INFLUENCE OF USING NON-STANDARD SPECIMEN ON COMPRESSIVE STRENGTH OF NORMAL AND HIGH STRENGTH CONCRETE EXPERIMENTAL AND SIMULATION.

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1 INFLUENCE OF USING NON-STANDARD SPECIMEN ON COMPRESSIVE STRENGTH OF NORMAL AND HIGH STRENGTH CONCRETE EXPERIMENTAL AND SIMULATION Thesis Submitted to the Post Graduate of Civil Engineering Program in Partial Fulfillment of the Requirements for the Degree of Master of Engineering in Material and Structural Engineering Name: Abdulati Mohamed Esbata S POST GRADUATE CIVIL ENGINEERING PROGRAMS SEBELAS MARET UNIVERSITY 2014 I

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4 STATEMENT OF ORIGINALITY This is to certify that I have write this thesis by myself - standard Specimen on Compressive Strength of Normal and High Strength Concrete sources of which are listed on the list of references. If then the pronouncement proves wrong, I am ready to accept any academic punishment, including the withdrawal or cancellation of my academic degree. Surakarta, 2014 ABDULATI MOHAMED ESBATA NIM. S IV

5 ACKNOWLEDGMENT I would like to express my greatest appreciation to my supervisors, Prof. SA. Kristiawan, M.Sc.Ph.D and Dr. Techn. Ir., MT for their guidance and precious supervision during this research. I would like also to express my grateful thanks to Dr. Kusno Adi Sambow,ST,PhD who was my first supervisor for guidance me in the proposal of this thesis. Also I would like to express my greatest appreciation to department of civil engineering staff in Seblas Maret University. My deep appreciations and my great thanks to my dear family; mother, father, wife, brothers and sisters, whom supported me in my study. Finally, I would like to express my thanks to everyone who has helped me during my master study. Surakarta, 2014 ABDULATI MOHAMED ESBATA NIM. S V

6 ABSTRAK Kuat tekan beton adalah salah satu tes yang paling penting untuk properti konstruksi untuk pengendalian kualitas beton dan desain konstruksi baru, ada cetakan yang berbeda yang digunakan untuk pengecoran beton spesimen selama beton bekerja sesuai dengan berbagai standar di negara yang berbeda. Di sisi lain, diketahui bahwa bentuk dan ukuran spesimen beton yang berbeda dapat menyebabkan perbedaan hasil kuat tekan. Dalam penelitian ini pengaruh ukuran spesimen dan bentuk pada kuat tekan beton mutu normal dan tinggi diteliti menggunakan studi eksperimental dan simulasi. Penelitian eksperimental dilakukan untuk enam jenis spesimen yang berbeda berbentuk kubus kubus dengan sisi 150 mm, 100 mm dan 75 mm, pada silinder dengan ukuran 150x300 mm, 100x200 mm, 75x150 mm. Pada enam tingkat kekuatan beton yang berbeda adalah 20,30,40,50,60 dan 70 MPa sesuai dengan spesimen kubus standar dan diuji di hari ke 28. Untuk studi eksperimental, kepadatan mengeras, tes non-destruktif (Rebound hammer dan UPV), kuat tekan dan kuat tarik belah untuk tingkat kekuatan beton yang berbeda dilakukan dan beberapa analisis yang dilakukan untuk mendapatkan faktor konversi dan beberapa hubungan antara tes tersebut. Studi simulasi dilakukan dengan menggunakan software ANSYS untuk dua ukuran specimen kubus yang berbeda dengan ukuran 150 mm dan 75 mm. Pada perbedaan tingkat kekuatan dua beton yang berbeda adalah 20 MPa pada kuat tekan yang normal dan 70 MPa pada kuat tekan yang tinggi. Analisis ini dilakukan untuk mengetahui pengaruh ukuran dan bentuk pada tes kuat tekan beton mutu normal dan tinggi. Hasil analisis menunjukkan bahwa untuk semua pengujian, ada pengaruh yang lebih besar dari variasi ukuran dan bentuk spesimen, dengan mengubah tingkat kuat tekan. Kuat tekan meningkat ketika ukuran spesimen menurun. Juga Kuat tekan kubus 150 mm umumnya lebih tinggi dari kekuatan silinder dengan ukuran 150x300 mm dan faktor konversi kuat tekan bervariasi antara 0,76-0,88 pada perancangan kubus dengan kuat tekan 20 sampai 70 MPa. Faktor konversi kuat tekan antara standar dan non-standar spesimen dengan kekuatan beton yang berbeda pada 28 hari yang setara 150 mm spesimen kubus standar telah ditentukan dan disajikan dalam tabel 4.7.Korelasi antara (split tensile test / Schmidt hammer test / UPV test) specimen kubus standar 150x150 mm dan kuat tekan spesimen non-standar yang telah ditentukan dan disajikan dalam tabel 4.8 dan 4.9.Pengaruh ukuran dan bentuk pada tes kuat tekan beton mutu normal dan tinggi telah dianalisa dengan menggunakan software ANSYS. Hal ini menyebabkan penurunan seiring meningkatnya kuat tekan. Kata kunci: tingkat kuat tekan, pengaruh ukuran dan bentuk spesimen, faktor konversi, kuat tarik belah, uji Schmidt hammer, UPV. VI

7 ABSTRACT Compressive strength of concrete is one of the most important test for construction properties for quality control of concrete and design new constructions, there are different molds that are used for casting concrete specimen during the concrete works according to various standards at different countries. On the other hand, it is known that different shapes and sizes of concrete specimen can cause differences in the results of compressive strength. In this research the influence of specimen sizes and shapes on compressive strength of normal and high strength concrete are investigated using experimental and simulation study. The experimental study was conducted for six different specimen types cube 150 mm, cube 100 mm, cube 75 mm, cylinder Ø150x300 mm, Ø100x200 mm, Ø75x150 mm. At six different concrete strength level was 20,30,40,50,60 and 70 MPa according to standard cube specimen and tested at 28 Days of age. For The experimental study, hardened density, non-destructive tests (Rebound hammer and UPV), compressive strength and splitting tensile strength for different concrete strength level were performed and some analyses were done to obtain conversion factors and some relations between these tests. The simulation study was conducted by using ANSYS software for two different specimen size cube 150 mm, cube 75 mm, At two different concrete strength level was for normal compressive strength 20 MPa and for high compressive strength 70 MPa. The analyses were done to know the influence of size and shape on the compressive strength tests of normal and high strength concrete. The results of analyses indicate that for all testing, there is a bigger influence of variation of size and shape of the specimens, by changing the compressive strength level. The compressive strength increases as the specimen size decreases.. Also The compressive strength of cube 150 mm is generally higher than strength cylinder Ø150x300 mm and The conversion factors of compressive strength between is varied from 0.76 to 0.88 for the designed cube compressive strength of 20 to 70 MPa. The conversion factors of compressive strength between standard and non-standard specimen at different concrete strength at 28 days to equivalent 150 mm standard cube specimen had been determined and presented in table 4.7. The correlation between (split tensile test / Schmidt hammer test/upv test) of standard specimen 150 x 150 mm cube to compressive strength of non-standard specimen had been determined and presented in the tables 4.8 and 4.9. The effect of size and shape on the compressive strength tests of normal and high strength concrete had been analysis by using ANSYS software. This affected decrease as compressive strength increase. Keywords: compressive strength level, influence of specimen sizes and shapes, conversion factors, splitting tensile strength, Schmidt hammer test, UPV. VII

8 TABLE OF CONTENTS COVER SHEET OF APPROVAL SHEET OF APPROVAL EXAMINATION STATEMENT OF ORIGINALITY ACKNOWLEDGMENT ABSTRAK ABSTRACT TABLE OF CONTENTS LIST OF FIGURES LIST OF TABLES LIST OF SYMBOLS AND ABBREVIATIONS LIST OF APPENDIX I II III IV V VI VII VIII VIII VIII VIII VIII VIII

9 Chapter I. Introduction Background Problem formulation Objectives Scope and limitation Experimental study Simulation study Contribution of research 4 Chapter II. Literature Review and Basic Theory 2.1. Literature Review Specimen shape and size in different standards Effects of Specimen Size and Shape Effects of Capping Hardened concrete tests Basic Theory Specimen shape and size in different standards Effects of Specimen Size and Shape Effects of Capping: Hardened concrete tests The difference between this research and previous researches Hypothesis of the research 35 Chapter III. Research Methodology 3.1. Location of Research Sample Population Data Collection Material 38 IX

10 Casting concrete Compacting and curing Tests on fresh concrete: Tests on hardened concrete Test of data: validation and clarification Variability associated with compressive strength test Effects of Cylinder End Condition on Within-Test Variation Data Analysis Experimental analysis Simulation analysis Flow chart of research 48 Chapter IV. Result and Discussions 4.1 Experimental Result Introduction Tests on fresh concrete Experiments on hardened concrete (non-destructive tests) Experiments on hardened concrete (destructive test) Validity of Correlation between Compressive Strength and Nondestructive Tests of UPV and Schmidt hammer for Non-standard specimen Simulation Works Introduction Modeling Meshing Simulation result and discussion Comparison between Simulation Result and Experimental Result 79 Chapter V 5.1 Conclusions of the Research 80 Reference 82 X

11 LIST OF FIGURES Figure 2.1: Wall effect (Neville, 2002) 15 Figure 2.2: Loading of the specimen in splitting tensile test. 22 Figure 2.3: Correlation Curves Obtained by Different Investigators with a Schmidt Rebound Hammer 24 Figure 2.4: Methods of propagation and receiving ultrasonic pulses (BS , 2004). 25 Figure 2.5: Relationships between UPV and Es (Yildirim & Sengul, 2011) 29 Figure 2.6: Relationships between Static and Dynamic Modulus of Elasticity (Yildirim & Sengul, 2011). 29 Figure 2.7: Relationships between UPV and Es, Ed and G (Trtnik, 2008) 30 Figure Figure 3.1: Slump test 39 Figure 3.2: Compressive strength testing machine 40 Figure 3.3: Cylinder specimens under splitting tension 41 Figure 3.4: Rebound hammer test 41 Figure 3.5: Pulse velocity instrument (V. Malhotra, N. Carino, 2004). 43 Figure 3.6: Between-lab and within-lab variability from (Kennedy et al., 1995) 45 Figure 3.7: Flow chart of the research 48 Figure 4.1: Compressive strength versus PUNDIT (the lines are trend line connecting different strength levels for 150 mm cube specimen) 51 Figure 4.2: Cubic specimens' compressive strength vs. rebound number 53 Figure 4.3: Cubical specimens' compressive strength vs. splitting tensile strength. 54 Figure 4.4: Cylindrical specimens' compressive strength vs. splitting tensile strength 55 Figure 4.5: All specimens' compressive strength 56 Figure 4.6: Relationship between standard cube specimens (Actual compressive strength) to non-standard cube specimen (Nominal compressive strength) 57 XI

12 Figure 4.7: Compressive strength of cubic specimens for different mix design. 57 Figure 4.8: Relationships between standard cube specimens (Actual compressive strength) to cylinder specimen (Nominal compressive strength) 58 Figure 4.9: Compressive strength of cylinder specimens for different mix design. 58 Figure 4.10: Conversion factor between standard specimens (cube 150 mm) to nonstandard cube specimen. 60 Figure 4.11: Conversion factor between standard specimens (cube 150 mm) to cylindrical specimen. 61 Figurers 4.12: The coarse mish by ANSYS software 67 Figurers 4.13: The fine mish by ANSYS software 67 Figure 4.14: Horizontal displacements in the elements of the surface loading of concrete specimen equal to zero 68 Figure 4.15: Principle stress of cube 75 mm 69 Figure 4.16: Principle stress of cube 150 mm 70 Figure 4.17: Horizontal displacements in the elements of the surface loading of concrete specimen not equal to zero. 70 Figure 4.18: Principle stress of cube 75 mm 71 Figure 4.19: Principle stress of cube 150 mm 72 Figure 4.20: Horizontal displacements in the elements of the surface loading of concrete specimen equal to zero. 73 Figure 4.21: Principle stress of cube 75 mm 74 Figure 4.22: Principle stress of cube 150 mm 74 Figure 4.23: Horizontal displacements in the elements of the surface loading of concrete specimen not equal to zero. 75 Figure 4.24: Principle stress of cube 75 mm 76 Figure 4.25: Principle stress of cube 150 mm 77 XII

13 LIST OF TABLES Table 2.1: Correction factors to convert concrete strength to equivalent 150 mm standard cube strength (Mansur and Islam, 2002). 15 Table 2.2: Correction factors to convert concrete strength to equivalent Ø 150 x 300 mm standard cylinder strength (Mansur and Islam, 2002). 16 Table 2.3: Transition coefficients of different specimens to standard specimens 17 Table 2.4: Conversion factors with sizes and shapes of the specimen for normal strength concrete (Yi et al., 2006). 18 Table 2.5: Conversion factors with sizes and shapes of the specimen for high-strength concrete (Yi et al., 2006). 19 Table 2.6: Relationships between concrete compressive strength and ultrasonic pulse velocity (Trtnik et al., 2009) 32 Table 3.1: Sample population for one concrete class 37 Table 3.2: Sample population for six concrete classes 37 Table 3.3: Concrete Mix Design 38 Table 4.1: Slump test results 49 Table 4.2: Hardened density test results 50 Table 4.3: Summary of PUNDIT results for 150 mm cubes 51 Table 4.4: Summary of rebound hammer results for standard cubic specimen 150 mm 52 Table 4.5: Summary result of splitting tensile strength. 54 Table 4.6: Compressive strength test results for cubic and cylindrical specimens 56 Table 4.7: Conversion Factors to Convert Concrete Strength to Equivalent 150 mm Standard Cube Specimen. 60 Table 4.8: Validity of correlation between compressive strength and UPV test. 63 Table 4.9: Validity of correlation between compressive strength and schmidt hammer test. 64 Table 4.10: Properties of concrete material were defined in ANSYS software 66 Table 4.11: Result of principle stress of cube 75 mm 68 XIII

14 Table 4.12: Result of principle stress of cube 150 mm 69 Table 4.13: Result of principle stress of cube 75 mm 71 Table 4.14 Result of principle stress of cube 150 mm 71 Table 4.15: Result of principle stress of cube 75 mm 73 Table 4.16: Result of principle stress of cube 150 mm 74 Table 4.17: Result of principle stress of cube 75 mm 75 Table 4.18: Result of principle stress of cube 150 mm 76 Table 4.19: Result of maximum principle stress of cube 75 mm and 150 mm 78 XIV

15 LIST OF SYMBOLS AND ABBREVIATIONS ACI = American Concrete Institute ASTM = American Society of Testing and Materials BS = British Standard CF = Conversion factor for effect of specimen type mm = milimeter f'c = Compressive strength of concrete (N/mm 2 ) fcy = Compressive strength of concrete cylinder (N/mm 2 ) f cu = Compressive strength of concrete cube (N/mm 2 ) HSC = High-strength concrete NSC = Normal-strength concrete kg = Kilogram l = Length or height of specimen l/d = Aspect ratio mm = Millimeter MPa = Mega Pascal or Newton per square millimeter n = Number of samples N = Newton XV

16 LIST OF APPENDIX Appendices A AP A-1 Appendices B AP B-1 Appendices C AP C-1 Appendices D AP D-1 XVI