eccentricity.

Table 1Details of tensile test results.

Sl. No Length (mm) Width (mm) Thickness (mm) Area (mm2) Ultimate load (kN) Failure stress (MPa) Strain

1 278.0 22.70 3.60 81.72 16.30 199.50 0.00802 303.0 20.90 3.23 67.50 12.63 187.20 0.00803 315.0 28.18 5.33 150.20 25.69 171.10 0.0070Average = 185.93 0.0076

(a) Test setup (b) Failure pattern

Fig. 3. Failure patterns of bamboo specimen under tension test.

Table 2Details of pull out test results.

Sl. No Adhesive Bamboowidth (mm)

Bamboo thickness(mm)

Contact areaper unit height (mm)

Pull outload (kN)

Bond stress(MPa)

Average bondstress (MPa)

1 Plain Bamboo 30.84 4.99 71.66 0.37 0.052 0.1272 37.08 4.05 82.26 1.78 0.2163 40.03 5.11 90.28 1.02 0.1134 Araldite 44.91 4.43 98.68 2.44 0.247 0.2325 35.95 3.82 79.54 1.82 0.2296 41.32 4.85 92.34 2.04 0.2217 Araldite With Wire 27.23 3.19 60.84 3.08 0.506 0.5398 28.78 4.86 67.28 3.44 0.5119 23.48 2.97 52.90 3.17 0.599

10 Tapecrete P 151 37.89 4.89 85.56 2.72 0.318 0.31511 37.65 4.33 83.96 2.56 0.30512 38.7 3.89 85.18 2.74 0.32213 Anti Corr RC 30.54 3.13 67.34 1.16 0.172 0.15914 36.88 5.73 85.22 1.47 0.17215 36.97 4.2 82.34 1.08 0.13116 Sikadur 32 Gel 29.81 3.415 66.45 4.42 0.665 0.58817 35.11 5.31 80.84 4.22 0.52218 39.24 3.21 84.90 4.90 0.577

A. Agarwal et al. / Construction and Building Materials 71 (2014) 610–617 613

3.3. Axial compression test on short columns

Axial compression test is performed on short columns ofdimension 150 mm � 150 mm � 1000 mm casted using designmix of M20 concrete. Total 24 columns are casted which includes3 numbers of plain concrete columns, 3 numbers of steel

reinforced concrete columns (with reinforcement of 0.89%) andthree columns each for untreated and treated bamboo reinforcedconcrete columns with reinforcement of 3%, 5% and 8% respec-tively. It is observed from the pull out test reported in Table 2 thatSikadur 32 gel is the best adhesive for getting maximum bondstrength between bamboo and concrete. Therefore, this adhesive

Fig. 4. Failure patterns during pull out test.

0

50

100

150

200

250

300

350

400

450

500

0 1 2 3 4 5 6 7

Axi

al L

oad

(kN

)

Axial deformation (mm)

Bamboo ReinforcedPlain ConcreteSteel Reinforced

Fig. 5. Axial load-axial deformation curves for short columns.

614 A. Agarwal et al. / Construction and Building Materials 71 (2014) 610–617

has been considered for treatment of bamboo for BRC members.Table 3 shows the load carried by different columns under axialcompression. The ultimate load and axial deformation for eachcase has been taken as average of three specimens. It is observedfrom the table that, the load carried by the minimum steel rein-forced column was comparable to the load sustained by the treatedbamboo reinforced column with 8% reinforcement. The untreatedbamboo reinforced columns can sustain significantly lower loadthan that in treated bamboo reinforced columns. This is due to lessbonding strength between bamboo and concrete and may be dueto significant water absorption by the untreated bamboo from sur-rounding mortar.

The load–deformation behaviors of plain concrete, steel rein-forced and treated bamboo (8%) reinforced columns under axialcompression are plotted in Fig. 5. It is observed from this figurethat, the area under the load–deformation curves for bamboo rein-forced concrete is more than that of steel reinforced concretewhich indicates that, the bamboo has the capacity to absorbenergy. Furthermore, this indicates better ductility property ofBRC columns. Moreover, failure modes for these sets of columnsare compared. Fig. 6 presents the crack patterns of different col-umns under uniaxial loading. It is observed that, plain concreteand untreated bamboo columns showed brittle behavior in which,small cracks occurred at the surface of the columns at about 70–80% of maximum axial force. Then, the load capacity decreasedabruptly on reaching the maximum compression load and failedsuddenly. There are no visible signs of spoiled concrete coveringto warn of impending failure. In comparison, the steel and treatedbamboo reinforced columns showed more ductile behavior. Here,minor cracks are visible at surfaces towards the failure whichgrows in size with the increase of the load for significant timeand finally fails at a higher load than the plain and untreatedBRC columns. However, it is observed that all columns are failedby axially splitting cracks under axial compressive loading.

Table 3Details of axial compression test results.

Sl. No Specimen type Reinforcement percentage

1 Pain concrete –2 Reinforced concrete 0.893 BRC (untreated) 3.004 BRC (untreated) 5.005 BRC (untreated) 8.006 BRC (treated) 3.007 BRC (treated) 5.008 BRC (treated) 8.00

3.4. Transverse loading test on concrete columns

This test is conducted on BRC columns in order to ascertaintheir behavior under the applications of both axial as well as trans-verse load. Total 15 numbers of columns are casted as detailed inTable 4. The dimensions are kept similar to axial compression testspecimens. The test is conducted under a constant axial load of10 kN. Results of the test are presented in Table 4. It is observedthat in average the transverse load sustained by steel columns is15.20 kN whereas the transverse load sustained by BRC columnswith 8.0% reinforcement is 14.43 kN which is nearly 96.0% of theformer one. The transverse load – lateral deformation behavior ofplain concrete, steel reinforced and treated bamboo reinforced col-umn with 8% reinforcement under the test are plotted in Fig. 7. It isobserved from the figure that, treated bamboo reinforced columnsexhibited ductility behavior and energy absorption capacity is (thearea under the load–deformation curves) comparable to that ofsteel reinforced columns. The treated BRC columns could sustainnearly 26% more transverse load than the plain concrete columns.Fig. 8 presents the crack patterns of different columns. It isobserved from these photographs that, the crack pattern ofbamboo reinforced columns and steel reinforced columns are verysimilar in nature wherein the columns are failed by axial splittingwhich is grown as an extension of the flexural cracks. Further,these columns provides ample warning of impending failure;whereas the plain columns exhibited brittle behavior and failedsuddenly without giving any visible warnings.

3.5. Two point load test on beams

A two point load test is done on BRC beams to study theirstrength under bending, deflection behavior and failure patterns.Total 12 beams of dimension 75 mm � 150 mm � 1000 mm arecasted and tested. These 12 beams include 3 beams each for plainconcrete, reinforced concrete, untreated and treated bamboo

Ultimate axial load (kN) Axial deformation at ultimate load (mm)

245 1.50444 2.85302 4.80315 5.10328 5.32315 4.82396 5.52432 5.80

(c) BRC Column (a) PCC Column (b) RCC Column

Fig. 6. Crack patterns in columns under uniaxial load test.

Table 4Maximum transverse load sustained by columns.

Sl. No. Material Sample no Reinforcementpercentage

Transverse loadat failure (kN)

Averageload (kN)

Max deflectionat failure (mm)

Average deflection(mm)

1 Plain concrete 1 – 10.009 10.622 4.44 4.622 Plain concrete 2 – 10.728 4.623 Plain concrete 3 – 11.130 4.804 RCC 1 0.89 15.667 15.197 6.49 6.325 RCC 2 0.89 15.468 6.326 RCC 3 0.89 14.457 6.157 BRC 1 3.00 11.121 11.127 4.42 4.358 BRC 2 3.00 10.630 4.129 BRC 3 3.00 11.631 4.52

10 BRC 1 5.00 12.496 12.389 4.90 4.8911 BRC 2 5.00 12.440 4.7412 BRC 3 5.00 12.233 5.0413 BRC 1 8.00 14.457 14.434 5.48 5.5414 BRC 2 8.00 13.698 5.5415 BRC 3 8.00 15.148 5.60

0.02.04.06.08.0

10.012.014.016.018.020.0

0 1 2 3 4 5 6 7

Tran

sver

se L

oad

(kN

)

Transverse deformation (mm)

Plain ConcreteSteel ReinforcedBamboo Reinforced

Fig. 7. Transverse loading–transverse deformation curves for short columns.

A. Agarwal et al. / Construction and Building Materials 71 (2014) 610–617 615

reinforcement concrete. Table 5 compares the ultimate load anddeflection corresponding to collapse load for the test columns. It

may be observed from the tabular results that, use of treated bam-boo reinforcement significantly improves the strength of the beam,which is apparent from the increased value of failure load sus-tained by treated BRC beams.

However, no significant improvement is observed by untreatedBRC beams. This is because of weaker bond between bamboo andconcrete. From theoretical calculation the ultimate cracking loadfor BRC beam is obtained as 1404 kg (13.769 kN) considering mod-ulus of elasticity of bamboo and concrete as 24.20 kN/mm2 and22.36 kN/mm2 respectively. The area of bamboo reinforcement istaken as 140 mm2. The value is well comparable with experimentalvalue which is equal to 1337.6 kg (13.117 kN). It is interesting tonote that the failure load for steel reinforced beam becomes1276.8 kg (12.521 kN) while 2 Nos. of 8 mm diameter bar(area = 100.48 mm2) is considered.

Fig. 9 provides the load–displacement behavior of above sets ofcolumns, wherein it is observed that the treated bamboo rein-forced beams sustained much higher deflection compared to plainconcrete beams before failure exhibiting high energy absorption

PCC Column RCC Column BRC Column

Fig. 8. Crack patterns in columns under transverse load test.

Table 5Two point load test results on beams.

Sl. No. Reinforcing material sample no Failure load (kN) Average failure load (kN) Deflection at failure (mm) Average deflection at failure (mm)

1 Plain concrete 1 9.541 10.136 0.25 0.362 2 10.136 0.373 3 10.732 0.464 Untreated bamboo reinforced 1 9.937 9.838 1.69 1.685 2 11.130 1.796 3 8.447 1.567 Treated bamboo reinforced 1 12.323 13.117 1.99 2.188 2 13.608 2.389 3 13.421 2.16

10 Steel reinforced 1 11.918 12.521 1.91 1.9711 2 12.804 2.1212 3 12.843 1.88

0

2

4

6

8

10

12

14

0 0.5 1 1.5 2 2.5

Load

(kN

)

Displacement (mm)

Plain ConcreteUntreated Bamboo ReinforcedTreated Bamboo ReinforcedSteel Reinforced

Fig. 9. Load–deflection curve for beams under two point loading test.Fig. 10. Crack patterns of bamboo reinforced concrete.

616 A. Agarwal et al. / Construction and Building Materials 71 (2014) 610–617

capacity of the bamboo. Moreover, after the appearance of the firstvisible cracks there is a noticeable change of gradient for the bam-boo reinforced concrete beams. Thereafter, the central deflection ofthe beams goes on increasing and it attains maximum deflectionbefore the failure. It is observed from the test that initial cracksare developed on the bottom of the beam mostly bellow the load-ing points, and then it is propagated to the top surface as shown inFig. 10. This is due to the combined action of both flexure and shearloads. Some small horizontal cracks are also observed at thesupport of beam near the ultimate load. However it is observedthat, the bamboo reinforced beams exhibits ductile behavior. Here,the cracks become visible at surface of beams firstly near 80% ofultimate collapse load. Finally, failure is accompanied by growing

signs of cracks and spalling of concrete. In contrast, for untreatedbamboo reinforced beams it is observed that cracks appear inbeams along the bamboo strips indicating bond failures whichfinally lead to the failure of beam member.

4. Conclusions

In this study, the feasibility of usage of bamboo as a reinforce-ment in concrete has been evaluated through a series of experi-mental investigations on of various beams and column members.The tests performed in the due course of research includes tensilestrength test of bamboo specimens, pull out testing of bambooslats embedded in concrete, axial load test and transverse load test

A. Agarwal et al. / Construction and Building Materials 71 (2014) 610–617 617

on BRC columns and two-point load test on BRC beams. It isobserved from pull out test that, the bonding strength at the inter-face of the bamboo concrete composite is highest for Sikadur 32 gelamong the adhesives compared (i.e. Tapecrete P-151, Sikadur 32Gel, Araldite and Anti Corr RC).

From axial load test it is observed that, both the plain concreteand untreated bamboo reinforced concrete columns exhibited brit-tle behavior and shows little warning of impending axial failurewhereas the treated BRC column (Sikadur 32 Gel) exhibits ductilebehavior and provides sufficient warning before failure. Further,it is found that, treated BRC column with 8.0% bamboo reinforce-ment provides almost the same strength and the behavior underaxial as well as transverse loading as that of RCC column with0.89% steel reinforcement. It is observed from two-point load testthat, the load carrying capacity of the beam increased up to29.41% by using merely 1.49% by area of treated bamboo asreinforcement. Hence, in conclusion all these tests suggest that,bamboo has the potential to substitute steel as reinforcement forbeam and column like members.

Acknowledgement

This research is financially supported by Building Materials andTechnology Promotion Council, Ministry of Housing and UrbanPoverty Alleviation, Govt. of India.

References

[1] Mansur MA, Aziz MA. A study of jute fibre reinforced cement composites. Int JCem Compos Lightweight Concr 1982;4(2):75–82.

[2] Chakraborty S, Kundu SP, Roy A, Adhikari B, Majumder SB. Polymer modifiedjute fibre as reinforcing agent controlling the physical and mechanicalcharacteristics of cement mortar. Constr Build Mater 2013;49:214–22.

[3] Islam SM, Hussain RR, Morshed MAZ. Fiber-reinforced concrete incorporatinglocally available natural fibers in normal-and high-strength concrete and aperformance analysis with steel fiber-reinforced composite concrete. J ComposMater 2012;46(1):111–22.

[4] Ali M, Liu A, Sou H, Chouw N. Mechanical and dynamic properties of coconutfibre reinforced concrete. Constr Build Mater 2012;30:814–25.

[5] Filho T, Dias R, Silva FDA, Fairbairn EMR. Durability of compression moldedsisal fiber reinforced mortar laminates. Constr Build Mater2009;23(6):2409–20.

[6] Kankam CK, Odum-Ewuakye B. Babadua reinforced concrete two-way slabssubjected to concentrated loading. Constr Build Mater 2006;20(5):279–85.

[7] Kriker A, Debicki G, Bali A, Khenfer MM, Chabannet M. Mechanical propertiesof date palm fibres and concrete reinforced with date palm fibres in hot-dryclimate. Cem Concr Compos 2005;27(5):554–64.

[8] Kankam CK. Raffia palm-reinforced concrete beams. Mater Struct1997;30(5):313–6.

[9] Ghavami K. Ultimate load behaviour of bamboo-reinforced lightweightconcrete beams. Cem Concrete Compos 1995;17(4):281–8.

[10] Rahman MM, Rashid MH, Hossain MA, Hasan MT, Hasan MK. Performanceevaluation of bamboo reinforced concrete beam. Int J Eng Technol2011;11(4):142–6.

[11] Ramaswamy HS, Ahuja BM, Krishnamoorthy S. Behaviour of concretereinforced with jute, coir and bamboo fibres. Int J Cem Compos LightweightConcr 1983;5(1):3–13.

[12] Ghavami K. Bamboo as reinforcement in structural concrete elements. CemConcr Compos 2005;27(6):637–49.

[13] Mansur MA, Aziz MA. Study of bamboo mesh reinforced cement composites.Int J Cem Compos Lightweight Concr 1983;5(3):165–71.

[14] Akeju TAI, Falade F. Utilization of bamboo as reinforcement in concrete forlow-cost housing. In: Proc engineering research for the industries, Universityof Lagos; 1997. p. 10–11.

[15] Prasad J, Pandey BS, Ahuja R, Ahuja AK. Low cost housing for hilly regions usinglocally available material. Asian J Civil Eng Build Hous 2005;6(4):257–65.

[16] Maity D, Behera SK, Mishra M, Majumdar S. Bamboo reinforced concrete wallas a replacement to brick and mud wall. IE (I) J-AR 2009;90:5–10.

[17] Lima Jr, Humberto C, Willrich FL, Barbosa NP, Rosa MA, Cunha BS. Durabilityanalysis of bamboo as concrete reinforcement. Mater Struct2008;41(5):981–9.

[18] Salau MA, Ismail A, Efe EI. Characteristic strength of concrete columnreinforced with bamboo strips. J Sustain Dev 2011;5(1):133–43.

[19] Terai M, Minami K. Fracture behavior and mechanical properties of bambooreinforced concrete members. Proc Eng 2011;10:2967–72.

[20] Yamaguchi M, Kiyoshi M, Koji T. Flexural performance of bamboo-reinforced-concrete beams using bamboo as main Rebars and Stirrups. In: 3rd Int’l Conf.Sust. Constr. Mater. Tech, Kyoto; 2013, E273.

[21] Bhonde D, Nagarnaik PB, Parbat DK, Waghe UP. Experimental Investigation ofBamboo Reinforced Concrete Slab. Am. J. Eng. Res. 2014;3(1):128–31.