UNIVERSITI PUTRA MALAYSIA - COnnecting REpositories · Gentian kulit kenaf (KBF) kaya dengan...

UNIVERSITI PUTRA MALAYSIA

AMEL BASHER AHMED BASHER

IPTPH 2013 5

PROPERTIES OF KENAF BAST FIBRE CEMENT COMPOSITE BOARD

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By


Thesis Submitted to the School of Graduate Studies, Universiti Putra Malaysia

in Fulfillment of the Requirements for the Degree of Doctor of philosophy

June 2013

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COPYRIGHT

All material contained within the thesis, including without limitation text, logs, icons,

photographs and all other artwork, is copyright material of Universiti Putra Malaysia

unless otherwise stated. Use may be made of any material contained within the thesis

for non-commercial purposes from the copyright holder. Commercial use of material

may only be made with the express, prior, written permission of Universiti Putra

Malaysia.

Copyright© Universiti Putra Malaysia

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DEDICATIONS

This work is dedicated to my family,

my brothers and sisters

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Abstract of thesis presented to Senate of Universiti Putra Malaysia in fulfillment of

the requirement for the degree of Doctor of Philosophy


By


February 2013

Chairman : Professor Paridah Md. Tahir, PhD.

Institute : Institute of Tropical Forestry and Forest Products

Kenaf bast fibre (KBF) is rich in cellulose and, has high tensile strength, which is

suitable for reinforcement of cement-bonded board. This study used kenaf bast fibre

as partial replacement for cement as well as reinforcement for cement board. The

work comprised the evaluation of mechanical and physical properties of kenaf bast

fibre which were separated using different extraction methods (water, decortication

and chemical), hydration behaviour, and the effects of different board formulations

on the properties of cement-bonded kenaf board (CBKB). The objectives of the study

were: 1) to evaluate the effects of fibre separation method on the physical, chemical

and mechanical properties of kenaf bast fibre, 2) to determine the effect of

incorporation of kenaf bast fibre, accelerators (calcium chloride (CaCl2), aluminium

chloride (AlCl3), sodium sulfate (Na2SO4) and calcium oxide (CaO2)) and additives

(silica fume and superplasticiser) on the hydration properties of Portland cement, 3)

to evaluate the mechanical properties and dimensional stability of cement-bonded

kenaf board, 4) to examine the curing behaviour of cement-bonded kenaf board, and

5) to characterize the permeability , surface and thermal behaviour of cement-bonded

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kenaf board. The performance of different CBKB densities was evaluated based on

the strength – modulus of rupture (MOR), the stiffness – modulus of elasticity

(MOE) and internal bonding (IB). The dimensional stability was assessed by

determining the percentage of water absorption (WA) and thickness swelling (TS).

The morphological properties of kenaf bast fibre were found to be significantly

affected by the extraction methods used. Using sodium hydroxide (NaOH) for retting

reduced the fibre lumen diameter and increased the cell wall thickness significantly.

Both benzoate- and water-retted fibres experienced the same but at a much lesser

effect. Mechanical decortication however was found to excessively reduce the cell

wall thickness much thinner than the crude (unprocessed) fibre. There was a small

increment in fibre density for NaOH-retted and benzoate-retted bast fibres over those

of water, decorticated and crude (control). The densified fibre may be contributed by

the amount of chemicals being absorbed into the fibre. Among the different

extraction methods used, decorticated, water and NaOH-retted fibres have

significantly higher tensile strengths.

The hydration test suggests that NaOH and benzoate were not suitable for the kenaf

retting. Both NaOH- and benzoate-retted fibres had relatively higher pH hydration

time and low maximum hydration temperature which is not conducive for curing of

cement-bonded kenaf board. Both water-retted and decorticated KBF had good

hydration properties, and suitable for cement board production. The suitable fibre

size is > 3.5 mm. Fibres with smaller size apparently require the addition of

accelerators to enhance their compatibility. Among the different accelerators used,

CaCl2, AlCl3, Na2SO4 and CaO, both CaCl2 and CaO proved to be the best with their

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optimal concentration at 2%. Between the two additives used, silica fumes (SF) and

superplasticiser (SP), the former was found to be a better choice based on it is

hydration properties. Among the methods of fibre separation, water retting and

decortication produced fibres of good quality, high tensile strength, good hydration

properties, good fibre morphology and high cellulose content.

Incorporation of KBF in cement-bonded board generated reasonably light and strong

panel, however, the IB was reduced significantly. The main reason for this is the

separation of kenaf fibres from cement creating a weak inter-particle bonding within

the board. Almost all the failures were observed to occur at the interface. Adding SF

at 7% improved the IB by 83%. The presence of board density also has a negative

effect on the mechanical properties and the dimensional stability of the boards.

Among the three cement: KBF proportions (2:1, 2.5:1 and 3:1) used in this study,

using 2:1 resulted in boards with the best performance in terms of MOR, MOE, WA

and TS. The best combination to produce acceptable performance CBKB is by using

decorticated KBF, at 2:1 (cement: KBF), 7% SF and board density (1100 kg/m3).

The properties: MOR (10.9 MPa), MOE (5061 MPa), IB (0.15 MPa), WA after 2h

and 24h (23.7 and 27%, respectively), TS after 2 and 24h (0.87 and 3.01%,

respectively).

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Abstrak tesis yang dikemukakan kepada Senat Universiti Putra Malaysia sebagai

memenuhi keperluan untuk Ijazah bagi Doktor Falsafah

CIRI-CIRI PAPAN SIMEN KOMPOSIT DARI SERAT KULIT KENAF

Oleh


Jun 2013

Pengerusi : Profesor Paridah Md. Tahir, PhD.

Institut : Institut Perhutanan Tropika dan Produk Hutan

Gentian kulit kenaf (KBF) kaya dengan selulosa dan mempunyai daya regangan yang

tinggi di mana ia sesuai untuk penghasilan papan simen terikat. Kajian ini

menggunakan gentian kulit kenaf sebagai pengganti separa dan bahan pengukuhan

bagi penghasilan papan simen. Kajian ini terdiri daripada evaluasi sifat mekanikal

dan fizikal gentian kulit kenaf yang mana yang telah diasingkan dengan

menggunakan kaedah pengekstrakan yang berbeza (air, dekortikator dan kimia), sifat

penghidratan dan kesan perbezaan formula kepada sifat papan kenaf bersimen terikat

(PKBT). Objektif kajian ini adalah : 1) untuk menilai kesan kaedah pengasingan

gentian kepada sifat fizikal dan mekanikal gentian kulit kenaf, 2) untuk menentukan

kesan mencampurkan gentian kulit kenaf, pemangkin/aselarator (CaCl2, AlCl3,

Na2SO4, CaO) dan bahan aditif (silika and superplasticiser) ke atas sifat penghidratan

simen “Portland”, 3) menilai sifat mekanikal dan kestabilan dimensi PKBT, 4) untuk

menilai prilaku pematangan bagi PKBT dan 5) untuk mencirikan ketelapan,

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permukaan dan sifat haba bagi PKBT. Prestasi ketumpatan yang berbeza telah PKBT

dinilai berdasarkan kekuatan - modulus kepecahan (MOR), kekukuhan - modulus

kekenyalan (MOE) dan ikatan dalaman (IB). Kestabilan dimensi telah dinilai dengan

menentukan peratusan penyerapan air (WA) dan pembengkakan ketebalan (TS).

Sifat morfologi gentian kulit kenaf secara jelas dipengaruhi oleh kaedah

pengekstrakan. Penggunaan sodium hidroksida (NaOH) semasa proses rendaman

telah mengurangkan diameter lumen gentian dan meningkatakan ketebalan dinding

sel secara signifikan. Benziot dan gentian yang direndam di dalam air menunjukkan

hasil yang sama tetapi kesannya agak sedikit. Walaubagaimanapun, penyahkulitan

mekanikal didapati secara berlebihan telah mengurangkan ketebalan dinding sel

berbanding gentian yang tidak diproses. Terdapat sedikit peningkatan ketumpatan

gentian bagi rendaman NaOH dan rendaman benziot bagi kulit kenaf berbanding

rendaman air, penyahkulitan dan sampel kawalan. Gentian yang agak tumpat

mungkin disebabkan oleh serapan bahan kimia ke dalam gentian. Antara beberapa

kaedah pengekstrakan yang digunakan, gentian yang diproses melalui penyahkulitan,

rendaman air dan rendaman NaOH menunjukkan kekuatan tegangan yang signifikan.

Ujian hidrasi mencadangkan NaOH dan benziot adalah tidak sesuai bagi rendaman

kenaf. Kedua-duanya rendaman gentian memerlukan masa penghidratan pH yang

lebih lama dan suhu penghidaratan maksimum yang rendah, di mana ia adalah tidak

konduktif bagi rawatan PKBT. Rendaman air dan penyahkulitan papan gentian kenaf

menunjukkan sifat hidrasi yang baik dan sesuai untuk penghasilan papan simen. Saiz

gentian yang sesuai ialan >3.5mm. gentian yang lebih kecil memerlukan

penambahan bahan pecutan untuk meningkatkan keserasian. Di antara beberapa

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bahan pemangkin yang digunakan, CaCl2, AlCl3, Na2SO4 dan CaO, CaCl2 dan CaO

terbukti terbaik dimana kepekatan optimumnya adalah pada bacaan 2%. Di antara

dua bahan tambah yang digunakan iaitu wasap silika dan superplasticiser,

superplasticiser didapati pilihan yang lebih baik berdasarkan sifat hidrasi.

Perbandingan di antara kaedah pengasingan gentian menunujukkan rendaman air dan

penyahkulitan menghasilkan gentian yang berkualiti baik, kekuatan tegangan yang

tinggi, kandungan selulosa yang tinggi, sifat hidrasi dan morfologi gentian yang baik.

Gabungan papan gentian kenaf dan simen terikat menghasilkan panel ringan yang

bersesuaian dan kuat. Walaubagaimanpun , ikatan dalaman secara signifikan telah

menurun. Punca utama kepada penurunan ini ialah pengasingan gentian kenaf dari

simen yang mewujudkan ikatan partikel yang lemah. Hampir semua kegagalan

terjadi pada bahagian antara muka. Penambahan 7 % wasap silika telah membaiki

ikatan dalaman sebnyak 83%. Ketumpatan papan juga telah memberikan kesan

negatif ke atas sifat mekanikal dan kestabilan dimensi papan. Di antara ketiga-tiga

simen: perkadaran PGF (2:1, 2.5:1 dan 3:1) yang digunakan dalam kajian ini, kadar

2:1 menghasilkan keputusan papan pada prestasi terbaik bagi ujian modulus

kepecahan, elastik, serapan air dan kekuatan tegangan. Kombinasi terbaik untuk

menghasilkan PKBT ialah dengan menggunakan penyahkulitan papan gentian kenaf

pada kadar 2:1 (simen : PGF), 7% wasap silica dan berketumpatan (1100 kg/m3).

Sifat: Modulus kepecahan (10.9 MPa), Modulus elastik (5061 MPa), ikatan dalaman

(0.15 MPa), serapan air selepas 2j dan 24j (23.7 dan 7%), kekuatan regangan selepas

2j dan 24j (0.87 dan 3.01%).

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ACKNOWLEDGEMENTS

Praise to Allah the mighty for without him; I would not be able to complete this

research. A good work needs positive feedback from persons with constant

preoccupation, compromise, and defined purposes. I am very thankful and grateful

to Professor Dr. Paridah Md. Tahir, the chairman of the supervisory committee, for

her constant guidance, cooperation and advice which are vital parts for the

completion of my research. Her constant feedback was a wonderful way to

implement new ideas and to overcome the problems found in the path of my

research. I would like to express my gratitude to Dr. Rahim Sudin, Dr. H’ng Paik

San, Assoc. Prof. Dr. Zakiah Ahmed and Assoc. Prof. Dr. Zeinab A. Osman, the

members of the supervisory committee for their kindness, encouragement and

valuable suggestions every time that I required their advice.

I would like to thank Prof. Dr. Zaidon Ashari, Faculty of Forestry and all the staff

members at the Institute of Tropical Forestry and Forest Product, especially those in

the Department of Biocomposite, all employees and technicians. I also wish to

express my appreciation to Mr. Mohammed Lufti, Zira and my friends, Janet,

Adrian, Aisyah Humaira, Juhidah, Juliana, for their kind help. My sincere gratitude is

also extended to School of Graduate Studies, Universiti Putra Malaysia, for their

kind help. .

Special thanks to the staff of Forest Research Institute of Malaysia (FRIM) for

assistance given. I wish to express my sincere thanks to Dr. Mohd Khairun Anwar,

Mr. Ahmed Sharafi, Mr. Jalali, Mr. Saimin, Mr. Mohd Hashim, Mr. Mohd Yusouf,

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Mr. Nordin, Sabariah and Mr. Rusli who were willing to spare some of their time,

their knowledge and their resources which had enabled me to conduct this work.

My ultimate thanks are also extended to my father (Basher Ahmed Basher), my

mother (Batoul Abdul Rahim), my brothers and sisters for their patience and support

while lifting my spirit during my difficult times. Last but not least thanks are also

extended to my husband Ahmed and my daughter Samar who always give me

support and inspiration when I feel down and distracted for their love, patience and

encouragement.

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I certify that a Thesis Examination Committee has met on 3 June 2013 to conduct the

final examination of Amel Basher Ahmed Basher on her thesis entitled “Properties of

Kenaf Bast Fibre Cement Composite Board” in accordance with the Universities and

University Colleges Act 1971 and the Constitution of the Universiti Putra Malaysia

[P.U. (A) 106] 15 March 1998. The Committee recommends that the student be

awarded the Doctor of Philosophy.

Members of the Thesis Examination Committee were as follows:

Edi Syams bin Zainudin, PhD

Associate Professor

Faculty of Enineering

Universiti Putra Malaysia

(Chairman)

Mohd Sapuan b Salit@Sinon, PhD

Professor

Faculty of Enineering


(Internal Examiner)

Rasmina binti Halis, PhD

Lecturer

Faculty of Forestry


(Internal Examiner)

Alcides Lopes Leao, PhD

Professor

College of Agricultural Sciences

Sao Paulo State University, Brazil

(External Examiner)

__________________________________

NORITAH OMAR, PhD

Assoc. Professor and Deputy Dean

School of Graduate Studies


Date: 2 August 2013

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This thesis is submitted to the Senate of Universiti Putra Malaysia and has been

accepted as fulfillment of the requirement for the degree of Doctor of Philosophy.

The members of the Supervisory Committee were as follows:

Paridah Md. Tahir, PhD

Professor

Faculty of Forestry


(Chairman)

H’ng Paik San, PhD

Associate Professor

Faculty of Forestry


(Member)

Rahim Sudin, PhD

Senior Researcher

Forest Research Institute of Malaysia (FRIM)

(Member)

Zakiah Ahmed, PhD

Associate Professor

Universiti Technologi Mara, Malaysia.

(Member)

Zeinab A. Osman, PhD

Associate Professor

Institute for Technological Research,

Natural Centre for Research, Sudan

(Member)

_____________________

BUJANG KIM HUAT , PhD

Professor and Dean

School of Graduate Studies


Date:

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DECLARATION

I hereby declare that the thesis is based on my original work except for quotations

and citations which have been duly acknowledged. I also declare that it has not been

previously or concurrently submitted for any other degree at Universiti Putra

Malaysia or other institutions.


Date: 3 June 2013

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TABLE OF CONTENTS

Page

DEDICATION

ABSTRACT

ABSTRAK

ACKNOWLEDGEMENTS

APPROVAL

DECLARATION

LIST OF TABLE

LIST OF FIGURE

LIST OF ABBREVIATIONS

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iv

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CHAPTER

1. INTRODUCTION

1.1. Background

1.2. Problem statement

1.3. Objectives of the study

1.4. Thesis layout

1

1

3

5

6

2. LITERATURE REVIEW

2.1. Supply of building materials

2.2. Wood-cement composite products

2.2.1. Current products and technology

2.2.2. Advantages of cement-bonded natural fiberboard

2.3. Development of fiber reinforced composite

2.3.1. Definition of fibre reinforced cement composite

2.4 Bonding mechanism

2.5 Factors influencing the physical and mechanical properties of wood-

cement composite

2.5.1 Wood species

2.5.2 Cement

2.6 Curing behaviour

2.6.1 Curing methods

2.7 Fibres

2.7.1 Effect of natural fibre on hydration rate

2.8 Potential utilization of natural fibres in the cement-bonded board industry

2.8.1 Kenaf fibre

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3 BASIC PROPERTIES OF KENAF BAST FIBRE

3.1 Introduction

3.2 Materials and methods

3.2.1 Analysis for fiber surface morphology

3.2.2 Fibre density

3.2.3 Chemical analyses

3.2.4 Tensile strength

3.3 Statistical analysis

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3.4 Results and discussion

3.4.1 Effect of extraction method on the morphology of kenaf bast fibres

3.4.2 Effect of extraction methods and liguid on the density of kenaf bast

fibres

3.4.3 Chemical analyses

3.4.4 Effect of extraction methods on the tensile strength of kenaf bast

fibres

3.5 Conclusions

4 EFFECTS OF KENAF FIBRES ON THE HYDRATION PROPERTIES

OF PORTLAND CEMENT

4.1 Introduction


4.3 Statistical Analysis


4.4.1 Effect of extraction methods of kenaf bast fiber on the hydration

rate

4.4.2 Effect of extraction methods, accelerators and concentration on the

hydration properties

4.4.3 Effect of extraction methods and particle size on hydration

properties

4.4.4 Effect of additives and concentration on the hydration properties

4.5 Conclusions

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5 PROPERTIES OF CEMENT-BONDED KENAF COMPOSITE BOARD

(CBKB)

5.1 Introduction


5.2.1 Preparation of kenaf bast fiber (KBF)

5.2.2 Cement bonded kenaf board (CBKB) manufacture

5.2.3 Board testing

5.3 Data analysis


5.4.1 Fibre size distribution

5.4.2 Effect of board density (BD) on the properties of CBKB

5.4.3 Effect of cement: KBF/proportion on the properties of CBKB

5.4.4 Effect of cement: KBF proportions and concentration of SF on the

properties of CBKB

5.5 Conclusions

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6 CURING BEHAVIOUR OF CEMENT-BONDED KENAF COMPOSITE

BOARD

6.1 Introduction


6.2.1 Board curing profile

6.3 Data analysis


6.4.1 Curing profile of cement bonded kenaf board (CBKB)

6.5 Conclusions

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7 PERMEABILITY, SURFACE AND THERMAL CHARACTERISTICS

OF CEMENT-BONDED KENAF COMPOSITE BOARD

7.1 Introduction


7.2.1 Gas permeability

7.2.2 Microscope image analysis

7.2.3 Thermal analysis


7.3.1 Permeability

7.3.2 Microscope image analysis

7.3.3 Thermal analysis

7.4 Conclusions

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8 GENERAL CONCLUSIONS AND RECOMMENDATIONS FOR

FUTURE RESEARCH

8.1 Conclusions

8.2 Recommendations for future research

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REFERENCES 186

BIODATA OF STUDENT 203

LIST OF PUBLICATIONS 204

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