UNIVERSITI PUTRA MALAYSIA

NOR AZIZI BT SAFIEE

FK 2011 24

STRUCTURAL BEHAVIOR OF INTERLOCKING MORTARLESS PUTRA BLOCK WALL SYSTEM

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STRUCTURAL BEHAVIOR OF INTERLOCKING MORTARLESS PUTRA BLOCK WALL SYSTEM

By

NOR AZIZI BT SAFIEE

Thesis Submitted to the School of Graduates Studies, Universiti Putra Malaysia, in Fulfilment of the Requirement for the Degree of Doctor of Philosophy

March 2011

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Dedication

To my husband, Zahid and my son, Alif Farhan and

to all my family members

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Abstract of thesis presented to the senate of Universiti Putra Malaysia in fulfilment of the requirement for the degree of Doctor of Philosophy

STRUCTURAL BEHAVIOR OF INTERLOCKING MORTARLESS PUTRA BLOCK WALL SYSTEM

By

NOR AZIZI BT SAFIEE

March 2011

Chairman : Professor Ir Mohd Saleh Jaafar, PhD

Faculty : Engineering

The masonry industry has undergone changes where designers now have a variety of

choices from the types of block to types of construction. Traditional bonded

masonry system can now be replaced with mortarless masonry systems. Interlocking

block mortarless wall systems can be defined as walls made of assemblages of

interlocking block unit without use of any mortar or adhesive material at interlayer

between courses. However, the structural behavior of interlocking block mortarless

wall has not yet been completely explained. The structural behavior and design

parameters for this system are expected to be different than the conventional wall

system. In order to understand the performance of the wall system, the behavior and

important design parameters of walls under different loadings need to be determined

and identified.

This study was primarily conducted through experimental investigation and finite

element analysis. A total of 21 full scale specimens were used to observe the

behavior and response of three different groups of interlocking mortarless wall

systems namely walls without opening, walls with openings and walls with pilasters.

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For walls without opening, the experimental investigation was carried out under in-

plane and out-of-plane loading. Whereas for the other two groups, they were

investigated under compressive loading only. A parametric study using finite element

analysis was carried out to study the effect of different parameters on each

interlocking wall group considered in addition to the existing data. The finite element

program used was developed using the Fortran language while considering important

features of the interlocking block mortarless interface. Four different models were

developed to represent the different wall systems in this study. Results obtained from

the simulation were validated with the corresponding experimental results to check

its appropriateness and accuracy. The validation study revealed the finite element

results based on the proposed models were in good agreement with the experimental

results.

The wall specimens under in-plane and out-of-plane loads were tested under constant

pre-compressive vertical load and increasing lateral load. The maximum lateral load

carrying capacity, development of strain and failure characteristics were recorded. In

the in-plane case, shear stress capacity of the wall became a major concern in this

observation. Failure of the in-plane wall is controlled by diagonal shear failure and

moderate toe crushing. The main outcome from this in-plane wall investigation was

the relationship between average pre-compressive stress and shear stress at failure.

For walls under out-of-plane load, the results indicated that pre-compressive vertical

loads and reinforcement significantly affected the structural behavior of interlocking

block mortarless walls. The failure of wall was dominated by opening between dry

joint, cracking, flexure deflection and toe crushing. The design of walls under out-of-

plane was controlled by dry joint opening mechanism at mid height of the wall.

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Wall panels with opening were tested under vertical compressive loading taking into

consideration different sizes of opening and slenderness ratio. The results revealed

that the opening size would reduce the maximum load carrying capacity of the wall.

The location of openings within the wall also affected the behavior of the wall with

opening.

The test results of walls with pilaster revealed that the slenderness ratio had

significant effect on the load carrying capacity. The pilasters may also increased the

lateral resistance with respect to the out-of-plane displacement and load carrying

capacity of the wall systems. By adding pilasters to the wall system failure may be

delayed in comparison to that expected to occur in similar specimens of walls

without pilaster.

The results indicate that pre-compressive load and slenderness ratio has a significant

effect on walls under combined loading. While for other wall groups (wall with

opening and wall with pilaster) which were primarily subjected to compressive

vertical loads, the slenderness ratio and size opening were factors affecting the

behavior of wall systems. The effect of the important parameters contributed to the

behavior and prediction of strength for each groups of mortarless interlocking wall

system considered. As a contribution, a few formulae, tables and curves were

proposed to be used in predicting the ultimate strength of interlocking mortarless

Putra block wall system according to their loading condition on each group of wall

system. Finally, with a deeper understanding of the behavior of mortarless masonry

wall systems, it may contribute to a better application of design and construction.

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Abstrak tesis yang dikemukakan kepada senat Universiti Putra Malaysia sebagai memenuhi keperluan untuk ijazah Doktor Falsafah

KELAKUAN STRUKTUR SISTEM DINDING PUTRA BLOK BERKUNCI TANPA MORTAR

Oleh

NOR AZIZI BT SAFIEE

Mac 2011

Pengerusi : Professor Ir Mohd Saleh Jaafar, PhD

Fakulti : Kejuruteraan

Industri masonri telah mengalami perubahan di mana sekarang perekabentuk

mempunyai pelbagai pilihan dari jenis batu bata sehinggalah kepada jenis

pembinaan. Sekarang sistem tradisi masonri terikat boleh diganti dengan sistem

masonri tanpa mortar. Sistem dinding blok berkunci tanpa mortar boleh

didefinasikan sebagai dinding diperbuat daripada penyatuan blok berkunci tanpa

menggunakan sebarang mortar atau bahan pelekat diantara lapisan.

Walaubagaimanapun, kelakuan struktur dinding blok berkunci tanpa mortar belum

lagi difahami sepenuhnya. Kelakuan struktur dan parameter rekabentuk untuk sistem

ini dijangka berlainan dengan sistem dinding konvensional. Bagi tujuan untuk

memahami kelakuan sistem dinding, sifat dan parameter penting untuk rekabentuk

dinding di bawah beban yang berlainan perlu ditentukan dan dikenal pasti.

Kajian ini dijalankan melalui penyelidikan bereksperimen dan analisis unsur

terhingga. Sejumlah 21 spesimen berskala penuh telah digunakan untuk memerhati

kelakuan dan tindakbalas tiga kumpulan berlainan bagi dinding blok berkunci tanpa

mortar yang dinamakan sebagai dinding tanpa bukaan, dinding dengan bukaan dan

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dinding dengan pilaster. Bagi dinding tanpa bukaan, penyelididikan bereksperimen

telah dijalankan dibawah beban satah dan luar satah. Manakala bagi dua kumpulan

dinding yang lain, ia diselidik dibawah beban mampatan sahaja. Satu kajian

parametrik menggunakan analisis unsur terhingga telah dijalankan untuk mengkaji

kesan parameter berlainan ke atas setiap kumpulan dinding blok berkunci yang

dipertimbangkan dalam menambahkan data yang sedia ada. Program unsur terhingga

yang digunakan telah dibangunkan menggunakan bahasa Fortran dengan

mempertimbangkan elemen penting bagi lapisan antara muka blok berkunci. Empat

model berlainan telah dibangunkan bagi mempertimbangkan kumpalan dinding yang

berbeza dalam kajian ini. Keputusan yang diperolehi dari simulasi kemudiannya

dibandingkan dengan keputusan eksperimen untuk memeriksa kecukupan dan

ketepatannya. Kajian validasi menunjukkan keputusan unsur terhingga berdasarkan

model yang dicadangkan dengan keputusan eksperimen adalah bagus.

Spesimen dinding di bawah beban satah dan luar satah telah diuji di bawah beban

pra-mampatan tegak malar dan beban tepi ditingkatkan. Kapasiti beban tepi

maksimum yang boleh ditanggung, perkembangan terikan dan ciri-ciri kegagalan

telah direkodkan. Dalam kes di bawah beban satah, kapasiti tegasan ricih menjadi

tumpuan penting dalam pemerhatian ini. Kegagalan dinding di bawah beban satah

dikawal oleh kegagalan ricih pepenjuru dan kehancuran sederhana di kaki dinding.

Hasil penting kajian dinding dibawah beban satah ialah hubungan antara tegasan pra-

mampatan purata dan tegasan ricih pada kegagalan. Bagi dinding di bawah beban

luar satah, keputusan menunjukkan bahawa beban pra-mampatan tegak dan tetulang

pengukuh memberi kesan penting kepada kelakuan struktur dinding blok berkunci

tanpa mortar. Kegagalan dinding adalah didominasi oleh bukaan antara join kering,

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keretakan, anjakan lenturan dan kehancuran kaki dinding. Rekabentuk dinding di

bawah beban luar satah dikawal oleh mekanisma bukaan join kering di tengah

ketinggian dinding.

Panel dinding dengan bukaan telah diuji di bawah beban mampatan tegak dengan

mengambil kira saiz bukaan berbeza dan nisbah kelangsingan. Keputusan

menunjukkan bahawa saiz bukaan boleh mengurangkan kapasiti beban maksimum

yang boleh ditanggung oleh dinding. Lokasi bukaan di dinding juga menyumbangkan

kesan terhadap kelakuan dinding dengan bukaan.

Keputusan dinding dengan pilaster menunujukkan bahawa nisbah kelangsingan

mempunyai kesan penting terhadap kapasiti beban yang boleh ditanggung oleh

pilaster. Pilaster juga boleh meningkatkan rintangan tepi terhadap anjakan luar satah

dan kapasiti beban yang boleh ditanggung oleh sistem dinding. Dengan menambah

sendi/pilaster kepada sistem dinding, mod kegagalan mungkin boleh dilambatkan

dalam kontak kegagalan yang dijangka berlaku dalam spesimen dinding yang sama

tetapi tanpa pilaster.

Keputusan menunjukkan bahawa beban pra-mampatan dan nisbah kelangsingan

mempunyai kesan penting terhadap dinding di bawah beban gabungan. Manakala

bagi kumpulan dinding lain (dinding dengan bukaan dan dinding dengan pilaster)

yang mana di bebani oleh beban mampatan tegak, nisbah kelangsingan dan saiz

bukaan ialah faktor yang memberi kesan kepada kelakuan sistem dinding. Kesan

parameter penting menyumbang kepada ramalan sifat dan kekuatan untuk setiap

kumpulan yang dipertimbangkan bagi sistem dinding Putra blok berkunci tanpa

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mortar. Sebagai sumbangan, beberapa formula, jadual dan lengkung telah

dicadangkan untuk digunakan dalam meramal kekuatan maksimum bagi sistem

dinding tanpa mortar mengikut keadaan beban bagi setiap kumpulan sistem dinding.

Akhirnya, dengan kefahaman yang mendalam ke atas sifat sistem dinding masonri

tanpa mortar ianya menyumbangkan kegunaan yang lebih baik di dalam rekabentuk

dan pembinaan.

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ACKNOWLEDGEMENT

Praises and thanks to Allah SWT for giving the opportunity to further my study at

this level and able to complete it. I would like to express my deep thanks and

gratitude to my Supervisor, Prof Ir Dr Mohd Saleh Jaafar, for his great supervision

and valuable help and encouragement. Many thanks also go to Assoc Prof Dr

Jamaloddin Norzaei and for his valuable advice and discussion especially on the

numerical method. Thanks also to Dr Ahmed Hassan Al-Wathaf whose comment on

my thesis during my writing process.

Thanks also go to structural laboratory technician, Mr Mohd Halim Othman and Mr

Jaafar for their valuable assistance in helping me during my tiring day performing

my lab work especially in helping fixing test setup and instrumentation.

Thanks you also to Ministry of Higher Learning of Malayisa and University Putra

Malaysia for their sponsorship for this study.

I would also like to express my great appreciation and deep gratitude to my husband,

Mohamad Zahid Abd Wahab and my son, Alif Farhan whose being understanding

during this study period, to my father and mother also father and mother in-law for

their encouragement and for all my family members.

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I certify that a Thesis Examination Committee has met on 28 Mac 2011 to conduct the final examination of Nor Azizi binti Safiee on her thesis entitled “ Structural Behavior of Interlocking Mortarless Putra Block Wall System” in accordance with the Universities and University College 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: Abdul Halim bin Ghazali, PhD Associate Professor Faculty of Engineering Universiti Putra Malaysia (Chairman) Abang Abdullah bin Abang Mohamad Ali, P.Eng Professor Faculty of Engineering Universiti Putra Malaysia (Internal Examiner) Raizal Saifulnaz bin Muhammad Rashid, PhD Faculty of Engineering Universiti Putra Malaysia (Internal Examiner) Tan Kiang Hwee, PhD Professor National University of Singapore (External Examiner) _____________________________ ZULKARNAIN ZAINAL, PHD Professor and Deputy Dean School of Graduate Studies Universiti Putra Malaysia

Date: 24 May 2011

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This thesis was submitted to the Senate of Universiti Putra Malaysia and has been accepted as fulfilment of the requirement for the degree of Doctor of Philosophy. The members of the Supervisory Committee were as follows: Mohd. Saleh Jaafar, PhD, P.Eng Professor Faculty of Engineering Universiti Putra Malaysia (Chairman) Jamalodin Noorzaie, Phd Associate Professor Faculty of Engineering Universiti Putra Malaysia (Member) Mohd. Razali Abdul Kadir, Phd, P.Eng Associate Professor Faculty of Engineering Universiti Putra Malaysia (Member) _____________________________ HASANAH MOHD GHAZALI, PHD Professor and Dean School of Graduate Studies Universiti Putra Malaysia Date:

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DECLARATION

I declare that the thesis is my original work except for quotations and citations which have been acknowledged. I also declare that it has not been previously and is not concurrently submitted for any other degree at Universiti Putra Malaysia or other institutions. _____________________ NOR AZIZI BT SAFIEE Date: 28 March 2011

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TABLE OF CONTENTS Page ABSTRACT iii ABSTRAK vi ACKNOWLEDGEMENT x APPROVAL xi DECLARATION xiii LIST OF TABLES xvii LIST OF FIGURES xix LIST OF ABBREVIATIONS xxix CHAPTER 1 INTRODUCTION

1.0 Introduction 1 1.1 Development of Putra block interlocking system 2

1.2 Problem Statement 3 1.3 Objectives 3 1.4 Scope of study 4 1.5 Significance of the research 4 1.6 Thesis Outline 5

2 LITERATURE REVIEW

2.1 Introduction 7 2.2 Wall subjected to compressive load 7 2.3 Wall subjected to lateral load 13

2.3.1 Wall under in-plane load 13 2.3.2 Wall under Out-of-plane load 36

2.4 Wall with Opening 52 2.5 Wall with Pilasters 62

3 METHODOLOGY

3.1 Introduction 67 3.2 Experimental Work 70

3.2.1 Individual and prism test 71 3.2.2 Test setup and instrumentation 72

3.3 Finite Element Method 85 3.3.1 Finite Element Formulation 85 3.3.2 Masonry Discretization 88 3.3.3 Constitutive Modelling 99 3.3.4 Nonlinear Finite Element program 104 3.4 Design Aspect 3.4.1 Wall subjected to in-plane load 107 3.4.2 Walls subjected to out-of-plane load 109 3.4.3 Walls with openings 112 3.4.3 Wall pilasters 113

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4 STRUCTURAL BEHAVIOR OF WALL WITHOUT OPENING 4.1 Introduction 117 4.2 Individual and prism results 118

4.3 Wall subjected to in-plane load 121 4.3.1 Experimental Investigation 122

4.3.2 Parametric study for in-plane load case 139 4.3.3 Proposed equations/curve for shear and displacement prediction of wall under in-plane load 153 4.4 Wall subjected to out-of-plane load 161

4.4.1 Experimental investigation 162 4.4.2 Parametric study for out-of-plane loads case 178 4.4.3 Proposed approach/curve for strength prediction of wall under out-of-plane load 190

5 STRUCTURAL BEHAVIOR OF WALL WITH OPENING

5.1 Introduction 200 5.2 Wall with opening subjected to vertical load 201 5.2.1 Experimental investigation 201

5.2.2 Parametric study 216 5.2.3 Proposed tables for strength and stiffness prediction of wall with opening under vertical load 237

5.3 Wall with opening subjected to lateral load 241 5.3.1 Parametric study 241 5.3.2 Proposed tables for strength and rigidity prediction of wall with opening under lateral load 247 6 STRUCTURAL BEHAVIOR OF WALL WITH PILASTERS

6.1 Introduction 250 6.2 Experimental results & discussion 251

6.2.1 Vertical Deflection of pilasters 251 6.2.2 Lateral deflection of pilaster 253 6.2.3 Compression capacity of pilasters sections 258 6.2.4 Strain on pilasters 260 6.2.5 Modes of failure 263

6.3 Parametric study 267 6.3.1 Characteristics of finite element model 268 6.3.2 Finite element modelling and experimental

verification 269 6.3.3 Discussion on parametric study 271

6.4 Proposed equations for strength prediction of pilasters 282 6.4.1 Concentric load case 283 6.4.2 Eccentric load case 286

7 CONCLUSION & RECOMMENDATION FOR FUTURE WORK

7.1 Introduction 290 7.2 Summary 290

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7.3 Recommendation for future work 296 REFERENCES 297 APPENDIXES 305 BIODATA OF STUDENT 316