Upload
ngoanh
View
213
Download
0
Embed Size (px)
Citation preview
UNIVERSITI PUTRA MALAYSIA
AMEL BASHER AHMED BASHER
IPTPH 2013 5
PROPERTIES OF KENAF BAST FIBRE CEMENT COMPOSITE BOARD
© COPYRIG
HT UPM
i
PROPERTIES OF KENAF BAST FIBRE CEMENT COMPOSITE BOARD
By
AMEL BASHER AHMED BASHER
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
© COPYRIG
HT UPM
ii
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
© COPYRIG
HT UPM
iv
Abstract of thesis presented to Senate of Universiti Putra Malaysia in fulfillment of
the requirement for the degree of Doctor of Philosophy
PROPERTIES OF KENAF BAST FIBRE CEMENT COMPOSITE BOARD
By
AMEL BASHER AHMED BASHER
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
© COPYRIG
HT UPM
v
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
© COPYRIG
HT UPM
vi
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).
© COPYRIG
HT UPM
vii
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
AMEL BASHER AHMED BASHER
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,
© COPYRIG
HT UPM
viii
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
© COPYRIG
HT UPM
ix
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%).
© COPYRIG
HT UPM
x
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,
© COPYRIG
HT UPM
xi
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.
© COPYRIG
HT UPM
xii
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
Universiti Putra Malaysia
(Internal Examiner)
Rasmina binti Halis, PhD
Lecturer
Faculty of Forestry
Universiti Putra Malaysia
(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
Universiti Putra Malaysia
Date: 2 August 2013
© COPYRIG
HT UPM
xiii
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
Universiti Putra Malaysia
(Chairman)
H’ng Paik San, PhD
Associate Professor
Faculty of Forestry
Universiti Putra Malaysia
(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
Universiti Putra Malaysia
Date:
© COPYRIG
HT UPM
xiv
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.
AMEL BASHER AHMED BASHER
Date: 3 June 2013
© COPYRIG
HT UPM
xv
TABLE OF CONTENTS
Page
DEDICATION
ABSTRACT
ABSTRAK
ACKNOWLEDGEMENTS
APPROVAL
DECLARATION
LIST OF TABLE
LIST OF FIGURE
LIST OF ABBREVIATIONS
iii
iv
vii
x
xii
xiv
xviii
xx
xxiv
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
7
7
10
11
13
14
17
18
23
24
26
27
28
31
34
35
36
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
43
43
45
47
48
49
59
59
© COPYRIG
HT UPM
xvi
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
4.2 Materials and methods
4.3 Statistical Analysis
4.4 Results and discussion
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
60
62
67
68
70
71
73
73
77
79
80
80
84
91
93
96
5 PROPERTIES OF CEMENT-BONDED KENAF COMPOSITE BOARD
(CBKB)
5.1 Introduction
5.2 Materials and methods
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 Results and discussion
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
97
97
102
103
104
108
115
116
116
118
125
129
136
6 CURING BEHAVIOUR OF CEMENT-BONDED KENAF COMPOSITE
BOARD
6.1 Introduction
6.2 Materials and methods
6.2.1 Board curing profile
6.3 Data analysis
6.4 Results and discussion
6.4.1 Curing profile of cement bonded kenaf board (CBKB)
6.5 Conclusions
138
138
139
140
140
141
141
146
© COPYRIG
HT UPM
xvii
7 PERMEABILITY, SURFACE AND THERMAL CHARACTERISTICS
OF CEMENT-BONDED KENAF COMPOSITE BOARD
7.1 Introduction
7.2 Materials and methods
7.2.1 Gas permeability
7.2.2 Microscope image analysis
7.2.3 Thermal analysis
7.3 Results and discussion
7.3.1 Permeability
7.3.2 Microscope image analysis
7.3.3 Thermal analysis
7.4 Conclusions
148
148
152
152
154
155
156
156
159
163
181
8 GENERAL CONCLUSIONS AND RECOMMENDATIONS FOR
FUTURE RESEARCH
8.1 Conclusions
8.2 Recommendations for future research
182
182
184
REFERENCES 186
BIODATA OF STUDENT 203
LIST OF PUBLICATIONS 204