Behavior of circular steel tube confined uhpc and uhpfrc columns under axial compression

BEHAVIOR OF CIRCULAR STEEL TUBE CONFINED UHPC AND UHPFRC COLUMNS UNDER AXIAL COMPRESSION zur Erlangung des akademischen Grades Doktor-Ingenieur (Dr.-Ing.) an der Fakultät Bauingenieurwesen der Universität Kassel vorgelegt von An Le Hoang geboren am 10 Januar 1983 in Thua Thien Hue, Vietnam Erster Gutachter: Prof Dr.-Ing Ekkehard Fehling (Universität Kassel) Zweiter Gutachter: Prof Dr.-Ing habil Nguyen Viet Tue (TU Graz) Tag der mündlichen Prüfung: Februar 2018 Kassel, 2018 Vorwort der Herausgeber Konstruktionen aus Ultrahochfestem Beton ermöglichen erhebliche Einsparungen beim Konstruktionsgewicht und damit grưßere Spannweiten, hưhere Gebäude und filigranes Bauen mit Beton Durch Verwendung von Faserbewehrung wird ultrahochfester Beton duktil, besonders in Hinsicht auf Zugbelastung Für Druckbelastung kann jedoch auch durch Umschnürung duktiles Verhalten erzielt werden Für eine Stütze bietet sich insofern besonders die Umschnürung durch ein Stahlrohr an Während für Verbund-Rohrstützen mit normalfestem und hochfestem Beton hierzu viele Forschungsergebnisse vorliegen und nationale und internationale Normen die praktische Anwendung erleichtern, fehlt dies für ultrahochfesten Beton weitgehend In seiner Dissertation untersucht Herr Le Hoang An daher das Tragverhalten von Verbundstützen aus Stahlrohren mit ultrahochfestem hochfestem Beton (Concrete Filled Steel Tubes CFSTs) Er konzentriert sich dabei auf den Fall der Lasteinleitung auf den Betonquerschnitt (Steel Tube Confined Concrete CSTC) Dabei wird sowohl der Fall der Füllung mit Ulltrahochleistungsbeton ohne Fasern (Ultra High Performance Concrete UHPC) als auch mit Ultrahochleistungsbeton mit Fasern (UHPFRC) experimentell, analytisch und numerisch untersucht Die eigenen experimentellen Untersuchungen umfassen 18 kurze und mittellange Verbundstützen mit zentrischer axialer Belastung Die Ergebnisse zeigen, dass sich insbesondere durch eine steife Umschnürung mithilfe eines ausreichend dicken Stahlrohrs die besten Ergebnisse erzielen lassen Das Last-Verformungsverhalten zeigt damit eine ausgeprägte Resttragfähigkeit im Nachbruchbereich Der Autor entwickelt einen baupraktischen Näherungsansatz, der seine Versuchsergebnisse wie auch die experimentellen Ergebnisse anderer Forscher in guter Übereinstimmung abbilden kann Die numerische Modellierung mithilfe der Finite-Elemente-Software ATENA wird dargestellt und mit den Versuchsergebnissen verglichen Dabei zeigt sich der Einfluss des Reibungsbeiwerts zwischen Beton und Stahlzylinder sehr deutlich Das numerische Modell ist in der Lage, die Traglasten sowie das Verhalten im Nachbruchbereich sehr gut abzubilden Weiterer Forschungsbedarf wird vor allem in Hinblick auf exzentrische Belastung sowie auf längere Stützen gesehen Kassel, im Februar 2018 Die Herausgeber i Preface of the Editors Structures made of ultra-high-strength concrete enable considerable savings in the design weight and thus larger spans, higher buildings as well as filigree construction with concrete By using fiber reinforcement, ultra high strength concrete becomes ductile, especially in terms of tensile load However, ductile behavior in compression can also be achieved by confinement For confinement, in particular a steel tube can be utilized, thus leading to a composite steel concrete column While many research results are available for tubular composite columns with normal-strength and high-strength concrete and since national and international standards facilitate practical application, such support is largely absent for ultra-high-strength concrete In his dissertation, Mr Le Hoang An examines the load-bearing behavior of steel tube composite columns with ultra high-strength concrete (Concrete Filled Steel Tubes CFSTs) He focuses on the case of load transfer to the concrete section only (Steel Tube Confined Concrete CSTC) Both the case of filling with ultra high performance concrete (UHPC) and ultra-high performance concrete with fibers (UHPFRC) are investigated experimentally, analytically and numerically The own experimental investigations comprise 18 short and medium length composite columns with centric axial loading The results show that the best results can be achieved, in particular, by confining the concrete core by a sufficiently thick steel tube The load-deformation behavior thus shows a pronounced residual capacity in the post-peak range The author develops an engineering approximation approach that can map his experimental results as well as the experimental results of other researchers in good agreement The numerical modeling using the finite element software ATENA is presented and compared with the test results The influence of the coefficient of friction between concrete and steel cylinder is very clear The numerical model is able to map the load capacities as well as the behavior in the post-peak range very well Further research is needed, especially with regard to eccentric load and longer supports Kassel, February 2018 The Editors ii Vorwort des Verfassers Die Forschungsarbeiten dieser Dissertation wurden am Institut für Konstruktiven Ingenieurbau am Fachbereich Bauingenieur- und Umweltingenieurwesen der Universität Kassel durchgeführt Ich danke dem Ministerium für Bildung und Ausbildung Vietnams, dem Institut für Bautechnik der Universität Kassel (IKI, Fakultät für Bau- und Umweltingenieurwesen) und dem Deutschen Akademischen Austauschdienst (DAAD) für finanzielle Unterstützung Mein aufrichtiger Dank gilt dem Institut für Konstruktiven Ingenieurbau des Fachbereichs Bauingenieur- und Umweltingenieurwesen für die Bereitstellung der notwendigen Einrichtungen für meine Experimente Ich möchte meinem Betreuer, Prof Dr.-Ing Ekkehard Fehling, für seine engagierte Betreuung, unschätzbare wissenschaftliche Begleitung und die großzügige Unterstützung während meiner Doktorarbeit danken Ich danke speziell Prof Dr.-Ing habil Nguyen Viet Tue von der TU Graz für seine aufschlussreiche Anleitung und umfangreiche Unterstützung Weiterhin möchte ich mich bei Prof Dr rer nat Bernhard Middendorf und Prof Dr.-Ing Anton Matzenmiller für die Teilnahme an der Promotionskommission bedanken Mein Dank gilt auch allen akademischen und administrativen Mitarbeitern des Instituts für Bautechnik der Universität Kassel Besonderer Dank geht an Dr.-Ing Jenny Thiemicke, MSc Paul Lorenz, Frau Ute Müller, Dr.-Ing Mohammed Ismail, MSc Yuliarti Kusumawardaningsih, MSc Attitou Abu Bakr, Dipl.-Ing Thomas Pfetzing, MSc Yahia Al-Ani für ihre kontinuierliche Unterstützung während des Testens und ihre nützlichen Ratschläge und Diskussionszeit Ich bedanke mich bei allen Mitarbeitern des Labors für Konstruktiven Ingenieurbau und der AMPA, insbesondere Klaus Trost und Dipl.-Ing Beniamino Faion, Dr.-Ing Thomas Hahn für seine unermüdliche Hilfe bei der Probenvorbereitung und Prüfung; und allgemein den Herren Dr.-Ing Wolfgang Rưmer, Burkhard Deiß, Frau Anna-Katharina Reim, Herrn Timo Bauch, Herrn Dominik Hübenthal für ihre Hilfe und ihre freundliche Unterstützung beim Herstellen der Probekörper und Durchführung von Referenztests Darüber hinaus möchte ich allen meinen Kollegen und Freunden in Vietnam und Deutschland für ihre kontinuierliche Ermutigung danken Last but not least, möchte ich meine Liebe zu meiner Familie übermitteln, meinen Eltern Lê Văn Minh und Hoàng Thị Tuệ Thi; sowie an meine beiden jüngeren Brüder, Le Hoàng Ân, Le Hoàng Nhût; meinen Sohn, Le Hoàng Bảo Lâm; meinen Neffen, Lê Hoàng Minh Đức, in der Stadt Pleiku, Provinz Gia Lai, Vietnam, und Ihnen für ihre fortwährende Geduld und Unterstützung während meiner Zeit im Ausland, und für ihre Anwesenheit bei mir in guten und schlechten Zeiten danken Ich mưchte meine Doktorarbeit auch meinem Grvater Hồng Như Hàn widmen, der mehr als jeder andere mein Leben beeinflusst hat Kassel, Februar 2018 Lê Hoàng An iii Preface of the Author The research work reported in this dissertation has been carried out at the Faculty of Civil Engineering, Institute of Structural Engineering, University of Kassel, Germany I would like to express thanks to Ministry of Education and Training of Vietnam, Institute of Structural Engineering of University of Kassel (IKI, Faculty of Civil and Environmental Engineering), and German Academic Exchange Service (DAAD) for financial support My sincere appreciation is dedicated to the Institute of Structural Engineering of University of Kassel (IKI, Faculty of Civil and Environmental Engineering) for providing necessary facilities for my experiments I would like to express my deepest gratitude to my major supervisor, Prof Dr.-Ing Ekkehard Fehling, for his dedicated supervision, invaluable academic guidance and generous support throughout my PhD study I would specially thank Prof Dr.-Ing habil Nguyen Viet Tue from TU Graz, for his enlightening guidance and extensive support Furthermore, I would like to thank Prof Dr rer nat Bernhard Middendorf and Prof Dr.-Ing Anton Matzenmiller for being part of the defence commission My thanks also extend to all academic and administrative staff members of Institute of Structural Engineering - University of Kassel Special thanks go to Dr.-Ing Jenny Thiemicke, MSc Paul Lorenz, Mrs Ute Müller, Dr.-Ing Mohammed Ismail, MSc Yuliarti Kusumawardaningsih, MSc Attitou Abu Bakr, Dipl.-Ing Thomas Pfetzing, MSc Yahia Al-Ani for their continuous supports during testing and their useful advices, and discussion time as well I gratefully acknowledge the kindly assistance from all the staff members of the Structural Engineering Laboratory and AMPA, in particular Mr Klaus Trost and Dipl.-Ing Beniamino Faion, Dr.Ing Thomas Hahn for their tireless assistance during preparation of test specimens and testing; and generally to Dr.-Ing Wolfgang Rưmer, Burkhard Deiß, Mrs Anna-Katharina Reim, Mr Timo Bauch, Mr Dominik Hübenthal for their help and their kind support in casting specimens and conducting reference tests Still further, I would like to thank all my colleagues and friends in Vietnam and Germany as well for their continuous encouragement Last but not least, I would like to convey my love to my family, my parents Lê Văn Minh and Hoàng Thị Tuệ Thi; my two younger brothers, Lê Hoàng Ân, Lê Hoàng Nhật; my son, Lê Hoàng Bảo Lâm; my nephew, Lê Hoàng Minh Đức, in Pleiku City, Gia Lai province, Vietnam, for their continuous patience and support when I am abroad, and for their standing by me and cheering me up through the good and bad times I would like as well to dedicate my dissertation to my grandfather, Hoàng Như Hàn, who impacted my life more than anybody else Kassel, February 2018 Lê Hoàng An iv Kurzfassung Es ist bekannt, dass mit Beton gefüllte Stahlrohrstützen (CFSTCs) im Bereich des Bauingenieurwesens viel Aufmerksamkeit auf sich gezogen und breite Anwendungen gefunden haben Mit der rasanten Entwicklung der Betontechnologie hat sich ultrahochfester Beton (UHPC) aufgrund seiner überlegenen Leistungen, wie der extrem hohen Druckfestigkeit bis zu 200 MPa, nutzbare Zugfestigkeit und sehr hohe Haltbarkeitseigenschaften, zu einer potenziellen Alternative zu normalfestem Beton (NSC) und hochfestem Beton (HSC) entwickelt, so dass Ingenieure die Grưße von Bauteilen reduzieren und die Tragfähigkeit erhöhen und neuartige Strukturelemente entwickeln können UHPC weist jedoch eine enorme Drucksprödigkeit auf, die mit der Zunahme der Betonfestigkeit einhergeht, was zu einigen Einschränkungen für seine Anwendungen in der Konstruktion führt Um diesen Nachteil zu überwinden, wurden Forschungsbemühungen auf CFSTCs mit der Verwendung von UHPC gerichtet Das Einschließen von UHPC mit kreisförmigen Stahlrohren erweist sich als eine attraktive Option aufgrund der effizienten Kombination von zwei Materialien, um ein Hochleistungselement zu bilden, das von einer signifikanten Zunahme sowohl der Festigkeit als auch der Duktilität im Vergleich zu unbeschränkten UHPC-Elementen profitiert Über umfangreiche Forschungen über das Verhalten von CFST-Stützen, die NSC oder HSC unter konzentrischer axialer Stauchung verwenden, wurde in der Literatur berichtet Daten zum Verhalten von UHPC-gefüllten Stahlrohrstützen (UHPC-FSTCs) fehlen jedoch noch Darüber hinaus sind bestehende Nachweisnormen für CFSTCs nicht auf UHPC anwendbar Vor diesem Hintergrund zielt diese Dissertation darauf ab, eine kombinierte experimentelle und theoretische Studie über das Verhalten von kreisförmigen UHPC-FSTCs-Stützen unter konzentrischer axialer Belastung nur auf dem Betonkern durchzuführen Dieses Belastungsmuster bezieht sich auf die Form von STCC-Stützen (Steel Tube Confined Concrete), die im Vergleich zu dem Fall einer Belastung des gesamten Abschnitts eine bessere Zunahme sowohl der Duktilität als auch der Festigkeit aufweisen Diese Dissertation berichtete in der ersten Linie über eine Bewertung des axialen Stauchungsverhaltens von runden STCC-Stützen auf der Grundlage der bisherigen Versuchsergebnisse und eines entwickelten Finite-Elemente-Modells (FEM) in der ATENA3D-Programm für diese Stützen mit unterschiedlichen Betonstärken Dies ist der Ausgangspunkt für die Hauptversuchungen, die in dieser Dissertation vorgestellt wurden Dann wurde das konstitutive Verhalten von UHPC ohne Faser und mit Stahlfasern (UHPFRC) durch Druckversuche an zylindrischen Proben und direkte Zugversuche an gekerbten Prismen untersucht, wodurch der Einfluss von Stahlfasergehalt und Aspektverhältnis auf die einaxialen Druck- und Zugbeanspruchungen bestimmt wurde Experimentelle Versuchungen an 18 kreisförmigen Stahlrohr-eingeschlossenen UHPC (CSTC-UHPC) und UHPFRC (CSTC-UHPFRC) Stumpfstützen und Mittelstützenwurden durchgeführt Alle Proben hatten einen Durchmesser von 152.4 mm Versuchparemeter v enthalten: Stahlrohrdicken von 5.0 mm, 6.3 mm und 8.8 mm; Stahlfaservolumen von 0%, 1% und 2%; Stützenlängen von etwa 600 mm für Stumpfstützen und etwa 1000 mm für Mittelstützen Die Versagensarten aller Proben waren hauptsächlich mit dem Querkraftversagen des Betonkerns verbunden Zusätzlich zeigten die Versuchsergebnisse, dass eine Verbesserung der Festigkeit und Duktilität erreicht werden kann, indem nur der Betonkern belastet wird Die inhärente Sprödigkeit von UHPC und UHPFRC bei der Stauchung war durch die zusammengesetzte Wirkung von zwei Materialien deutlich eingeschränkt Bei der Eingliederung von Stahlfasern zeigte sich jedoch sogar bei Verwendung von Vol.-% Stahlfaser keine merkliche Steigerung der Festigkeitsverbesserung Darüber hinaus kann die Verwendung von Stahlfasern die Duktilität der Mittelstützen leicht erhöhen, während die Duktilität der kurzen Stützen nachteilig beeinflusst wird Die Festigkeits- und Duktilitätsverbesserung ist bei dickerer Stahldicke signifikant erhöht Unter den in dieser Studie untersuchten variablen Parametern hat die Stahlrohrdicke den grưßten Einfluss auf das Verhalten von CSTC-UHPC- und CSTCUHPFRC-Stützen Daher wäre es sinnvoller, UHPC ohne Stahlfasern in Kombination mit dickeren Stahldicken für diese Art von Stützen zu verwenden Basiert auf der Analyse der Versuchsergebnisse wurden die Formeln zur Vorhersage der begrenzten Spitzenspannung und ihrer entsprechenden Dehnung und eine vereinfachte Spannungs-Dehnungs-Kurve für CSTC-UHPC- und CSTC-UHPFRC-Stützen vorgeschlagen Die Anwendbarkeit der aktuellen Entwurfsnormen wie EC4 (2004), AISC (2010), AIJ (2001), ACI 318R, CISC (2007) und einige verfügbare analytische Modelle für Beton, die durch Stahlrohre eingeschlossen sind, wurde auch durch den Vergleich der Grenzlasten zwischen Vorhersagen und Versuchsergebnisse validiert Schließlich wurde ein FEM in ATENA-3D Programm entwickelt, um 18 getestete Proben zu simulieren und den Einfluss des Reibungskoeffizienten auf das Druckverhalten modellierter Stützen zu untersuchen Die Vorhersagen von FEM zeigten sehr gute Übereinstimmung mit den Versuchsergebnissen Schlüsselwörter: CFSTCs, UHPC, UHPFRC, NSC, HSC, eingeschlossener Beton, Stahlrohr, STCC Stützen vi Abstract It is well known that concrete filled steel tube columns (CFSTCs) have drawn much research attentions and widespread applications in the field of civil engineering In addition, with the rapid development of concrete technology, ultra high performance concrete (UHPC) has recently become a potential alternative to normal strength concrete (NSC) and high strength concrete (HSC) because of its superior performances such as extremely high compressive strength up to 200 MPa, usable tensile strength and very high durability properties, thus allowing engineers to reduce the size of structural members and to increase the load bearing capacity, and to develop novel structural elements However, UHPC exhibits enormous compressive brittleness accompanying with the increase of concrete strength, leading to some limitations for its applications in construction To overcome this drawback, research effort has been directed towards CFSTCs employing UHPC Confining UHPC with circular steel tubes is found to be an attractive option due to the efficient combination of two materials to form a high-performance member that benefits from a significant increase in both strength and ductility as compared to unconfined UHPC members An extensive amount of research has been reported in previous literature on the behavior of CFST columns employing NSC or HSC under concentric axial compression However, data on the behavior of UHPC filled steel tube columns (UHPC-FSTCs) is still lacking Moreover, existing design codes for CFSTCs are not applicable to UHPC Set against this background, this dissertation aims at performing a combined experimental and theoretical study on the behavior of circular UHPC-FSTCs columns under concentric axial loading on only the concrete core This loading pattern refers to the form of steel tube confined concrete (STCC) columns, which is found to exhibit a better increase in both ductility and strength as compared to the case of loading on the entire section This dissertation reported primarily an assessment of the axially compressive behavior of circular STCC stub columns based on the previous test results and a developed finite element model (FEM) in ATENA-3D software for these columns with various concrete strengths This provides the starting point for the main experimental investigations presented in this dissertation Then the constitutive behavior of UHPC without fiber and with steel fibers (UHPFRC) was investigated by the compression tests on cylindrical specimens and direct tension tests on notched prisms, thereby determining the influence of steel fiber content and aspect ratio on the uniaxial compressive and tensile responses Experimental tests on 18 circular steel tubes confined UHPC (CSTC-UHPC) and UHPFRC (CSTC-UHPFRC) stub and intermediate columns were conducted All the specimens were 152.4 mm in outer diameter Test variables included: steel tube thicknesses of 5.0 mm, 6.3 mm and 8.8 mm; steel fiber volumes of 0%, 1% and 2%; column lengths of about 600 mm for stub columns and about 1000 mm for intermediate columns The failure modes of all specimens were mainly associated with the shear plane failure of concrete core In addition, the test results indicated that an improvement in the strength and ductility can be obtained by loading on only the concrete core The inherent brittleness of UHPC and UHPFRC in vii compression was significantly restricted by the composite action of two materials However, there was no noticeable increase in the strength enhancement with incorporation of steel fibers even with the use of 2% steel fibers by volume Furthermore, the use of steel fibers may slightly increase the ductility of the intermediate columns, while there was an adverse influence on the ductility of the short columns The strength and ductility enhancement were significantly increased with thicker steel thickness It is found that, among the variable parameters investigated in this study, the steel tube thickness had the most tremendous impact on the behavior of CSTC-UHPC and CSTC-UHPFRC columns Hence, it would have more sense to use UHPC without steel fibers in combination with thicker steel thickness for this type of columns Based on the analysis of test results, the formulae for predicting the confined peak stress and its corresponding strain and a simplified stress-strain curve for CSTC-UHPC and CSTCUHPFRC columns were proposed The applicability of current design codes such as EC4 (2004), AISC (2010), AIJ (2001), ACI 318R, CISC (2007) and some available analytical models for concrete confined by steel tube was also validated by comparison of ultimate loads between predictions and test results Finally, a FEM in ATENA-3D was developed to simulate 18 tested specimens and to investigate the effect of friction coefficient on the compressive behavior of modelled columns The predictions of FEM showed very good agreement with the test results Keywords: CFSTCs, UHPC, UHPFRC, NSC, HSC, confined concrete, steel tube, steel fibers, STCC columns viii Table of contents Vorwort der Herausgeber Author’s Preface Kurzfassung Abstract Table of contents Notations i iii v vii ix xiv Chapter 1: Introduction 1.1 Background 1.2 Aims and Objectives 1.3 Methodology 1.4 Layout of dissertation Chapter 2: Literature review 2.1 Ultra high performance concrete (UHPC) 2.1.1 Definition of UHPC 2.1.2 Development of UHPC 2.1.3 Constituent materials of UHPC 2.1.3.1 Principle 2.1.3.2 UHPC compositions 2.1.4 Applications of UHPC 2.1.4.1 General advantages 2.1.4.2 General disadvantages 2.1.4.3 Worldwide examples of UHPC applications 2.1.5 Mechanical behaviour characterization of UHPC 2.1.5.1 Time development of compressive strength 2.1.5.2 Compressive behavior of hardened UHPC 2.1.5.3 Tensile response of hardened UHPC 2.1.5.4 Bi-axial and multi-axial behavior of UHPC 2.1.5.5 Time dependent properties of UHPC 2.2 Concrete filled steel tube (CFST) columns 2.2.1 Introduction of CFST columns 2.2.2 The mechanical behavior of CFST columns 2.2.2.1 The interaction between steel tube and concrete core 2.2.2.2 The different Poisson’s ratio of steel and concrete 2.2.2.3 The failure mechanism in steel tube and concrete core 2.2.2.4 The implication of loading pattern 2.2.2.5 Confinement effect in circular CFST columns 2.2.2.6 Classification of axial load versus vertical deformation of CFST columns under concentric compression 2.2.2.7 Residual strength in circular CFST columns 2.2.3 An overview of the experimental investigation on circular CFST columns under axial compression 2.2.3.1 Tests on circular CFST stub columns under loading on the entire section 2.2.3.2 Tests on circular CFST stub columns under loading on the concrete core (STCC columns) 2.2.3.3 Tests on steel-fibers reinforced concrete filled steel tube columns 2.2.3.4 Tests on circular CFST columns employing UHPC or UHSC 2.2.4 Overview of some existing design guidelines for CFST columns ix 7 9 11 11 12 12 17 17 19 24 30 33 36 36 37 38 39 42 45 47 49 52 54 54 58 61 64 67 References Cai, J.M; Pan J.L.; and Shan, Q.F (2015): Failure mechanism of full-size concrete filled steel circle and square tubes under uniaxial compression Sci China Tech Sci, 58: 16381647, doi: 10.1007/s11431-015-5890-4 Cai, S.H.; and Gu, W.P (1996): Behavior and Ultimate Strength of Steel Tube Confined High Strength Concrete Columns 4th Int Symp on Utilization of High-Strength/High- Performance Concrete, Paris, 827-833 Campione, G.; Mendola, L.L.; Sanpaolesi, L.; Scibilia, N.; and Zingone, G (2002): Behavior of fiber reinforced concrete-filled tubular columns in compression Material Structures, 35(250): 332– 337 CEB-FIB (1990): Structural Concrete - Textbook on behaviour, design and performances (Updated knowledge of CEB/FIP Model Code 1990), Volume - fib - International Federation for Structural Concrete (fib), Lausanne, Switzerland, 1999 CEB-FIB (1995): High Performance Concrete-Recommended Extensions to the Model code 90, Research Needs International Federation for Structural Concrete (fib), Lausanne, Switzerland, 1995 CEB-FIB (2013): Code-type models for concrete behaviour, Background of MC2010 International Federation for Structural Concrete (fib), Lausanne, Switzerland, 2013 CECS 28:90 (1992): Specification for design and construction of concrete-filled steel tubular structures, China Planning Press; Beijing, China [In Chinese] Cederwall, K (1988): Some Ideas and Studies Concerning the Ultimate Capacity of Composite Steel and Concrete Elements Nordic Concrete Journal, 1988:5, Stockholm CEN - European Committee for Standardization (2005) Eurocode (EC4): Design of composite steel and concrete structures – Part 1-1: General rules and rules for buildings Cervenka, V.; Jendele, L.; and Cervenka, J (2013): ATENA Program Documentation part 1Theory Cervenka Consulting s.r.o, Na Hrebenkach 55, 150 00 Prague, Czech Republic Cheyrezy, M.; Maret, V.; Frouin, L (1995): Microstructural analysis of Reactive Powder Concrete Cement and Concrete Research, 25(7): 1491-1500 Choi, M.S.; Kang, S.T.; Lee, B.Y.; Koh, K.T.; and Ryu, G.S (2016): Improvement in predicting the post-cracking tensile behavior of ultra-high performance cementitious composites based on fiber orientation distribution Materials, 9, 829 Chu, K (2014): Axial load behaviour of steel tube columns in-filled with various high-performance concretes Master Thesis, Ryerson University, Toronto, Ontario CISC (2007): Handbook of steel construction 9th ed Ontario, Canada, Canadian Institute of Steel Construction [Lakeside Group Inc.] Clark, W.S (1994): Axial load capacity of circular steel tube columns filled with high strength concrete Bachelor thesis, Department of Civil and Building Engineering Victoria University of Technology Victoria Australia Collins, M.P.; Mitchell, D.; and MacGregor, J.G (1993): Structural design considerations for highstrength concrete Concrete International: Design and Construction 1993, 15(5): 27-34 Curbach, M.; and Speck, K (2007): Zweiaxiale Druckfestigkeit von ultrahochfestem Beton Betonund Stahlbetonbau, 102(10), pp 664-673 (in German) Curbach, M.; and Speck, K (2008): Ultra high performance concrete under biaxial compression In: Ultra High Performance Concrete (UHPC), Proceedings of the Second International Symposium on Ultra High Performance Concrete, 5-7 March 2008, Kassel, Germany, Eds E Fehling, M Schmidt, S Stürwald (Kassel, Germany: Kassel University Press, 2008), pp 477-484 (in book pdf) Cusson, D.; and Paultre, P (1995): Stress-Strain Model for Confined High-Strength Concrete Journal of Structural Engineering, ASCE, Vol 121, No 3, March, 468-477 DBJ 13-51-2003 (2003): Technical specification for concrete-filled steel tubular structures China Planning Press, Beijing, China [In Chinese] De Larrard, F.; and Sedran, T (1994): Optimization of ultra-high-performance concrete by the use of a packing model Cement and Concrete Research, 24(6), pp 997-1009 De Nardin, S.; El Debs A.L.H.C (2007): Axial load behaviour of concrete-filled steel tubular columns Proceeding of the Institution of Civil Engineers, Structures & Buildings, 160(SB1):1322 317 References De Nicolo, B.; Pani, L.; and Pozzo E (1994): Strain of concrete at peak compressive stress for a wide range of compressive strengths Materials and Structures, 27:206-210 De Oliveira, W.L.A.; De Nardin, S.; De Cresce El Debs, A.L.H.; and El Debs, M.K (2010): Evaluation of passive confinement in CFT columns Journal of Constructional Steel Research; 66(4): 487-495 De Oliveira, W.L.A.; De Nardin, S.; De Cresce El Debs, A.L.H.; and El Debs, M.K (2009): Influence of concrete strength and length/diameter on the axial capacity of CFT columns Journal of Constructional Steel Research, 65(12): 2103-2110 DIN 1048-5:1991-06, Prüfverfahren für Beton, Teil 5: Festbeton, gesondert hergestellte Probekörper Normenausschuss für Bauwesen (NABau) im DIN Deutsches Institut für Norming e.V., Beuth Verlag GmBH, Berlin, 1991 DIN EN 12350-8:2010-12, Testing fresh concrete-Part 8: Self-compacting concrete-Slump-flow test, German version EN 12350-8, 2010, Beuth Verlag, Berlin DIN EN 12390-3:2009-7, Testing hardened concrete-Part 3: Compressive strength of test specimens, German version EN 12390-3:2009, Beuth Verlag, Berlin DIN EN 12390-6:2009: Testing Hardened concrete – Part 6: Tensile splitting strength of test specimens DIN EN 13263-1:2009-07: Silica fume for concrete – Part 1: Definitions, requirements and conformity criteria; German version EN 13263-1:2005 Ding, F.X.; Tan, L.; Liu, X.M.; and Wang, L (2017): Behavior of circular thin-walled steel tube confined concrete stub columns Steel and Composite Structures, An Int\'l Journal, 23(2): 229238 Ding, F.X.; Yu, Z.W.; Bai, Y.; and Gong, Y.Z (2011): Elasto-plastic analysis of circular concretefilled steel tube stub columns Journal of Constructional Steel Research, 67: 1567-1577 Du, Y.; Chen, Z.; and Yu, Y (2016): Behavior of rectangular concrete-filled high strength steel tubular columns with different aspect ratio Thin-Walled Structures, 109: 304-318 Dugat, J.; Roux, N.; and Bernier, G (1996): Mechanical properties of reactive powder concrete Material and Structures, Vol 29: 233-240 El-Helou, R.G.; Moen, C.D.; and Cusatis G (2014): Ultra-High Performance Fiber-Reinforced Concrete: Extensive Material Characterization, Model Validation, and Structural Simulations Presentation at ACI Fall 2014 Convention, Washington, DC, October 27, 2014 Ellobody, E.; Ghazy, M.F (2012): Experimental investigation of eccentrically loaded fibre reinforced concrete-filled stainless steel tubular columns Journal of Constructional Steel Research 76: 167–176 Empelmann, M.; Teutsch, M.; and Steven, G (2004): Improvement of the post fracture behaviour of UHPC by fibres Proceeding of 2nd International Symposium on Ultra High Performance Concrete, March, Kassel, Kassel university press GmbH, 2004: pp.177-184 Empelmann, M.; Teutsch, M.; and Steven, G (2008): Load-bearing behaviour of centrically loaded UHPFRC-columns Proceeding of Second International Symposium on Ultra High Performance Concrete, Kassel, Germany, pp 521-528 EN 1993-1-1 Eurocode (2005): Design of steel structures – Part 1-1: General rules and rules for buildings, European Committee for Standardization Endicott, W.A (2007): A Whole New Cast, ASPIRE, Summer 2007, pp 26–29 Available at http://www.aspirebridge.org Eppers, S.; Müller, C (2008): Autogenous shrinkage strain of ultra-high-performance concrete (UHPC) Proceedings of the Second International Symposium on Ultra High Performance Concrete, 5-7 March 2008, Kassel, Germany, Eds E Fehling, M Schmidt, S Stürwald (Kassel, Germany: Kassel University Press, 2008), pp 433-441 (in book pdf) (Muller) Eurocode (2004): Design of composite steel and concrete structures, Part 1.1, General rules and rules for Building, BS EN 1994-1-1, British Standards Institution, London, UK Eurocode Design of concrete structures – Part 1-1: General rules and rules for building European Committee for Standardization (CEN), Brussels, Belgium, 2004 European standard EN 10002-1.(2001): Metallic material – Tensile testing – Part 1: Method of test at ambient temperature, Brussels Fam, A.; Qie, F.S.; and Rizkalla, S (2004): Concrete-filled steel tubes subjected to axial compression and lateral cyclic loads Journal of Structural Engineering, ASCE, 130(4): 631-640 318 References Fehling, E.; Bunje, K.; and Leutbecher, T (2004a): Design relevant properties of hardened ultra high performance concrete Proceedings of the International Symposium on Ultra High Performance Concrete, 13-15 September 2004, Kassel, Germany, Eds M Schmidt, E Fehling, C Geisenhanslüke (Kassel, Germany: Kassel University Press, 2004), pp 327-338 Fehling, E.; Bunje, K.; Schmidt, M.; and Schreiber, W (2004b): Ultra high performance composite bridge across the River Fulda in Kassel – Conceptual design, design calculations and invitation to tender Proceedings of the International Symposium on Ultra High Performance Concrete, 13-15 September 2004, Kassel, Germany, Eds M Schmidt, E Fehling, C Geisenhanslüke (Kassel, Germany: Kassel University Press, 2004), pp 69-75 Fehling, E.; Leutbecher, T.; Röder, F.K.; and Stürwald, S (2008a): Structural Behavior of UHPC under biaxial loading”, Proceeding of 2nd International Symposium on Ultra High Performance Concrete, kassel university press, Kassel, March, 569-576 Fehling, E.; Bunje, K.; Schmidt, M.; and Schreiber, W (2008b): The “Gärtnerplatzbrücke”–Design of first hybrid UHPC-steel bridge across the river Fulda in Kassel, Germany Proceedings of the Second International Symposium on Ultra High Performance Concrete, 5-7 March 2008, Kassel, Germany, Eds E Fehling, M Schmidt, S Stürwald (Kassel, Germany: Kassel University Press, 2008), pp 581-588 (in book pdf) Fehling, E.; Schmidt, M.; Walraven, J.; Leutbecher, T.; and Fröhlich, S (2014): Ultra-High Performance Concrete: Fundamental – Design – Example, Wilhelm Ernst & Sohn, Verlag für Architektur und technische Wissenschaften GmbH & Co KG, Rotherstraße 21, 10245 Berlin, Germany Fujii, K (1994): Structural and Ultimate Behavior of Two Types of Mortar Filled Steel Tubes in Compression Steel-Concrete Composite Structures, Proceedings of the Fourth International Conference on Steel-Concrete Composite Structures, Javor, T (ed.), Kosice, Slovakia, June 20-23, 1994, Association for International Cooperation and Research in Steel-Concrete Composite Structures, Expertcentrum, Bratislava, Slovakia, pp 194-197 Fujimoto, T.; Mukai, A.; Nishiyama, I.; and Sakino, K (2004): Behavior of eccentrically loaded concrete-filled steel tubular columns Journal of Structural Engineering, ASCE, 130(2):203-212 Gajalakshmi, P.; and Helena, H.J (2014): Experimental and computational study of SFRC in-filled steel circular columns under axial compression Asian Journal of Civil Engineering (BHRC), 15(2): 231-243 Gardner, N.J.; and Jacobson, E.R (1967): Structural behavior of concrete-filled steel tubes ACI Structural Journal, 64(7): 404-412 Giakoumelis, G.; and Lam, D (2004): Axial capacity of circular concrete-filled tube columns Journal of Constructional Steel Research, 60(7): pp 1049-1068 Girgin, Z.C.; Arιoglu N.; and Arιoglu E (2007): Evaluation of strength criteria for very-high-strength concretes under triaxial compression ACI Structural Journal, 104(S27): 277-283 Goode, C D (2008): Composite columns - 1819 tests on concrete-filled steel tube columns compared with Eurocode Structural Engineer, 86(16): 33-38 Gopal, S.R.; and Manoharan, P.D (2004): Tests on fibre reinforced concrete filled steel tubular columns, Steel and Composite Structures, 4: 37–48 Gopal, S.R.; and Manoharan, P.D (2006): Experimental behaviour of eccentrically loaded slender circular hollow steel columns in-filled with fibre reinforced concrete Journal of Constructional Steel Research, 62 (5): 513–520 Gourley, B.C.; Tort, C.; Denavit, M.D.; Schiller, P.H.; and Hajjar, J.F (2008): A Synopsis of Studies of the Monotonic and Cyclic Behaviour of Concrete-Filled Steel Tube Members, Connections, and Frames Report No NSEL-008 Grauers, M (1993): Composite Columns of Hollow Steel Sections Filled with High Strength Concrete Publication 93:2, Ph.D thesis, Chalmers University of Technology, Div of Concrete Struct., Göteborg, Sweden Graybeal B.A (2005): Characterization of the behavior of ultra-high performance concrete Ph.D Dissertation, University of Maryland, USA Graybeal, B.A (2006): Material property characterization of ultra-high performance concrete Publication No FHWA-HRT-06-103, US Department of Transportation, Federal Highway Administration, Turner-Fairbank Highway Research Center, McLean, VA (August), 188 pgs 319 References Graybeal, B.A (2007): Compressive behavior of ultra-high-performance fiber-reinforced concrete ACI Materials Journal, pp 146-152 Graybeal, B.A (2011): Ultra-high performance concrete FHWA Technote HRT-11-038 Graybeal, B.A (2015): Tensile Mechanical Response of Ultra-High-Performance Concrete Advances in Civil Engineering Materials Doi:10.1520/ACEM20140029 ISSN 2165-3984 Graybeal, B.A.; and Baby, F (2013): Development of Direct Tension Test Method for Ultra-High Performance Fiber-Reinforced Concrete ACI Materials Journal/March-April 2013: 177-186 Grünberg, J.; Lohaus, L.; Ertel, C.; and Wefer, M (2008): Multi-axial and fatigue behaviour of ultrahigh-performance concrete (UHPC) Proceedings of the Second International Symposium on Ultra High Performance Concrete, 5-7 March 2008, Kassel, Germany, Eds E Fehling, M Schmidt, S Stürwald (Kassel, Germany: Kassel University Press, 2008), pp 485-492 (in book pdf) (Grunberg) Guler, S (2014): Axial behavior of FRP-wrapped circular ultra high performance concrete specimens Structural Engineering and Mechanic, An International Journal, 50(6): 709-722 Guler, S.; Aydogan, M.; and Copur, A (2013): Axial capacity and ductility of circular UHPC-filled steel tube columns Magazine of Concrete Research, 65(15): 898-905 Guler, S.; Lale, E.; Aydogan, M (2013): Behaviour of SFRC filled steel tube columns under axial load Advanced Steel Construction, 9(1): 14-25 Guo, Z (2014): Principle of reinforced concrete Book, ISBN: 9780128008591 Gupta, P.; Sarda, S M.; and Kumar, M S (2007): Experimental and computational study of concrete filled steel tubular columns under axial loads Journal of Constructional Steel Research, 63(2), 182-193 Gupta, P.K.; Singh, H (2014): Numerical study of confinement in short concrete filled steel tube columns Latin American Journal of Solids and Structures, 11: 1445-1462 Haghinejad A.; and Nematzadeh M (2016): Three-dimensional finite element analysis of compressive behavior of circular steel tube-confined concrete stub columns by new confinement relationships Latin American Journal of Solids and Structures, 13: 916-944 Han, L.H (2002): Tests on stub columns of concrete-filled RHS sections Journal of Constructional Steel Research, 58(3): 353-372 Han, L.H.; and Yao, G.H (2004): Experimental behaviour of thin-walled hollow structural steel (HSS) columns filled with self-consolidating concrete (SCC) Thin-Walled Structures, 42(9): 1357-1377 Han, L.H.; Yao, G.H.; Zhao, X.L (2005): Tests and calculations of hollow structural steel (HSS) stub columns filled with self-consolidating concrete (SCC) Journal of Constructional Steel Research, 61(9): 1241-1269 Han, L.H.; Zhao, X.L.; and Tao, Z (2001): Tests and mechanics model of concrete-filled SHS stub columns, columns and beam-columns Steel and Composite Structures, An International Journal, 1(1): 51-74 Han, L.H (2000): Influence of concrete compaction on the strength of concrete filled steel tube Advances in structural engineering, 3(2): 131-137 Han, L.H.; Li, W.; and Bjorhovde, R (2014): Development and advanced applications of concretefilled steel tubular (CFST) structures: members Journal of Constructional Steel Research, Vol 100: 211-228 Han, L.H.; Yao, G.H.; Chen, Z.P.; and Yu, Q (2005): Experimental behavior of steel tube confined concrete (STCC) columns Steel and Composite Structures, An International Journal, 5(6): 45984 Han, L.H.; Liu, W.; and Yang, Y.F (2008): Behavior of thin walled steel tube confined concrete stub columns subjected to axial local compression Thin-Walled Structures, 46: 155-164 Hansen, S (2011): Numerical and Experimental Study of Partially Concrete-Filled Circular Steel Sections Master thesis, Faculty of Engineering and Science Aalborg University Harish, K.V.; Dattatreya, J.K.; and Neelamegam (2013): Experimental investigation and analytical modeling of the -characteristics in compression of heat-treated ultra-high strength mortars produced from conventional materials Construction and Building Materials, 49: 781-796 Hassan, A.M.T.; Jones, S.W.; and Mahmud, G.H (2012): Experimental test methods to determine the uniaxial tensile and compressive behaviour of ultra high performance fibre reinforced concrete (UHPFRC) Construction and Building Materials, 37: 874-882 320 References Hatzigeorgiou, G.D (2008): Numerical model for the behavior and capacity of circular CFT columns, Part I: Theory Engineering Structures, 30(6): 1573-1578 Heimann, M.: Tragwerkszuverlässigkeit hochbeanspruchter Druckglieder aus ultrahochfestem Beton Ph.D Dissertation, Helf 28, Technische Universität Darmstadt, 2013 Hosinieh, M.M.; Aoude, H.; Cook, W.D.; and Mitchell, D (2015): Behavior of ultra-high performance fiber reinforced concrete columns under pure axial loading Engineering Structures, 99: 388-401 Hu, H.T.; Huang, C.S.; Wu, M.H.; and Wu, Y.M (2003): Nonlinear analysis of axially loaded concrete-filled tube columns with confinement effect Journal of Structural Engineering, ASCE, 129(10): 1322-1329 Huang, F.; Yu, X.; Chen, B (2012): The structural performance of axially loaded CFST columns under various loading conditions Steel and Composite Structures, An International Journal, 13(5): 451-471 Johansson, M (2002): Composite Action and Confinement Effects in Tubular Steel-Concrete Columns Ph.D Dissertation, Department of Structural Engineering, Concrete Structures, Chalmers University of Technology, Göteborg, Sweden Johansson, M.; Åkesson, M (2001): Finite element study of concrete-filled steel tubes using a new confinement-sensitive concrete compression model Nordic Concrete Research, Oslo, (27): 4362 Johansson, M.; and Gylltoft, K (2001): Structural behavior of slender circular steel-concrete composite columns under various means of load application”, Steel and Composite Structures, An International Journal, 1(4): 393-410 Johansson, M.; and Gylltoft, K (2002): Mechanical behavior of circular steel-concrete composite stub columns Journal of Structural Engineering, ASCE, 128(8): 1073-1081 Kamo, T.; Ando, R.; Sasaki, M.; Suzuki, T.; and Watanabe, Y (2015): Ultra high steel for sustainable building structure Technical Report, Nippon Steel and Sumitomo Metal, No 110, Japan Kang, S.T.; and Kim, J.K (2011): The relation between fiber orientation and tensile behavior in an ultra high performance fiber reinforced cementitious composites (UHPFRCC) Cement and Concrete Research, 2011, 41: 1001-1014 Kang, S.T.; and Ryu G.S (2011): The effect of steel fiber content on the compressive stress-strain relation of ultra high performance cementitious composites (UHPCC) Journal of the Korea Concrete Institute, Vol 23, No 1, pp 67-75, February, 2011 Kang, W.H.; Uy, B.; Tao, Z.; and Hicks, S (2015): Design strength of concrete-filled steel columns Adv Steel Construct., 11(2): 165-184 Kazemi, S.; and Lubell A.S (2012): Influence of specimen size and fiber content on mechanical properties of ultra-high-performance fiber-reinforced concrete ACI Materials Journal, 109(6): 675-684 Keierleber, B (2008): Design of Buchanan County, Iowa, Bridge, Using Ultra High- Performance Concrete and PI-Beam Cross Section,” Proceedings of the PCI National Bridge Conference, October 4–7, 2008, Orlando, FL, Compact Disc, Paper 27 Keierleber, B (2010): FHWA, Iowa Optimize Pi Girder ASPIRE, Winter 2010, pp 24–26 Available at http://www.aspirebridge.org Kennedy, S J (1984): End Connection Effects on the Strength of Concrete Filled HSS Beam Columns M.Sc Thesis, Department of Civil Engineering, Edmonton, Alberta, Canada Kilpatrick, A E.; and Rangan, B V (1999): Influence of interfacial shear transfer on behavior of concrete-filled steel tubular columns ACI Struct J., 96(S72): 642–648 Knowles, R.B., and Park, R (1969): Strength of concrete-filled steel tubular columns J Struct Div., 95(ST12): 2565–2587 Koh, K.T.; Park, J.J.; Ryu, G.S.; and Kang, S.T (2007): Effect of the compressive strength of ultrahigh strength steel fiber reinforced cementitious composites on curing method J Korean Soc Civ Eng., 27: 427–432 Kuranovas A.; Goode, C.D.; Kvedaras, A.K.; and Zhong S (2009): Loading-bearing capacity of concrete-filled steel columns Journal of Civil Engineering and Management, 15(1): 21-33 Lai, M.H.; and Ho, J.C.M (2014): Behaviour of uni-axially loaded concrete-filled-steel-tube columns confined by external rings The Structural Design of Tall and Special Buildings, 23: 403-426, Wiley Online Library 321 References Le, T.T; Soutsos, M.N.; Millard, S.G.; and Barnett, S.J (2007): UHPFRC Optimization of Mix Proportions, In: Proc of CONCRETE PLATFORM Inter Conf., Belfast, Northern Ireland, 2007, pp 339-348 Lee, C.D.; Kim, K.B.; and Choi S (2013): Application of ultra-high performance concrete to pedestrian cable-stayed bridges Journal of Engineering Science and Technology, 8(3): 296 – 305, School of Engineering, Taylor’s University Lee, J.H.; Hong, S.G.; Joh, C.; Kwahk, I.; Lee, J.W (2017): Biaxial tension–compression strength behaviour of UHPFRC in-plane elements Material and Structures, 50:20 DOI 10.1617/s11527016-0918-1 Legeron, F.; and Paultre, P (2003): Uniaxial confinement for normal and high-strength concrete columns Journal of Structural Engineering, ASCE, 129(2): 241-252 Leutbecher, T (2008): Rissbildung und Zugtragverhalten von mit Fasern und Stabstahl bewehrtem Ultrahochfesten Beton (UHPC) Ph.D Dissertation, Heft 9, kassel university press GmbH, University of Kassel, Germany [In German] Liang, Q.Q.; and Fragomeni, S (2009): Nonlinear analysis of circular concrete-filled steel tubular short columns under axial loading Journal of Constructional Steel Research, 65(12): 21862196 Liew, J.Y.R., Xiong, M.X and Xiong, D.X (2016): Design of concrete filled tubular beam-columns with high strength steel and concrete Structures, 8: 215-221 Liew, J.Y.R.; and Xiong, D.X (2012): Ultra-high strength concrete filled composite columns for multi-storey building construction Advances in Structural Engineering, 15(9): 1487-1503 Liew, J.Y.R.; and Xiong, D.X (2015): Design Guide For Concrete Filled Tubular Members With High Strength Materials to Eurocode Research Publishing, Blk 12 Lorong Bakar Batu, 349568 Singapore Liew, J.Y.R.; Xiong, M.X.; and Xiong, D.X (2014): Design of high strength concrete filled tubular columns for tall buildings International Journal of High-Rise Building, 3(3): 215-221 Liew, J.Y.R.; and Xiong, D.X (2010): Experimental investigation on tubular columns infilled with ultra-high strength concrete”, Tubular Structures XIII, The University of Hong Kong, 637-645 Lim, J.C.; and Ozbakaloglu, T (2015): Influence of size and slenderness on compressive strain softening of confined and unconfined concrete Journal of Materials in Civil Engineering, ASCE, 06015010-1: 06015010-7 Liu, J.; Zhang, S.; Zhang, X.; and Guo, L (2009): Behavior and strength of circular tube confined reinforced-concrete (CTRC) columns”, Journal of Constructional Steel Research, 65:1447-1458 Liu, J.; Zhou, X.; and Gan, D (2016): Effect of friction on axially loaded stub circular tubed columns Advances in Structural Engineering, 19(3): 546-559 Liu, S.H., Li, L.H., and Feng, J.W (2012): Study on mechanical properties of reactive powder concrete Journal of Civil Engineering and Construction, 1(1): 6-11 Lu, Y.; Li, N.; Li, S.; Liang, H (2015): Behavior of steel finer reinforced concrete-filled steel tube columns under axial compression Construction and Building Materials, 95: 74-85 Lu, Z H.; and Zhao, Y G (2010): Suggested empirical models for the axial capacity of circular CFT stub column Journal of Constructional Steel Research, 66: 850-862 Ma, J (2010): Faserfreier Ultrahochfester Beton – Entwicklung und Materialeigenschaften Ph.D Dissertation, University of Leipzig, Germany, 2010 [In German] Ma, J.; and Schneider, H (2002): Properties of Ultra-High-Performance Concrete Leipzig Annual Civil Engineering Report (LACER), pp 25-32 Ma, J.; Orgass M.; Dehn F.; Schmidt D.; and Tue N.V (2004): Comparative investigations on ultrahigh performance concrete with and without coarse aggregate In Proceeding of International Symposium on Ultra High Performance Concrete, 13-15 September, 2004, Kassel, Germany, No 3, kassel university press Ma, J.; and Orgass, M (2004): Comparative investigations on ultra-high performance concrete with and without coarse aggregates Leipzig Annual Civil Engineering Report, LACER 9, 10 pgs Ma, J.; and Schneider, H (2003): Creep of ultra-high performance concrete under compressive stresses Leipzig Annual Civil Engineering Report, LACER 8, pp 39-50 Ma, J.; Dehn, F.; and Koenig, G (2003): Autogenous shrinkage of self-compacting ultra-high performance concrete (UHPC) In Proceedings of the International Conference on Advances in Concrete and Structures (ICACS), 17-19 September 2003, Xuzhou, P.R China, pp 255-262 322 References Ma, J.; Dietz, J.; and Dehn, F (2003): Ultra high performance self compacting concrete In Proceedings of the Third International Symposium on Self-Compacting Concrete, 17-20 August 2003, Reykjavik, Iceland, Eds O Wallevik, I Nielsson, PRO 33 (Bagneus, France: RILEM 2003), pp 136-142 Mander, J.B.; Priestley, M.J.N.; and Park R (1988): Theoretical stress-strain model for confined concrete Journal of Structural Engineering, ASCE, 114(8): 1804-1826 Markeset, G (1993): Failure of Concrete under Compressive Strain Gradients Ph.D Thesis, University of Trondheim, Trondheim, Norway Matsumoto, M.S.; Komuro, K.T.; Narihara, N.H.; Kawamoto, K.S.; Hosozawa, H.O.; and Morita, M.K (2012): Structural design of an ultra-high rise building using concrete filled tubular column with ultra high strength materials Proceeding of 15th World Conference on Earthquake Engineering, Lisbon, Portugal Morino, S.; Uchikoshi, M.; and Yamaguchi, I (2001): Concrete-filled steel tube column system - its advantages Steel Structures, No 1, 33-44 O’Shea, M.D.; and Bridge, R.Q (1994): Test of thin-walled concrete-filled steel tubes Twelfth International Specialty Conference on Cold-Formed Steel Structures, St Louis, Missouri, U.S.A, October 18-19, pp 399-419 O’Shea, M.D.; and Bridge, R.Q (1997a): Test on circular thin-walled steel tubes filled with medium and high strength concrete Department of Civil Engineering Research Report No R755, The University of Sydney, Sydney, Australia O’Shea, M.D.; and Bridge, R.Q (1997b): Test on circular thin-walled steel tubes filled with very high strength concrete Department of Civil Engineering Research Report No R754, The University of Sydney, Sydney, Australia O’Shea, M.D.; and Bridge, R.Q (2000): Design of circular thin-walled concrete filled steel tubes Journal of Structural Engineering, ASCE, 126(11): 1295-1303 Olofsson, U.; and Holmgren, M (1992): Användning av en servo-hydraulisk drag-vridningsmaskin för friktionsmätning mellan stål och betong vid låga glidhastigheter (Using a Servo Hydraulic Tension-Torsion Machine for Measurement of Friction at Low Sliding Speed, in Swedish.) Swedish National Testing and Research Institute, Borås, Sweden Orito, Y.; Sato, Y.; Tanaka, N.; and Watanabe, K (1987): Study on the unbonded steel tube concrete structure Engineering Foundation Conf on Composite Constructions, Henniker, New Hampshire, USA, 786-804 Pagoulatou, M.; Sheehan, T.; Dai, X.H.; and Lam, D (2014): Finite element analysis on the capacity of circular concrete-filled double-skin steel tubular (CFDST) stub columns Engineering Structures, 72: 102-112 Pan, Y.G.; and Zhong, S.T (1991): Discussion on the Definition of Column Strength of Concrete Filled Steel Tubes Proc of the 3rd International Conference on Steel Concrete Composite Structures, Fukuoka Japan, 26-29 September, pp 7-12 Papadakis, V.G (1999): Experimental investigation and theoretical modeling of silica fume activity in concrete Cement and Concrete Research, 29(1): 79-86 Papanikolaou, V.K.; and Kappos, A.J (2007): Confinement-sensitive plasticity constitutive model for concrete in triaxial compression International Journal of Solids and Structures, 44: 7021-7048 Park, S.H.; Kim, D.J.; Ryu, G.S.; Koh, K.T (2012): Tensile behavior of Ultra High Performance Hybrid Fiber Reinforced Concrete Cement and Concrete Composites, 34:172–184 Perry, V (2006): Ductal® - A revolutionary new material for new solutions Association of Professional Engineers and Geoscientists of the Province of Manitoba (APEGM) [download from http://www.apegm.mb.ca/pdnet/papers/ductal.pdf] Popa, M.; and Kiss, Z (2013): State of the art regarding the protection of ultra-high performance concrete columns at brittle failure Proceeding of the 13th International Scientific Conference VSU’ 2013, Sofia, Bulgaria, pp 292-297 Portolés, J.M.; Serra, E.; and Romero, M.L (2013): Influence of ultra-high strength infill in slender concrete-filled steel tubular columns Journal of Constructional Steel Research, Vol 89: 107-114 Prem, P.R.; Bharatkumar, B.H.; and Murthy, A.R (2015): Influence of curing regime and steel fibers on the mechanical properties of UHPC Magazine of Concrete Research, 67(18):988-1002 Prion, H.G.L.; and Boehme, J (1993): Beam-Column Behaviour of Steel Tubes Filled with High Strength Concrete Canadian Journal of Civil Engineering, 21: 207-218 323 References Pryl, D.; and Cervenka, J (2015): ATENA Program Documentation part 11- Troubleshooting Manual, Cervenka Consulting s.r.o., Na Hrebenkach 55, 150 00 Prague, Czech Republic Pryl, D.; Cervenka, J (2015): ATENA Program Documentation part 11-Troubleshooting Manual, Cervenka Consulting s.r.o., Na Hrebenkach 55, 150 00 Prague, Czech Republic Pu, X.; Wan, C.; Wang, Y.; Pu, H.; and Wang, C (2004): Kilometer compressible material and its preparation”, Proceeding of International Symposium on Ultra High Performance Concrete, Kassel, Germany, March, 783-796 Qi, H.; Guo, L.; Liu, J.; Gan, D.; and Zhang, S (2011): Axial load behavior and strength of tubed steel reinforced-concrete (SRC) stub columns Thin-Walled Structures, 49: 1141-1150 Qu, X.; Chen, Z.; Nethercot, D.A.; Gardner, L.; and Theofanous, M (2015): Push‐out tests and bond strength of rectangular CFST columns Steel and Composite Structures, 19(1): 21‐41 Rabbat, B.G.; and Russell, H.G (1985): Friction coefficient of steel on concrete or grout Journal of Structural Engineering, 126(1):1295-1303 Racky, P (2004): Cost-effectiveness and sustainability of UHPC In Proceeding of International Symposium on Ultra High Performance Concrete, 13-15 September 2004, Kassel, Germany, Eds M Schmidt, E Fehling, C Geisenhanslüke (Kassel, Germany: Kassel University Press, 2004), pp 797-805 Resplendino, J.; and Petitjean, J (2003): Ultra-High-Performance Concrete: First Recommendations and Examples of Application Proceedings of the 3rd International Symposium on High Performance Concrete/PCI National Bridge Conference, October 19–22, 2003, Orlando, FL, Compact Disc, Paper 77 Ricciotti, R.; Lamoureux, G.; and Ricciotti, R (2010): The Jean Bouin Stadium, in Designing and Building with UHPFRC Proc of intl workshop “Designing and Building with Ultra-High Performance Fibre-Reinforced Concrete (UHPFRC): State of the Art and Development” (eds J Resplendino and F Toulemonde), JohnWiley & Sons, pp 101–108 Richard, P.; and Cheyrezy, M (1995): Composition of Reactive Powder Concretes Cement and Concrete Research, 25(7): 1501-1511 Richart, F.E.; Brandzaeg, A.; and Brown, R.L (1928): A Study of the Failure of Concrete under Combined Compressive Stresses Bulletin No 185, University of Illinois, Engineering Experimental Station, Urbana, Illinois, USA Richart, F.E.; Brandzaeg, A.; and Brown, R.L (1929): Failure of plain and spirally reinforced concrete in compression Bulletin 190, University of Illinois Engineering Experimental Station, Champaign, I11 Roeder, C W.; Cameron, B.; and Brown, C.B (1999): Composite Action in Concrete Filled Tubes Journal of Structural Engineering, 125(5): 477-484 Roth, M.J.; Boone, N.R.; Kinnebrew, P.G.; Davis, J.L.; and Rushing, T.S (2008): Development of New Protective Solutions to Counter Emerging and Adaptive Threats Roy, D.M.; Gouda, G.R.; and Bobrowsky, A (1972): Very high strength cement pastes prepared by hot pressing and other high pressure techniques Cement and Concrete Research, 2(3): 349-366 Russell, H.G.; and Graybeal, B.A (2013): Ultra-High Performance Concrete: A State-of-the-Art Report for the Bridge Community Publication No FHWA-HRT-13-060, US Department of Transportation, Federal Highway Administration, Turner-Fairbank Highway Research Center, McLean, VA Rutland, C.A.; and Wang, M.L (1997): The Effects of Confinement on the Failure Orientation in Cementitious Materials Experimental Observations Cement and Concrete Composites, 19: 149160 Sakino, K.; Nakahara, H.; Morino, S.; and Nishiyama, I (2004): Behavior of centrally loaded concretefilled steel-tube short columns Journal of Structural Engineering, ASCE, 130(2): 180-188 Sakino, K.; Tomii, M.; and Watanabe, K (1985): Sustaining load capacity of plain concrete stub columns confined by circular steel tubes Proc of the Int Specialty Conf on Concrete-Filled Steel Tubular Structures, ASCCS, Harbin, China, 112-118 Sakino, K.; Tomii, M.; and Watanabe, K (1985): Sustaining load resistance of plain concrete stub columns by circular steel tubes Proc., Int Spec Conf on Concrete-Filled Steel Tubular Structures, The Science and Technology Exchange of Heilongjian Province, Harbin, China, 112– 118 324 References Samani, A.K.; and Altard, M.M (2012): A stress-strain model for uniaxial and confined concrete under compression”, Engineering Structrtures, 41: 335-349 Schmidt, M (2006): Von der Nanotechnologie zum Ultra-Hochfesten Beton, Ultra high performance concrete - 10 years of research and development at the University of Kassel, Ibausil, Weimar, 2006, Tagungsband, S 2-1405 – 1416, Kassel University Press GmbH, Kassel, pp 98-110 Schmidt, M (2012): Sustainable building with ultra high performance concrete – Research program in Germany Presentation in 3rd International Symposium on UHPC and Nanotechnology for high performance construction materials, Kassel, March 7-9 Schmidt, M.; and Fehling, E (2005): Ultra-high-performance concrete: research, development and application in Europe ACI Structural Journal, Special Publication, 228: 51-78 Schmidt, M.; Fehling, E.; Fröhlich, S.; and Thiemicke, J (2015): Sustainable Building with UltraHigh Performance Concrete, Results of the German Priority Programme 1182 funded by Deutsche Forschungsgemeinschaft (DFG), No 22, kassel university press GmBH, Germany, 2015 Schneider, H (2006): Zum tragverhalten kurzer, umschnürter, kreisförmiger, druckglieder aus ungefasertem UHFB Ph.D Dissertation, University of Leipzig, Leipzig, Germany [In German] Schneider, S.P (1998): Axially loaded concrete-filled steel tubes Journal of Structural Engineering, ASCE, 124(10): 1125-1138 Scholle, N.; and Lohaus, L (2012): Numerical analyses of Filigree Steel-wrapped UHPC tubes In XIIIth Bilateral Czech/German Symposium, Prague, June, 47-50 Serras, D.N.; Skalomenos, K.A.; Hatzigeorgiou, G.D.; and Beskos, D.E (2016): Modeling of circular concrete-filled steel tubes subjected to cyclic lateral loading Structures, 8: 75-93 Serras, D.N.; Skalomenos, K.A.; Hatzigeorgiou, G.D.; and Beskos, D.E (2015): On the nonlinear cyclic behavior of circular concrete-filled steel tubes 8th GRACM International Congress on Computational Mechanics, Volos, 12-15 July, 2015 Setunge, S.; Attard, M.M.; and Darvall, P.P (1993): Ultimate strength of confined very high-strength concretes ACI Structural Journal, 90(6): 632-641 Shams, M.; and Saadeghvaziri, M.A (1997): State of the art of concrete-filled steel tubular columns ACI Structural Journal, 94(51): 558-571 Shin, H.O.; Soon, Y.S.; Cook, W.D.; and Michell, D (2015): Effect of confinement on the axial load response of Ultrahigh-strength concrete columns Journal of Structural Engineering, ASCE, 141(6): 04014151-1:04014151-12 Skalomenos, K.A.; Hatzigeorgiou, G.D.; Beskos, D.E (2014): Parameter identification of three hysteristic models for the simulation of the response of CFT columns to cyclic loading Engineering Structures, 61: 44-60 Skazlic, M.; Serder, M.; and Bjegovic, D (2008): Influence of test specimens geometry on compressive strength of ultra high performance concrete Proceeding of Second International Symposium on Ultra High Performance Concrete, March 2008, Kassel, Germany, pp 295-302 Song, T.Y.; and Liew, J.Y.R (2012): Simulation Model for Ultra-High Strength Concrete Filled Composite Column under Static Loads Proc Of the 10th Intl Conf on Advances in Steel Concrete Composite and Hybrid Structures, National University of Singapore, Singapore, pp 314-321 Speck, K (2008): Concrete under multiaxial loading conditions – A constitutive model for short-time loading of high performance concretes Ph.D Dissertation, TU Dresden [In German] Speck, K.; and Curbach, M (2011): Mehraxiale Festigkeit von UHPC (Drug-Zug und Zug-ZugFestigkeit) In Vortrag in Zwischenkolloquium SPP1182, Kassel Standards Association of Australia (2014), AS/NZS 2327-2014, Composite structures, Sydney, Australia [In preparation] Standards Association of Australia (2014a) AS/NZS 5100:Part 6-2014, Bridge Structures: Steel and Composite Structures, Sydney, (In preparation) Standards Association of Australia (2014b) AS/NZS 2327-2014, Composite Structures, Sydney, (In preparation) Standards Australia (2009) AS3600-2009 Australian Standard: Concrete Structures Standards Australia AS5100.6-2004, Bridge Design, Part 6: Steel and Composite Construction, 2004 325 References Starossek, U.; Falah, N.; Löhning (2008): Numerical analisys of the force transfer in concrete-filled steel tube columns The 4th International Conference on Advances in Structural Engineering and Mechanics, Jeju, Korea Stürwald, S (2011): Versuche zum Biegetragverhalten von UHPC mit kombinierter Bewehrung Technical Report, Fachgebiet Massivbau, Fachbereich Bauingenieurwesen, Universität Kassel, 2011 [In German] Sugano, S.; Kimura, H.; and Shirai, K (2007): Study of new RC structures using ultra-high-strength fiber-reinforced concrete (UFC)-The challenge of applying 200 MPa UFC to earth-quake resistant building structures Journal of Advanced Concrete Technology, 5(2): 133-147 Sun, Y (2008): Proposal and application of stress-strain model for concrete confined by steel tubes In Proceeding of the 14 th World Conference on Earthquake Engineering, October 12-17, 2008, Beijing, China Susantha, K.A.S; Ge, H.; and Usami, T (2001): Uniaxial stress-strain relationship of concrete confined by various shaped steel tubes Engineering Structures, 23(10): 1331-1347 Tan, K.; Nichol, J.M and Pu, X (2003): Mechanical properties of high strength concrete filled steel tubular columns: Part – Concentrically loaded Submission for review in ACI Journal, 22, April, 2003 Tang, J.; Hino, S.; Kuroda, I.; and Ohta T (1996): Modeling of stress-strain relationships for steel and concrete in concrete filled circular steel tubular columns Steel Construction Engineering, JSSC, 3(11): 35-46 Tao, Z.; Uy, B.; Han, L.H.; and Wang, Z.B (2009): Analysis and design of concrete-filled stiffened thin-walled steel tubular columns under axial compression Thin-Walled Structures, 47(12):1544– 1556 Tao, Z.; Wang, Z.B; Yu, Q (2013): Finite element modelling of concrete filled steel stub columns under axial compression Journal of Constructional Steel Research, 89: 121-131 Tasdemir, M.; Tasdemir, C.; Akyüz, S.; Jefferson, A.; Lydon, F,; and Barr, B (1998): Evaluation of strains at peak stress in concrete: A three-phase composite model approach Cement and Concrete Composites, 20: 301-318 Thai, H.T.; Uy, B.; Khan, M.; Tao, Z.; and Mashiri, F (2014): Numerical modelling of concrete-filled steel box columns incorporating high-strength materials, Journal of Constructional Steel Research, 102: 256–265 Thibaux, T (2010): UHPFRC development: The experience of BSI applications In Designing and Building with UHPFRC, Proc of intl workshop “Designing and Building with Ultra-High Performance Fibre-Reinforced Concrete (UHPFRC): State of the Art and Development” (eds J Resplendino and F Toulemonde), JohnWiley & Sons, pp 63–76 Thiemicke, J (2015): Zum Querkrafttragverhalten von UHPC-Balken mit kombinierter Bewehrung aus Stahlfasern und Stabstahl PhD Dissertation, No 25, Universität Kassel, kassel university press, 2015 [In German] Tokgoz, S.; and Dundar, C (2010): Experimental study on steel tubular columns in-filled with plain and steel fiber reinforced concrete Thin Wall Structures, 48 (6): 414–422 Tomii, M.; Sakino, K.; Watanabe, K.; and Xiao, Y (1985): Lateral load capacity of reinforced concrete short columns confined by steel tube Proc of the Int Specialty Conf on Concrete Filled Steel Tubular Structures, ASCCS, Harbin, China, 19-26 Tue, N.V (2008): Precast element made of UHPC - From Research to Application Presentation Website: http://www.set.eesc.usp.br/2enpppcpm/apresentacoes_pdf/Palestras.pdf/UHPC.pdf Tue, N.V.; Küchler, M.; and Henze, S (2008): Modular truss construction made of Ultrahigh Performance Concrete Proceeding of the 3rd ACF International Conference ACF/VCA 2008: pp 1239-1244 Tue, N.V.; Schneider, H.; Simsch, G.; and Schmidt, D (2004a): Bearing capacity of stub columns made of NSC, HSC and UHPC confined by a steel tube Proc of 1st Int Symposium on Ultra High Performance Concrete, Kassel, Germany, March, 339-350 Tue, N.V.; Küchler, M.; Schenck, G.; and Jürgen, R (2004b): Application of UHPC filled tubes in buildings and bridges Proceeding of International Symposium on Ultra High Performance Concrete, Kassel, Germany, March, 807-817 326 References Uy, B.; Khan, M.; Tao, Z.; and Mashiri, F (2013): Behaviour and design of high-strength steel concrete filled columns Proceedings of the 2013 World Congress on Advances in Structural Engineering and Mechanics (ASEM13), Jeju, Korea, pp 150-167 Van Herwijnen, F.; and Fielt, R.W.S (2005): Zonnestraal folly in very-high-strength concrete Cement, vol 57(3), pp 39–43 (in Dutch) Van Mier, J G M (1984): Strain-Softening of Concrete under Multiaxial Loading Conditions Eindhoven University of Technology, Eindhoven, The Netherlands Van Nalta, R.; and Baek Hansen, T (2012): Ultra thin Hi-Con Balconies – First Application in Holland In Ultra High Performance Concrete and Nanotechnology in Construction, 3rd Intl Symp on Ultra High Performance Concrete and Nanotechnology for High Performance Construction Materials, Structural Materials & Engineering Series No 19 (eds M Schmidt, E Fehling, C Glotzbach, S Fröhlich, and S Piotrowski), Kassel University Press GmbH, Kassel, pp 1005–1010 Vicenzino, E.; Culham, G.; Perry, V.H (2005): First use of UHPFRC in thin precast concrete roof shell for Canadian LRT station PCI Journal, 50(5): 50–67 Vincent, T.; and Ozbakkaloglu, T (2015a): Influence of concrete strength and confinement method on axial compressive behavior of FRP confined high-and ultra high strength concrete Composites Part B Engineering, 50:413–428 Vincent, T.; and Ozbakkaloglu, T (2015b): Influence of slenderness on stress-strain behavior of concrete-filled FRP tubes: Experimental study Journal of Composite Constructions, 19(1):1-13 Virdi, K.S.; and Dowling, P.J (1980): Bond Strength in Concrete Filled Steel Tubes IABSE Proceedings P-33/80, Zürich, Switzerland, August 1980, 125-139 Vrcelj, Z.; and Uy, B (2002): Strength of slender concrete-filled steel box columns incorporating local buckling Journal of Constructional Steel Research, 58(2): 275-300 Wang, C.; Yang, C.H.; Liu, F.; Wan, C.J.; and Pu, X.C (2012): Preparation of ultra-high performance concrete with common technology and materials Cement Concrete Composites, 34: 538–544 Wang, Y (2004): Research on preparation and mechanical performances of Kilometer Load-Bearing Material Ph.D Dissertation, Chongqing University, China [In Chinese] Wang Z.; Wang, J.; Liu, T.; and Zhang, F (2016): Modeling seismic performance of high-strength steel-ultra-high-performance concrete piers with modified Kent-Park model using fiber elements Advances in Mechanical Engineering, 8(2): 1-13 Wille, K.; El-Tawil, S.; and Naaman, A.E (2014): Properties of strain hardening ultra high performance fiber reinforced concrete (UHP-FRC) under direct tensile loading Cement and Concrete Composites, 48: 53-66 Wille, K.; Naaman, A.E.; and Parra-Montesinos, G.J (2011): Ultra-high performance Concrete with compressive strength exceeding 150 MPa (22 ksi): a simpler way ACI Materials Journal, 108(1), pp 46–54 Wu, Z.; Shi, C.; He, W.; and Wang, D (2016b) Uniaxial compression behavior of ultra-high performance concrete with hybrid steel fiber Journal of Materials in Civil Engineering, ASCE, 28(12): 06016017-1 to 06016017-7 Wu, Z.; Shi, C.; He, W.; and Wu, L (2016a): Effects of steel fiber content and shape on mechanical properties of ultra high performance concrete Construction and Building Materials, 103: 8-14 Xie, T.; and Ozbakkaloglu T (2015): Behavior of steel fiber-reinforced high-strength concrete-filled FRP tube columns under axial compression Engineering Structures, 90: 158-171 Xiong, D.X (2012): Structural behaviour of concrete filled steel tube with high strength materials Ph.D Dissertation, National University of Singapore, Singapore Xiong, M.X.; Xiong, D.X.; and Liew, J.Y (2017): Axial performance of short concrete filled steel tubes with high-and ultra-high-strength materials Engineering Structures, 136: 494-510 Yamamoto, T.; Kawaguchi, J.; Morino, S (2000): Experimental study of scale effects on the compressive behavior of short concrete-filled steel tube columns Proceeding of the 14th International Conference on Composite Constructional in Steel and Concrete, Banff, Alberta, Canada, 2000, p.879-890 Yan, P.Y.; and Feng, J.W (2008): Mechanical behavior of UHPC and UHPC filled steel tubular stub columns Proceeding of Second International Symposium on Ultra High Performance Concrete, Kassel, Germany, 355-362 327 References Yang, X.; Zohrevand, P.; and Mirmiran, A (2015): Behavior of Ultrahigh-Performance concrete confined by steel J Mater Civil Eng ASCE, 28(10), 04016113-1: 04016113-8 Yang, Y.F.; Han, L.H (2011): Behaviour of concrete filled steel tubular (CFST) stub columns under eccentric partial compression Thin-Walled Structures, 49: 379-395 Yang, Z.; Fu, G.Y.; Yu, C.J.; Chen, B.; Zhao, S.X.; and Li, S.P (2016): Experimental behavior of circular flyash-concrete-filled steel tubular stub columns Steel and Composite Structures, An International Journal, 22 (4): 821-835 Yang, Z.; Zhang, Y.; Chen, M.; and Chen, G (2013): Numerical simulation of ultra-strength concrete-filled steel columns Engineering Review, 33(3), 211-217 Yi, S.T.; Yang, E.I.; and Choi J.Ch (2006): Effect of specimen sizes, specimen shapes, and placement directions on compressive strength of concrete Nuclear Engineering and Design, 236: 115-127 Yoo, D.Y.; Kim, S.; Park G.J.; Park, J.J; Kim, S.W (2017): Effects of fiber shape, aspect ratio, and volume fraction on flexural behavior of ultra-high-performance fiber-reinforced cement composites Composite structures, 174: 375-388 Yoo, D.Y.; Lee, J.H.; and Yoon Y.S (2013): Effect of fiber content on mechanical and fracture properties of ultra high performance fiber reinforced cementitious composites Composite Structures, 106: 742-753 Yu, Q.; Tao, Z.; Liu, W.; and Chen, Z.B (2010): Analysis and calculations of steel tube confined concrete (STCC) stub columns Journal of Constructional Steel Research, 66(1): 53-64 Yu, Q.; Tao, Z.; and Wu, Y.X (2008): Experimental behaviour of high performance concrete-filled steel tubular columns Thin-Walled Structures, 46: 362- 370 Yu, Z.w.; Ding, F.X.; and Cai, C.S (2007): Experimental behavior of circular concrete-filled steel tube stub columns Journal of Constructional Steel Research, 63: 165-174 Yudenfreund, M.; Hanna, K.M.; Skalny, J.; Odler, I.; and Brunauer, S (1972): Hardened Portland Cement Pastes of Low Porosity and Compressive Strength Cement and Concrete Research, 2(6): 731-743 Zeghiche, J.; Chaoui, K (2005): An experimental behaviour of concrete-filled steel tubular columns Journal of Constructional Steel Research, 61(1): 53-66 Zhang, S.; Guo, L.; Ye, Z.; and Wang, Y (2005): Behavior of steel tube and confined high strength concrete for concrete-filled RHS tubes Adv Struct Eng., 8(2): 101-116 Zhong, S.T.; and Miao, R.Y (1988): Stress-Strain Relationship and Strength of Concrete Filled Tubes Proceeding of Engineering Foundation Conference on Composite Constructions, Henniker, New Hampshire, USA, 773-785 Zhou, B.; and Uchida, Y (2013): Fiber orientation in ultra high performance fiber reinforced concrete and its visualization In Proceeding of VIII International Conference on Fracture Mechanics of Concrete and Concrete Structures, FraMCos-8, 10-14 March, 2013, Toledo, Spain Zhou, X.; Li, J.; Wang, X.; and Chen, Y.F (2016): Behavior and design of slender circular tubedreinforced-concrete columns subjected to eccentric compression Engineering Structures, 124: 17-28 Zhu, L.; Ma, L.; Bai, Y.; Li, S.; Song, Q.; Wie, Y.; Zhang, L.; Zhang, Z.; and Sha, X (2016): Large diameter concrete-filled high strength steel tubular stub columns under compression Thin-Walled Structures, 108:12-19 Zohrevand, P.; and Mirmiran, A (2011): Behavior of ultrahigh-performance concrete confined by fiber reinforced polymers J Mater Civil Eng ASCE, 23(12): 1727-1734 328 Publications by the author related to this dissertation International conferences An, L.H.; Fehling, E.; and Ismail, M (2016): Numerical Modelling of Circular Concrete filled Steel Tube Stub Columns” In Proceedings of HiperMat 2016 4th International Symposium on Ultra-High Performance Concrete and High Performance Construction Materials, Kassel, March 9-11, 2016 Ismail, M.; Fehling, E.; An, L.H (2016): Comparative analytical Modelling of reinforced UHPCFRC under Pure Torsion In Proceedings of HiperMat 2016 4th International Symposium on Ultra-High Performance Concrete and High Performance Construction Materials, Kassel, March 9-11, 2016 An, L.H.; and Fehling, E (2016): Finite element analysis of circular steel tube confined UHPC stub columns In Proceedings of 1st International Conference on UHPC Materials and Structures (UHPC 2016China), Changsha, China, October 27-30, 2016, published by RILEM (105) An, L.H.; and Fehling, E (2017): Test on circular steel tube confined UHPC columns under axial loading 3rd International Symposium on Ultra-High Performance Fiber-Reinforced Concrete, UHPFRC 2017 Montpellier, France, October 27-30, 2017, published by RILEM An, L.H.; and Fehling, E (2017): Effect of steel fiber on the behavior of circular steel tube confined UHPC columns under axial loading 4th International Conference on Strain-Hardening Cement-Based Composites (SHCC4), Dresden, Germany, 18-20 September, 2017, published by RILEM and Springer An, L.H.; and Fehling, E (2017): Experimental study on the compressive behavior of circular steel tube confined UHPC columns 16th International Symposium on Tubular Structures (ISTS16), 4-6 December 2017, Monash, Australia, published by Taylor & Francis An, L.H.; and Fehling, E (2018): An investigation on UHPC without steel fibers confined by circular steel tube columns under axial compression 12th International Conference on Advances in Steel-Concrete Composite Structures (ASCCS 2018, Valencia, Spain (Accepted) Journals An, L.H.; and Fehling, E (2017): A review and analysis of UHPC filled steel tube columns Structural Engineering and Mechanic, 61(2): 417-430 An, L.H.; and Fehling, E (2017): Numerical analysis of steel tube confined UHPC stubs columns Computer and concrete, 19(3): 263-273 An, L.H.; and Fehling, E (2017): Analysis of circular steel tube confined UHPC stub columns Steel and Composite Structures, An International Journal, Techno press, 23(6): 669-682 An, L.H.; and Fehling, E (2017): Influence of steel fiber content and type on the uniaxial tensile and compressive behavior of UHPC Construction and Building Materials, 153: 790-806 An, L.H.; and Fehling, E (2017): Numerical study of circular steel tube confined concrete (STCC) stub columns with various concrete strengths Journal of Constructional Steel Research, 136: 238-255 An, L.H.; and Fehling, E (2017): Assessment of axial stress-strain model for UHPC confined by circular steel tube stub columns Structural Engineering and Mechanic, 63(3): 371-384 An, L.H.; Fehling, E (2018): Behavior of circular steel tube confined UHPC and UHPFRC columns under axial compression: Part – Experimental study Construction and Building Materials, Elsevier (In submit) An, L.H.; Fehling, E (2018): Behavior of circular steel tube confined UHPC and UHPFRC columns under axial compression: Part – Effect of test variables and numerical assessment Construction and Building Materials, Elsevier (In submit) An, L.H.; Fehling, E (2018): Evaluation of axial strength of circular steel tube confined UHPC and UHPFRC columns under axial compression Journal of Constructional Steel Research, Elsevier (In submit) 10 An, L.H.; Fehling, E (2018): Simplified stress-strain model for circular steel tube confined UHPC and UHPFRC columns under axial compression Steel and Composite Structures, An International Journal, Techno press (In submit) 329 Curriculum Vitae Name: Date of birth: Place of birth: Email: Le Hoang An 10-01-1983 Thua Thien Hue, Vietnam lehoangancdv@uni-kassel.de; lehoangancdv@gmail.com;lehoangan@tdt.edu.vn Educations 2001 - 2006 2007 - 2009 2006 - present 2013 - present Bachelor of Civil Engineering, majoring in Bridge & Highway Engineering, University of Transport and Communication, Campus in Ho Chi Minh City, Vietnam Master of Civil Engineering, majoring in Bridge & Highway Engineering, Ho Chi Minh City University of Technology, Vietnam Lecturer at Department of Civil Engineering, Ho Chi Minh City University of Transport, Vietnam Doctoral Candidate at Institute of Structural Engineering, University of Kassel, Germany Work experiences 2008-2013 2006-2008 Structural Engineer and Construction Supervisor at Technology Institute of Bridge and Road in the Southern, Vietnam Structural Engineer at Sub Institute of Transport Science and Technology in the Southern, Vietnam Honour and awards 2001 2002 2005 2012 2016 2017 Highest ranking in University Entrance Examination in Vietnam (Score: 29/30) Third Prize on Mathematics at Annual National Olympiad on Mathematics for Undergraduates in Vietnam Third Prize on Strength of Materials subject in the 17th Annual National Olympiad on Mechanics for Undergraduates in Vietnam DAAD-MOET full scholarship for PhD study in Germany DAAD STIBET scholarship for teaching and research assistance at University of Kassel Completion scholarship funded by University of Kassel for PhD student DAAD STIBET scholarship for teaching and research assistance at University of Kassel Kassel, September 2017 Lê Hoàng An 330 Erklärung (German Declaration) Hiermit versichere ich, dass ich die vorliegende Dissertation selbstständig, ohne unerlaubte Hilfe Dritter angefertigt und andere als die in der Dissertation angegebenen Hilfsmittel nicht benutzt habe Alle Stellen, die wưrtlich oder sinngemäß aus verưffentlichten oder unverưffentlichten Schriften entnommen sind, habe ich als solche kenntlich gemacht Dritte waren an der inhaltlich-materiellen Erstellung der Dissertation nicht beteiligt; insbesondere habe ich hierfür nicht die Hilfe eines Promotionsberaters in Anspruch genommen Kein Teil dieser Arbeit ist in einem anderen Promotions - oder Habilitationsverfahren verwendet worden Kassel, 18.12.2017 Signed: Lê Hoàng An 331 ... Standard deviation Concrete filled steel tube Concrete filled steel tube columns Steel tube confined concrete Circular steel tube confined UHPC columns Circular steel tube confined UHPFRC columns. .. of UHPC 2.1.5.1 Time development of compressive strength 2.1.5.2 Compressive behavior of hardened UHPC 2.1.5.3 Tensile response of hardened UHPC 2.1.5.4 Bi -axial and multi -axial behavior of UHPC. .. Compressive strength of confined concrete Hoop stress of steel tube Poisson’s ratio of steel Hoop strain of steel tube Steel contribution ratio Coefficient of confinement for steel tube Strain at the