FATIGUE ANALYSIS AND DESIGN OF STEELCONCRETE-STEEL SANDWICH COMPOSITE STRUCTURES DAI XUEXIN NATIONAL UNIVERSITY OF SINGAPORE 2009 FATIGUE ANALYSIS AND DESIGN OF STEELCONCRETE-STEEL SANDWICH COMPOSITE STRUCTURES DAI XUEXIN (B.Eng., Tianjin Urban Construction Institute; M.Eng., Tianjin University) A THESIS SUBMITTED FOR THE DEGREE OF DOCTOR OF PHILOSOPHY DEPARTMENT OF CIVIL ENGINEERING NATIONAL UNIVERSITY OF SINGAPORE 2009 Acknowledgements ACKNOWLEDGEMENTS I wish to express my deepest gratitude to my supervisor, Prof. Liew Jat Yuen, Richard for his full support, invaluable guidance and constructive advices on research, paper writing and presentation skills. I would also like to thank Prof. Zhang Min-Hong for her kindly help and informative suggestions. My sincere appreciation is dedicated to Dr. Chia Kok Seng in concrete development, Mr. Wang Zhen in ship theory and Dr. Kazi Md. Abu Sohel for many times of valuable discussions and supports. The kindly assistance from all the staff members in NUS Structural and Concrete Laboratory is deeply appreciated. Special thanks goes to Ms. Tan Annie, Mr. Ang Beng Oon, Mr Koh Yian Kheng, Mr Ishak Bin A Rahman, Mr. Choo Peng Kin and Mr Ow Weng Moon for their continuous support during testing. Sincere thanks are also given to colleagues in my office during the year 2004 to 2008 for the happy moments we have shared. I also like to thank my parents for their full supports in my course of study. Finally, the research scholarship provided by National University of Singapore is greatly acknowledged. i Table of Contents TABLE OF CONTENTS ACKNOWLEDGEMENTS………………………………………… i TABLE OF CONTENTS …………………….………………………… . ii SUMMARY ……………………………….………………………… vi LIST OF TABLES ………………………….…………………… viii LIST OF FIGURES …………………….…………………… xii LIST OF SYMBOLS………………….…………… xix LIST OF ACRONYMS ………………….……….… . xxii CHAPTER INTRODUCTION…………………….………….…….….… …………1 1.1 Literature Review………………….…………….………….……….… …………1 1.1.1 Sandwich Construction…….……….….……….………… … …….……1 1.1.2 Steel-Concrete-Steel (SCS) Sandwich Construction…… … … .….……3 1.1.3 Fatigue on Steel-Concrete Composite Structures.… …… … .….………8 1.2 Motivation of Research…….…………….………….……….… …………11 1.3 Research Scope and Objectives………………………….……… ………….…15 1.4 Overview of Contents ……………….…………….………….…….…….…….16 CHAPTER FEASIBILITY STUDY ON DOUBLE HULL STRUCTURE.…… 24 2.1 Introduction …………………………… …….…………………… .…… … .24 2.1.1 Sandwich Effect of Structural Component….…….…… … … 24 2.1.2 Sandwich Effect on Ship Structure………………… .…… ……… .27 2.2 Global Comparison………………………….…………………… .………… 32 2.2.1 Global Comparison under Sagging Moment Load Condition … … … 33 2.2.2 Global Comparison under Hogging Moment Load Condition … ….… 36 ii Table of Contents 2.3 Local Comparison with Stiffened Steel Plate ……………….… ….…… 38 2.4 Weight Comparison……………….………………………… ………… .… 42 2.5 Summary …………………………….………………………….…………… 43 CHAPTER DEVELOPMENT OF LIGHTWEIGHT CONCRETE….… 66 3.1 Introduction …………….……………….…….…………….… .…….…… 66 3.2 Lightweight Aggregate Concrete (LWAC) .……………….…………… ………68 3.2.1 Experimental Details.………………….…….……….… … …………70 3.2.2 Static Properties.……………………… …………….…… .… .………74 3.2.3 Toughness.……………………….…………….…….…… .……………75 3.2.4 Comparison of S–N Curves…….………….………….………….………76 3.2.5 Concluding Remarks…………….…………….………… ……………78 3.3 LWAC with Air Entraining Agent (AEA).………….…………….……….… …79 3.3.1 Fibers…………….…………….………….….……….….………………79 3.3.2 Static Properties…………….…………….………….….…… .…… .…80 3.3.3 Toughness…………….…………….………….….………… …….……81 3.3.4 Fatigue Performance…………….…………….………… …… .………82 3.3.5 Cost Analysis…………….…………….………….….……….…….……83 3.3.6 Concluding Remarks…………….…………….………………… … …83 3.4 LWAC with Expanded Glass Granules.……………………… ……………… .84 3.4.1 Density Check of Trial Mix………………….……… .……….…….… 84 3.4.2 Fiber-reinforced LWAC (FL) Development……………….… … …….87 3.4.3 Concluding Remarks…………….…………….……………… … …87 3.5 Summary…………….…………….………….….……….… .………… .…… 88 CHAPTER STATIC BEHAVIOR OF STEEL-CONCRETE-STEEL SANDWICH COMPOSITES…………… …….… .… .………126 4.1 Introduction …………………………….…………… …………… .…………126 4.2 Analytical Studies………………………………… …………… .……………131 iii Table of Contents 4.3 Test Specimens …………………………….…………….……….…………….134 4.4 Test Setup and Instrumentations……………….………… … .……… .……. 135 4.5 Testing Procedures …………………………….…………… ……….……… 137 4.6 Results and Discussions……………………….……………… .….… …… 138 4.6.1 Load Deflection Behaviour……………… …….……….….… …… 138 4.6.2 Load Slip Behaviour……………………….…………… ……….… 140 4.6.3 Strain Readings……………………….……………….…….… … . 141 4.7 Summary ……………………………….……………………………….…… . 142 CHAPTER FATIGUE PERFORMANCE OF STEEL-CONCRETE-STEEL SANDWICH COMPOSITES………………………………… .……158 5.1 Research Significance …………………………….………….……… … ……158 5.2 Test Program …………………………….…………………….………… ……159 5.3 Results and Discussions ………… ……………….…………………… ……160 5.3.1 Three-parameter Fatigue Load Relationship……….………… … … 160 5.3.2 Hysteretic Responses……………………………….… ……………….161 5.3.3 Permanent Deformation……………………………… …… ……… 163 5.3.4 Stiffness Degradation………………………………….…… …… .….165 5.3.5 Energy Dissipation……………………………… ………… .… .….168 5.4 Design Implications……………………….……… …………… .…… …… 171 5.4.1 Three-parameter Fatigue Design Equation………………… .…… … .172 5.5 Summary …………………………….………………………………………….179 CHAPTER STRENGTH IMPROVEMENT OF STEEL-CONCRETE-STEEL SANDWICH BY TEXTURED INTERFACE…….… … .……… 194 6.1 Introduction …………………………….… .…………………… .…… …….194 6.2 Expamet …………………………….……………………… ……… .……….195 6.3 Test Program …………………………….… ……………………… .….…….196 iv Table of Contents 6.3.1 Push-out Tests……………………… …….….………………….…….196 6.3.2 Beam Tests………………………… …… …………….……….…….198 6.4 Results and Discussions …………………… .……….………………… …….200 6.4.1 Push-out Tests…………………………… .… …….….……… …….201 6.4.2 Beam Static Tests………………………… .…………… .…… …….203 6.4.3 Beam Fatigue Tests…………………………… .………….….……….208 6.5 Summary …………………………….………… ………………… .… .…….213 CHAPTER CONCLUSIONS AND FUTURE WORK…………………… …….240 7.1 Conclusions …………………………….…………… …………… .…………240 7.2 Future Work ………………………………… …………… .……………245 REFERENCES ……………………………….……………………………… 249 APPENDIX I: CALCULATION FOR SANDWICH STRUCTURAL COMPONENT COMPARISON .…… …… ….…………… ….…….261 APPENDIX II.1: CALCULATION PROCEDURE FOR GLOBAL COMPARISON UNDER SAGGING MOMENT LOAD CONDITION 263 APPENDIX II.2: CALCULATION PROCEDURE FOR GLOBAL COMPARISON UNDER HOGGING MOMENT LOAD CONDITION 267 APPENDIX III: MIX PROPORTIONING DESIGN OF FL TRIALS … … .272 PUBLICATION LIST……………………… ……………….…………… 281 v Summary SUMMARY Lightweight and relatively high stiffness are main characteristics that make sandwich composite to be feasible in marine and offshore applications. It is thus proposed that by filling steel face plates with lightweight concrete may create a promising sandwich structural system. This steel-concrete-steel (SCS) sandwich possessing lightweight by means of thinner core depth and lightweight infill concrete will lead to lightweight sandwich composite system. Comparison studies were conducted to determine profile of SCS sandwich panel employed in marine and offshore applications. Based on global comparison of a product/chemical carrier, thickness of steel face plates in SCS sandwich panel can be set as half of original steel plate thickness. A type of fiber-reinforced lightweight aggregate concrete (LWAC) with expanded glass granules is developed for the proposed lightweight sandwich composite system. A standard casting procedure is also established for quality control of fresh concrete. To minimize brittleness and enhance ductility of the concrete, steel fibers were added in. Static test results show that tensile, flexural strength and energy absorption capacity are enhanced by addition of fibers. Fatigue performance of steel fiber reinforced LWAC is also improved. From comparison of concrete with three types of fibers, hook-ended steel fibers show superior properties and is recommended. One percent volume fraction dosage is recommended if cost is taken into account. A fatigue test program with SCS sandwich beams aimed to investigate the effect of two loading parameters is conducted. Test results demonstrate that both maximum applied load and load range affect equally and independently on structural behavior of SCS sandwich member. Fatigue life reduces when load range or maximum applied load increases. A three-parameter fatigue design equation is proposed based on test results. The three-parameter fatigue design equation shows that maximum applied stress yields significant effect on fatigue performance when the difference between the maximum applied stress and the stress range is considerable. In this case, only considering stress range without taking into account maximum applied stress will lead to un-conservative vi Summary prediction of fatigue life. The three-parameter fatigue design equation can also be degenerated to similar design equations in existing codes by assuming minimum applied stress to be zero. From the S-N curves comparison, it is demonstrated the hooked connector perform as well as conventional headed shear studs. A type of textured interface, Expamet, is proposed to be used for strength improvement of SCS sandwich composites. Push-out tests show that bonding strength of textured interface increased significantly compared to that without it. Mechanical anchorage of this type of textured interface inhibits formation of cracks in infill concrete core and enhances bonding at steel-concrete interface, thus increasing static load carrying capacity of SCS sandwich composites. Expamet meshes can serve as a type of ‘linear or surface connector’ which is complementary with ‘point connector’ such as shear stud. Expamet also improves fatigue performance of SCS composite structures with no addition on structural weight. This is a superior choice with an aim to increase fatigue life for weightsensitive structures. vii List of Tables LIST OF TABLES Table 2.1 Comparison of flexural rigidity and response stress in case study (1) 45 Table 2.2 Comparison of flexural rigidity and response stress using ductile material in case study (1) .45 Table 2.3 Moments on ship and stresses at deck and bottom in case study (2) 45 Table 2.4 Comparison of case study (2) .45 Table 2.5 Steel grades for offshore applications 46 Table 2.6 Comparison table for HISTAR grades 46 Table 2.7 Tensile properties of steel in ASTM A 913 standard 46 Table 2.8 Principal dimensions of 16K DWT class product/chemical carrier 46 Table 2.9 Dimensions and section properties of side shell longitudinal stiffeners .47 Table 2.10 Section properties of simplified half ACS .47 Table 2.11 Properties comparison between steel and concrete 47 Table 2.12 Moment load of 16K DWT class product/chemical carrier .48 Table 2.13 Minimum thickness of core material under sagging moment load condition and S d  S d ( M , h f ,37.3, t )  150 .48 Table 2.14 Minimum thickness of core material under hogging moment load condition and S b  S b ( M , h f ,37.3,  t )  150 48 Table2.15 Integrating parts on cross section of SCS model 48 Table 2.16 Required thicknesses for SCS panel with equivalent flexural rigidity D to stiffened steel plate 49 Table 2.17 Proposed plate girder systems for alternative SCS profiles .49 Table 2.18 Weight comparison of ACS constructed with SCS infilled with different lightweight concrete .50 Table 3.1 Properties of Liapor lightweight coarse aggregate (LWAC) .90 Table 3.2 Properties of steel fibers 91 viii Appendix Table II.1.2 Moment of inertia under sagging moment load condition Item No. A  y2 b  h3 /12 123 [1.4  ( t  2)h f ]  [2h f ]  {e  [0.7  ( t /  1)h f ]}2 1/12  [2h f ]  [1.4  ( t  2)h f ]3 45 [10.6  ( t  2)h f ]  [2h f ]  {[6.7  ( t /  1)h f ]  e}2 1/12  [2h f ]  [10.6  ( t  2)h f ]3 [12  ( t  2)h f ]  [2h f ]  {[6  ( t /  1)h f ]  e}2 1/12  [2h f ]  [12  ( t  2)h f ]3 789 1/  E  [12  e]  [ t h f ]  [6  e / 2]2 1/(12 E )  [ t h f ]  [12  e]3 10 [11.5  ( t /  1)h f ]  [h f ]  [e  h f / 2]2 -- 11 [11.5  ( t /  1)h f ]  [h f ]  [e  ( t  / 2)h f ]2 -- 12 [10.3  ( t /  1)h f ]  [h f ]  [e  (1.4  h f / 2)]2 -- 13 [10.3  ( t /  1)h f ]  [h f ]  {e  [1.4  ( t  / 2)h f ]}2 -- 14 [1.2  ( t  2)h f ]  [h f ]  [e  (2.9  h f / 2)]2 -- 15 [1.2  ( t  2)h f ]  [h f ]  {e  [2.9  ( t  / 2)h f ]}2 -- 16 [1.2  ( t  2)h f ]  [h f ]  [(6.4  h f / 2)  e]2 -- 17 [1.2  ( t  2)h f ]  [h f ]  {[6.4  ( t  / 2)h f ]  e}2 -- 18 1/  E  [1.2  ( t  2)h f ]  [ t h f ] {[6.4  ( t /  1)h f ]  e}2 -- 19 [1.2  ( t  2)h f ]  [h f ]  [(9.9  h f / 2)  e]2 -- 20 [1.2  ( t  2)h f ]  [h f ]  {[9.9  ( t  / 2)h f ]  e}2 -- 21 1/  E  [1.2  ( t  2)h f ]  [ t h f ] {[9.9  ( t /  1)h f ]  e}2 -- 22 [11.5  ( t /  1)h f ]  [h f ]  [(12  h f / 2)  e]2 -- 23 [11.5  ( t /  1)h f ]  [h f ]  {[12  ( t  / 2)h f ]  e}2 -- 24 1/  E  [11.5  ( t /  1)h f ]  [ t h f ]  {[12  ( t /  1) h f ]  e}2 -- - 266 - Appendix Appendix II.2: Calculation Procedure for Global Comparison under Hogging Moment Load Condition Central Line 26 25 2100 27 3500 24 22 10 11 12 20 21 Neutral Axis 3500 12000 23 500 e 19 1200 16 14 4350 13 15 4350 11500 2900 1400 17 18 Z 2300 Z* represent steel face plate represent concrete core Figure II.2.1 Half ACS under hogging moment load condition (mm) - 267 - Appendix Table II.2.1 Location of NA under hogging moment load condition Item No. 123 Integrating Range         ( t  2) h f 1.4 456  ( t  2) h f 1.4 78 [1.4  ( t  2) h f ] 12  ( t  2) h f 12 10 11 [1.4  ( t  2) h f ] e 12  ( t  2) h f e 13 hf 14   ( t 1) h f  hf  1.4  [1.4  ( t 1) h f ]  [1.4  h f ]  2.9  ( t  2) h f 15  ( t 1) h f 16  (1.4  h f ) 17 [1.4  ( t  2) h f ] 18 [1.4  ( t 1) h f ] 19  (2.9  h f )  E  b  z dz *  E  b  dz * * E f /  [2h f ]  {[( t  2)h f ]2  1.42 } E f  [2h f ]  [1.4  ( t  2)h f ] E f /(2 E )  [ t h f ] {[( t  2) h f ]2  1.42 } E f /  E  [ t h f ]  [1.4  ( t  2)h f ] E f /  [2h f ]  {[1.4  ( t  2)h f ]2  122 } E f  [2h f ]  [12  1.4  ( t  2)h f ] E f /  [2h f ]  {[( t  2)h f ]2  122 } E f  [2h f ]  [12  ( t  2)h f ] E f /(2 E )  [ t h f ]  {[1.4  ( t  2)h f ]2  e } E f /  E  [ t h f ]  [e  1.4  ( t  2)h f ] E f /(2 E )  [ t h f ]  {[( t  2)h f ]2  e } E f /  E  [ t h f ]  [e  ( t  2)h f ] E f /  [11.5  ( t /  1)h f ]  {0  h f } E f  [11.5  ( t /  1)h f ]  [h f ] E f /  [11.5  ( t /  1)h f ]  {[( t  1)h f ]2  [( t  2)h f ]2 } E f  [11.5  ( t /  1)h f ]  [h f ] E f /(2 E )  [11.5  ( t /  1)h f ]  {h f  [( t  1)h f ]2 } E f /  E  [11.5  ( t /  1)h f ]  [ t h f ] E f /  [10.3  ( t /  1) h f ] {1.42  (1.4  h f ) } E f  [10.3  ( t /  1)h f ]  [h f ] E f /  [10.3  ( t /  1)h f ]  {[1.4  ( t  1)h f ]2  [1.4  ( t  2)h f ]2 } E f  [10.3  ( t /  1)h f ]  [h f ] E f /(2 E )  [10.3  ( t /  1)h f ] {[1.4  h f ]2  [1.4  ( t  1)h f ]2 } E f /  E  [10.3  ( t /  1)h f ]  [ t h f ] E f /  [1.2  ( t  2)h f ]  {2.92  (2.9  h f ) } E f  [1.2  ( t  2)h f ]  [h f ] 268 Appendix 20  [2.9  ( t 1) h f ]  [2.9  h f ]  6.4  [6.4  ( t 1) h f ]  9.9  [9.9  ( t 1) h f ]  12  [12  ( t 1) h f ] [2.9  ( t  2) h f ] 21 [2.9  ( t 1) h f ] 22  (6.4  h f ) 23 [6.4  ( t  2) h f ] 24  (9.9  h f ) 25 [9.9  ( t  2) h f ] 26  (12  h f ) 27 [12  ( t  2) h f ] 27 27 i 1 i 1 E f /  [1.2  ( t  2)h f ]  {[2.9  ( t  1) h f ]2  [2.9  ( t  2)h f ]2 } E f  [1.2  ( t  2)h f ]  [h f ] E f /(2 E )  [1.2  ( t  2)h f ] {[2.9  h f ]2  [2.9  ( t  1)h f ]2 } E f /  E  [1.2  ( t  2)h f ]  [ t h f ] E f /  [1.2  ( t  2)h f ]  {6.42  (6.4  h f ) } E f  [1.2  ( t  2)h f ]  [h f ] E f /  [1.2  ( t  2)h f ]  {[6.4  ( t  1)h f ]2  [6.4  ( t  2)h f ]2 } E f  [1.2  ( t  2)h f ]  [h f ] E f /  [1.2  ( t  2)h f ]  {9.92  (9.9  h f ) } E f  [1.2  ( t  2)h f ]  [h f ] E f /  [1.2  ( t  2)h f ]  {[9.9  ( t  1)h f ]2  [9.9  ( t  2)h f ]2 } E f  [1.2  ( t  2)h f ]  [h f ] E f /  [11.5  ( t /  1)h f ]  {122  (12  h f ) } E f  [11.5  ( t /  1)h f ]  [h f ] E f /  [11.5  ( t /  1)h f ]  {[12  ( t  1)h f ]2  [12  ( t  2)h f ]2 } E f  [11.5  ( t /  1)h f ]  [h f ] From   E  b  z *dz *  e(  E  b  dz * )  , function of e  e ( E , h f ,  t ) can be obtained. 269 Appendix Table II.2.2 Moment of inertia under hogging moment load condition Item No. A  y2 b  h3 /12 123 [1.4  ( t  2)h f ]  [2h f ]  {e  [0.7  ( t /  1)h f ]}2 1/12  [2h f ]  [1.4  ( t  2)h f ]3 456 1/  E  [1.4  ( t  2)h f ]  [ t h f ] {e  [0.7  ( t /  1)h f ]}2 1/(12 E )  [ t h f ]  [1.4  ( t  2)h f ]3 78 [10.6  ( t  2)h f ]  [2h f ]  {[6.7  ( t /  1)h f ]  e}2 1/12  [2h f ]  [10.6  ( t  2)h f ]3 [12  ( t  2)h f ]  [2h f ]  {[6  ( t /  1)h f ]  e}2 1/12  [2h f ]  [12  ( t  2)h f ]3 10 11 1/(4 E )  [ t h f ]  {e  [1.4  ( t  2)h f ]}3 1/(12 E )  [ t h f ]  {e  [1.4  ( t  2) h f ]}3 12 1/(4 E )  [ t h f ]  [e  ( t  2)h f ]3 1/(12 E )  [ t h f ]  [e  ( t  2)h f ]3 13 [11.5  ( t /  1)h f ]  [h f ]  (e  h f / 2) -- 14 [11.5  ( t /  1)h f ]  [h f ]  [e  ( t  / 2)h f ]2 -- 15 1/  E  [11.5  ( t /  1)h f ]  [ t h f ]  [e  ( t /  1) h f ]2 -- 16 [10.3  ( t /  1)h f ]  [h f ]  [e  (1.4  h f / 2)]2 -- 17 [10.3  ( t /  1)h f ]  [h f ]  {e  [1.4  ( t  / 2)h f ]}2 -- 18 1/  E  [10.3  ( t /  1)h f ]  [ t h f ]  {e  [1.4  ( t /  1)h f ]}2 -- 19 [1.2  ( t  2)h f ]  [h f ]  [e  (2.9  h f / 2)]2 -- 20 [1.2  ( t  2)h f ]  [h f ]  {e  [2.9  ( t  / 2)h f ]}2 -- 21 1/  E  [1.2  ( t  2)h f ]  [ t h f ] {e  [2.9  ( t /  1)h f ]}2 -- 22 [1.2  ( t  2)h f ]  [h f ]  [(6.4  h f / 2)  e]2 -- 23 [1.2  ( t  2)h f ]  [h f ]  {[6.4  ( t  / 2)h f ]  e}2 -- 24 [1.2  ( t  2)h f ]  [h f ]  [(9.9  h f / 2)  e]2 -- 25 [1.2  ( t  2)h f ]  [h f ]  {[9.9  ( t  / 2)h f ]  e}2 -- 270 Appendix 26 [11.5  ( t /  1)h f ]  [h f ]  [(12  h f / 2)  e]2 -- 27 [11.5  ( t /  1)h f ]  [h f ]  {[12  ( t  / 2)h f ]  e}2 -- 271 Appendix Appendix III: Mix proportioning design of FL trials Table III.1 Mix design of FL1 Components Effective water Cement LWCA (OD*) LWFA Grain density (kg/m3) 1000 3150 850 503 7800 1000 Mix mass (kg/m3) 175 500 315 127 78 55 Volume (liter) 175 159 371 252 10 55 967 Steel fiber Absorbed water Mix water Total Volume fraction of cement paste & LWA Steel fiber Absorbed water Mix water 230 Total 1250 0.33 : 0.62 Water / cement ratio 0.35 Air content 0.03 Mix volume (liter) and Mixer liter by Hobart mixer (* OD: oven dried state to remove all the moisture in the aggregates) Table III.2 Mix design of FL2 Components Effective water Cement LWCA (OD) LWFA 1000 3150 800 447 7800 1000 Mix mass (kg/m ) 147 420 300 150 78 54 Volume (liter) 147 133 375 336 10 54 Grain density (kg/m ) Volume fraction of cement paste & LWA 0.28 : 0.71 Water / cement ratio 0.35 Air content 0.00 Mix volume (liter) and Mixer liter by Hobart mixer 272 201 1149 1001 Appendix Table III.3 Mix design of FL3 Components Effective water Cement LWCA (OD) LWFA 1000 3150 850 447 7850 1000 Mix mass (kg/m ) 175 500 315 127 78.5 55 Volume (liter) 175 159 371 284 10 55 Grain density (kg/m ) Volume fraction of cement paste & LWA Water / cement ratio Steel fiber Absorbed water Mix water 230 Total 1250 999 0.33 : 0.65 0.35 (SP SP20 dosage based on all cementitious material: ml/kg added to fresh concrete) Air content 0.00 Mix volume (liter) and Mixer 20 liters by drum mixer Table III.4 Mix design of FL4 Components Effective water Cement LWCA (OD) LWFA Grain density (kg/m3) 1000 3150 850 447 7850 1000 Mix mass (kg/m3) 210 600 300 100 78.5 51 Volume (liter) 210 190 353 224 10 51 Volume fraction of cement paste & LWA Water / cement ratio Steel fiber Absorbed water Mix water 261 Total 1340 987 0.40 : 0.58 0.35 (SP SP20 dosage based on all cementitious material: 7.5 ml/kg added to fresh concrete) Air content 0.01 Mix volume (liter) and Mixer 20 liters by drum mixer 273 Appendix Table III.5 Mix design of FL5 Components Effective water Cement LWCA (OD) LWFA 1000 3150 850 447 7850 1000 Mix mass (kg/m ) 245 700 260 90 78.5 44 Volume (liter) 245 222 306 201 10 44 Grain density (kg/m ) Volume fraction of cement paste & LWA Steel fiber Absorbed water Mix water 289 Total 1418 985 0.47 : 0.51 0.35 (SP SP20 dosage based on all cementitious material: 6.43 ml/kg added to fresh concrete) Water / cement ratio Air content 0.02 Mix volume (liter) and Mixer 20 liters by drum mixer Table III.6 Mix design of FL6 Components Effective water Cement LWCA (OD) LWFA 1000 3150 850 447 7850 1000 Mix mass (kg/m ) 227.5 650 280 95 78.5 48 Volume (liter) 227.5 206 329 213 10 48 Grain density (kg/m ) Volume fraction of cement paste & LWA Water / cement ratio Steel fiber Absorbed water Mix water 275 Total 1379 986 0.43 : 0.54 0.35 (SP SP20 dosage based on all cementitious material: 7.31 ml/kg added to fresh concrete) Air content 0.01 Mix volume (liter) and Mixer 20 liters by drum mixer 274 Appendix Table III.7 Mix design of FL7 Components Effective water Cement LWCA (OD) LWFA 1000 3150 850 447 7850 1000 Mix mass (kg/m ) 202 808 119 167 78.5 28 Volume (liter) 202 257 140 373 10 28 Grain density (kg/m ) Volume fraction of cement paste & LWA Steel fiber Absorbed water Mix water 230 Total 1402 980 0.46 : 0.51 0.25 (SP ADVA® 108 dosage based on all cementitious material: 8.24 ml/kg added to fresh concrete) Water / cement ratio Air content 0.02 Mix volume (liter) and Mixer 20 liters by drum mixer Table III.8 Mix design of FL8 Components Effective water Cement LWCA (OD) LWFA 1000 3150 850 447 7850 1000 Mix mass (kg/m ) 170 850 125 175 78.5 29 Volume (liter) 170 270 147 392 10 29 Grain density (kg/m ) Volume fraction of cement paste & LWA Water / cement ratio Steel fiber Absorbed water Mix water 199 Total 1428 989 0.44 : 0.54 0.20 (SP ADVA® 108 dosage based on all cementitious material: 18.82 ml/kg added to fresh concrete) Air content 0.01 Mix volume (liter) and Mixer 20 liters by drum mixer 275 Appendix Table III.9 Mix design of FL9 Components Effective water Cement LWCA (OD) LWFA 1000 3150 850 447 7850 1000 Mix mass (kg/m ) 200 800 170 140 78.5 34 Volume (liter) 200 254 200 313 10 34 Grain density (kg/m ) Volume fraction of cement paste & LWA Steel fiber Absorbed water Mix water 234 Total 1422 977 0.45 : 0.51 0.25 (SP ADVA® 108 dosage based on all cementitious material: 8.13 ml/kg added to fresh concrete) Water / cement ratio Air content 0.02 Mix volume (liter) and Mixer 20 liters by drum mixer Table III.10 Mix design of FL10 Effective water Cement Silica Fume LWCA (OD) LWFA Steel fiber Absorbed water Grain density (kg/m3) 1000 3150 2200 850 447 7850 1000 Mix mass (kg/m3) 180.4 740 80 125 165 78.5 29 Volume (liter) 180.4 235 36 147 369 10 29 Components Volume fraction of cement paste & LWA Water / cement ratio Mix water Total 209 1398 978 0.45 : 0.52 0.22 (SP ADVA® 108 dosage based on all cementitious material: 15.12 ml/kg added to fresh concrete) Air content 0.02 Mix volume (liter) and Mixer 15 liters by Hobart mixer 276 Appendix Table III.11 Mix design of FL11 Effective water Cement Silica Fume LWCA (OD) LWFA Steel fiber Absorbed water Grain density (kg/m3) 1000 3150 2200 850 447 7850 1000 Mix mass (kg/m3) 170 770 80 120 150 78.5 27 Volume (liter) 170 244 36 141 336 10 27 Components Volume fraction of cement paste & LWA Mix water Total 197 1396 938 0.45 : 0.48 0.20 (SP ADVA® 108 dosage based on all cementitious material: 20.86 ml/kg added to fresh concrete) Water / cement ratio Air content 0.06 Mix volume (liter) and Mixer 15 liters by Hobart mixer Table III.12 Mix design of FL12 Effective water Cement Silica Fume LWCA (OD) LWFA Steel fiber Absorbed water Grain density (kg/m3) 1000 3150 2200 850 447 7850 1000 Mix mass (kg/m3) 180.4 740 80 200 110 78.5 37 Volume (liter) 180.4 235 36 235 246 10 37 Components Volume fraction of cement paste & LWA Water / cement ratio Mix water Total 217 1426 943 0.45 : 0.48 0.22 (SP ADVA® 108 dosage based on all cementitious material: 17.2 ml/kg added to fresh concrete) Air content 0.06 Mix volume (liter) and Mixer 50 liters by large yellow drum mixer 277 Appendix Table III.13 Mix design of FL13 Effective water Cement Silica Fume LWCA (OD) LWFA Steel fiber Absorbed water Grain density (kg/m3) 1000 3150 2200 850 447 7850 1000 Mix mass (kg/m3) 171.6 700 80 200 120 78.5 37 Volume (liter) 171.6 222 36 235 269 10 37 Components Volume fraction of cement paste & LWA Mix water Total 209 1387 944 0.43 : 0.50 0.22 (SP ADVA® 108 dosage based on all cementitious material: 16 ml/kg added in water) Water / cement ratio Air content 0.06 Mix volume (liter) and Mixer 50 liters by yellow pan mixer Table III.14 Mix design of FL14 Effective water Cement Silica Fume LWCA (OD) LWFA Steel fiber Absorbed water Grain density (kg/m3) 1000 3150 2200 850 447 7850 1000 Mix mass (kg/m3) 162 730 80 200 120 78.5 37 Volume (liter) 162 232 36 235 269 10 37 Components Volume fraction of cement paste & LWA Water / cement ratio Mix water Total 199 1408 944 0.43 : 0.50 0.20 (SP ADVA® 108 dosage based on all cementitious material: 10 ml/kg added in water and 2.6 ml/kg added to fresh concrete) Air content 0.06 Mix volume (liter) and Mixer 50 liters by yellow pan mixer 278 Appendix Table III.15 Mix design of FL15 (The finalized design of FL) Effective water Cement Silica Fume LWCA (OD) LWFA Steel fiber Absorbed water Grain density (kg/m3) 1000 3150 2200 850 447 7850 1000 Mix mass (kg/m3) 162 730 80 200 130 78.5 38 Volume (liter) 162 232 36 235 291 10 38 Components Volume fraction of cement paste & LWA Mix water Total 200 1418 966 0.43 : 0.53 0.20 (SP ADVA® 108 dosage based on all cementitious material: 10 ml/kg added in water and 1.87 ml/kg added to fresh concrete) Water / cement ratio Air content 0.03 Mix volume (liter) and Mixer 85 liters by yellow pan mixer Table III.16 Mix design of plain lightweight aggregate concrete (PL) corresponding to FL Effective water Cement Silica Fume LWCA (OD) LWFA Steel fiber Absorbed water Grain density (kg/m3) 1000 3150 2200 850 447 7850 1000 Mix mass (kg/m3) 164 738 80 202 131 38 Volume (liter) 164 234 36 237 294 38 Components Volume fraction of cement paste & LWA Water / cement ratio Mix water Total 202 1354 966 0.43 : 0.53 0.20 (SP ADVA® 108 dosage based on all cementitious material: ml/kg added in water and 3.96 ml/kg added to fresh concrete) Air content 0.03 Mix volume (liter) and Mixer 85 liters by yellow pan mixer 279 Appendix Table III.17 Standard casting procedure for FL Step Timing (minutes) Procedure Cement + silica fume + LWFA of smaller sizes premix for about minutes Timing start Add in water (premixed with SP* of dosage 10 ml/kg cementitious materials) 1.5~2nd Add in 1st half SF** when paste mix well 3rd Add in all LWFA of 2~4 mm size th 4~5 Check mixer blade, move out bundled SF 6~7th Add in 2nd half SF + 1st half LWCA 8th Check mixer blade, move out bundled SF 9~10th Add in 2nd half LWCA 11th Check mixer blade, move out bundled SF th 10 11~12 Add in extra SP to fresh concrete 11 13th Check mixer blade, move out bundled SF 12 14~15th Casting (* SP is superplasticizer ADVA® 108; dosage is based on all cementitious material: 10ml/kg added in water and 1.87ml/kg added to fresh concrete. ** SF stands for steel fiber) (To prevent and minimize crushing of LWCA and LWFA of 2~4 mm size, they are added after cement paste are mixed well and steel fibers are added in. Total mixing time should not be longer than 15 minutes) 280 Publication list PUBLICATION LIST Conference paper X. X. Dai and J. Y. Richard Liew, Steel-Concrete-Steel Sandwich System for Ship Hull Construction, International Colloquium on Stability and Ductility of Steel Structures, pp. 877-884, Lisbon, Portugal, September 6-8, 2006. X. X. Dai and J. Y. Richard Liew , A Novel Concept to Enhance Fatigue Performance of Steel-Concrete-Steel Sandwich Panel, International Colloquium on Stability and Ductility of Steel Structures, pp. 885-891, Lisbon, Portugal, September 6-8, 2006. X. X. Dai, Sohel K.M.A., K. S. Chia, J. Y. Richard Liew, Investigation of FiberReinforced Lightweight Aggregate Concrete for Steel-Concrete-Steel Sandwich Structures, 5th International Conference on Advances in Steel Structures, pp. 885-891, Singapore, – December 2007. X. X. Dai and J. Y. Richard Liew, Improving the Strength of Steel-Concrete-Steel Sandwich by Increased Interface Roughness, The 21st KKCNN Symposium on Civil Engineering, pp. 129-132, October 27–28, 2008, Singapore. Journal paper X. X. Dai and J. Y. Richard Liew, Fatigue Performance of Fiber-Reinforced Lightweight Aggregate Concrete, Singapore Maritime and Port Journal (SMPJ) 2007. X. X. Dai and J. Y. Richard Liew, Fatigue Performance of Lightweight Steel-ConcreteSteel Sandwich with Hooked Connectors, Journal of Constructional Steel Research, under review. Strength Improvement of Steel-Concrete-Steel Sandwich by Textured Interface, to be submitted. 281 [...]... elastic modulus ratio between steel and concrete An inherent characteristic of this model is that the plates are connected to the concrete only at the nodal points This means that there is no bond between steel and concrete 1.1.3 Fatigue on Steel- Concrete Composite Structures Research on fatigue of steel- concrete composite structures mainly comes from composite bridges or composites-strengthened bridges... form of Steel- ConcreteSteel (SCS) sandwich construction which will be discussed in details in the following section 1.1.2 Steel- Concrete -Steel (SCS) Sandwich Construction The early form of Steel- Concrete -Steel (SCS) sandwich construction was originally proposed as an alternative form of construction for immersed tube tunnels (see Figure 1.3 a) as a result of collaboration between the University of Wales... cross section of interface b Width of sandwich component B Width of the steel plate or sandwich beam Bt Width at which τ is calculated C, k, g, h Constants in equation derivation or fatigue design equation Cb Block coefficient d Diameter of the connector or hole on a sandwich component D Flexural rigidity of sandwich panel E Elastic modulus of materials Ef Elastic modulus of face plate in sandwich panel... III.9 Mix design of FL9 .277 Table III.10 Mix design of FL10 277 Table III.11 Mix design of FL11 278 Table III.12 Mix design of FL12 278 Table III.13 Mix design of FL13 279 Table III.14 Mix design of FL14 279 Table III.15 Mix design of FL15 (The finalized design of FL) 280 Table III.16 Mix design of plain lightweight aggregate concrete. .. and dynamic loads such as strong wind Inspired by nature, man creates sandwich composite structures as shown in Figure 1.1 This type of sandwich composite consists of two steel face plates separated and supported by folded steel web plates welded to them This provides a composite structure that is much stiffer than the sum of stiffness of individual components The infill foam can prevent buckling of. .. Moment of inertia under hogging moment load condition 271 Table III.1 Mix design of FL1 .273 Table III.2 Mix design of FL2 .273 Table III.3 Mix design of FL3 .274 Table III.4 Mix design of FL4 .274 Table III.5 Mix design of FL5 .275 Table III.6 Mix design of FL6 .275 Table III.7 Mix design of FL7 .276 Table III.8 Mix design of FL8... elements can make steel plates and concrete core work together by overlapping connectors, but its composite interaction is not so strong since there is only connection between concrete and steel plates linked by connectors and no direct connection between the steel face plates To increase the strength and composite action between steel face plates and concrete core in SCS sandwich, a new type of connector... neutral axis of a cross section; The position of the neutral axis, measured from the underneath of the compression steel plate E The ratio of elastic modulus between steel and concrete, i.e E s / E c xx List of Symbols t Thickness ratio between core material and face plate in sandwich panel, i.e h c /h f d Density ratio between core material and face plate in sandwich panel α Degree of composite δ... core material in sandwich panel hf Thickness of face plate in sandwich panel Kt Stress concentration factor K tg Gross concentration factor K tn Net concentration factor In Toughness related parameters l Length of sandwich component or sandwich beam Nf Fatigue life, i.e the number of cycles to failure m , K Constants determined by regression analysis of fatigue test data M Moment capacity of cross section... location of the curve -9- Chapter 1 Introduction Some research on fatigue performance of stud connectors in composite structures adopts similar relationship as abovementioned equations, only replacing Sr by shear stress range in connectors, ∆τ These include report both on conventional steel- concrete composite structures (Lee et al, 2005; Ahn et al, 2007) and steel- concrete- concrete (SCS) sandwich composites . FATIGUE ANALYSIS AND DESIGN OF STEEL- CONCRETE -STEEL SANDWICH COMPOSITE STRUCTURES DAI XUEXIN NATIONAL UNIVERSITY OF SINGAPORE. NATIONAL UNIVERSITY OF SINGAPORE 2009 FATIGUE ANALYSIS AND DESIGN OF STEEL- CONCRETE -STEEL SANDWICH COMPOSITE STRUCTURES DAI XUEXIN . Mix design of FL1 273 Table III.2 Mix design of FL2 273 Table III.3 Mix design of FL3 274 Table III.4 Mix design of FL4 274 Table III.5 Mix design of FL5 275 Table III.6 Mix design of FL6