SPECIFICATION OF MOVEMENT JOINTS FOR MASONRY STRUCTURES IN SRI LANKA Dhammika Nanayakkara PhD/C/01/94 Degree of Doctor of Philosophy Department of Civil Engineering University of Moratuwa Sri Lanka August 2011 SPECIFICATION OF MOVEMENT JOINTS FOR MASONRY STRUCTURES IN SRI LANKA Dhammika Nanayakkara PhD/C/01/94 Thesis submitted in fulfillment of the requirements for the degree of Doctor of Philosophy Department of Civil Engineering University of Moratuwa Sri Lanka August 2011 i Declaration I declare that this is my own work and this thesis does not incorporate without acknowledgement any material previously submitted for a Degree or Diploma in any other University or Institute of higher learning and to the best of my knowledge and belief it does not contain any material previously published or written by another person except where the acknowledgement is made in the text. Also, I hereby grant to University of Moratuwa the non-exclusive right to reproduce and distribute my thesis, in whole or in part in print, electronic or other medium. I retain the right to use this content in whole or part in future works (such as articles or books). Signature: Date: The above candidate has carried out research for the PhD thesis under my supervision. Signature of the supervisor: Date: ii Abstract Masonry is the most commonly used building material for construction of low rise buildings and even for infill-walls of some high-rise buildings in Sri Lanka. Propagation of cracks in masonry walls is one of the main problems in masonry structures as it affects aesthetics and serviceability greatly. Movement in masonry is the prime cause for such cracks. Especially when movements are restrained, stresses will be set up which may lead to cracking. Even though these cracks may not be of structural significance, due to the difficulties in concealing them permanently and due to increase in maintenance costs of buildings, it has become one of the main concerns in the construction industry. In a few Codes of Practice and Standards, various guidelines are stipulated to control cracking in masonry, but still there are no hard and fast rules for predicting movements accurately at the design stage, due to its complexity. The guidelines specified for design of movement joints for masonry in other countries cannot be directly used in Sri Lanka for local masonry, due to differences in environmental conditions and material properties. Therefore, there is a strong need to develop a methodology for movement joint design and a specification of movement joints for masonry structures in Sri Lanka. To achieve this goal, a comprehensive research study was carried out. It consisted of a literature survey, a field study, an experimental study, a theoretical study and a finite element study. The literature survey was carried out to identify the important parameters to be studied, to assess the current state of knowledge, and to gather necessary information on the design of movement joints. A field study was carried out by conducting a detailed questionnaire survey to collect information on cracking of local masonry walls. Most of the houses had at least one or more cracked walls and majority of the cracks was present only in the superstructure. Wall thickness, exposure to direct sunlight /rain, wall length/height ratio, existence of openings, cross sectional variations in walls, and existence of wall junctions or wall returns were found to be influential parameters on movements. The experimental study included an extensive investigation of movements in different types of masonry wall panels, where 34 wall panels were tested for movements over long period of time till movements stabilized. As brickwork is the most widely used masonry material in Sri Lanka, greater emphasis was given to it. With these tests, long-term movements in different types of masonry were investigated. Numerous tests were also carried out to determine the required properties of brickwork and constituents of brickwork, needed for the theoretical study and the finite element study. The experimental study also resulted in the development of a simple, accurate and inexpensive method for measurement of long term movements in masonry. A theoretical model accounting for elastic, creep, shrinkage and thermal deformations of bricks and mortar was developed with an accuracy of 96% to predict the long-term movements in masonry, which can be used to investigate various aspects which influence design of movement joints for masonry walls. Parametric study highlighted its usefulness. A finite element analysis, using SAP 2000 with thin shell elements, was carried out to study the behaviour of masonry walls subjected to restrained shrinkage, using varying sizes and varying end conditions of a rectangular wall. Significant influence of L/H ratios of walls on stresses iii developed in masonry walls was seen. Influence of openings, wall returns, and restraints were also studied. Finally a methodology for design of movement joints was developed and presented. Further, simplified guidelines for design of movement joints with minimum calculations, were also proposed. Some important conclusions of the study were that moisture expansion of local bricks is insignificant in comparison to that reported for high strength bricks in other countries; movement of local masonry can be described by three parameters maximum shrinkage (ε0), maximum expansion (εex) and critical shrinkage (εcr) of which last is the most decisive parameter; and first year after construction is the critical period as regards movement of local masonry. iv To my father, mother, husband, sister, brother and son whose love and understanding have brought me happiness in my life v ACKNOWLEDGEMENTS I am greatly indebted to my supervisor, Prof. S.R.de S. Chandrakeerthy for his guidance, encouragement and valuable advice given throughout this research study. Indeed I would never have been able to complete this study if not for his unstinted, generous support and valuable suggestions. I wish to express my sincere thanks to Prof. M.T.R. Jayasinghe, Head of the Department of Civil Engineering and former heads of the department for providing facilities to carry out this research project. I also wish to thank all academic staff for their support and advice given at all the needy times. I wish to express my deepest appreciation to my husband Anura for his valuable suggestions, support and encouragement given to complete this study successfully. He was behind me always willing to provide support at any needy event. He was a great strength to me throughout the duration of this study. I wish to express my deepest appreciation to my parents, son Kushan and all my relatives and friends for their continuous encouragement and support given throughout this period. Especially I would like to thank my colleagues Premani, Harsha, Ananda and Priyan for their support and encouragement given to me to complete this work successfully. I greatly appreciate the support given by the research staff especially Isuru, and Amila for their valuable support. Also I would like to offer my sincere thanks to Mr. S.P. Madanayake, Mr. Nalinda Fernando, Mr. Leenus Perera and other non-academic staff members of the Building and Structural Engineering Division for their help and assistance given to conduct my experimental work. Finally I would like to thank Amila, Pradeepa and Nishanthi for helping me with typing of this report, and all others who helped me in various ways. vi TABLE OF CONTENTS Declaration of the candidate & supervisor i Abstract ii Dedication iv Acknowledgments v Table of content vi List of Figures xiv List of Tables xxiv Chapter 1: Introduction 1 1.1 General 2 1.2 Movements in buildings 3 1.2.1 General 3 1.2.2 Sources of Movements 4 1.2.2.1 Movements Due to Loads on the Building 4 1.2.2.2 Movements Due to Creep Deformations 5 1.2.2.3 Thermal Movements 7 1.2.2.4 Movements due to Changes in the Moisture Content 8 1.2.2.5 Movements Due to Chemical Changes in the Material 8 1.2.2.5.1 Movements due to Carbonation 8 1.2.2.5.2 Movement due to Adsorption of Water Vapour 9 1.2.2.6 Movements in Foundations 9 1.2.2.7 Dynamic Movements 10 1.2.3 Effects of Movements on the Building 10 1.2.4 Design for Movement 11 1.3 Need for research 15 1.4 Objectives of the investigation and the adopted Methodology 18 Chapter 2: Literature survey 20 2. 2.1 Introduction 21 2.2 Review of literature on movement of masonry and similar materials 22 2.2.1 Estimation of Thermal and Moisture Movements and Stresses: Part1, Part2, Part 3 (Building Research Establishment Digests 227; 228; 229; July ~ September, 1979.) 22 2.2.2 British Standard Institution, Code of Practice vii for Use of Masonry, Part 3. Materials and Components, Design and Workmanship. (BS 5628 : Part 3: 1985) 33 2.2.3 Moisture Movement in Clay Brickwork: A Review 43 2.2.3.1 General 43 2.2.3.2 Designing for Moisture Expansion 50 2.2.4 Moisture Movement in Concrete Masonry; A Review 51 2.2.5 Volume Changes - Analysis and Effects of Movement 55 2.2.6 Movement Design and Detailing of Movement Joints (part II) 58 2.2.7 Standard Guide for Calculating Movement and Other Effects When Establishing Sealant Joint Width 62 2.2.7.1 General 62 2.2.7.2 Sealant Joint Width Required to Accommodate Movements 68 2.2.7.3 Tolerances 71 2.2.7.3.1 Butt Sealant Joint 71 2.2.7.3.2 Fillet Sealant Joint 72 2.2.7.3.3 Bridge Sealant Joint 73 2.2.7.3.4 Sealant Joint Depth 74 2.2.7.3.5 General Remarks 74 2.2.8 Australian Standard, Masonry Structures, AS3700-2001 76 2.2.9 Concrete Masonry Handbook 82 2.2.10 British Standard Guide to Selection of Constructional Sealants 83 2.2.10.1 General 83 2.2.10.1.1 Calculation of the Width of a Butt Joint 84 2.2.10.1.2 Sealant Types and Their Selection 85 2.2.10.1.3 Sealant Geometry 87 2.2.10.1.4 Sealant Joint Preparation 88 2.2.11 British Standard Institution, Eurocode 6 – Design of Masonry Structures- Part 1-1 General Rules for Reinforced and Unreinforced Masonry. (BS EN 1996-1-1: 2005) 88 2.2.12 British Standards Institution, Selection of Construction Sealants – Guide, (BS 6213: 2000) 90 2.2.13 Standards Australia, Residential Slabs and Footings – Construction, (AS 2870 – 1996) 92 2.2.14 Standards Australia, Masonry in Small Buildings – Part I: Simplified Design of Masonry in Small Buildings (Revision of viii AS 3700 (in part)… 93 2.2.15 Clay Brick and Pavers Institute, Manual 2 – The Properties of Clay Masonry Units, Australia 96 2.2.16 Clay Brick and Pavers Institute, Design of Clay Masonry for Serviceability, CBPI, Australia 97 2.2.17 Think Brick Australia, Manual of Detailing of Clay Masonry, Manual 9 102 2.2.17.1 General 102 2.2.17.2 Horizontal movement 103 2.2.17.3 Calculation process for horizontal movement 104 2.2.17.4 Vertical movement 105 2.2.17.5 Calculation Process for vertical movement 106 2.2.18 British Standard Institution, Building Construction – Jointing Products – Classification and Requirements for Sealants, BS ISO 11680 : 2002 108 2.2.19 Standards Australia, Masonry Units and Segmental Pavers – Methods of Test – Method II – Determining Coefficients of Expansion, AS 4456.11 : 1997 109 2.2.20 British Standard Institution, Eurocode 6 – Design of Masonry Structures – Part 3: Simplified Calculation Methods for Un-reinforced Masonry Structures, BS EN 1996 – 3 : 2006 111 2.2.21 British Standard Institution, Eurocode 6 – Design of Masonry Structures – Part 2: Design considerations, selection of materials and execution of masonry, BS EN 1996-2 : 2006 111 2.2.21.1 General 111 2.2.21.2 Spacing of Movement Joints: 112 2.2.22 British Standard Institution, Design of Joints and Jointing in Building Construction – Guide, BS 6093 : 2006 113 2.2.23 Standards Australia, Masonry in Small Buildings-Part 1:Design AS 4773.1-2010 121 2.2.24 South African Bureau of Standards, Structural Use of Masonry-Part 1: Unreinforced Masonry Walls, SABS 0164-1:1980 122 2.2.24.1 General: 122 2.2.24.2 Magnitude of Movement 122 ix 2.2.24.3 Width of Control Joint 123 2.2.24.4 Spacing of Control Joints 124 2.2.25 Indian Standard Institution, Code of Practice for Design and Installation of Joints in Buildings, IS: 3414-1968 (Reprinted in 1978) 127 2.2.25.1 General 127 2.2.25.2 Types of Joints 128 2.2.25.3 Materials 129 2.2.25.4 Design 130 2.2.25.5 Maintenance 133 2.3 Review of previous research studies: 134 2.3.1 Site Surveys of Movement in Calcium Silicate Brickwork, W.M. Churchill, Masonry International, Vol. 2, No.2, June 1988 134 2.3.2 Influence of size on moisture movements in unrestrained Masonry 135 2.3.3 Feasibility Study on the Use of Brickwork and Reinforced Brickwork Columns to Replace Reinforced Columns in up to Two- storeyed Houses 137 2.3.4 Elastic, Creep and Shrinkage Behavior of Masonry 138 2.4 Conclusions from the literature survey 139 2.4.1 General 139 2.4.2 Methodology for Design of Movement Joints (Formulated from the Results of the Literature Survey) 153 2.4.2.1 General 153 2.4.2.1.1 Design Procedure 154 2.4.3 Draft Specification (Formulated from the Results of the Literature Survey) for Use of Sealants within Movement Joints 158 Chapter 3: Field Study 161 3. 3.1 Introduction: 162 3.2 Analysis of results of the questionnaire 163 3.2.1 Section a (walls in buildings) 163 3.2.1.1 General information 163 3.2.1.1.1 Results pertaining to general information 164 3.2.1.1.2 Findings 168 3.2.1.2 Information on cracking 170 3.2.1.2.1 Results pertaining to information on cracking 170 3.2.1.2.2 Findings 175 3.2.1.3 Analysis of crack locations in walls 177 x 3.2.1.3.1 General 177 3.2.1.3.2 Walls with door openings 180 3.2.1.3.3 Walls with only window openings 180 3.2.1.3.4 Walls without openings 181 3.2.2 Section B (freestanding walls) 182 3.2.2.1 Results from questionnaire survey of the field study on freestanding walls 182 3.2.2.2 Findings 187 3.3 Conclusions from the field study 189 3.3.1 Walls in buildings 189 3.3.2 Freestanding walls 191 3.3.3 Summary of important conclusions 192 Chapter 4: Experimental study 193 4. 4.1 General 194 4.2 The measurement of movement 194 4.2.1 Techniques considered 194 4.2.2 Findings 197 4.3 Details of test series 1 197 4.3.1 Main Parameters of the Test Series 1 198 4.3.2 Details of Masonry Panels (Test series 1) 200 4.3.2.1 Brickwork Panels 200 4.3.2.2 Blockwork Panels 201 4.3.3 Details of Measurements (Test series 1) 201 4.3.4 Results of the Experimental Work and Discussion 203 4.3.5 Conclusions from Test Series 1 208 4.4 Details of test series 2 211 4.4.1 Main parameters of the test series 2 212 4.4.2 Details of masonry panels (test series 2 ) 214 4.4.3 Details of measurements (test series 2) 214 4.4.4 Results and discussion (test series 2) 215 4.4.5 Conclusions from Test Series 2 231 4.5 Details of test series 3 235 4.5.1 Main Parameters of the Test Series 3 235 4.5.2 Details of Masonry Panels (Test Series 3) 237 4.5.2.1 Details of brickwork panels 237 4.5.2.2 Details of Blockwork Panels 237 4.5.3 Details of Measurements (Test Series 3) 239 4.5.4 Results of the Test Series 3 and Discussion 239 4.5.5 Conclusions from Test Series 3 264 4.6 Details of test series 4 268 4.6.1 Main parameters of the test series 4 268 xi 4.6.2 Details of masonry panels (test series 4 ) 269 4.6.3 Details of measurements (test series 4) 270 4.6.4 Results of the experimental work and discussion 270 4.6.5 Conclusions from test series 4 275 4.7 Details of test series 5 277 4.7.1 Investigation of Movements in Burnt Clay Bricks 278 4.7.2 Determination of Elastic Properties of Bricks in Longitudinal Direction 279 4.7.2.1 Bricks subjected to compression in longitudinal direction 279 4.7.2.2 Bricks subjected to tension in longitudinal Direction 282 4.7.3 Determination of Coefficient of Thermal Expansion of Bricks 284 4.7.4 Investigation of Creep Deformations in Bricks 286 4.7.4.1 Creep Deformation of Bricks Under Compression 286 4.7.4.2 Creep of Bricks Under Tension 289 4.7.5 Shrinkage Test on Saturated Brick Samples 291 4.7.6 Determination of Elastic Properties of Mortar 293 4.7.6.1 Mortar Specimens Subjected to Compressive loads 293 4.7.6.2 Mortar Specimens Subjected to Tensile loads 294 4.7.7 Determination of Coefficient of Thermal Expansion of Mortar 295 4.7.8 Investigation of Creep Deformation of Mortar 296 4.7.8.1 Creep Deformation of Mortar Under Compression 296 4.7.8.2 Creep Deformation of Mortar Under Tension 298 4.7.9 Investigation of Drying Shrinkage of Different Mortar 300 4.7.9.1 Calculation of Shrinkage Strain of a Specimen 301 4.7.10 Determination of Material Properties of Brickwork Needed for FEM Analysis 308 4.7.10.1 Test to Determine Compressive Strength of Brickwork 308 4.7.10.2 Test to Determine Flexural Strength of Brickwork 310 4.7.10.3 Tests to Determine Density, Modulus of Elasticity and Poisson’s Ratio of Brickwork 315 4.7.10.3.1 General 315 4.7.10.3.2 Test Results of Elastic Properties and Density of Brickwork 316 4.7.11 Conclusions from Test Series 5 316 4.8 Main conclusions from the experimental study 319 Chapter 5: Mathematical model to predict the deformation of masonry 322 5. xii 5.1 General 323 5.2 Modeling of movements in masonry walls 324 5.2.1 Modeling of Half-Brick Thick Wall Element 324 5.2.1.1 Calculation of Creep Deformation in Masonry Element 330 5.2.1.2 Calculation of Shrinkage in Masonry Element 332 5.2.1.3 Calculation of Thermal Movements in Masonry Element 332 5.2.2 Modeling of One-Brick Thick Wall Element 333 5.2.3 Physical and Mechanical Properties of Constituents of Brick Masonry Used for modeling 340 5.2.4 Development of the Computer Program to Model Masonry Element 343 5.2.5 Masonry Model Predictions and Comparison of the Experimental Results 347 5.2.5.1 Comparison of masonry model predictions with experimental work 347 5.2.5.2 Parametric Study 348 5.2.6 Conclusions from Theory and Prediction of the Masonry Model 357 Chapter 6: Finite element analysis of masonry walls subjected to movement restraints 359 6. 6.1 General 360 6.2 Computer modeling of masonry walls 361 6.2.1 Material properties of brickwork used for the analysis of walls 362 6.3 Analysis and results of masonry walls using finite element method 363 6.3.1 Influence of Wall Length on the Behaviour of Freestanding Masonry Walls under Restrained Shrinkage 363 6.3.2 Influence of Wall Length to Height Ratio (L/H Ratio) on the Behaviour of Freestanding Masonry Walls under Restrained Shrinkage 366 6.3.3 Influence of Boundary Conditions of Walls on Behaviour of Walls under Restrained Shrinkage 367 6.3.4 Influence of Wall Thickness on Behaviour of Walls under Restrained Shrinkage 371 6.3.5 Influence of Wall Openings on the Behaviour of Walls under Restrained Shrinkage 372 6.3.6 Identification of crack locations and cracking Pattern associated with Restrained Shrinkage of walls 374 xiii 6.4 Conclusion 375 Chapter 7: Design of movement joints for masonry walls and selection of sealants 376 7. 7.1 General 377 7.2 Design of movement joints for masonry walls 377 7.2.1 Estimation of Expected Total Movement in Walls 377 7.2.1.1 Moisture Movements in Different Types of Masonry 378 7.2.1.2 Thermal Movements in Different Types of Masonry 378 7.2.1.3 Calculation movement joint spacing 381 7.2.1.4 Designed Movement Joint Width and Depth 383 7.2.1.4.1 Designed Movement Joint Width 383 7.2.1.4.2 Movement Joint Depth 384 7.3 Selection of sealants 386 7.3.1 Types of Sealants and Their Applications 386 7.3.2 Method of Applying Sealant in Movement Joints 389 7.4 Simplified Method for design of movement joints for walls of local masonry 389 7.4.1 General 389 7.4.2 The recommended simplified design method for movement joints in local masonry 390 7.4.2.1 General 390 7.4.2.2 Detailing of Open Joints and joints filled with sealants 391 7.4.2.3 Width and spacing of Vertical Movement joints 392 7.4.2.4 Other considerations for specific location of movement joints 393 7.4.2.5 The recommended simplified method 394 7.5 Concluding Summary 395 Chapter 8: Main conclusions and Recommendations for further Research 397 8.1 Main conclusions 398 8.2 Recommendations for further research 407 References 409 Appendix A 417 Appendix B 432 Appendix C 515 Appendix D 624 xiv LIST OF FIGURES Page Figure 1.1 Common problems caused by movement between frames and walls 12 Figure 2.1 Causes of deformation 23 Figure 2.2(a) Factors affecting thermal movement 34 Figure 2.2(b) Factors affecting moisture movement of concrete and calcium silicate masonry units 37 Figure 2.2(c) The moisture movement of mortars 38 Figure 2.3 Locations where movement joints are required in walls 42 Figure 2.4 Vertical Expansion Joints 58 Figure 2.5 Expansion Joints at Corners 60 Figure 2.6 Expansion Joints at an Offset 60 Figure 2.7 Movement Joint near an Opening 61 Figure 2.8 Movement Joint to Separate Walls Having Different Heights or exposure conditions 61 Figure 2.9 Flexible Anchorage to Beams and Columns 62 Figure 2.10(a) Typical Sealant Joint Movements 67 Figure 2.10(b) Longitudinal or Transverse Extension Movement 67 Figure 2.11 Extension and Compression Movement with Transverse Extension 67 Figure 2.12 Extension and Compression Movement with Longitudinal Extension 68 Figure 2.13 Diagonal Extension Movement of a Sealant Joint 69 Figure 2.14 Movement combinations in a sealant 70 Figure 2.15 Cross Section of a Typical Butt Sealant Joint 72 Figure 2.16 Cross Section of a Typical Fillet Sealant Joint 73 Figure 2.17 Cross Section of a Typical Liquid - Applied Bridge sealant joint 74 xv Figure 2.18 Movement joint with chases 76 Figure 2.19 Details of Intersections at Unreinforced Walls 77 Figure 2.20 Intersection of a Reinforced wall 77 Figure 2.21(a) Typical Control Joint Details 78 Figure 2.21(b) Flowchart for Selection of a Sealant 91 Figure 2.22 Crack Types in Masonry 97 Figure 2.23(a) Typical Cracking from a Doming Foundation 98 Figure 2.23(b) Typical Cracking from a Dishing Foundation 98 Figure 2.24(a) Movement of Articulated Walls in a Doming Foundation 99 Figure 2.24(b) Movement of Articulated Walls in a Dishing Foundation 99 Figure 2.25 Typical Flexible Masonry Anchors 100 Figure 2.26 Slip Joint between Masonry and a Concrete Slab 100 Figure 2.27 Recommended Locations for Control Joints 104 Figure 2.28 Gun Applied Sealant 114 Figure 2.29 Tooled Sealant 115 Figure 2.30(a) Method 1 116 Figure 2.30(b) Method 2 117 Figure 2.30(c) Method 3 118 Figure 2.31 Minimum Gaps of Control Joints 126 Figure 2.32 Expansion Joint Filler and sealing compound 133 Figure 3.1 Treatment of Walls with Openings 178 Figure 3.2 Cracking of walls due to settlement or uplift 179 Figure 4.1 Measurement of Horizontal Movement in a Brickwork Panel 195 Figure 4.2 Measuring movement using a multi-position mechanical strain gauge 196 Figure 4.3 Arrangement for Measurement of Movements Using Dial Gauges 196 Figure 4.4 Moisture Content of Bricks Versus Immersion Time in Water 200 Figure 4.5 The Typical Test Panels Made of Brickwork and Blockwork 201 xvi Figure 4.6 Location of Demec Gauge Points on Brickwork and Blockwork Panels 202 Figure 4.7 Average Strain versus Time for Panels A & B 204 Figure 4.8 Average Strain Versus Time for Panels C & D 204 Figure4.9 Average Strain Versus Time for Panels E & F 205 Figure 4.10 Average Strain Versus Time for Panels G & H 205 Figure 4.11 Average Strain versus Time for Panels I & J 206 Figure 4.12 Strains in Panels A&B and C & D 206 Figure 4.13 Horizontal Strains in Panels A, B and E, F 207 Figure 4.14 Horizontal Strains in Panels A, B and G, H 207 Figure 4.15(a) Variation of Temperature During the Period 213 Figure 4.15(b) Variation of Relative Humidity During the Period 213 Figure 4.16 Typical Brickwork Test Panel in Series 2 214 Figure 4.17 The Variation of Horizontal Strain Versus Time for All Panels 216 Figure 4.18 Horizontal Strain Versus Time for Panels with Low Strength Bricks 217 Figure 4.19 The Horizontal Strain Versus Time for Panels with Medium Strength Bricks 218 Figure 4.20 The Horizontal Strain Versus Time for Panels with High Strength Bricks 219 Figure 4.21(a) The Horizontal Strain Versus Time for Panels with 1:8 Mortar but with Different Strengths of Bricks 220 Figure 4.21(b) The Horizontal Strain Versus Time for Panels with 1:5 Mortar but with Different Strengths of Bricks 221 Figure 4.22(a) Typical Strain Versus Time for Brickwork 222 Figure 4.22(b) Displacement in Movement Joints (with no sealant, but only two cover sheets on either side) 226 Figure 4.22(c) Displacement in Movement Joints (with joint sealant) 227 xvii Figure 4.23 The Maximum Shrinkage Strain (εo )Versus Brick Strength 228 Figure 4.24 The Maximum Expansion (εex) Versus Brick Strength 229 Figures 4.25 Critical shrinkage (εcr) Versus Brick Strength 230 Figure 4.26 The Brickwork Test Panel(225 mm) in Series 3 237 Figure 4.27 The Brickwork Test Panel(110 mm) in Series 3 238 Figure 4.28 The Blockwork Test Panel in Series 3 238 Figure 4.29 The Graph of Strain Versus Time for All Brickwork Panels 240 Figure 4.30 The Graph of Strain Versus Time for Blockwork panels 241 Figure 4.31 Strain Vs Time for Panels(225 thick) Made of Saturated Bricks with Different Mortar Mixes 242 Figure 4.32 Strain Versus Time for Panels(110 thick) made of saturated bricks with different mortar Mixes 243 Figure 4.33 Strain Versus Time for Panels(225 thick) Made of Dry Bricks with Different Mortar Mixes 244 Figure 4.34 Strain Versus Time for Panels(110 thick) Made of Dry Bricks with different mortar Mixes 245 Figure 4.35 Strain Versus Time for Panels(225 thick) Made with 1:8 Mortar Mix and with Different Moisture Contents in Bricks 246 Figure 4.36 Strain Versus Time for Panels(225 thick) Made with 1:6 Mortar Mix and with different moisture contents in bricks 247 Figure 4.37 Strain Versus Time for Panels(110 thick) Made with 1:8 Mortar Mix and with Different Moisture Contents in Bricks 248 Figure 4.38 Strain Versus Time for Panels(110 thick) Made with 1:6 Mortar Mix and with Different Moisture Contents in Bricks 249 Figure 4.39 Strain Versus Time for Hollow Block Panels Made with Different Moisture Contents in Blocks 250 Figure 4.40 Strain Versus Time for Solid Block Panels Made with Different Moisture Contents in Blocks 251 xviii Figure 4.41 Strain Versus Time for Panels Made with 1:6 Mortar, Saturated Bricks with varied wall thickness 252 Figure 4.42 Strain Versus Time for Panels Made with 1:6 Mortar & Dry bricks with varied wall thickness 253 Figure 4.43 Strain Versus Time for Panels Made with 1:8 Mortar & Saturated Bricks but with Varied Wall Thickness 254 Figure 4.44 Strain Versus Time for Panels Made with 1:8 Mortar & Dry Bricks but with Varied Wall Thickness 255 Figure 4.45 Strain Versus Time for Panels Made with 1:5 Mortar & Saturated Blocks 256 Figure 4.46 Strain Versus Time for Panels Made with 1:5 Mortar & Dry Blocks 257 Figure 4.51 Typical Rubble Masonry Panel 269 Figure 4.52 A Rubble Masonry Panel in Test Series - 4 269 Figure 4.53 Strain Versus Time Graph for All Rubble Masonry Panels 271 Figure 4.54 Strain Versus Time for Rubble Masonry Panels with 1:8 Mortar Mix 271 Figure 4.55 Strain Versus Time for Rubble Masonry Panels with 1:6 Mortar Mix 272 Figure 4.56 Strain Versus Time for Rubble Masonry Panels with 1:5 mortar Mix 272 Figure 4.57 Brick specimen used to measure movements 278 Figure 4.58 Movements in Local Bricks 279 Figure 4.59 A brick sample under compression load 280 Figure 4.60(a) The Stress-Strain Curves of Type 2-Grade I Bricks Under Compression 280 Figure 4.60(b) The Stress- Strain Curves of Type 2-Grade II Bricks Under Compression 281 Figure 4.61 Loading arrangement of a brick sample under tension 282 xix Figure 4.62(a) The stress- strain curves of Type 2-Grade I bricks 283 Figure 4.62(b) The stress- strain curves of Type 2-Grade II bricks 283 Figure 4.63 A Brick Sample Used to Determine Coefficient of Thermal Expansion 285 Figure 4.64 The Creep Testing Apparatus. 286 Figure 4.65 The Creep Strain Versus Time for Bricks under Compression load 287 Figure 4.66 The variation of Specific creep with time for bricks 288 Figure 4.67 Prediction of Specific Creep Versus Time for Different Grades of Bricks 289 Figure 4.68 Loading arrangement for tension creep test 290 Figure 4.69 Brick specimen for shrinkage test 291 Figure 4.70(a) The shrinkage strain Versus time for saturated brick specimens 291 Figure 4.70(b) The Predicted Shrinkage Strain Vs time for saturated brick specimens 292 Figure 4.71(a) Test Specimen 293 Figure 4.71(b) Loading arrangement to determine properties of mortar under compression 293 Figure 4.72 Mortar specimen under tension 294 Figure 4.73 Mortar specimen used to determine coefficient of thermal expansion of mortar 295 Figure 4.74(a) Loading arrangement used to monitor creep of mortar under compression 297 Figure 4.74(b) Dummy specimen to monitor shrinkage 297 Figure 4.75 Specific Creep Versus Time for Mortar under Compression 297 Figure 4.76 Loading arrangement used to determine creep deformations of mortar under tension 298 Figure 4.77 The specific creep of mortar vs time 299 xx Figure 4.78 Monitoring Shrinkage of mortar using length comparator 301 Figure 4.79(a) Shrinkage strains versus time for 1cement: 5sand mortar (cured) 302 Figure 4.79(b) Shrinkage strains and prediction curve for the highest values versus time for 1cement: 5sand mortar-(cured) 302 Figure 4.79(c) Shrinkage strains and prediction curve for the average values versus time for 1cement: 5sand mortar (cured) 303 Figure 4.80(a) Shrinkage strains versus time for 1cement: 5sand mortar (uncured) 303 Figure 4.80(b) Shrinkage strains and prediction curve for highest values versus time for 1cement:5sand mortar (uncured) 304 Figure 4.80(c) Shrinkage strains and prediction curve for the Average values versus time for 1cement: 5sand mortar (uncured) 304 Figure 4.81(a) Shrinkage strains versus time for 1cement: 8sand mortar (uncured) 304 Figure 4.81(b) Shrinkage strains and prediction curve for the highest values versus time for 1cement: 8sand mortar(uncured) 305 Figure 4.81(c) Shrinkage strains and prediction curve for average values versus time for 1cement: 8sand mortar (uncured) 305 Figure 4.82(a) Shrinkage strains versus time for 1cement: 8sand mortar (cured) 305 Figure 4.82(b) Shrinkage strains and prediction curve for the Highest values versus time for 1cement: 8sand mortar(cured) 306 Figure 4.82(c) Shrinkage strains and prediction curve for the average values versus time for 1cement: 8sand mortar(cured) 306 Figure 4.83(a) Loading Arrangement for Compression Test 308 Figure 4.83(b) Failure Pattern of a Masonry Panel 308 Figure 4.84 Variation of Compressive Strength of Brickwork With Compressive Strength of Mortar 309 xxi Figure 4.85 Test Panels used to Determine Flexural Strength of Brickwork 311 Figure 4.86(a) Flexural Strength Test When Plane of Failure Parallel to Bed Joints 311 Figure 4.86(b) Flexural Strength Test When Plane of Failure Perpendicular to Bed Joints 312 Figure 4.87 Flexural Strength of Brickwork Vs Mortar Strength(failure parallel to Bed Joint) 314 Figure 4.88 Flexural Strength of Brickwork Vs Mortar Strength (failure perpendicular to Bed Joint) 314 Figure 4.89 The loading arrangement of a brickwork specimen 315 Figure 5.1 Repeating Masonry Element of a Half- Brick Thick Wall 324 Figure 5.2 Masonry Element used in modeling 325 Figure 5.3 Repeating Masonry Element of One- Brick Thick Wall 333 Figure 5.4 Repeating Masonry Element in One- Brick Thick Wall 334 Figure 5.5(a) 3-D view of Element 1 334 Figure 5.5(b) 3-D view of Element 2 335 Figure 5.5(c) 3-D view of Element 3 335 Figure 5.6 Variation of Km and Kb Factors with V/A Ratios 341 Figure 5.7 Flow Chart of the Masonry Model Used to Predict Movements in One-Brick Thick Brickwork Panel 344 Figure 5.8 Total Movement vs Time for Test Panel A 347 Figure 5.9(a) Prediction of Movement of One-Brick Thick Masonry Panel 348 Figure 5.9(b) Prediction of Movement of Half-Brick Thick Masonry Panel 349 Figure 5.10 Individual Components of Total Strain in Element 1 350 Figure 5.11 Individual Components of Total Strain in Element 2 350 Figure 5.12 Individual Components of Total Strain in Element 3 351 Figure 5.13 Drying Shrinkage in Brick and Mortar in element 1 351 xxii Figure 5.14 Variation of Internal Forces Developed in Elements 352 Figure 5.15 The Influence of Mortar Bed-Joint Thickness on Movement of Masonry 352 Figure 5.16 Influence of the size of the Masonry Units on Movement 353 Figure 5.17 Effect of Temperature Variation on Movement of Masonry 354 Figure 5.18 Initial Expansion of Masonry Element due to Temperature Rise 354 Figure 5.19 Effect of Modulus of Elasticity of Bricks on Movement 355 Figure 5.20 Variation of Force F1 Developed in Element 1 of the Masonry Element 356 Figure 5.21 Variation of Elastic Deformation in Element 1of the Masonry Element 356 Figure 6.1(a) The Maximum tensile Stress Contours in 3m x 3m wall (L/H = 1.0) 363 Figure 6.1(b) The Principal Tensile Stress Directions in 3m x 3m wall (L/H = 1.0) 364 Figure 6.2(a) The Maximum Tensile Stress Contours in 3m x 9m wall (L/H = 3.0) 364 Figure 6.2 (b) The Principal Tensile Stress Directions in 3m x 9m wall (L/H = 3.0) 365 Figure 6.3(a) The Maximum Tensile Stress Contours in 3m x 30m wall (L/H =10.0) 365 Figure 6.3 (b) The Principal Tensile Stress Directions in 3m x 30m wall(L/H =10.0) 365 Figure 6.4 Variation of Tensile Stresses at Mid-Section of Walls 366 Figure 6.5 Stress Distribution Across the Mid-Section of Walls with Different L/H Ratios 367 Figure 6.6(a) Maximum Tensile stresses Developed in 3m x 9m freestanding Wall(L/H=3.0) 368 xxiii Figure 6.6(b) Principal stresses Developed in 3m x 9m freestanding Wall (L/H =3.0) 368 Figure 6.7(a) Maximum Tensile stresses Developed in 3m x 9m Wall with Three Sides Restrained (L/H=3.0) 369 Figure 6.7(b) Principal Tensile stresses Developed in 3m x 9m Wall with Three Sides Restrained (L/H=3.0) 369 Figure 6.8(a) Maximum Tensile stresses Developed in 3m x 9m Wall (L/H =3.0) with all sides restrained 370 Figure 6.8(b) Principal Tensile stresses Developed in 3m x 9m Wall (L/H =3.0) with all sides restrained 370 Figure 6.9 Maximum Tensile stresses Developed in Half-Brick Thick, 3m x 9m freestanding wall 371 Figure 6.10(a) Stress Distribution in 3m x 9m wall with a 1.5m x 2.0m Window Opening, When Subjected to Restrained Shrinkage 372 Figure 6.10(b) Principal Stress Distribution in 3m x 9m wall with a 1.5m x 2.0m Window Opening, When Subjected to Restrained Shrinkage 372 Figure 6.11(a) Stress Distribution in 3m x 9m wall with a 2.0m x 1.5m Window Opening, When Subjected to Restrained Shrinkage 373 Figure 6.11(b) Principal Stress Distribution in 3m x 9m wall with a 2.0m x 1.5m Window Opening, When Subjected to Restrained Shrinkage 373 Figure 7.1 Cross Section of a Typical Butt Sealant Joint 385 xxiv LIST OF TABLES Page Table 2.1 Properties of commonly used building materials 25 Table 2.2 Suitable material properties for local masonry 31 Table 2.3 Service temperature ranges of materials 32 Table 2.4 Linear thermal movement of masonry units and mortar 35 Table 2.5 Moisture movement of concrete and calcium silicate masonry units 36 Table 2.6 Shrinkage of mortars due to change in moisture content 38 Table 2.7 Types of movement of building materials 56 Table2.8(a) Coefficients of solar absorption for some building materials 65 Table2.8(b) Heat capacity constants 65 Table 2.9 Coefficients of linear moisture growth for some building materials 66 Table 2.10 Spacing of articulation joints for unreinforced masonry walls 81 Table 2.11 Joints in external walling and cladding 86 Table 2.12 Sealant geometry of different sealants 88 Table 2.13 Ranges of coefficients of creep, moisture expansion or shrinkage and thermal properties of masonry 89 Table 2.14 Spacing of contraction joints for unreinforced masonry wall 93 Table 2.15 Spacing of expansion joints for clay masonry walls 95 Table 2.16 Maximum values of lm 112 Table 2.17 Fillers for movement joints 119 Table 2.18 Coefficients of linear expansion 120 Table 2.19 Coefficient of thermal expansion of various building materials 131 xxv Table2.20 Recommendations for spacing of expansion Joints 132 Table2.21(a) The average values of the difference of annual maximum and minimum temperatures in different cities in Sri Lanka 155 Table2.21(b) The maximum and minimum temperatures in different cities in Sri Lanka, recorded during 1987~2004 156 Table 2.22 Strength data for local masonry 158 Table 3.1 Type of house/ building 164 Table 3.2 Age of the house/ building 164 Table 3.3 Topographical location of the house/ building 165 Table 3.4 The Location of the house/ building 165 Table 3.5 Special considerations in the area 166 Table 3.6 Foundation condition 166 Table 3.7 Building materials used for walls 167 Table 3.8 Building materials used for plinth wall 167 Table 3.9 Type of wall finishes used for external walls 168 Table 3.10 Type of wall finishes used for internal walls 168 Table 3.11 Existence of cracks on plinth wall 170 Table 3.12 Existence of cracks in super structure 170 Table 3.13 Details of houses which have cracked walls 171 Table 3.14 Distribution of number of cracks in internal and external cracked walls as a percentage of total number of cracked walls 172 Table 3.15 Details of crack widths in different masonry walls for different wall thicknesses 173 Table 3.16 Cracked brickwork walls with different L/H ratios 173 Table 3.17 Details of crack widths of masonry walls under different exposure conditions to sunlight 174 Table 3.18 Details of crack widths of masonry walls under different exposures to rain 174 Table 3.19 Details of orientation of cracked external walls 174 Table 3.20 Visibility of cracks on external walls 175 xxvi Table 3.21 Details of crack widths and colour of walls 175 Table 3.22 Existence of cracks in walls with door openings only 180 Table 3.23 Existence of cracks in walls with window openings 181 Table 3.24 Types of walls 182 Table 3.25 Wall foundation condition 182 Table 3.26 Materials used for walls 182 Table 3.27 Colour of the boundary wall 183 Table 3.28 Existence of cracks in the superstructure 183 Table 3.29 Existence of cracks in plinth walls 183 Table 3.30 Crack widths for different masonry walls with different wall thicknesses 184 Table 3.31 Crack widths for different exposure conditions of walls (exposure to Sun light) 184 Table 3.32 No. of Cracks in freestanding walls with different L/H ratios 185 Table 3.33 No. of Cracks in freestanding walls for different pier spacing 185 Table 3.34 No. of Cracks in freestanding walls for different wall materials 186 Table 3.35 Location of cracks in freestanding walls 186 Table 4.1 Summary of the variables and similarities in Test Series 1 199 Table 4.12 Summary of the variables and similarities in Test Series 2 212 Table4.19(a) Results of maximum expansion, shrinkage strain and critical shrinkage strain in masonry panels 223 Table4.19(b) Movement joint details (Open but covered by strips of plywood / asbestos sheets) 224 Table4.19(c) Movement joint details (filled with joint sealant) 225 Table 4.20 Details of the test variables of masonry panels in test series-3 236 xxvii Table4.21(a) Results of maximum expansion, shrinkage strains and critical shrinkage strain due to horizontal movement (Test Series –3) 261 Table4.21(b) Movement joint details(Open joints, but covered by strips of plywood/asbestos sheets) 262 Table4.21(c) Movement joint details (Filled with joint sealant) 263 Table4.22(a) The test variables and similarities of rubble masonry panels 268 Table4.22(b) Results of maximum expansion and shrinkage strains, and critical shrinkage due to horizontal movement of Test Series 4 273 Table4.22(c) Movement joint details(Open but covered by strips of plywood/ asbestos sheets) 274 Table4.22(d) Movement joint details (filled with joint sealant) 274 Table4.23 Elastic properties of different brick samples under compression loading 281 Table 4.24 Elastic properties of different brick samples under tension loading 284 Table 4.25 The coefficient of thermal expansion of brick samples 285 Table 4.26 Creep test parameters 287 Table 4.27 Constants A and B for different grades of bricks 289 Table 4.28 Applied tensile stresses on different bricks 290 Table 4.29 Elastic properties of mortar under compression 294 Table 4.30 Elastic properties of mortar under tension 295 Table 4.31 The Coefficient of Thermal Expansion of Mortar 296 Table 4.32 Details of Test Variables of Mortar Specimens 300 Table 4.33 Constants A and B for different mortars 307 Table 4.34 Compressive Strengths of Brickwork with Different Mortar Mixes 309 Table 4.35 Number of Panels Tested and Test Variables of the Test for Flexural Strength of Masonry 310 xxviii Table 4.36 Flexural Strengths of Brickwork When Failure Parallel to Bed Joints 312 Table 4.37 Flexural Strengths of Brickwork When Failure Perpendicular to Bed Joints 313 Table 5.1 Constants A and B for Calculation of Specific Creep of Bricks 342 Table 7.1 Critical Drying Shrinkage Strains for Different Types of Masonry 378 Table 7.2 Average Maximum and Minimum Temperatures in Different Cities 379 Table 7.3 Movement Joint Spacing for Different Masonry Walls 383 Table 7.4 Movement Joint Depths for Different Joint Widths 384 Table 7.5 Chemical Type of Different Sealants 386 Table 7.6 Expected Service Life for Different Sealants 387 Table 7.7 Sealants Suitable for Different Applications and Exposure Conditions of Masonry Walls 388 Table 7.8 Maximum Horizontal Distance lm, Between Vertical Movement Joints for Unreinforced Masonry Walls 392 Table 7.9 Recommended Maximum Horizontal Distance lm, Between Vertical Movement Joints for Unreinforced Masonry Walls 394