hipermat 2012 kassel

Heft 19 No.19
S c h r i f t e n r e i h e B a u s t o f f e u n d M a s s i v b a u
S t r u c t u r a l M a t e r i a l s a n d E n g i n e e r i n
g S e r i e s
U N I K A S S E L
V E R S I T A T
Ultra-High Performance Concrete and
Nanotechnology for High Performance
Edited by
M. Schmidt
E. Fehling
Heft 19
No. 19
Proceedings of Hipermat 2012 3
rd International Symposium on UHPC and
Nanotechnology for High Performance Construction Materials Kassel, March 7–9, 2012
Edited by M. Schmidt E. Fehling
C. Glotzbach S. Fröhlich
Die Deutsche Nationalbibliothek verzeichnet diese Publikation in der Deutschen Nationalbibliografie; detaillierte bibliografische Daten sind im Internet über http://dnb.d-nb.de abrufbar
ISBN print: 978-3-86219-264-9 ISBN online: 978-3-86219-265-6 URN urn:nbn:de:0002-32656
© 2012, kassel university press GmbH, Kassel www.uni-kassel.de/upress
Herausgeber
Prof. Dr.-Ing. habil. M. Schmidt Prof. Dr.-Ing. E. Fehling Universität Kassel Universität Kassel Fachbereich Bauingenieur- Fachbereich Bauingenieur- und Umweltingenieurwesen und Umweltingenieurwesen Institut für Konstruktiven Ingenieurbau Institut für Konstruktiven Ingenieurbau Fachgebiet Werkstoffe des Bauwesens Fachgebiet Massivbau und Bauchemie Kurt-Wolters-Str. 3 Mönchebergstr. 7 D-34125 Kassel D-34125 Kassel Tel. +49 (561) 804 2656 Tel. +49 (561) 804 2601 Fax +49 (561) 804 2803 Fax +49 (561) 804 2662 [email protected]
[email protected] www.uni-kassel.de/fb14/massivbau www.uni-kassel.de/fb14/baustoffkunde
Ultra-High Performance Concrete (UHPC), one of the recent breakthroughs in concrete
technology, impresses us with its high durability and a compressive strength comparable to that
of steel. It permits the design of sustainable concrete structures such as wide-span bridges,
filigree shells and high-rise towers and allows for spectacular architectural designs.
In 2004 and 2008, two International Symposia on UHPC took place at the University of Kassel,
organized by the Department of Structural Materials and Construction Chemistry and the
Department of Structural Engineering. Since then, the set of knowledge about the Ultra-High
Performance Concrete has been substantially widened and its practical application has rapidly
increased worldwide. New researchers and users of UHPC have joined the community and
broadened the scope of its potential.
This conference as well has substantially grown since 2008. In 2012, about 130 speakers presented their impressions, research, and practical experience. It also attracted the attention
of many international standardization bodies.
Even though the material is already highly developed, it is still possible to increase its potential
even further using recent advancements in nanotechnology and colloidal chemistry. Nowadays,
the reactions of binders can be studied at the nanoscale, synthetic nanoparticles of various
oxides can significantly improve microstructure and reaction potential. This knowledge gives
rise to many new possibilities that allow developing impregnable ceramics or multifunctional
materials. They can, for example, carry agents for environmental protection, provide additional
self-healing potential, and act as part of heating or cooling measures. As nanotechnology provides many new and auspicious approaches to improve the performance of construction
materials and to open up new applications, the 3rd International Symposium on UHPC
extended its focus towards nano-optimized construction materials and its recent advancements.
This additional aspect led us to establish the new conference name HiPerMat, derived from
High Per formance Construction Materials.
This volume thus contains more than 120 contributions from many research disciplines that are
influenced by High Performance Materials and UHPC in particular: material sciences, structural
engineering, environmental engineering, nanotechnology, chemistry, architecture, codification,
and economy. A design adequate to the materials and to the construction of durable and sustainable high performance structures receives special attention.
We hope that our conference, Hipermat 2012, has once more contributed to the development of
modern and progressive buildings and materials for construction and will continue to do so in
the future.
Prof. Dr.-Ing. habil. Michael Schmidt Prof. Dr.-Ing. Ekkehard Fehling
8/15/2019 HiPerMat 2012 Kassel
Chairmen
Prof. Mouloud Behloul
Prof. Françoise de Larrard Lafarge, F
Prof. Marco di Prisco
Politecnico di Milano, I
Prof. Harald Müller Karlsruhe University of Technology, D
Prof. Aurelio Muttoni
EPFL Lausanne. CH
Prof. Jan Vitek
Prof. Alphose Zingoni
Symposium organizers
The Path to Ultra-High Performance Fiber Reinforced Concrete (UHP-FRC): Five
Decades of Progress
Naaman, Antoine E.
Michael Schmidt
17
State of the art of design and construction of UHPFRC structures in France
Jacques Resplendino
Theresa Ahlborn, Eric Steinberg
43
On the way to international design recommendations for Ultra High Performance Fibre
Reinforced Concrete
Ehsan Ghafari, Hugo Costa, Eduardo Júlio, António Portugal, Luisa Durães
71
Genady Shakhmenko, Aleksandrs Korjakins, Patricija Kara, Janis Justs, Inna Juhnevica
79
Cavitation Treatment of Nano and Micro Filler and Its Effect on the Properties of UHPC
Janis Justs, Genady Shakhmenko, Viktors Mironovs, Patricija Kara
87
Nanoparticles as accelerators for cement hydration Gerrit Land, Dietmar Stephan
93
Christoph Glotzbach, Dietmar Stephan, Michael Schmidt
101
Investigation the Effects of Nano-Silica Colloidal Solutions on Properties of Mortars
Ali Akbar Ramezanianpour, Shabnam Firoozmakan, Hamed Bahrami Jovein
109
Ali Akbar Ramezanianpour, Mahdi Mahdikhani, S. Sina Yousefian Moghaddam, Morteza Nikravan, S.Rahimeh Mousavi
117
A comparison between the pozzolanic reactivity of nanosilica sols and pyrogenic nanosilicas
Hesam Madani, Alireza Bagheri, Parhizkar Tayebe
125
http://slidepdf.com/reader/full/hipermat-2012-kassel 11/1056
Fluid Catalytic Cracking Residue additions such an alternative to Silica Fume in
UHPFRC
133
Photocatalysis
visible light irradiation
Shuai Yuan, Meihong Zhang, Jianping Zhang, Yin Zhao, Zhuyi Wang, Liyi Shi
141
Nanoparticles
147
Synthesis of Photoactive Silica Spheres with Titania Nano Coating as Potential Nano-
Composites for Mortar and Concrete
Sameena Kamaruddin, Dietmar Stephan
161
Jeffrey Chen, Matthieu Horgnies
Andreas Winzenburg, Rüdiger Faust
Raw Materials, Mixtur e Compositi ons and Fresh Concrete
Synergistic Effect of Rce Husk Ash and Fly Ash on Properties of Self-Compacting High
Performance Concrete
187
Proportioning Optimization of UHPC Containing Rice Husk Ash and Ground Granulated
Blast-furnace Slag
197
Per Fidjestol, Rein Terje Thorsteinsen, Paul Svennevig
207
Control of Rheology, Strength and Fibre Bond of UHPC with Additions – Effect of
Packing Density and Addition Type
Dirk Lowke, Thorsten Stengel, Peter Schießl, Christoph Gehlen
215
Influences on Repeatability and Reproducibility of Testing Methods for Fresh UHPC
Susanne Fröhlich, Michael Schmidt
Hybrid Intensive Mixer with integrated Rheometer for High Performance Concrete
Harald Garrecht, Christian Baumert, Andreas Karden
233
Influence of vacuum mixing on the mechanical properties of UHPC
Jeroen Dils, Geert De Schutter, Veerle Boel, Egon Braem
241
Definition of three levels of performance for UHPFRC-VHPFRC with available materials
Esteban Camacho, Juan Ángel López, Pedro Serna
249
Incorporating Coarse Aggregate
257
UHPC composites based on glass fibers with high fluidity, ductility, and durability Jeffrey Chen
265
Concrete (UHPFRC)
273
Effect of Heat Treatment Method on the Properties of UHPC
Detlef Heinz, Liudvikas Urbonas, Tobias Gerlicher
283
Hydration and Early Ag e
Modeling Cement Hydration Kinetics using the Equivalent Age Concept Xueyu Pang, Dale P. Bentz, Christian Meyer
291
Mechanical Properties of Ultra-High Performance Concrete (UHPC) at Early Age
Harald Budelmann, Jens Ewert
Andina Sprince, Aleksandrs Korjakins, Leonids Pakrastinsh, Genadijs Shakhmenko, Girts Bumanis
309
Shrinkage Behavior of Ultra High Performance Concrete at the Manufacturing Stage
Sungwook Kim, Jungjun Park, Dooyeol Yoo, Youngsoo Yoon
317
Creep and shrinkage prediction for a heat-treated Ultra High Performance Fibre-
Reinforced Concrete
325
Creep Behavior of UHPC under Compressive Loading with Varying Curing Regimes
Jason C. Flietstra, Theresa M. Ahlborn, Devin K. Harris, Henrique de Melo e Silva
333
Mitigation of early age shrinkage of Ultra High Performance Concrete by using Rice Husk
Ash
341
Durability
Microstructure of Ultra High Performance Concrete (UHPC) and its Impact on Durability
Jennifer C. Scheydt, Harald S. Mueller
349
Computer Modeling and Investigation on the Chloride Induced Steel Corrosion in
Cracked UHPC
Marine Performance of UHPC at Treat Island
Michael David Arthur Thomas, Brian Green, Ed O'Neal, Vic Perry, Sean Hayman, Ashlee Hossack
365
Evaluation of Durability Parameters of UHPC Using Accelerated Lab Tests
Julie Pierard, Bram Dooms, Niki Cauberg
371
Bond Strength between UHPC and Normal Strength Concrete (NSC) in accordance with
Split Prism and Freeze-Thaw cycling tests.
Miguel A. Carbonell, Devin K. Harris, Sarah V. Shann, Theresa M. Ahlborn
377
Concretes with Improved Acid Resistance
Ricarda Tänzer, Dietmar Stephan, Michael Schmidt
385
Tension and Bending
Direct and Flexural Tension Test Methods for Determination of the Tensile Stress-Strain
Response of UHPFRC
395
Experimental and Analytical Analysis of the Flexural Behavior of UHPC Beams
Eric T. Visage, K. D. S. Ranga Perera, Brad D. Weldon, David V. Jauregui, Craig M. Newtson, Lucas Guaderrama
403
Characterization of the Fracture Behavior of UHPC under Flexural LoadingEric L. Kreiger, Theresa Ahlborn, Devin K. Harris, Henrique A. de Melo e Silva
411
Johannes Gröger, Nguyen Viet Tue, Kay Wille
419
Tests on the Flexural Tensile Strength of a UHPFRC subjected to Cycling and Reversed
Loading reversed loading
427
Flexural Model of Doubly Reinforced Concrete Beams Using Ultra High Performance
Fiber Reinforced Concrete
Simone Stürwald, Ekkehard Fehling
Niki Cauberg, Julie Pierard, Benoit Parmentier, Olivier Remy
451
Charles Kennan Crane, Lawrence F. Kahn
459
Numerical Study on the Shear Behavior of Micro-Reinforced UHPC BeamsMartina Schnellenbach-Held, Melanie Prager 469
Experimental Investigations on I-Shaped UHPC Beams with Combined Reinforcement
under Shear Load
Ultimate Shear Strength of Ultra High Performance Fibre Reinforced Concrete Beams
Florent Baby, Joël Billo, Jean-Claude Renaud, Cyril Massotte, Pierre Marchand, François Toutlemonde
485
Guido Bertram, Josef Hegger
Experimental Investigations on UHPC Structural Elements Subject to Pure Torsion
Ekkehard Fehling, Mohammed Ismail
Changbin Joh, Jung Woo Lee, In Hwan Yang, Byung-Suk Kim
509
Martin Empelmann, Vincent Oettel
Guido Bertram, Josef Hegger
Ekkehard Fehling, Paul Lorenz, Torsten Leutbecher
533
Effect of adding micro fibers on the pullout behavior of high strength steel fibers in UHPC
matrix
Seung Hun Park, Dong Joo Kim, Gum Sung Ryu, Kyung Taek Koh
541
Literature Review on the Behaviour of UHPFRC at High Temperature
Pierre Pimienta, Jean-Christophe Mindeguia, Alain Simon, Mouloud Behloul, Roberto Felicetti, Patrick
Bamonte, Pietro G. Gambarova
Sung-Gul Hong, Sung-Hoon Kang, Eo-Jin Lee, Soo-Min Jeong
557
Elevated Temperatures Richard Way, Kay Wille
565
Behaviour of Ultra High Performance Concrete (UHPC) in Case of Fire
Dietmar Hosser, Björn Kampmeier, Dirk Hollmann
573
583
Ultra High Performance Concrete Structures under Aircraft Engine Missile Impact
Markus Nöldgen, Ekkehard Fehling, Werner Riedel, Klaus Thoma
593
Material Models
A Triaxial Fatigue Failure Model for ultra high performance concrete (UHPC)
Jürgen Grünberg, Christian Ertel
Ludger Lohaus, Nadja Oneschkow
Mechanical Behaviour of Ultra High-Performance Fibrous-Concrete Beams Reinforced
by Internal FRP Bars Emmanuel Ferrier, Laurent Michel, Philippe Lussou, Bruno Zuber
619
Fatigue Behaviour of plain and fibre reinforced Ultra-High Performance Concrete
Ludger Lohaus, Kerstin Elsmeier
Kenneth K. Walsh, Eric P. Steinberg
639
Composite Structures and Connection Technol ogy
Design Models for Composite Beams with Puzzle Strip Shear Connector and UHPC
Joerg Gallwoszus, Josef Hegger, Sabine Heinemeyer
647
Josef Hegger, Nguyen Viet Tue, Janna Schoening, Martina Winkler
655
Benjamin A. Graybeal, Matthew Swenty
663
V.H. Perry, Peter Seibert
Petr Hajek, Magdalena Kynclova, Ctislav Fiala
679
Hasan Han, Steffen Grünewald, Joost Walraven, Jeroen Coenders, Pierre Hoogenboom
685
Joerg Gallwoszus, Josef Hegger, Sabine Heinemeyer
693
Application of Steel Shares as Shear Connectors in Slender Composite Structures
Wolfgang Kurz, Jürgen Schnell, Susanne Wiese
701
Structural Behaviour and Load-Bearing Capacity of Reinforced Glued Joints of UHPC-
Elements
709
Adhesion of fine-grained HPC and UHPC to Steel and Glass
Joachim Juhart, Bernhard Freytag, Gerhard Santner, Erwin Baumgartner
717
725
Ultra High Performance Spun Concrete Columns with High Strength Reinforcement
Corinna Mueller, Martin Empelmann, Helmut Lieb, Florian Hude
733
Experimental analysis and numerical simulation of Ultra-High-Performance Concrete
tube columns with a steel sheet wrapping for large sized truss structures
Ludger Lohaus, Jürgen Grünberg, Nick Lindschulte, Sven Kromminga
741
Lionel Moreillon, Joanna Nseir, René Suter
749
Pierre Marchand, Florent Baby, Waël Al Khayer, Mohammed Attrach, François Toutlemonde
757
765
Analytical and experimental investigations on the introduction of compressive loads in
thin walled elements made of UHPFRC by the use of implants
Jan Mittelstädt, Werner Sobek
Load-Bearing Behaviour of Sandwich Strips with XPS-Core and Reinforced HPC-
Facings
781
APPLICATIONS
Microstructural Optimization of High-Strength Performance Air Hardened Foam Concrete
Bernhard Middendorf, Armin Just
UHPC Under Intensive Autoclave Cycles for Energy Storage Water Tanks.
Mohamed Abd Elrahman, Bernd Hillemeier
799
Ultra-High Performance Concrete for Drill Bits in Special Foundation Engineering
Hursit Ibuk, Karsten Beckhaus
807
Effect of Fibres on Impact Resistance of Ultra High Performance Concrete
Sandy Leonhardt, Dirk Lowke, Christoph Gehlen
811
On the way to micrometer scale: applications of UHPC in machinery construction
Bernhard Sagmeister
825
Sewer pipes and UHPC - Development of an UHPC with earth-moist consistency Michael Schmidt, Torsten Braun, Heiko Möller
833
Development of an Ultra-High Performance Concrete for precast spun concrete columns
Thomas Adam, Jianxin Ma
841
Infrastructure
Whiteman Creek Bridge – A Synthesis of Ultra High Performance Concrete and Fibre
Reinforced Polymers for Accelerated Bridge Construction
Wade Francis Young, Jasan Boparai, Vic Perry, Brent Archibald, Sameh Salib
849
Current Research on Ultra High Performance Concrete (UHPC) for Bridge Applications in Iowa
Sri Sritharan, Sriram Aaleti, Dean Bierwagen, Jessica Garder, Ahmad Abu-Hawash
857
R&D Activities and Application of Ultra High Performance Concrete to Cable Stayed
Bridges
Byung-Suk Kim, Seungwook Kim, Young-Jin Kim, Sung Yong Park, Kyung-Teak Koh, Changbin Joh
865
Structural Performance of Prestressed UHPC Ribbed Deck for Cable-Stayed Bridge
Sung Yong Park, Keunhee Cho, Jeong Rae Cho, Sung Tae Kim, Byung Suk Kim
873
Bernhard Freytag, Günter Heinzle, Michael Reichel, Lutz Sparowitz
881
Practical Use of Fibre-reinforced UHPC in Construction - Production of Precast Elements
for Wild-Brücke in Völkermarkt
Structural Design and Preliminary Calculations of a UHPFRC Truss Footbridge
Juan Angel López, Esteban Camacho, Pedro Serna Ros, Juan Navarro Gregori
897
Behaviour of an Orthotropic Bridge Deck with a UHPFRC Topping Layer Pierre Marchand, Fernanda Gomes, Lamine Dieng, Florent Baby, Jean-Claude Renaud, Cyril Massotte, Marc Estivin, Joël Billo, Céline Bazin, Romain Lapeyrere, Dominique Siegert, François Toutlemonde
905
Benjamin Scheffler, Michael Schmidt
913
"Whitetopping" of Asphalt and Concrete Pavements with thin layers of Ultra-High-
Performance Concrete - Construction and economic efficiency
Cornelia Schmidt, Michael Schmidt
Application of Ultra-High Performance Concrete (UHPC) as a Thin-Topped Overlay for
Concrete Bridge Decks Sarah V. Shann, Devin K. Harris, Miguel A. Carbonell, Theresa M. Ahlborn
929
Assessment of a UHPFRC based bridge rehabilitation in Slovenia, two years after
application
937
Structural Health Monitoring of the Gaertnerplatz Bridge over the Fulda River in Kassel
Based on Vibration Test Data and Stochastic Model Updating
Michael Link, Matthias Weiland
945
Life-Cycle Cost Analysis of a UHPC-Bridge on Example of two Bridge Refurbishment
DesignsSiemon Piotrowski, Michael Schmidt
957
Material performance control on two large projects: Jean-Bouin stadium and MUCEM
museum
Innovative design of bridge bearings by the use of UHPFRC
Simon Hoffmann, Hermann Weiher
Study on the Application of UHPC for Precast Tunnel Segments
Norbert Randl, Arnold Pichler, Walter Schneider, Joachim Juhart
981
Architectural Concrete with UHPC for facades and interior design - recent application in
Germany
The First Architectural UHPC Façade Application in North America
Peter J. Seibert, Vic H. Perry, Gamal Ghoneim, Gerald Carson, Rafaat El-Hacha, Ignacio Cariaga, Don Zakariasen
997
Rogier Friso van Nalta, Tommy Bæk Hansen
1005
Precast thin shells made of UHPFRC for a large roof in a waste water treatment plant
near Paris
1011
Off-shore Foundations
Design of Grouted Connections for Offshore Wind Energy Converters and Composite
Structures using UHPC
1027
As part of the conference bag, you received a storage device containing the online version of this volume. You can
access all the information in this book, skim through it via a fulltext search, filter the contributions, and get further
information on the authors and the visitors of HiPerMat 2012.
To access the online proceedings, all you need is a recent web browser and a PDF viewer, you can use any operating
system. Just plug the USB storage device into a compatible computer and open the file start.html in its root
directory.
On the USB stick, you will find one additional contribution:
Grouted Connections with HPC and UHPC for Offshore Wind Power Plants - Material
Properties and Quality
The Path to Ultra-High Performance Fiber Reinforced Concrete (UHP-FRC): Five Decades of Progress
Antoine E. Naaman1, Kay Wille2
1: Department of Civil and Environmental Engineering, University of Michigan, Ann Arbor, Michigan, USA 2: Department of Civil & Environmental Engineering, University of Connecticut, Storrs, Connecticut, USA
Following the onset of modern developments of fiber reinforced concrete in the early 1960’s, there has
been a continuous search for its improved performance. One can thus follow such progress in milestones
along four inter-related paths: one path for the cementitious matrix, another for the fiber, the third for the
interface bond between fiber and matrix, and the forth for the composite itself. After identifying some key
milestones for each path, over a period of five decades, leading to today’s ultra-high performance fiber
reinforced concretes (UHP-FRCs), the composition and key mechanical properties of newly designed
UHP-FRC mixtures obtained without heat or pressure curing while using materials available on the US
market are described. Record breaking performance in direct tension (in terms of strength, ductility, and
fracture energy) is reported and sets limits to exceed in the future.
Keywords: bond strength, ductility, fiber reinforced concrete, fracture energy, high strength, high
performance, steel fibers, tensile testing, ultra-high performance.
1 Introduction
The past five decades mark the modern development and broad expansion of fiber reinforced
cement and concrete composites, which has led to today extensive applications and market
penetration worldwide. Their success is due in part to significant advances in the fiber
reinforcement, the cementitious matrix, the interface bond between fiber and matrix,
fundamental understanding of the mechanics of the composite, and improved cost-
effectiveness. Ultra-high performance cement or concrete (UHPC) composites are very brittle and, as such,
often compared to ceramics. Adding fibers to an UHPC matrix in order to improve its toughness
and ductility, has led to the terminology used here, that is: “ultra high performance fiber
reinforced cement or concrete composite” or UHP-FRC composite.
It is strongly believed that high performance and ultra-high performance fiber reinforced
cement composites are emerging materials well suited for use in the next generation of
infrastructure. There is real need to tailor-design these composites to satisfy certain demands
on strength, toughness, durability, ductility, and fracture energy. These include demand for
combined axial and bending resistance at the base of columns in high rise buildings, demand
for high rotational capacity, demand for combined plastic shear and plastic bending
deformations at the base of shear walls, high shear and bending resistance at the continuous
supports in long-span bridges, and, blast and impact resistant structures. Clearly high
performance mechanical properties are needed. UHP-FRC composites seem to be also
particularly suitable in thin products applications, such as panels and cladding, where they
could be used as stand-alone material. Enhanced durability properties could fulfill the need for
structures with longer lifetime, less maintainance and repair.
Combined properties of interest to civil engineering applications include strength, toughness,
energy absorption, stiffness, durability, freeze-thaw and corrosion resistance, fire resistance,
tightness, appearance, stability, construct-ability, quality control, and last but not least, cost and
user friendliness.
High strength and high performance concrete, high performance fiber reinforced concrete
(HPFRC), ultra-high performance concrete (UHPC), and ultra-high performance fiber reinforced
concrete (UHP-FRC) have been addressed in numerous investigations in the US and abroad [1-
52]. A recent review of their definitions, if available, can be found in Ref. [23]. For the purpose
of this paper and with the intent of providing extremely brief definitions until technical committees working on these materials provide some, the following definitions are suggested:
Ultra high performance concrete (UHPC) is a hydraulic cement-based concrete with a
compressive strength at least equal to 150 MPa, etc.
Ultra-high performance fiber reinforced concrete (UHP-FRC) is a UHPC with fibers added
in order to significantly improve a particular mechanical property (or properties), etc.
The additive “etc…” suggests that these short definitions could be qualified by one or a
combination of attributes, such as adopted by some researchers [19, 20]. For UHPC, these
attributes include, for instance, a minimum water to binder ratio, a minimum cement content, a
minimum packing density or a minimum level of durability performance. For UHP-FRC the
composite can be qualified by whether it is strain-softening or strain-hardening in tension [12,13], or whether it is deflection-softening or deflection-hardening in bending, as well as by a
minimum level of ductility, toughness or fracture energy. Other attributes may be imposed
depending on particular applications; examples include permeability, electrical conductivity,
resistance to chloride penetration, volume stability (shrinkage or expansion), etc.
How a recommended level of performance is achieved in practice should be of less interest
to a general definition. Thus UHPC could be obtained using heat curing or pressure curing or
none at all; it may necessitate the use of a particular mineral additive or a polymer additive, or a
special mixing procedure.
Whether a single or multiple attributes are used, reference to broadly acceptable standard
tests procedures and specimen dimensions is needed to help clearly identify a particular
composite.
3 Chronological Developments: Five Decades of Progress
It is difficult to put specific limits at technical advances and progress on a particular subject, not
only in terms of time but also geographic location. However, one can point out certain
milestones that helped improve the performance of cement and concrete composites in general
and somehow started a trend. For UHP-FRC, these milestones can be followed along four
paths and their combination, namely, the cement matrix, the fiber, the bond at the interface
between fiber and matrix, and the resulting composite.
3.1 Concrete Matrix and Fiber
In Table 1, the authors list in chronological order key advances related to the concrete matrix
(2nd column) and the fiber (3rd column) since the 1960’s, mostly as encountered in the Europe
and the US. It is likely that a similar evolution took place elsewhere around the world, but with
some slight delay (or advance) in adoption or implementation. Table 1 is self-explanatory.
3.2 Progress Leading to Ultra High Performance Fiber Reinforced Concrete
It has been a common aspiration for researchers dealing with cement and concrete composites
to race for increasing compressive strength. In the early 1970’s very high compressive
strengths of up to 510 MPa were reported from testing small specimens prepared under special
conditions with vacuum, heat and pressure curing [24, 25]. In the early 1980’s the addition of
special polymer and the use of very low water to cement ratios led to what was described as
micro-defect-free cement with a compressive strength exceeding 200 MPa [26]; no pressure or
4
heat curing was needed. Such discoveries, however, while illustrating the potential of the
material, did not translate into easily implemented applications. In Tables 2, the authors
summarize various milestones related to numerous such composites developed since the
1970’s. Widely used acronyms are highlighted. Table 2 covers the period from 1970 to 2011. It
gives the approximate date of introduction, the range of compressive strength reported, the
reference, the name and/or acronym used for the material developed, if any, and the special
conditions applied to achieve the reported properties. Related references can be found in the
reference list [24 to 49] Note that Table 2 is by no means exhaustive; it covers what the
authors consider key developments in the US and Europe. The emphasis is on materials that
have led to ultra-high performance concrete and ultra-high performance fiber reinforced
concrete as understood at time of this writing.
Table 1: Chronological Advances in the matrix and fibers since the 196 0’s.
Decade Cementitious Matrix and Concrete Fiber
1970’s

Better understanding shrinkage, creep, porosity, … High strength concrete to 50 MPa in practice
Development of water reducers
Smooth steel fibers; normal strength

1980’s
Increased development of chemical additives: HWRA, etc…
Increased utilization of fly ash and silica fume, and other mineral additives, etc…
Increased flowability (flowable concrete)
Reduction in W/C ratio;
High-Strength-Concrete terminology: up to 60 MPa; special high strength: up to 80 MPa; exotic high strength (special aggregate and curing): up to 120 MPa
High-Performance-Concrete terminology: high-strength- concrete with improved durability properties.
Deformed steel fibers: normal and high strength
Low-modulus synthetic fibers (PP, nylon, etc..)
Increased use of glass fibers
Micro fibers
1990’s
Increased use of supplementary cementitious materials as cement replacement
UHPC: application of concept of high packing density; addition of fine particles; low porosity; lower water to cementitious ratio;
Self consolidating concrete; self compacting concrete;
New steel fibers with a twist (untwist during pull- out)
PVA fibers with chemical bond to concrete
Improved availability of synthetic fibers
2000’s
UHPC: improved understanding of high packing density; application of nanotechnology concepts
Ultra high strength steel fibers: smooth or
deformed with diameters as low as 0.12 mm and strengths up to 3400 MPa
Carbon nano-tubes; carbon nano-fibers
…???...
Table 2: Developments in high str ength high performance cement composites from the 1970’s to date (in the
US and Europe).
1972 230 Yudenfreund, Skalny, et al.
Paste; vacuum mixing; low porosity; small specimens.
1972 510 Roy et al. (US)
Paste; high pressure and high heat; small specimens.
1981 200 Birchall et al. (UK)
MDF (Micro-Defect-Free) Paste; addition of polymer; bending strength up to 150 MPa
1981- 1983
DENSIT; COMPRESSIT Mortar and concrete; normal curing; use of microsilica
1980’ all
DSP (Densified Small Particles)
Improved particle packing; use of microsilica; use of superplasticizers;
1980’s Up to 120 Many researchers worldwide (Shah; Zia; Russell; Swamy; Malier; Konig; Aitcin; Malhotra)
High Strength Concrete; High Performance Concrete (HSC; HPC)
Concrete with special additives and aggregates for structural applications; use of superplasticizers; normal curing; better durability
1980’s
(US)
fractions of steel fibers (8% to 15% by volume)
1987 Up to 140 Bache (Denmark)
CRC (Compact Reinforced Concrete)
Concrete with high volume of steel fibers used with reinforcing bars
1987 Open range Naaman (US)
HPFRCC (High Performance Fiber Reinforced Cement Composites)
Mortar and concrete with fibers leading to strain-hardening response in tension
1991 Open range Reinhardt and Naaman (Germany, US)
HPFRCC (First International Workshop)
1992 Open range Li and Wu (US)
ECC (Engineered Cementitious Composites)
1994 In excess of
1995 Up to 800 Richard & Cheyrezy RPC (Reactive Powder Concrete)
Paste and concrete; heat and pressure curing; particle packing
1998 and later
DUCTAL 90 o C heat curing for 3 days; steel
fibers up to 6% (commercially available)
2000 and later
CEMTEC; CEMTEC-multi-scale
Early 2000
UHPC and UHP-FRC Many formulations based on DUCTAL
2005 Up to 140 Karihaloo (UK)
CARDIFRC Optimized particle packing and mixing procedure
2005 Up to 200 Jungwirth (Switzerland)
CERACEM Formulation similar to DUCTAL, larger fibers, larger aggregates
2004 Open range >150
First International Symposium on UHPC
Many formulations similar to DUCTAL with and without heat curing; with and without fibers.
2005 Open Schmidt et al. (Germany)
Sustainable Building with UHPC
Second International Symposium on UHPC
Many formulations similar to DUCTAL with and without heat curing; with and without fibers.
2011 >150 Accorsi & Meyer (US) UHPC Workshop First US Workshop
2011 Up to 290 Wille & Naaman
(US-Germany)
UHP-FRC No heat curing; optimized packing;
record direct tensile strength 2011 ACI UHPC Committee 239 First meeting: Oct. 2011
Also: PCI working group
6
German Research Program: Sustainable Building with UHPC
4 Summary of Key Mechanical Properties Achieved to Date
This section provides a summary of the composition, mixing procedure, and key mechanical
properties achieved using particular UHP-FRC composites developed by the authors and their
collaborators. Several references can be consulted for additional details [44 to 52].
4.1 Mixture Composition
Examples of mixture compositions for UHPC and UHP-FRC composites developed by the
authors in prior investigations [45, 48] are provided in Table 3. The ratio for each material is
given by weight of cement. The compressive and tensile strengths observed from tests are
given in the last rows of the table. A typical composition of UHPC by volume is illustrated in Fig.
1 and is compared to a conventional normal concrete (NC) with the same air content. It can be
observed that the paste phase in UHPC is more than 2.5 times that of NC while the inert
particle phase is much smaller to essentially compensate for the difference. A description of the
particle sizes of the various materials used and some of their recommended characteristics are
shown in Fig. 2. The average particle size of each material is compared in Fig. 3 to the ideal theoretical particle sizes that would optimize packing density [44]; the theoretical particles sizes
are shown as distribution functions around average diameters d 1, d 2 , d 3, … where d 1 is
assumed to be equal 0.5 mm, and the other diameters are derived for optimum packing.
Table 3: Examples of mixtures developed for UHPC and UHP-FRC.
Type UHPC UHP-FRC
Cement 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00
Silica Fume 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25
Glass Powder 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25
Water 0.220 0.195 0.190 0.180 0.212 0.200 0.185-0.195 0.18-0.20 0.207
Superplasticizer a 0.0054 0.0108 0.0108 0.0114 0.0054 0.0108 0.0108 0.0108 0.0108
Sand A 0.28 0.30 0.31 1.05 0.27 0.28 0.29 0.92 0.76
Sand B c 1.10 0.71 0.72 0.00 1.05 0.64 0.67 0.00 0.00
ratio Sand A/B 20/80 30/70 30/70 100/0 20/80 30/70 30/70 100/0 100/0
Fiber 0.00 0.00 0.00 0.00 0.15/0.25 0.22 0.18-0.27 0.22-0.31 0.71
Fiber Vol.% 0 0 0 0 1.5/2.5 2.5 2.0-3.0 2.5-3.5 5 e /8
]28,[' d cube f c MPa 194 207 220-240 232-246 207/213 219 227-261 251-291 270 e
/292 f
g ; 6.9-7.8
g ; 7.4-8.5
g ; 8.2-9.0
e
d non vibrated, non surface cut; e twisted (T) fiber;
f straight (S) fiber;
failure
7

Figure 1: An example of mix proportions by volume comparing UHP-FRC with normal concrete (NC).
Figure 2: Materials used in the mixtures developed and their particular characteristics [Ref. 48].
4.2 Mixing Procedure
In UHPC, the number of ingredients is higher and the fineness of the particles is smaller
compared to normal strength concretes. Therefore, it is important that all particles, especially
the very fine ones, are uniformly distributed. Because very fine particles tend to agglomerate
and form chunks, the minimal shear force for breaking these chunks can be reduced by keeping
the particles dry; it is thus recommended to mix all dry particles first before adding the water
and high –range water reducing (HRWR) additives.
In this investigation [45, 48], silica fume was first mixed with all the sand for about 5 minutes,
similar to [40]. Afterwards, cement and glass powder were added and mixed dry for at least
another 5 minutes before water was added. The whole amount of HRWR was added at once
after the water. The UHPC became fluid after approximately 5 minutes of adding the water and
HRWR. Fibers, if any, were then added during the following 5 min. A horizontal pan mixer
8
(capacity of around 60 Liter, 1.8 kW), with constant mixing speed (60 rpm), was sufficient for
mixing the UHPC described in this research.
10 100 1000
3

Figure 3: Comparison between particle sizes of materials used with theoretical sizes (di) obtained to optimize
packing density [Ref. 44].
Figure 4: Comparison of compressive strength of UHPC and UHP-FRC mixtures developed versus existing
data reported in the technical literature [Ref. 48].
4.3. Compressive Strength and Stress-Strain response
The average compressive strength at 28 days (using 50 mm cube specimens) of the various mixtures described in Table 4 is compared to equivalent cubic compressive strengths of various
UHPC composites reported in the technical literature. It can be observed that they compare
9
very favorably to existing data, particularly given the fact that they were obtained with no heat
treatment, no special mixer, and using materials commercially available on the US market.
Details can be found in [45, 48].
4.4 Bond Stress-Slip at the Fiber-Matrix Interface
In order to optimize the response of UHP-FRC after first percolation cracking, that is, to
essentially improve simultaneously its post-cracking tensile strength, the corresponding strain capacity, and its fracture energy, a thorough attempt was made to optimize the bond at the fiber
to matrix interface, and to use deformed steel fibers of tensile strength as high as can be
practically obtained from manufacturers of steel wires. The objective was to achieve the highest
possible bond without failing the fiber. Extensive pull-out tests were then carried-out on single
fibers with different characteristics [50, 51]. Examples of bond shear stress versus slip curves
obtained using smooth brass-coated steel fibers embedded in various matrices are shown in
Fig. 5. The shear stress was obtained from the pull-out load and the embedded length of fiber at
the slip considered. It can be observed that even with smooth fibers, very high local shear
stresses of up to 30 MPa can be obtained; unlike what is observed with conventional concrete,
this behavior seems to be particular to UHPC and is likely due to the very dense transition zone around the fiber and the very fine particles it contains. Details of the study can be found in Ref.
[50].
Figure 6 illustrates for a given fiber, the influence of the twist ratio on the pull-out load versus
slip response. Thus the higher the twisted ratio, the higher the maximum pull-out load, up to a
level where the fiber fails. Tensile stresses exceeding 3000 MPa are induced in the fiber. On
the right side of Fig. 6, the photograph shows the damage on the surface of the fiber where the
brass coating is abraded, likely due to the compactness of the zone around the fiber and the
presence of glass powder.
Figure 5: Typical bond stress versus relative slip relationships using different matrices [Ref. 50].
4.5 Tensile Response
Examples of stress-strain curves obtained from specimens tested in direct tension are shown in
Figs.7 and 8. Figure 7 compares the tensile stress strain response of UHP-FRC composites
using premixed twisted steel fibers with typical data reported in the literature from Ductal and
Ceracem [16, 35, 36, 37, 41]. It can be observed that for about the same fiber content, the
composite tensile strength is about doubled, and the strain at peak stress is about tripled. Note that, to the best of the authors knowledge, test series T12-1% (using high strength twisted steel
fibers with an equivalent diameter of 0.12 mm) gives the highest tensile strength (15.9 MPa) per
10
unit volume of composite recorded to date in the technical literature and also the highest strain
capacity, for any fiber reinforced cement composite using discontinuous fibers [49].
Figure 6: Typical effect of twist ratio of a steel fiber on its pull-out load versus slip response [Ref. 49].
Figure 8 also provides a comparison of the response of various UHP-FRC composites in
tension. In particular, it shows the best results obtained in Ref. [49], for a composite using a
Sifcon (slurry infiltrated fiber concrete) process, and an composite using a hybrid fiber mixture.
Although the fiber content by volume is 5.5% and 6% respectively, to the best of the authors
knowledge, the post-cracking tensile strength achieved (about 37 MPa) and its corresponding
strain capacity are the highest so far reported in the technical literature for a fiber reinforced
cementitious matrix subjected to direct tension. The tensile post-cracking strains at peak stress
(Figs. 7 and 8) exceeding in some cases 1% are also the highest observed to date for steel
fiber reinforced cement composites.
Similarly, to the best of the authors knowledge, the energy absorption capacity g obtained per 1% volume fraction of steel fibers for series T12 1% (Fig. 7) is the highest value (g = 128
kJ/m3) achieved to date for a cement composite with discontinuous fibers. It exceeds at least 5
times the energy values reported by other researchers for UHP-FRC composites [49].
Figure 7: Comparison of tensile stress-strain response of UHP-FRCs developed with composites from other
researchers [Ref. 49].
Figure 8: Tensile stress-strain response curves showing highest tensile strengths recorded to date [Ref. 49].
4.6 Fracture Energy Figure 9 illustrates typical values of fracture energy obtained from direct tensile tests of different
UHP-FRC-B (Table 3) varied by amount and type of fiber [47]. How the average fracture energy
Gf (in kJ/in2) of each test series was calculated is described in Ref. [47]. It comprises the
dissipated energy per unit volume during strain hardening g f,A, the dissipated energy per unit
ligament area Gf,A to open one crack up to pc and the dissipated energy per unit ligament area
Gf,B to completely separate the critical (localized) crack during softening.
The values shown in Fig. 9 are among the highest reported in the technical literature and
exceed the values of comparable UHP-FRC by a significant margin [47]. For instance, test
series UHPFRC-T1-1.5 obtained with no heat curing shows Gf = 31 kJ/m2, that is,
Gf = 20.67 kJ/m2 per 1% volume of fibers. In comparison, a fracture energy of 40 kJ/m2 is reported by Richard and Cheyrezy (1995) for Reactive Powder Concrete using 2.5 % steel
fibers with 90°C thermal treatment; that is equivalent to 16 kJ/m 2 per 1% volume of fiber.
Figure 9: Examples of fracture energy values obtained for some of the UHP-FRC developed [Ref. 47].
12
5 Concluding Remark
This paper summarized in a first part some historical developments since the 1960’s that led to
ultra-high performance (UHPC) and ultra-high performance fiber reinforced concrete (UHP-
FRC) as we understand them at time of this writing. The second half of the paper was devoted
to describing key information on several UHPC and UHP-FRC mixtures that led to composites
with record breaking tensile properties. Indeed by combining an ultra-high strength cementitous matrix and very high strength fine diameter steel fibers with tailored bond properties, tensile
strength up to 37 Mpa, strain at maximum stress up to 1.1%, and energy absorption capacity
prior to softening up to 304 kJ/m3 were realized for the composite. These values exceed by a
significant margin the current tensile properties of UHP-FRC reported in the technical literature.
Multiple cracking with crack spacing as small as 1 mm and crack widths as small as 4 microns
prior to localization of tension failure were observed.
Today the technical challenge for the use of ultra high performance fiber reinforced concrete
in structural applications is not through increased compressive strength (which can easily be
made to exceed 200 MPa) but rather through an increased combination of tensile strength,
tensile ductility and energy absorption capacity. Moreover, on the practical side, the challenge is to achieve the desired properties for design, in both the fresh and hardened state, at least
cost. Technically the record-breaking results mentioned above on tensile strength shall be
exceeded in the future, but the real success of the composite in practice will greatly depend on
its cost-benefit ratio in a given application.
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thousands of studies available at time of this writing.
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13
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Strength Cement-Based Materials, J. F. Young, Editor, Materials Research Society, Symposia
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Arbor, October 1987, 138 pp. Also published as AFWL-TR-87-115, August 1988.
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Journal , Vol. 86, No. 3, May-June 1989, pp. 244-251.
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Utilization of High Strength High Performance Concrete, Paris, France, 1996, pp. 1375-1381.
[35] Orange, G., Dugat, J., and Acker, P. “DUCTAL: New Ultra H igh Performance Concretes. Damage,
Resistance and Micromechanical Analysis,” BEFIB 2000, Fifth RILEM Symposium on Fiber-
Reinforced Concretes (FRC), Ed. By P. Rossi and G. Chanvillard, Lyon, 2000, pp. 781-790.
[36] Chanvillard, G., and Rigaud, S., “Complete Char acterization of Tensile Properties of Ductal UHPFRC According to the French Recommendations,” in High Performance Fiber Reinforced
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Pro. 30, June 2003, pp. 95-113.
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Schmidt, M., and Sturwald, S., Editors, “Ultra High Performance Concrete (UHPC)”, Proceedings of
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GmbH, Germany, May 2008, pp. 3-9.
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ultra-high-performance fiber-reinforced concrete.” ACI Materials Journal , Vol. 105, No. 6, 2008, pp.
603 –609.
[39] Benson, D.S.P., and Karihaloo, B.L., “CARDIFRC – Development and Mechanical Properties,“ Part
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433-443.
[40] Jungwirth, J., 2006, “Zum Tragverhalten von zugbeanspruchten Bauteilen aus Ultra-Hochleistungs-
Faserbeton,“ EPF Lausanne, Ph.D. thesis, 2006.
[41] Accorsi, M., and Meyer, C., „Ultra High Performance Concrete Workshop,“ Columbia University,
New York, Jan. 2011; unpublished report.
[42] Kim, D.J., Naaman, A.E., and El-Tawil, S., “High Tensile Strength Strain-Hardening FRC
Composites with Less Than 2% Fiber Content,” in Proceedings of 2nd International Symposium,
Ultra High Performance Concrete (UHPC), Edited by E. Fehling, M. Schmidt and S. Sturwald,
Universitat-Kassel, Germany, March 2008, pp. 169-176.
[43] Naaman, A.E., and Wille, K., “Some Correlation Between High Packing Density, Ultra-High
Performance, Flow Ability, and Fiber Reinforcement of a Concrete Matrix; BAC2010 – 2
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Iberian Congress on Self Compacting Concrete, University of Minho – Guimaraes, Portugal. July 1-2, 2010 ,
Proceedings Edited by J. Barros, J. Sena-Cruz, R.M. Ferreira, and A. Camoes, pp. 3-18.
[44] Wille, K., Naaman, A.E., and Parra-Montesinos, G. “Ultra High Performance Concrete with
Compressive Strength Exceeding 150 MPa: A Simpler Way,” ACI Materials Journal , Vol. 108, No.
No. 1, Jan. – Feb., 2011, pp. 46 – 54.
[45] Wille, K., Kim, D. and Naaman, A. E., “Strain-Hardening UHP-FRC with Low Fiber Contents”,
Materials and Structures, published online Aug. 4th 2010, in Journal Vol. 44, No. 3, 2011, pp. 583.
[46] Wille, K. and Naaman, A. E., “Fracture Energy of UHPFRC under Direct Tensile Loading”,
FraMCoS-7 International Conference, Jeju, KOREA, May 23-28, 2010. Electronic Proceedings.
[47] Wille, K., Naaman, A.E., and El-Tawil, S., and Parra-Montesinos, G., “Ultra-high performance
concrete and fiber reinforced concrete: achieving strength and ductility with no heat curing,”
Materials and Structures, accepted for publication. 2011. [48] Wille, K., Naaman, A.E., and El-Tawil, S. “Optimizing Ultra-High Performance Fiber Reinforced
Concrete: Mixtures with Twisted Fibers Exhibit Record Performance under Tensile Loading,”
Concrete International , Vol. 33, No. 9, Sept. 2011, pp. 35-41.
[49] Wille, K., and Naaman, A.E., “Bond-Slip Behavior of Steel Fibers Embedded in Ultra High
Performance Concrete,” Proceedings of 18 European Conference on Fracture and Damage of
Advanced Fiber-Reinforced Cement-Based Materials, Contribution to ECF 18, Dresden, V.
Mechtcherine & M. Kaliske (eds.), Aedificatio Publishers, Freiburg, September 2010, pp.99-111.
[50] Wille, K. and Naaman, A.E., “Pull-Out Behavior of High Strength Steel Fibers Embedded in UHPC ,”
ACI Materials Journal , accepted for publication, in press.
[51] Wille, K., and Parra-Montesinos, G., “Effect of Beam Size, Casting Method and Support Conditions
on the Flexural Behavior of Ultra High Performance Concrete,” ACI Materials Journal , in press,
2012.
[52] Zia, P., Leming, M.L., and Ahmad, S.H., “High Performance Concretes, A State -of-the-Art Report,”
Strategic Highway Research Program, National Research Council, Report No. SHRP-C/FR-91-103,
Washington, D.C., 1991.
Michael Schmidt
Institute of Structural Engineering, University of Kassel, Germany
In Germany, a 12 Mio. € Research Program on UHPC has just been fin ished. It started in 2005, covering
a wide range of topics related to UHPC. The program was funded by the German Research Foundation
(DFG) and coordinated by the University of Kassel. More than 20 research institutes were involved. Its
purpose was to elaborate the basic knowledge necessary to draft reliable Technical Standards covering
materials, material adequate design principles and innovative construction and fitting technologies to
make UHPC a reliable, commonly available, economically favorable, regularly applied material. This
paper describes the intention and the background of the program, and it gives an overview over the
topics being dealt with and the results recently available. It is part of a series of articles during this
conference presenting some topics of the program in more detail.
Keywords: Ultra-High Performance Concrete, materials, design, construction, state-of-the-art
1 Introduction
In Germany, a comprehensive 12 Mio. € Research Program on UHPC is practically completed
covering a wide range of topics related to UHPC. The program was funded by the German
Research Foundation (DFG) and coordinated by the University of Kassel. More than 20
research institutes were involved, striving to elaborate the basic knowledge necessary to draft
reliable technical standards covering both materials and design principles to make UHPC a
reliable, commonly available, economically favorable, and regularly applied material. The fields
of interest that the individual research projects concerned themselves with include the suitability
and performance of raw materials including cements, inert or reactive mineral fillers, artificial
nanoparticles, and improved plasticizers. Basic research on appropriate mix designs for
different applications, the rheological specifics of the fresh concrete and its hydration were
evaluated as well as the time dependent strength and deformation behavior of hardened UHPC
with and without fibers. Also involved were scientists and engineers working on adequate
design and construction procedures including new appropriate technologies to build high
performance light and slender and thus sustainable structures.
The Program was subdivided in 8 main topics, each being coordinated by a working group
combining several intertwined projects:
Time-Dependent Behavior (shrinkage, creep)
Failure and Fatigue Behavior
Design and Construction
Testing The paper will present the overall aims and visions of this project as well as the background
aspects that led to its installation, and the main results elaborated from 2005 to 2011. In 2009,
the last of three two-year-periods of research was started, primarily consisting of projects
researching design and construction. This contribution is a “keynote” introduction to a series of articles at this conference
presenting some results of the last research period in more detail [10-16].
17
2 Objectives and technical background
The most notable characteristic of Ultra-High Performance Concrete (UHPC) is its extremely
dense microstructure resulting in a steel-like compressive strength of about 180 to 250 MPa
combined with a significantly improved durability. The structural density results primarily from a
high packing density of fine and ultra-fine particles ≤ 125 μm in the cement matrix, and a
comparatively low w/c-ratio of about just 0.20. The technological basis was already laid by Bache [1] in Denmark in the 1980s. Among
others, Okamura et. al contributed to the theoretical background of particle optimization [2,3,4].
The large scale practical application did not begin until the 1990s when new
superplasticizers based on polycarboxylate ethers (PCE) with a significantly improved
performance were developed. For about 10 years, dry mixed UHPC products have been
commercially available and have already been successfully applied for bridges and other
visually and technically appealing, spectacular structures in several countries.a, e.g. for the very
first bridge made of UHPC in Sherbrook in Canada.
The first German large scale application was the “Gaertnerplatzbridge” in Kassel [5,6] built in
2007 (Figure 1). This very slender structure consists of a 3D steel truss in combination with longitudinal girders and deck slabs, both made of prefabricated, prestressed, fiber-reinforced
UHPC elements. Due to the high adhesive tensile strength of the material, the slabs were glued
to the girders with an epoxy resin without any additional mechanical fitting device [7]. The
bridge has been intensively monitored since its construction. This data is used to validate the
assumptions that had to be made concerning the mechanical behavior of the material, the
design and the load-bearing behavior of the whole structure in practice. Up to now, the
collected data comply with the expectations.
Figure 1: Gaertnerplatzbridge in Kassel, under construction (left) and in use (right) – a hybride bridge of
132 m span, longitudinal girders and deck plates fitted by gluing with an epoxy resin mortar. Slab
thickness 85 mm only.
Apart from a small number of pilot projects, the application of UHPC has been restricted due to
the fact that neither the material itself nor the material-specific design of the structures are
covered by technical standards that already exist for ordinary or even high performance concrete, e.g. the European Standard EN 206 or the design codes for concrete structures.
Thus, each application requires a single case approval from the Building Authorities.
18
was discovered that the real shape and the texture of the fine particles may significantly
increase the “effective” surface of the particle mix. Considering this fact allows for a much better
theoretical optimization of the packing density and gives a much better correlation between the
packing density, the water demand, the flowability, and the viscosity of the fresh concrete
compared to conventional models and algorithms merely based on spherical particles.
Microstructure
Electron microscopy investigations by Möser [10] using a NanoSEM microscope confirmed that
the hydrate phases in UHPC are significantly shorter owing to the high packing density, the low
w/c ratio of about 0.20 only and the high superplasticizer content of UHPC. Figure 3 gives an image showing some unhydrated microsilica particles surrounded by dense CSH-phases.
Table 1: Working groups inside the priority program and their individual research topic.
Working group # of projects
Raw materials, rheology,
processing,
sustainability
4 - Influence of shape and texture of fine grains and of interparticle forces on packing density and rheology
- Life cycle inventory on UHPC - UHPC with low-energy binders - Optimization of the mixing process
Hydration and
microstructure
2 - Characterization of the microstructure - Micro- and nanostructure of UHPC with nanotubes and
pyrogene SiO2
- Reduction of crack formation by internal curing
- Shrinkage-reducing chemical admixtures - Time-dependent stress-strain behavior - Early age cracking and durability - Autogenous shrinkage and microstructure
Fiber efficiency and
conventional
reinforcement
3 - Load-bearing capacity of elements reinforced with fibers and bars under tension and bending
- Ductility of UHPC with fibers and nanoparticles - Self-compacting UHPC with fiber meshes
Strength and
deformation
2 - Fatigue under uni- or multiaxial loads - Modelling of multiaxial strength
Durability 4 - Resistance to freezing and deicing agents
- Resistance to chemical attacks (acid, sulphate) - Fire safety of UHPC under load - Corrosion of steel fibers and influence on the
microstructure
Design, construction,
and application
11 - Prestressed beams - Performance of steel fitting elements for hybrid structures
(UHPC/steel) - Loadbearing of extensively loaded columns - Fitting of elements by gluing - Thin fiber-reinforced UHPC layers on conventional
concrete structures - UHPC under transverse (biaxial) forces
- Anchorage and overlapping joints of reinforcing bars
- UHPC/steel pipes for truss structures - Thin-walled pipes - Structural connection of precast elements - Miniaturized fitting devices for slender slabs
Testing 2 - Adjusted test procedures for rheology and strength - Fiber distribution and orientation
20
Sustainable Building with Ultra-High-Performance Concrete (UHPC) – Coordinated Research Program in Germany
Due to the dense matrix, the modulus of elasticity is significantly higher compared to ordinary
concrete. As a rule, the UHPC matrix shows brittle rupture. To prevent uncontrolled cracking,
steel fibers are of great importance for nearly all applications of UHPC. Usually, high strength
steel fibers are used to provide the brittle material with sufficient ductility, and they improve its
tension and bending tension strength up to about 15 to 40 MPa respectively. Thus UHPC
members are able to carry tension forces even without additional reinforcing bars. For the
realization of wide-span structures, fibers can be combined with non-prestressed or prestressed
reinforcement in the tensile zone. As a result of the interaction of both types of reinforcement,
the stiffness of tensile members with mixed reinforcement is significantly improved as
exemplified in Figure 4.
Figure 3: Matrix of UHPC, (left) compared to ordinary concrete (right). SEM pictures of same scale.
Leutbecher [12] developed a mechanical model, which combines the mechanical relationships
of the crack formation of reinforced concrete and the stress-crack opening-behavior of the fiber-
reinforced concrete considering the equilibrium of internal and external forces and the
compatibility of deformations. Experimental results confirmed that crack distribution and thus
the crack width can obviously be controlled much more effectively by a combination of fibers
and rebars than exclusively by high fiber content.
Figure 2: Interparticle forces between silica surfaces without (grey) and with four superplasticizers measured with AFM with different designed polymer-structures in nN [11].
Quartz
particle
UHPC
Matrix
21
17 mm); (a) stress-strain-relationship, (b) contribution of fiber concrete [12].
Multiaxial strength
At the TU Dresden, behavior under multiaxial stress was examined [13]. The tests were
performed in a triaxial test machine, as shown in Figure 5, which compressive or tensile forces
can be introduced with in all three spatial directions independently. The results indicated that
the multiaxial strength – related to the uniaxial strength – is considerably smaller than at normal
concrete. There was, for example, no strength increase whatsoever in some stress ratios under
biaxial compression, compared to the uniaxial strength ( Figure 6). Despite a steel fiber
content of up to 2.5 volume percent, UHPC exhibits very brittle behavior under uniaxial and biaxial compression. An all-side confinement due to increasing pressure components in both
lateral directions works against the progressive crack growth and so it leads to increasing
strength, to increasingly ductile behavior and to an early indication of failure (Figure 7). Related
to the uniaxial strength the strength increase of UHPC under triaxial compression is smaller
than for normal concrete.
Figure 5: Triaxial experimental setup. Figure 6: Strength under biaxial compression.[13]
22
-500
-400
-300
-200
-100
0
-30 -25 -20 -15 -10 -5 0 5 10 15
s 1/s 3 = s 2/s 3 =
0.17
0.12
0.09
Stress s 3 [MPa]
(edge length 10 cm)
s 1 s 2
Figure 7: Stress-strain-behavior on compressive meridian ( s 1 = s 2 > s 3 ).[13]
Shear Capacity
In the following projects [14,15], special design aspects were investigated: the anchorage
behavior of strands in UHPC, and the shear behavior. This knowledge is required basically for
an economic and safe design of material adequate slender pretensioned beams. Due to the
high tensile strength of fiber-reinforced UHPC, the height of such a beam can be reduced to
approx. 50 %. The remaining dead load amounts about 1/3 compared to normal strength
concrete and the steel fibers serve as shear reinforcement. The fiber action is illustrated in
Figure 8 by the red tensile forces in the simplified shear model. Nevertheless additional shear
reinforcement – in solid beams as well as in beams with openings – leads to further increase of
the shear capacity.
Figure 8: Crack pattern [14], simplified shear model and additional shear reinforcement [15].
23
Ultra-High Performance Concrete (UHPC) is a high performance material with steel-like
compressive strength of about 200 MPa and – reinforced with steel fibers – significantly
increased tensile, bending, and shear strength, therefore allowing for much lighter, longer
lasting and even more economic concrete structures – it is sustainable material. To endorse
widespread and regular use of this material, the German Research Foundation (DFG) funded an 12 Mio. € research program. About 20 research institutes were investigating in about 40
projects open scientific and technical questions covering the best fitting raw materials, their
mixing and processing, rheological aspects and the specifics of the hydration process, as well
as strength and deformation behavior of UHPC under uni- and multiaxial static and dynamic
loads, and the resistance to chemical and frost attacks. The wide arc of topics ends in the load-
bearing behavior of differently reinforced UHPC members and the development of new fitting
technologies for slim precast elements. In the end, the research results provided a safe
foundation to develop Technical Regulations for UHPC, enabling concrete producers to create
mixtures and structural members using regionally available raw materials, and to allow
designers and construction companies to build safe, long lasting, and economic UHPC structures.
References
[1] Bache, H. H., “Densified cement/ultra fine particle based materials”, 2nd International Conference on
Superplasticizers in Concrete, Ottawa, Canada, June 10-12, 1981.
[2] Okamura, H., Kazumasa, O., “Mix Design of Self -Compacting Concrete”, Proc. of JSCE,V. 25, No. 6,
1995, pp. 107-120.
[3] Geisenhandlüke, C., Schmidt, M., “Methods for Modelling and Calculation of High Density Packing
for Cement and Fillers in UHPC”, Proc. of the 1st International Symposium on UHPC, Sept. 2004, Kassel University Press, pp. 303-312.
[4] Teichmann, T., Schmidt, M., “Influence of the packing density of fine partickles on structure, strength
and durability of UHPC”, Proc. of the 1st International Symposium on UHPC, Sept. 2004, Kassel
University Press, pp. 313-323.
[5] Fehling, E., Bunje, K., Schmidt, M., Schreiber, W., “The Gärtnerplatzbrücke, Design of First Hybrid
UHPC-Steel Bridge across the River Fulda in Kassel, Germany”, Proc. of the 2nd Inter nat. Symp. on
UHPC, March 05-07, 2008, Kassel, pp.581-588.
[6] Schmidt, M., Jerebic, D., “UHPC: Basis for Substainable Structures – the Gaertnerplatz Bridge in
Kassel”, Proc. of the 2nd Internat. Symp. on UHPC, March 05-07, 2008, Kassel, pp. 619-625.
[7] Krelaus, R., Freisinger, S., Schmidt, M., “Adhesive Bonding of UHPC Structural Members at the
Gaertnerplatz bridge in Kassel”, Proc. of the 2nd Internat. Symp. on UHPC, March 05-07, 2008, Kassel, pp. 597-604.
[8] Wiens, U., Schmidt, M., “State of the Art Report on Ultra High Performance Concrete of the German
Committee for Structural Concrete (DAfStb)”. Proc. of the 2nd Internat. Symp. on UHPC, March 05-
07, 2008, Kassel, pp. 629-637.
[9] Fehling, E., Schmidt, M., Stürwald, S. (eds.), „Ultra -High Performance Concrete – Proc. of the 2nd
International Symposium on UHPC“, Structural Materials and Engineering Series, V. 10, Kassel
University Press, March 2008 – available online under www.upress.uni-
kassel.de/publi/abstract.php?978-3-89958-376-2
[10] Möser, B., Pfeiffer, C., “Microstructure and Durability of Ultra-High Performance Concrete”, Proc. of
the 2nd Internat. Symp. on UHPC, March 2008, pp. 417-424.
Sustainable Building with Ultra-High-Performance Concrete (UHPC) – Coordinated Research Program in Germany
[11] M. Schmidt, M., Stephan, D., Krelaus, R., Geisenhanslüke, C.: “The promising dimension in building
and construction: Nanoparticles, nanoscopic structures and interface phenomena pt.1,” Cement
International, V. 5, 2007, pp. 86-100.
[12] Leutbecher, T., Fehling, E., “Crack Formation and Tensile Behaviour of UHPC Reinforced with a
Combination of Rebars and Fibres”, Proc. of the 2 nd
Internat. Symp. on UHPC, March 2008, pp. 497-
504. [13] Curbach, M., Speck, K., “Ultra-High Performance Concrete under Biaxial Compression”, Proc. of the
2 nd
Internat. Symp. on UHPC, March 2008, pp. 477-484.
[14] Bertram, G., Hegger, J., “Anchorage Behavior of Strands in Ultra-High Performance Concrete,
Proceedings”, 8 th
Concrete, Tokyo, Japan in 2008, CD S3-3-6.
[15] Bertram, G., Hegger, J., “Pretensioned Concrete Beams made of Ultra-High Performance Concrete”,
Proceedings, International fib Symposium, London, The United Kingdom in 2009, CD (Mon 1600-
1730 D2).
Jacques Resplendino
Chief engineer, Chairman of the AFGC working group on UHPFRC, President of the AFGC Mediterraneen delegation, Director South Est SETEC TPI Vitrolles, France
After a fast reminder of the main caracteristics and compositions of UHPFRC, the paper makes a fast
presentation of the new AFGC recommendations on UHPFRC by emphasizing the evolutions which
benefit from experience feedback and from researches made on the last decade.The presentation
continues by a general presentation of diverse recent realizations. Every project will be presented by
trying to emphasize two essential points: the specific points of the design which justified the use of
UHPFRC, the delicate points of the realization which bring out of the fields of traditional structures.
The article ends by a synthesis of the technological breaks engendered by these materials as long in the
methods of conception than in the processes of implementation; breaks which impose on the engineers
and the designers to go out of the reflexes attached to the traditional reinforced or prestressed concrete
structures.
Keywords: AFGC recommendations, design method, construction process
1 Introduct ion – What is an Ultra High Performence Fiber-Reinfor ced
Concrete (UHPRFC)
Ultra High Performance Fiber-Reinforced Concrete are materials with a cement matrix, and a
characteristic compressive strength between 150 MPa and 250 MPa. They contain steel fibers,
in order to achieve ductile behavior in tension and overcome if possible the use of passive
reinforcement.
UHPFRC differ from high performance and very high performance concretes: - the systematic use of fibres ensures that the material is not brittle and can allow to avoid
any classical active or passive reinforcements,
- their compressive strength generally greater than 150 MPa,
- their composition with a high binder content that leads to the absence of any capillary
porosity,
- their direct tensile strength of the matrix systematically higher than 7 MPa.
The aim of UHPFRC development is to achieve high tensile strenths through the
participation of the fibres which provide tensile strength after the cement matrix has cracked.
When the tensile strength is sufficiently high, it may be possible, depending on the way the
structure works and the way the loads to which it is subject, to dispense with conventional
reinforcement.
In general, one removes any traditional passive reinforcement cage in order to keep only the
main passive or active reinforcement bars required when the resistance to major forces cannot
be provided by the fibers.
2 Major research and feedback from the 2002 recommendations
Reinforcement in the need to produce proofs o f convenience
To use UHPFRC structural material, the AFGC recommendations introduced in 2002 the
concept of suitability tests to validate the methodologies of implementation. The principle of these tests was to perform a suitability test upstream of the actual structure: realize a specimen
representative of the real structure, made of the same materials and following the same
procedures as those proposed for the execution of the actual structure.
27
In the case of industrialized products, the process corresponds to the phase of development of
industrial production processes. During completion of real structures, we were able to measure
how this approach was valid and necessary, including when companies in charge of the
construction were very experienced in the use of UHPFRC. Indeed, these suitability tests lead
almost invariably to optimize implementation process initially planned, or to adapt the original
design when technological and/or economical aspects prevent an adjustment of the process.
Sometimes suitability tests lead to slightly change the formula to better control the rheology of
the material.
Confirmation of the relevance of the K coefficient phil osophy
The influence of the UHPFRC implementation on the tensile strength of the material in the
actual structure is dealt with in the recommendations through a coefficient noted K that weights
the theoretical behavior laws issu from laboratory tests. This coefficient is determined from the
results of flexural tests performed on specimens sawn in the element built for suitability test
described above. This notion of K coefficient validated though suitability test does not exist in
Eurocodes but has been introduce in the last draft of the fib Model Code (MC2010 final draft
september 2011, article 5.6.7). This notion is essential for UHPFRC, and shall be taken into account in any fiber-reinforced concrete in which the structural strength is provided by the
fibers.
Fire behavior UHPFRC
Many recent tests [3] [4] (CERIB, CSTB) have determined for several UHPFRC materials all
temperature mechanical properties in order to achieve numerical simulations of fire resistance
(thermal conductivity, specific heat, thermal expansion, compression and tensile strength,
Young's modulus). The new recommendations make a synthesis of these tests and provide
values in order to make a first preliminary design of a UHPFRC structure subject to precise
specifications of stability under fire.The UHPFRC behaviour under high tempatures depending
strongly of the material, the recommandations remind that for a final design one must
absolutely use the actual behaviour law of the material used to build the structure.
Punching resistance
Several recent research on punching [5] [6] [7] [8] allow to propose formulations in accordance
with the philosophy of Eurocodes.
Abrasion
The new version of the recommendations provides the main results of abrasion tests (CNR test)
made under the realization of hydraulic works. The results confirm the interest of UHPFRC used
as a shield in case of strong mechanical stresses.
Shear resistance
In the context of drafting the new guidelines, a compilation of all existing international literature
on shear testing was performed. In addition, LCPC performed 12 additional tests beams made
with two different materials, with or without active and/or passive reinforcement.
The entire investigation on the reported results and additional testing campaign has allow to
adjust and consolidate the formula proposed in the recommendations.
Tensile strength
Numerous tests were conducted to examine the tensile behavior of traditionnal reinforced
UHPFRC (tension stiffening) [9] [10].
The new recommendations have been improved to better integrate the research results.
These considerations have led to distinguish:
28
- UHPFRC with a hardening characterictic law in direct tension (only very few material are
hardening in pure tension knowing that this requires a very high fiber content),
- UHPFRC with a hardening average law in direct tension, but with a softening

hipermat 2012 kassel

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