Experimental Study on the use of Bamboo as Structural Reinforcements in RCC Structures

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Experimental Study on the use of Bamboo as Structural Reinforcements in RCC Structures

Pushpanjali Verma

M.Tech Student Department of Civil Engineering

SHIATS, Prayagaraj Uttar Pradesh, India

Mr. Vipin Mahadeven

Assistant Professor, Department of Civil Engineering

Rajkiya Engineering College Azamgarh Azamgarh, Uttar Pradesh, India

AbstractBamboo is a natural material obtain from plants family. It is fast growing, light weighted, renewable and environment friendly. Bamboo material is very interesting topic in construction for research. Bamboo has good tensile strength; from a study it is found that tensile strength specific weight ratio of bamboo is 20 times more than that of steel. An experimental investigation of bamboo characteristics and bamboo as reinforcement in concrete study is carried out in this paper. Here we have focused on to identify water absorption in bamboo during curing period and flexure strength of bamboo reinforce beam, cracking pattern and other experimental value to step more towards bamboo as alternative to steel

Keywords- Bamboo, Reinforcement, flexure, compresssion, tension

  1. INTRODUCTION

    TABLE 1. Compressive Strength of Specimens (without Nodes)

    SPECIMEN

    CROSSECTIONAL AREA (mm2)

    COMPRESSIVE LOAD (N)

    COMPRESSIVE STRENGTH(N/mm2)

    DEFLECTION

    (mm)

    AN1

    2971.168

    140000

    47.11

    7

    AN2

    2909.907

    133400

    45.843

    4

    AN3

    2657.794

    129700

    48.799

    6

    TABLE 2. Compressive Strength of Specimens (with Nodes)

    SPECIMEN

    CROSSECTIONAL AREA (mm2)

    COMPRESSIVE LOAD (N)

    COMPRESSIVE STRENGTH(N/mm2)

    DEFLECTION

    (mm)

    AW1

    2510.14

    128100

    51.03

    5

    AW2

    2563.53

    120000

    46.81

    6

    AW3

    2565.90

    126700

    49.378

    6

    52 51.03

    50 49.38

    48

    In recent year, many researchers around the world have already begun to explore the use of low cost and low energy substitute construction materials. Among the many possibilities for such substitutions Bamboo, which is one of the fastest growing plants, has great potential. Bamboo has been used in construction of bridges and houses for thousands of years in Asia. Bamboo takes less energy to harvest and transport. Bamboo is hygroscopic material thats why it also

    48 47.11

    45.84

    46

    44

    42

    Specimen without

    node

    46.81

    Specimen with

    node

    absorbs moisture from surrounding hence determination of properties, improve over moisture absorption and bamboo reinforcement in concrete beam has been investigated by the authors in the lab and results are presented.

  2. EXPERIMENTAL PROCEDURE

A mix design of M25 concrete was used to conduct experiment. Bamboo used were collected from Local Market, Lalganj, Azamgarh Uttar Pradesh (India). The age of bamboo used was four and half year. Several tests were conducted to calculate different strength properties which are necessary to find such as compressive strength test, tensile strength test and water absorption test of bamboo specimen in laboratory.

  1. Compressive Strength Bamboo of Bamboo Specimen

    In this test we calculated how much compressive load can a bamboo specimen bear. This test helped out finding either bamboo is suitable as reinforcement in RCC construction or not. For this test we have selected 6 specimen of length 100mm, 3 (AW1, AW2, AW3) are with node and other (AN1, AN2, AN3) are without node.

    Figure 1: Compressive Strength of Bamboo Specimens in MPa

    Figure 2: Compressive test Specimen with node

    Source: Material Testing Lab, REC Azamgarh

  2. TENSILE TEST OF BAMBOO SPECIMEN

    The tensile test was carried out on bamboo splints to determine the ultimate tensile strength of bamboo. The ultimate tensile strength of bamboo is importance to calculate the maximum allowable tensile stress in bamboo, when bamboo is being used as reinforcement in concrete elements

    to take the tensile loads. We have taken 5 test specimens namely, A1, A2, A3, A4, A5.

    Figure 3: Bamboo Specimen for tensile test

    Source: Material Testing Lab, IIT BHU

    TABLE 3.(a) Bamboo splints tensile test

    SPECIMEN

    CROSSECTIONAL AREA (mm2)

    TENSILELOAD (KN)

    TENSILE STRENGTH(N/mm2)

    A1

    202

    33.50

    164.8515

    A2

    190

    29.5

    154.2105

    A3

    186

    26.80

    139.7849

    A4

    262

    47.04

    179.542

    A5

    224

    39.24

    176.428

    A3

    Linear (A3)

    176.42

    179.54

    139.79

    154.21

    164.85

    A3

    Linear (A3)

    176.42

    179.54

    139.79

    154.21

    164.85

    TABLE 3.(b) Bamboo splints tensile test

    SPECIMEN

    Elongation (mm)

    Strain

    Cracking Load (KN)

    A1

    8.50

    0.0168

    28.5

    A2

    8.00

    0.0158

    26.5

    A3

    8.00

    0.0158

    22.5

    A4

    9.32

    0.0170

    37.9

    A5

    8.75

    0.0164

    36.7

    45

    A2

    A4

    A1

    45

    A2

    A4

    A1

    0

    50

    100

    150

    200

    0

    50

    100

    150

    200

    Specimen

    Specimen

    Figure 4: Tensile Strength of Bamboo Specimens (MPa)

  3. WATER ABSORBTION TEST FOR BAMBOO

    Since Bamboo is a hygroscopic material having tending to absorb moisture from air and surroundings. In green concrete bamboo splints absorb moisture and swells, when the concrete becomes dry the bamboo splints contracts and creates spaces between the contacts, the bamboo-concrete bond strength decreases and member fails in bond. Hence water absorption is one of the main drawbacks of bamboo, when it is used as reinforcement in concrete so our main aim is to perform this test to find out percentage of water absorb by bamboo and percentage of volume increase.

    C.1 PROCEDURE

    We have taken six (WA1, WA2, WA3, W1, W2, W3) sample of bamboo specimen of 50*50mm2 and let it dry for 24hrs in an oven. After that the specimen was allowed to cool for 30 minute. 3 Specimen painted with water proof coating (W1, W2, W3) but remaining three were not. Calculation of dimension, weight was made initially. Then all the 6 samples were allowed to soak in water at normal temperature pressure. Reading for changes in dimension and weight was made at every 24-hour interval for next 28 days.

    Figure 5: Baboo Specimen into Water Source: REC Azamgarh Lab

    TABLE 4(a). Water absorption of bamboo sample without paint

    DAY

    WA1(g)

    %GAIN

    WA2(g)

    %GAIN

    WA3(g)

    %GAIN

    AVG % GAIN

    1

    4.273

    00.0%

    4.638

    00.0%

    4.404

    00.0%

    0%

    2

    6.671

    56.12%

    7.61

    64.08%

    7.215

    63.82%

    61.34%

    3

    7.429

    73.85%

    8.329

    79.58%

    7.956

    80.65%

    78.03%

    4

    7.584

    77.49%

    8.304

    79.04%

    7.923

    79.91%

    78.81%

    5

    7.700

    80.20%

    8.289

    78.71%

    7.945

    80.42%

    79.78%

    6

    7.783

    82.15%

    8.352

    80.77%

    7.852

    78.29%

    80.40%

    9

    8.3661

    95.67%

    8.920

    92.15%

    8.577

    94.75%

    94.19%

    11

    8.493

    98.75%

    8.952

    93.14%

    8.617

    95.66%

    95.85%

    14

    9.491

    122.2%

    10.228

    120.5%

    9.778

    122.3%

    121.67%

    28

    10.209

    138.92%

    11.647

    151.00%

    11.007

    164.46%

    151.46%

    TABLE 4(b). Water absorption of bamboo sample with paint

    DAY

    W1(g)

    %GAIN

    W2(g)

    %GAIN

    W3(g)

    %GAIN

    AVG % GAIN

    1

    5.878

    00.0%

    4.549

    00.0%

    4.557

    00.0%

    0%

    2

    8.405

    42.69%

    7.127

    56.67%

    6.856

    50.44%

    49.93%

    3

    9.194

    61.36%

    7.815

    73.77%

    7.616

    67.12%

    67.42%

    4

    9.572

    62.84%

    8.079

    77.59%

    7.825

    71.71%

    70.71%

    5

    9.836

    67.33%

    8.240

    81.38%

    7.989

    75.32%

    74.68%

    6

    10.154

    72.74%

    8.428

    85.27%

    8.046

    76.56%

    78.19%

    9

    10.940

    91.54%

    9.182

    101.8%

    8.507

    86.67

    93.34%

    11

    11.306

    92.34%

    9.558

    110.8%

    8.823

    95.83%

    99.66%

    14

    11.689

    98.86%

    10.114

    122.3%

    9.286

    103.7%

    108.29%

    28

    12.533

    113.22%

    10.684

    134.86%

    11.209

    145.97%

    131.35%

    151.46%

    121.67%

    151.46%

    121.67%

    0% DAY DAY DAY DAY DAY DAY DAY DAY DAY DAY 1 2 3 4 5 6 9 11 14 28

    0% DAY DAY DAY DAY DAY DAY DAY DAY DAY DAY 1 2 3 4 5 6 9 11 14 28

    Specimen With Paint

    Specimen Without Paint

    Specimen With Paint

    Specimen Without Paint

    78.03%78.81%79.78%80.40%

    78.03%78.81%79.78%80.40%

    94.19%95.85%

    94.19%95.85%

    61.34%

    61.34%

    108.29%

    108.29%

    131.35%

    131.35%

    49.93%

    49.93%

    67.42%70.71%74.68%78.19%93.34%99.66%

    67.42%70.71%74.68%78.19%93.34%99.66%

    Figure 6 : Water absorption vs time graph of bamboo specimens.

    TABLE 5. Calculation of c/s area change

    Sample

    Area before test (Without painted in mm2)

    Area After test (Without painted in mm2)

    %

    change in area (mm2)

    Area before test (Painted in mm2)

    Area After test (Painted in mm2)

    %

    change in area (mm2)

    Cement

    F.A

    C.A

    Water

    435.409 /

    653.384 /

    1173.782

    /

    216.49 /

    A1

    225

    239

    0.062

    225

    230

    0.022

    A2

    225

    232

    0.031

    225

    229

    0.017

    1

    1.5

    2.696

    0.497

    A3

    225

    236

    0.048

    225

    232

    0.031

    Sample

    Area before test (Without painted in mm2)

    Area After test (Without painted in mm2)

    %

    change in area (mm2)

    Area before test (Painted in mm2)

    Area After test (Painted in mm2)

    %

    change in area (mm2)

    Cement

    F.A

    C.A

    Water

    435.409 /

    653.384 /

    1173.782

    /

    216.49 /

    A1

    225

    239

    0.062

    225

    230

    0.022

    A2

    225

    232

    0.031

    225

    229

    0.017

    1

    1.5

    2.696

    0.497

    A3

    225

    236

    0.048

    225

    232

    0.031

    Figure 7 : Cross sectional detailing of Beam for Flexure Testing.

    TABLE 6. Design mix Grade of M25 concrete ratio

    Avg % Area Change in Without Painted Avg % Area Change in Painted2

    Avg % Area Change in Without Painted Avg % Area Change in Painted2

    0.047

    0.047

    0.035

    0.035

    Figure 7: % change in c/s area of bamboo sample

  4. FLEXURE STRENGTH OF BAMBOO REINFORCED BEAM

    Bamboo splints of 12*12mm2 were used as reinforcement. Bamboo splints were tied in frame of 55cm length and within 10*10cm2. Binding bar is use to tie. Since bamboo absorb water so a moisture resistance paint was applied over bamboo splints. Bamboo reinforced concrete beam of 150*150*600mm3 were casted with clear cover of 25mm. For casting beam, we have used mix designed concrete grade of M25. After 28 days of curing, beams were subjected to standard Flexure test and the flexural strength was calculated.

    Figure 8: Bamboo frame for reinforcement Source: Material Testing Lab, REC Azamgarh

    Figure 9: Beam during curing

    Source: Material Testing Lab, REC Azamgarh

    Figure 10: Bamboo reinforced Concrete Beam during test

    B1 B2 B3

    S P E C I M E N

    B1 B2 B3

    S P E C I M E N

    56.36

    56.36

    46.01

    46.01

    49.83

    49.83

    TABLE 7. Flexural strength of BRC beam after 28 days

    Sr. No

    Test Sample

    FLEXURAL STRENGTH (N/mm2)

    1

    B1

    56.36

    2

    B2

    46.01

    3

    B3

    49.83

    Figure 11: Flexural Strength of Test beams in MPa

    1. RESULT AND DISCUSSION

      • Avg Compressive strength with node = 49.07 MPa

      • Avg Compressive strength without node = 47.25 MPa.

        We have obtained compressive strength of bamboo was good for short building but on application of heavy load, it can fail along the longitudinal direction in form of buckling.

      • Average tensile strength of bamboo Specimen = 162.96 MPa

        It was found out that bamboo follow brittle failure.

      • Avg % Area Change (Paint) = 0.047%

      • Avg % Area Change (Non-Paint) =

0.035%

  • % by weight of max water absorbed in Painted = 131.55%

  • % by weight of max water absorbed in Non-Painted = 151.46%

    By experiment results it was found out that water absorption and change in area volume due to absorbed water, both are decreased when coated with moisture resistant paint. That is positive result and helping in maintaining strength of bamboo.

  • Avg Flexural strength of Specimen = 50.73 MPa

In our test, failure in beam is occurs at the mid of beam hence this was flexural type of failure.

  1. CONCLUSION

  1. The experimental analysis is done for compressive strength of bamboo specimen. And it was found that compressive strength of bamboo specimen with node has greater strength than that of specimens without node this could be because of additional cross-sectional area at nodes and due to the dense mass present at nodes. Some of the specimen showed an ideal failure by cracking longitudinally but most of them showed a mixed mode of failure where in the specimen cracked as well as got crushed and buckled along length.

  2. As per result an average ultimate tensile strength of bamboo splints is 160 MPa which is comparatively lower than the yield strength of structural steel i.e. 250MPa. But bamboo splints can resist sufficient tensile loads in a concrete flexure element. All the bamboo specimens shown brittle failure.

  3. The water absorption value is decreased by using moisture resistant paint and can help in maintain strength and shrinkage and swelling problem.

  4. Bamboo Reinforced Concrete Beam follows same pattern those in steel reinforcement elements. The ultimate moment is 50.733MPa i.e. good result for short building. After testing, cracks are developed at the mid span in beam i.e. flexural type failure.

REFERENCES

  1. American Journal of Engineering Research (AJER) e-ISSN: 2320- 0847 p-ISSN: 2320-0936 By Dinesh Bhonde, P. B. Nagarnaik, D. K. Parbat, U. P. Waghe.

  2. Investigation on properties of bamboo as reinforcing material in concrete by Harish Sakaray et al (2012).

  3. Kawamura, K.(1941). Bamboo reinforced Concrete, Sankaido Syuppan, Japan

  4. K. Ghavami, Application of Bamboo as a Low-Cost Construction Material, In Procoft International Bamboo Workshop, Cochin, India, pp. 270 279, 1988.

  5. K. Ghavami, Ultimate Load Behaviour of Bamboo Reinforced Lightweight Concrete Beams, J. Cement Concrete Compos, pp. 281288, 1995.

  6. Ranendra Nath Bhowmik et al. (2015)/ International Journal of Engineering and Technology (IJET) ISSN (Print): 2319-8613.

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