Ultra High Performance Concrete (UHPC)

UN I KASSEL V E R 5 I T "A" T

Ultra High Performance Concrete (UHPC)

International Symposium on Ultra High Performance Concrete September 13-15, 2004

Edited by M. Schmidt E. Fehling C. Geisenhansluke kassel • university press

Ultra High Performance Concrete (UHPC) with a high compressive strength of more than 200 MPa and an improved durability marks a quantum leap in concrete technology. This high performance material offers a variety of interesting applications. It allows the construction of sustainable and economic buildings with an extraordinary slim design. Its high strength and ductility makes it the ultimate building material e.g. for bridge decks, storage halls, thin-wall shell structures and highly loaded columns. Beside its improved strength properties, its outstanding resistance against all kinds of corrosion is an additional milestone on the way towards no-maintenance constructions. UHPC has very special properties that are remarkably different to the properties of normal and high performance concrete. For complete utilisation of UHPC's superior properties, special knowledge is requi red for production, construction and design. Worldwide this material is under detailed exploration. Several constructions or structural elements were already built utilizing UHPC. However, one of the first hybrid bridges consisting of precast UHPC elements and a steel construction will be built in Kassel in 2004. The bridge is designed as a foot and bike bridge with a total length of 150m. More than 75 experts from all over the world presented their research results and practical experiences with the new and outstanding material at the International Symposium on Ultra High Performance Concrete

which took place in September 13 to 15, 2004. The symposium was organized by the Departments of Structural Materials and of Structural Engineering of the University of Kassel, Germany. The experts gave a broad overview and a deep insight into all aspects of UHPC including raw materials, micro- and macro-structures, mechanical behaviour, durability as well as of construction and design specifications appropriate for this material. This Conference Proceedings contain the conference papers and presentations. We hope that the excellent papers will promote further develop and exploitation of Ultra High Performance Concrete the construction material of the 21st century.

ISBN 3- 8995 8-086-9

9 783899 580860

Committees

Invitation and Final Program International Symposium on

University of Kassel

Ultra High Performance Concrete September 13 - 15, 2004 Kassel, Germany

Scientific committee Prof. Michael Schmidt, University of Kassel, D (chairman) Prof. Ekkehard Fehling, University of Kassel, D (vice-chairman) Prof. Joost C. Walraven, Delft University of Technology, NL (vice-chairman) Prof. Paul Acker, Lafarge Company, F Prof. Peter Bartos, University of Paisley, GB Prof. Ignasi Casanova, Universitat Politecnica de Catalunya, E Prof. Manfred Curbach, Dresden University of Technology, D Prof. Robert Day, University of Calgary, CA Prof. Frank Dehn, University of Leipzig, D Prof. Harald S. Müller, Karlsruhe University of Technology, D Prof. Peter Schießl, München University of Technology, D Prof. Ulrich Schneider, Vienna University of Technology, A Prof. Karen Scrivener, École Polytechnique Fédérale de Lausanne, CH Prof. Surendra P. Shah, Northwestern University, USA Prof. Man-Chung Tang, T. Y. Lin International, USA Prof. Nguyen Tue, University of Leipzig, D Prof. Gerd Thielen, German Cement Work Association, D

Organizing committee Symposium’s Secretary: Mr. Carsten Geisenhanslüke

Supported by:

Chairman of the Organizing Committee: Mr. Walter Schreiber Fehling & Jungmann, Structural and Material Consulting Engineers, Kassel, D University of Kassel: Prof. Ekkehard Fehling (vice-chairman) Prof. Michael Schmidt Mrs. Elvira Berndt Mr. Torsten Leutbecher Mr. Roland Bornemann Dr. Bernhard Middendorf Mrs. Ute Müller Mrs. Claudia Rebmann Mrs. Nadine Sonntag Mr. Thomas Teichmann

Contact Mr. Carsten Geisenhanslüke University of Kassel Department of Structural Materials, FB14 Mönchebergstrasse 7 34125 Kassel, Germany Tel: Fax: Email:

www.uni-kassel.de/uhpc2004

+49 561 804 2601 +49 561 804 2662 [email protected]

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International Symposium on Ultra High Performance Concrete September 13 - 15, 2004, Kassel, Germany The development of Ultra High Performance Concrete (UHPC) with its high compressive strength of more than 200 MPa and its improved durability marks a quantum leap in concrete technology. This high performance material offers a variety of interesting applications. It allows the construction of sustainable and economic buildings with an extraordinary slim design. Its high strength and ductility makes it the ultimate building material e.g. for bridge decks, storage halls, thin-wall shell structures and highly-loaded columns. Beside its improved strength properties, its outstanding resistance against all kinds of corrosion is an additional milestone on the way towards no-maintenance constructions. The very special properties of UHPC distinguishes it remarkably from normal and high performance concrete. For complete utilisation of its advanced properties special know-how is necessary for its production, construction and design. Worldwide this material is under thorough investigation. Several applications were already been built. One of the first precast UHPC bridges in the world will be built in Kassel in this year. The bridge is designed as a foot and bike bridge with a total length of 150 m. This is one of the reasons to held the conference in Kassel. More than 75 experts from all over the world will present their scientific and practical experiences with the new and outstanding material. They will give a broad overview of all aspects of the raw materials, the micro- and macro-structure, the mechanical behaviour, the durability as well as of construction and design procedures appropriate for this material. The conference will promote the exchange of scientific and practical experiences and the common usage of this new and outstanding building material. We are pleased to welcome you at the University of Kassel! Prof. Dr.-Ing. habil. M. Schmidt

Prof. Dr.-Ing. E. Fehling

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Technical Program Timetable Sunday, Sep. 12

Technical Program Monday, September 13

Monday, Sep. 13

Tuesday, Sep. 14

Wednesday, Sep. 15

9:00 to 10:30

Opening Ceremony

Session B1, C1

Session D1, E1

10:30 to 11:00

Coffee Break

Coffee Break

Coffee Break

11:00 to 12:30

Session A1

Session B2, C2

Session D2, E2

12:30 to 14:00

Lunch

Lunch

Lunch

14:00 to 15:30

Session A2

Session B3, C3

Session D3

15:30 to 16:00

Coffee Break

Coffee Break

Coffee Break

16:00 to 18:00 20:00

Welcome Reception / Registration

Session A3

Session B4, C4

Conference dinner

Cultural event

Thursday, Sep. 16 Sunday, Sep. 19 PostConference Tour (Berlin or Heidelberg)

Closing Ceremony

Welcome Reception on Sunday We would like to invite you with sparkling wine and light refreshments on September, 12th 2004 at 06.00 p.m. It takes place in our "Gießhaus" at the University of Kassel. The registration for the Symposium will start at 04.00 p.m.

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09.00 - 10.30

Opening Ceremony

M. Schmidt, E. Fehling R.-D. Postlep President of the University of Kassel N. Witte Stadtbaurat of Kassel City High strength materials – past, present and future M.-C. Tang San Francisco, USA

Session A1 11.00 - 12.30

History and Experiences

Chairman: S. Ahmad Farmington Hills, USA P. Acker St. Quentin Fallavier, F P. Buitelaar Höjbjerg, DK

Prof. E. Fehling, Kassel, D 100 years of ACI activities in concrete

Session A2 14.00 - 16.00

Recent Applications

Chairman: F.-J. Ulm Cambridge, USA

Prof. M. Schmidt, Kassel, D The next generation of US-Highway Bridge Girders: From UHPC materials to High Performance Structures

Z. Hajar, A. Simon D. Lecointre, J. Petitjean Bagneux, F N.Kaptijn, J.Blom Tilburg, NL

Design and Construction of the world first Ultra-High Performance Concrete road bridges

U. Maeder, I. LallemantGamboa, J. Chaignon, J.-P. Lombard Zürich, CH A. Möller Aalborg, DK E. Fehling, K. Bunje, M. Schmidt, W. Schreiber Kassel, D

Ductal® Technology: a Large Spectrum of Properties, a Wide Range of Applications Ultra High Performance Concrete: Developments and Applications during 25 years

A new bridge deck for the Kaag bridges: The first CRC (Compact Reinforced Composite) application in civil infrastructure Ceracem, a new high performance concrete: characterizations and applications

Ultra High Performance grouts for offshore constructions Hybrid Bridge Construction with UHPC in Kassel: Design and Construction

Session A3 16.30 - 17.45

Regulations and Recommendations

Chairman: J. Resplendino Lyon, F M. Schmidt, U. Wiens Kassel, Berlin, D

Prof. M. Curbach, Dresden, D First French recommendations for Ultra-HighPerformance Concretes and examples of application State of the Art Report on UHPC materials and design of the German Committee for Structural Concrete (DAfStb)

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Technical Program Tuesday, September 14 Session B1 09.00 - 10.30

Binders and Fillers

Chairman: L. Elfgren, J.-E. Jonasson, V. Ronin Lulea, S N. B. Singh Gorakhpur, IND J. F. MartirenaHernández Santa Clara, C M. Shekarchizadeh, A. H. Iranmanesh, I. Talebinejad, A. Bassam Tehran, IR C. Vellmer, M. Gehrke, B. Middendorf Kassel, D

Prof. R. Trettin, Siegen, D EMC Cements for Ultra High Performance Concretes

Session B2 11.00 - 12.30

Silica Fume and Additives

Chairman: A. Korpa, R. Trettin Siegen, D

Prof. N. B. Singh, Gorakhpur, IND The use of synthetic colloidal silica dispersions for making HPC and UHPC systems, preliminary comparison results between colloidal silica dispersions and silica fumes (SF) Role of Silica fume Concrete in Concrete Technology

K. Jayakumar Coimbatore, IND I. Terzijski Brno, CZ R Hela, J. Zach Brno, CZ T. Kowald, R. Trettin Siegen, D

Highly reactive ß-Dicalcium silicate for Ultra-High Performance Concrete Lime-pozzolan Binder as a very fine mineral admixture in concrete Optimizing mix proportions of Normal Weight Reactive Powder Concrete with Strengths of 200-350 MPa Seeing at the nanoscale: reaction of pozzolanic and cementitous materials in UHPC

Compatibility of Components of High and Ultra High Performance Concrete Utilization of chemical admixtures in HPC concretes Influence of surface-modified Carbon Nanotubes on Ultra-High Performance Concrete

Session B3 14.00 - 15.30

Fillers and Aggregates

Chairman: J. Ma, M. Orgass, N. V. Tue, F. Dehn, D. Schmidt Leipzig, D P. Rougeau B. Borys Epernon, F H.-W. Röth Köln, D P. Haleerattanawattana, E. Limsuwan Bangkok, TH C. Geisenhanslüke, M. Schmidt, E. Schneider Kassel, Baden-Baden, D

Prof. K. van Breugel, Delft, NL Comparative Investigations on Ultra-High Performance Concrete with and without Coarse Aggregates Ultra High Performance Concrete with ultrafine particles other than silica fume Production of Calcium Carbonate based fine fillers for UHPC Strength-based gradation of coarse aggregate for ultrahigh-strength concrete Investigations on UHPC with fly ash and quartz fines

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Technical Program Tuesday, September 14

Technical Program Tuesday, September 14

Technical Program Wednesday, September 15

Session B4 16.00 - 18.00

Material Modelling and Prediction

Session C3 14.00 - 15.30

Design Specific Material Aspects

Session D1 09.00 - 10.30

Processing and Early Age Behaviour

Chairman: K. van Breugel, Ye Guang Delft, NL J. Adolphs, A. Schreiber Hofheim, D H. Taghaddos, F. Mahmoodzadeh, A. Pourmoghaddam, M. Shekarchizadeh Tehran, IR K. Droll Wiesbaden, D U. Stark; A. Müller Weimar, D C. Geisenhanslüke, M. Schmidt Kassel, D T. Teichmann, M. Schmidt Kassel, D

Prof. D. Heinz, München, D Analyses of hydration processes and microstructural development of UHPC through numerical simulation Microstructural Characterisation of Ultra-High Performance Concrete Prediction of Compressive Strength Behaviour in RPC with applying an Adaptive Network-Based Fuzzy Interface System

Prof. H. S. Müller, Karlsruhe, D Static and fatigue bending tests of UHPC

Chairman: J. Schubert, O. Mazanec, I. Schachinger Baden-Baden, München, Hannover, D T. Teichmann, U. Goldbach Kassel, D S. Staquet, B. Espion Brussels, B H. Ito, I. Maruyama, R. Sato Hiroshima, J B. Piscaer Köln, D

Prof. R. Day, Calgary, CDN Effect of Mixing und Placement Methods on Fresh and Hardened Ultra High Strength Concrete

Influence of Additions of Ultra High Performance Concretes – Grain Size Optimization Particle Size and Shape – an important factor for Packing Density Modelling and Calculation of High Density Packing of Cement and Fillers in UHPC

Chairman: E. S. Lappa, C.R. Braam, J. C. Walraven Delft, NL S. Ortlepp, M. Curbach Dresden, D K. Holschemacher, F. Dehn, S. Klotz, D. Weiße Leipzig, D T. Stiel Cardiff, Kassel, UK, D L. Kraft, L. Hermansson Uppsala, S

Influence of Particle Packing on Structure, Strength and Durability of UHPC

Session C4 16.00 - 18.00

Design and Construction

Fibre Reinforcement

Session C1 09.00 - 10.30


Prof. J. Hegger, Aachen, D Textile reinforced ultra high performance concrete

Chairman: E. Fehling, K. Bunje Kassel, D N. V. Tue, H. Schneider Leipzig, D J. Hegger, D. Tuchlinski Aachen, D K.-H. Reineck, S. Greiner Stuttgart, D K. Holschemacher, D. Weiße, S. Klotz Leipzig, D

Prof. A. Muttoni, Lausanne, CH Design relevant properties of fixed Ultra High Performance Concrete Bearing Capacity of Short Columns made of UHPC confined by a Steel Tube Bond Anchorage Behavior and Shear Bearing Capacity of Ultra High Performance Concrete Beams Tests on ultra-high performance fibre reinforced concrete for designing hot-water tanks and UHPFRCshells Bond of Reinforcement in Ultra High Strength Concrete

Chairman: L. Lohaus, S. Anders Hannover, D Y. Klug, M. Orgass Leipzig, D G. Güvensoy, A. Ilki, F. Bayramov, M. A. Taºdemir Istanbul, TR A. Si-Larbi, E. Ferrier, P. Hamelin Lyon, F R. Bornemann, S. G. Faber Kassel, D

Dr. F. Dehn, Leipzig, D Effects of polymer- and fibre modifications on the ductility, fracture properties and micro-crack development of ultra-high performance concrete Fibre Reinforced Ultra-High Strength Concretes

Session C2 11.00 - 12.30


Chairman: W. Brameshuber, T. Brockmann, B. Banholzer Aachen, D M. Teutsch, J. Grunert Braunschweig, D J. Jungwirth, A. Muttoni Lausanne, CH J. Aronoff; A. Katz; Y. Frostig Haifa, IL B. Freytag, J. Juhart, L. Sparowitz, E. Baumgartner Graz, Spittal, A

Session D2 11.00 - 12.30

Prof. N. V. Tue, Leipzig, D Structural response of hybrid “UHPFRC-concrete members under bending Loading Capacity and Behaviour of Ultra High Performance Concrete Structural Elements subject to Shear and Punching Loads Stress state optimization in steel-concrete composite elements Push-Out Tests on Headed Studs embedded in UHPC

Session D3 14.00 - 15.30

Durability

Chairman: K. Habel, E. Denarié, E. Brühwiler, Lausanne, CH K. Bunje, E. Fehling Kassel, D J. Brauns, K. Rocens Riga, LV J. Hegger, S. Rauscher, C. Goralski, Aachen, D T. Leutbecher, E. Fehling Kassel, D

Chairman: G. Herold, H. S. Müller Karlsruhe, D L. Ay Stockholm, S D. Heinz, F. Dehn, L. Urbonas Munich, D D. Heinz, H.-M. Ludwig Munich, D F. Dehn Leipzig, D

Prof. W. Brameshuber, Aachen, D Investigation on the Durability of Ultra High Strength Concrete Curing tests on ultra high strength plain and steel fibrous cement based composites Fire Resistance of Ultra High Performance Concrete (UHPC) – Testing of Laboratory Samples and Columns under Load

Structural Behaviour of UHPC under Tensile Stress and Biaxial Loading

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Research into high-strength concrete at high rates of loading Ultra High Strength Concrete under Concentrated Loading

Effect of the Casting Direction on the Mechanical Properties of CARDIFRC Deformation Characteristics in various Calcium Aluminate Cement Admixtures investigated using three different Methods

Bending design of steel-fibre-strengthened UHPC Structural Behavior of Tension Members in UHPC The Behaviour of Very High Strength Reinforced Concrete Structures with CFRP Reinforcing Bars The use of UHPC in composites – Ideas and realisations

Laboratory of materials and constructions, University of Kassel 8

Influence of the precasting process on the material properties of fibre reinforced UHPC Early-age autogenous shrinkage development of UHPC incorporating very fine fly ash or metakaolin in replacement of silica fume Expansive behaviour of high-strength expansive concrete and its induced stress Cross Fertilisations from the Refractory Industry

Mechanical Behaviour of Ultra High Performance Steel Fibre Reinforced Concretes under Cyclic Loading Condition Flexural behaviour of Ultra High Performance Concrete reinforced with mixed short fibers and CFRP rebars UHPC with steel and non-corroding high strength polymer fibres under static and cyclic loading

Heat Treatment and the Risk of DEF Delayed Ettringite Formation in UHPC Temperature Behaviour of Ultra High-Performance Concrete (UHPC) - A Micro Analytical Reflect

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Technical Program Wednesday, September 15 Session E1 09.00 - 10.30

Applications

Chairman: B. Middleton, R. Day, L. Cowe Falls Calgary, CDN J. Kaufmann Dübendorf, CH C. Vogt, B. Lagerblad, T. Hugo-Persson Stockholm, S X. Pu, C. Wan, Y. Wang, H. Pu, C. Wang Chongqing, China P. Racky Kassel, D

Prof. J. C. Walraven, Delft, NL Durability and Mechanical Properties of High Performance Concrete for Ultra-Thin Whitetopping Pavements

Session E2 11.00 - 12.30

Applications

Chairman: E. Fehling, M. Schmidt, N. V. Tue, K. Bunje, T. Teichmann Kassel, D S. S. Gaharwar, S. Kumar, R. Kumar, M.V.B. Rao New Delhi, IND N. V. Tue, H. Schneider, G. Schenk Leipzig, D A. Lichtenfels Keltern, D G. Zimmermann, T. Teichmann, M. Grohmann Kassel, D

Prof. F.-J. Ulm, Cambridge, USA Ultra High Performance Composite Bridge above the Fulda in Kassel – Accompanying Investigations as Basis for the required Agreement of the Authorities –

16.00 - 17.15

Closing Ceremony

J. C. Walraven Delft, NL M. Schmidt, E. Fehling Kassel, D

Development of special mortars for an application in centrifugal casting process Optimization of UHPC for selective stabilization of deep boreholes

Social Program Accompanying Persons Program

Hotel Accommodation

Social Program

Hotel Accommodation

" Welcome reception (September 12, 2004) " Conference dinner (September 13, 2004) " Cultural event (September 14, 2004) " Guided city tours " Fulda boat trip

The participants can book rooms at preferential rates in several hotels located in Kassel. To get a complete hotel list please visit our symposium’s website (www.uni-kassel.de/uhpc2004). Hotels

Kilometer Compressible Material and Its Preparation

Accompanying persons program Cost-effectiveness and sustainability of UHPC

Accompanying persons are invited to the opening and closing sessions of the Symposium, the Welcome reception on Sunday evening, the Dinner on Monday evening and a cultural event on Tuesday evening. Also, various sightseeing tours will be organized in and around Kassel. Sunday, Sep. 12

Tuesday, Sep. 14

Wednesday, Sep. 15

9:00 Opening Ceremony and Welcome

A Visionary Approach for the Health Monitoring of Ultra High Performance Concrete Bridges in Indian Conditions Application of UHPC Tubes as Building Members

Monday, Sep. 13

Morning Hillside Park Wilhelmshöhe (Museum Castle Wilhelmshöhe; Sightseeing in Museum Tour Boat trip on the Park with (Neue Galerie, the Fulda river famous Orangerie) (incl. Coffee) fountain; Coffee break)

Sightseeing Tour in Kassel Ultra-High Performance Fibre Reinforced Concrete for shells Membrane Concrete Grid Shells

Afternoon

Designing with ultra high strength concrete: basics, potential and perspective Visions in UHPC Will the tower of Babylon come true?

Closing Ceremony

Welcome Reception

La Strada Courtyard by Marriot Schlosshotel Wilhelmshöhe Gude Astoria Moevenpick Kurfuerst Wilhelm I. Stadthotel Kassel Chassalla

Varta Hotel Guide Category *** **

Room rate per night Location of single/double Hotel 78 € / 90 € (w.b.) 1 49 € / 49 € (w.b.) 2

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48 € / 66 € (w.b.)

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79 € / 104 € (i.b.) 51 € / 71 € (i.b.) 82 € / 112 € (o.b.) 60 € / 87 € (i.b.) 57 € / 77 € (i.b.) 52 € / 72 € (i.b.) 69 € / 87 € (i.b.) standard 77 € / 97 € (i.b.) comfort 62 € / 79 € (i.b.) 49 € / 67 € (i.b.)

4 5 8 11 6 7

*

Mercure Hessenland

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Schweizer Hof Deutscher Hof

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10 11

(w.b. = breakfast not included) (i.b. = breakfast included)

The locations of the hotels offering special rates are shown on the enclosed citymap. The University and location of Symposium is marked with a red dot.

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Post-Conference Tours (September 16 - 19)

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5 11 7

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Post-Conference Tours to Heidelberg or Berlin can be booked by filling-in the enclosed registration form. To get more informations please visit our symposium’s website (www.uni-kassel.de/uhpc2004). 4

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Informations

Registration

Commercial exhibition

Registration Participation to the Symposium and the excursions organized for accompanying persons may be registered by filling-in the enclosed Symposium Registration Form, according to the instructions therein, and sending it by fax or mail with payment, directly to the conference office. before August 1, 2004

after August 1, 2004

Delegate

€ 380,-

€ 410,-

Lecturer

€ 280,-

€ 280,-

Accompanying person

€ 130,-

€ 150,-

Cancellations: before August 31: 75% refund; after August 31: no refund

These fees include, for delegates and lecturers: ! Attendance to Opening and Closing Ceremonies ! Attendance to the Symposium Technical Sessions ! Two coffee-breaks per day (September 13-15) ! Welcome reception on Sunday, September 12 ! Conference Dinner on Monday, September 13 ! Cultural event on Tuesday, September 14 ! One copy of the Symposium Proceedings

Kassel and its University

The city of Kassel

A commercial exhibition for products, services and projects is organized during the Symposium. There are stands of variable sizes available. Companies and organizations interested in participating may contact the Symposium’s Secretary for reservation before August 1, 2004.

Language The Symposium’s language is English.

To get to Kassel By plane: ! to Frankfurt or Hannover Airport (from there about 1.5 hrs by train) By train: ICE-train station Kassel-Wilhelmshoehe Hourly trains from: ! Hannover (airport) ! Berlin ! Frankfurt (airport) ! Munich From ICE station to the venue: ! Tram line 1 or 2 Stop Holländischer Platz/Universität By car: ! Autobahn A7 - Exit Kassel-Nord ! follow Dresdener Strasse to Zentrum/town centre ! At Crossing Dresdener Strasse - Ysenburgstrasse turn right ! Behind Fulda river bridge turn left ! Behind Buildings of University turn right twice towards parking spaces

Kassel is situated in the very heart of Germany. It is offering fast and easy access by the ICE-train or motorway. Visitors who appreciate nature, love the arts and want to relive history will get their money's worth in this town, with its host of internationally famous art treasures, historic monuments, and cultural and educational institutions. Kassel is the town of the famous Documenta exhibition of modern art. Kassel is an ideal venue for conferences and congresses - its central location, the excellent facilities, the efficiency of its hotels and its fringe amenities such as Wilhelmshöhe, the biggest hillside park in Europe formed in the 17th century, and the Kurhessen Thermal Baths, the Casino and the Palace. Add to these the museums, State Theatre, pedestrian precincts and shopping malls.

The campus of the University of Kassel

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P Location of Symposium

The “Herkules” and the “Lions Castle” The town’s landmarks of Kassel in the biggest hillside park of Europe

Tram 1 or 2 Stop Hollaendischer Platz

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More informations: www.kassel-tourist.info www.kassel.de www.uni-kassel.de 15

The forthcoming UHPC bridge in Kassel

The Symposium is supported and co-sponsored by: fédération internationale du béton (fib) American Concrete Institute (aci) Deutscher Beton- und Bautechnik-Verein e.V. (dbv) Deutscher Ausschuss für Stahlbeton im DIN (DAfStb)

University of Kassel Department of Structural Materials, FB14 Mr. Carsten Geisenhanslüke Mönchebergstrasse 7 34125 Kassel Germany Tel:+49 561 804 2601 Fax:+49 561 804 2662 Email:[email protected] Web: www.uni-kassel.de/uhpc2004

Ultra High Performance Concrete: Developments and Applications during 25 years Summary During the last 25 years exciting new developments have been taking place in the developments of cementitious materials. The compressive strength rose from circa 60 MPa to more than 300 MPa. This is made possible by techniques for the densification of the microstructure of the fresh cement paste with the use of efficient surface active agents (super plasticizers) and ultra fine reactive particles. Two systems were developed in the seventies: Macro Defect Free concrete (MDF) and the Densified Systems containing homogeneously arranged, ultra-fine Particles (DSP). In my paper I will discuss the last system including new developments and the applications of these materials. Keywords: HPC, UHPC,

DSP, CRC, HRUHPC, wear protection, concrete repair, offshore,

industrial floors. 1

Introduction

In this paper, based on the Danish experiences and my personal experiences during 19 years with UHPC in two Dutch companies and in two Danish companies, I will explain the development and applications of the High Performance Concrete (HPC), Ultra High Performance Concrete (UHPC) and Heavy Reinforced High Performance Concrete and Heavy Reinforced Ultra High Performance Concrete (HRHPC and HRUHPC). A normal hardened Portland cement paste is a heterogeneous and porous material in which the porosity to some extent reflects the original spaces between the cement particles within the chemical structure. This is primarily because the surface forces between the cement-particles tend to prevent these from sliding in relation to each other during mixing and casting, and the finer the cement particles; the greater is the effect of the surface forces. Because of this a relatively high amount of mixing water is necessary to get a certain workability with the mortar or concrete. The overall porosity of 25-30% in volume compromises two pore families: gel pores and capillary pores. Compared to materials like steel or sintered alumina, a Portland cement paste develops low mechanical strength during its harding. The weakness of these mechanical performances has been mostly related to the capillary porosity and the excess of water needed for the workability of the fresh cement paste. Already 2000 years ago Lucretius made this observation:’ The more vacuum a thing contains within it, the more readily it yields.......’. Féret, who developed the empirical relationship between strength and volumes of cement, water and air, first applied this principle to concrete in 1892. Many other strength vs. porosity relationships has been made since work reasonably well for “ordinary” cementitious materials over the narPlenary Session International Symposium on UHPC September 13 - 15, 2004, Kassel, Germany. Peter Buitelaar

row range of porosities, or water/cement ratios, that are found in convential concrete practice, since there is no doubt that the total porosity is the most important single determinant of strength. Because they involve only the total porosity, these relationships must represent a considerable simplification of the system; the pore size distribution, the pore shape whether the pores are empty or filled with a fluid and the nature of the solid material itself must also be important, particularly when dealing with materials outside of the range of normal concretes and mortars. 2

The development of HPC and UHPC

The role of Hans Henrik Bache, researcher during his whole professional career, as a pioneer in the development of HPC, UHPC and HRUHPC is of great importance for the concrete history in the future and finally starts to be recognized by others. Professor Pierre-Claude Aïtcin wrote in his highly recommended book High Performance Concrete the following observations: “The first interesting results obtained by the Scandinavians in usual concrete, the very impressive discoveries of Bache and co-workers in Denmark and a significant research effort in the early 1980s in several other countries, resulted in the rapid acceptance of silica fume as a supplementary cementitious material for concrete almost everywhere in the world in less than 5 years.” and “In fact, Bache’s work showed that the ultimate compressive strength of concrete depends not only on the quality, quantity and efficiency of the cementitious materials used, but also on the degree of compaction and ultimate porosity of the solid matrix formed after the hardening process is completed. About 100 years after first being proposed (Féret, 1892), the w/b law concerning compressive strength can be said to have been extended!”

Photo 1: Professor Emeritus Hans Henrik Bache (left) and Knud Lund Eriksen.

Plenary Session International Symposium on UHPC September 13 - 15, 2004, Kassel, Germany. Peter Buitelaar

2.1

The development of HPC in the sixties and seventies

Around 1964 the first research started in the Concrete and Research Laboratory in Denmark to investigate the possibilities to produce a soft cast concrete with a higher compressive strength. The strongest concrete made had an fc of about 60 – 80 MPa with a w/c ratio of 0.30. Three important questions raised during research had to be answered: 1. Is it possible to reach a much denser packing in cement paste than corresponding to a w/c ratio of 0.30? 2. Will this, when possible, result in a much higher strength? 3. Could a much higher strength than be utilized in concrete? Treval C. Powers from the Portland Cement Association reports about strengths of about 280 MPa in small specimens of heavily compacted cement paste, indicating possibilities to achieve much denser packing of cement, and through this, higher strengths. The comparisons with other fine particles showed that cement particles are less dense packed than other fine particles with approximately the same particulate shape and size distribution. From purely geometrical considerations it should thus be possible to pack cement particles much denser, corresponding to a w/c ratio of 0.20 instead of a w/c ratio of 0.30. Vibratory compaction at light pressure was used to make small samples since this is a much better method for compacting without a risk to crush the aggregates like in high pressure compaction. The results of the tests demonstrated Powers conclusions but didn’t lead directly to a stronger concrete. But it gave new indications that a much denser packing of cement particles was possible. Figure 1: Relationship between compressive strength and porosity for vibrated and under pressure compacted hardened cement paste (Bache 1970).

500 MPa

100 MPa

50 MPa

The experiments resulting in cement paste strength of up to 350 MPa, thus 5 – 10 times higher than the strength of cement paste in normal concrete.

cement paste

0.3

0.4

0.5

0.6

0.7

Relationship between compressive strength and porosity

In the period 1967 – 1972 more investigation was made in the combined action of pressure and vibration to compact concrete. It was with this process possible to improve the concrete qualities and also to produce low cement/ high amount of aggregates mixes with an fc of 100 – 130. Based on the classic theory (Griffith, 1921) for the tensile strength of brittle materials Bache made his model of strength for brittle materials built up of particles joined at points of contact.


Griffith’s theory still provides us with a lot of information, it is not only giving a qualitative explanation of the importance of the porosity to the strength but it also tells us that the strength will increase if pores and/or the crack size is reduced, and that the strength will also increase if the pores and cracks are filled with material that can “reinforce” the pores and/or cracks, even while the material itself is not particularly strong. In sintered ceramic there is a dependence on the particle size but the use of extra fine grinded cement particles did only resulted in a fast strength development but not in a stronger matrix. This was of course because at that time it was not possible to disperse ultra fine cement particles in an aqueous suspension to get a dense packing of the fine particles due too the very high attractive surface forces. Around 1970 Stephen A. Brunauer from the Portland Cement Association developed a special cement containing surface active substances added during the grinding process which eliminated the attractive surface forces in cement/ water mixes. Research with the “Brunauer” cement started in Denmark in 1971 and large concrete objects were made. Brunauer was never able to produce a concrete and visit the research lab in Denmark interested in the Danish experiences. Bache suggested using the same quantity by volume of cement paste instead of the same quantity by weight as Brunauer, which requires 50% more cement and was thus able to produce concrete. In the same period synthetic surface active agents, the so called superplasticizers, were developed. In Japan concrete structures were build with a fc 90 MPa in the middle of the seventies. Hattori made soft cast concrete in the laboratory with a w/c ratio of 0,25 and a fc up to 120 MPa.

2.2

The development of the DSP system in the seventies

Due too the development of the superplasticizers it became finally possible to disperse ultra-fine – and normal cement particles much better in an aqueous solutions and thus permitting a dense packing between the cement particles. Bache starts to make special graded cement blends with 30% ultra fine cement to establish a very dense particle packing. After contact with a Norwegian colleague during a seminar in Stockholm he became familiar with micro-silica, a by-product from the silicon- and ferrosilicon industry. For several reasons this ultra fine powder would be much better than ultra-fine ground cement: •

The micro-silica particles are much finer than the finest cement grains.

•

The micro-silica particles are amorphous; this makes them very suitable for dense packing between the angular and sharp cement particles.

•

The micro-silica is less reactive in the first hours than very fine cement particles.


Micro-silica in concrete has been studied and used in civil engineering since the early 1950. Micro-silica consists of ultra fine (less than 1 micron), superpozzolanic, and amorphous silica particles. The superpozzolanic reactivity converts a part, depending on the amount of microsilica; of the less useful calcium hydroxide crystals into the useful calcium silicate hydrate binder. The abundance of the ultra fine particles places some 100.000 micro-silica particles around each cement particle in a typical mixture.

Cement particles

Fine aggregates

Photo 2: Micro-silica particles.

Micro-silica

Figure 2: Dense packing of the mortar.

At 8 May 1978 the first specimens with concrete and micro silica were made, the next day the heat cured cylinders showed a very promising mechanical strength of fc 128 MPa. The D.S.P. paste incorporates: • • • •

A certain amount of special cement. A large dose of micro-silica. An effective superplasticizers provided in a dosage large enough to insure physiochemical deflocculating of the cement- and micro-silica particles as well. An effective mixing to produce a completely consolidated paste with a minimum content of water.

By making a very dense packing of the cement particles and filling the spaces between with the much finer micro-silica particles there is only a little space to fill with water. During mixing the water will surround each particle in a thin layer and works like lubrication. The w/b ratio is 0,18 0,25. This results in an ultra strong – and very dense binder with a very low porosity. By combining the binder phase with fine and coarse aggregates it is possible to produce different materials like f.i. grouts, mortars and concrete. Later research was focussed on modifying the aggregates since the strength of the hardened binder was much more than the strength of normal aggregates in contradiction to normal concrete practice. Some increase was achieved with hard granite and basalt but a real increase of the strength was obtained with the use of calcinated bauxite, up to more than fc 280 MPa. Plenary Session International Symposium on UHPC September 13 - 15, 2004, Kassel, Germany. Peter Buitelaar

Bache presents his very impressive discoveries on the second international conference on superplasticizers in concrete in 1981 and shocked the concrete community which still had trouble to produce a 25 tot 30 MPa concrete in the field.

A Cement paste.

B Superplasticized cement C DSP binder paste. paste. Figure 3: The structure of cementpaste in fresh concrete based on: A Portland cement; B Portland cement with a superplasticizer and C Portland cement with a superplasticizer and well dispersed micro silica.

Different companies and joint ventures were founded in that period. First companies were Aalborg Portland and Elkem. Licensees were sold to specialized companies for different special applications like tools and moulds. The key strategy is to find industrial applications for the new developed materials. Especially in the period until 1990 large research is made to investigate: Durability, density, wear resistance, chemical resistance, storage of nuclear waste, chloride permeability, corrosion protection, etc. In the period 1982 – 1986 intensive research was started to find solutions for the high autogeneous shrinkage and the brittleness of the DSP materials. Due to the good coordination between research and sales, new applications were found and a range of products was developed. Mixes were optimized with high percentages of aggregates with an optimum particle size.

2.3

The development of the Compact Reinforced Composite (CRC)

Already in 1986 research was made in the Netherlands by the author and co-workers to investigate multi fibre mixes in combination with DSP concrete to develop less brittle structures.


Soon after the development of the DSP materials many questions rose if the strong materials could be used efficient in load carrying structures. This because of the fact that the very strong matrix was also very brittle. Based on fracture mechanics a large body or structure will be much more brittle than small bodies or structures made of the same material.

Photo 3: From an extreme brittle binder.

Photo 4: To an extreme ductile composite.

The use of a high concentration of strong aggregates will increase both the strength and the fracture energy. The addition of small steel fibre reinforcement will result in even greater improvements but both modifications didn’t avoid that cracks were forming at very low tensile strains (approx. 0.2 mm/m). Due to the possibility to give the matrices high viscosity, what gave the possibility to add high amounts of fibres compared to conventional concrete, a certain ductile behaviour could be obtained. This, with the fact that the fixation on the fibres was extremely well, led to the idea to exploit this much better. This resulted in the development of the Compact Reinforced Composite (CRC) in 1986 by Hans Henrik Bache. CRC is a very strong and stiff composite material with exceptionally high ductility. CRC is build up of strong, densely arranged main reinforcement in a strong, rigid and ductile matrix of UHPC. The 4 basic principles of CRC are: 1. To enable brittle matrix materials (UHPC) to strain under tensile loading. This is achieved by making a matrix material with a high modulus of elasticity and high fracture energy and reinforcing that matrix with a high volume of fine, strong and stiff fibres. 2. To increase still further the ultimate tensile strain of the matrix material when this deforms together with the main reinforcement. This is secured by effective fixation of the fibre reinforced UHPC to the main reinforcement. The reinforcement will acts as a stiff Plenary Session International Symposium on UHPC September 13 - 15, 2004, Kassel, Germany. Peter Buitelaar

frame en thus ensures the formation of a multiple crack zone system with very large tensile strain capacity. 3. To ensure a high degree of local and global ductility by means that ensure a small brittleness numbers: the UHPC is given very high ductility with the use of fibers and a high volume of strong aggregates. 4. To enable a very dense and homogeneous particle and fibre packing at micro and macro level during casting by effective use of geometrical and kinematical principles. The UHPC must thus have a substantially viscous behaviour during the whole process (mixing, casting and compaction), even with very dense main reinforcement, assisted by well designed mechanical vibration. CRC consists of the following materials: •

UHPC with aggregates a diameter up to 1/3 of the space between the main reinforcement rebars and a w/binder ratio 0,13 – 0,18.

•

5 – 20% Main reinforcement (high strength steel, traditional rebars, carbon, etc.).

•

5 – 10% steelfibers.

CRC has the following properties: •

Compressive strength 150 – 400 MPa

•

Strength in bending 100 – 350 MPa

•

Strength in shear 15 – 150 MPa

CRC is in fact reinforced concrete, but deviates fundamentally from it in several ways, which is reflected in a load capacity more like that of structural steel. The design principles, the composition and production are different than from traditional reinforced concrete.

2.4

The development of new DSP systems

In 1993 Contec ApS was founded to be able to solve various problems with the original DSP concrete and to develop new materials like selfleveling fast setting and shrinkage compensated mortars and a large range of products between HPC and UHPC. Contec ApS also developed the heavy reinforced HPC and UHPC for different applications like industrial floors and ultra thin white toppings.


Photo 5: HRUHPC.

Photo 6: selfleveling fast setting and shrinkage compensated UHPC.

In the period 1992 – 1994 there was a close cooperation between the large French contractor Bouygues and Aalborg Portland to develop commercial applications for the Compact Reinforced Composite. In 1994 Bouygues (Richard and Cheyrezy) developed in cooperation with other industrial partners like Lafarge a new DSP concrete, named Reactive Powder Concrete, with down scaled particles size and multi fiber reinforcement. With the use of very fine aggregates and fillers a very dense packing is made possible by eliminating a part of the wall effect of the particles as earlier suggested by Bache in the nineteen eighties. RPC showed very high compressive and bending tensile strength with high amounts of steelfibers and a combined heat – and pressure treatment, to remove air and the excess of mixing water and to get chemical reactions to change the material properties, but this will not always be possible for large constructions.

Figure 4: Pedestrian bridge in Sherbrooke.

Figure 5: UHPC beams in Cattenom.

In 1996 Quillery developed their DSP concrete named BSI (Special Industrial Concrete). At this moment the two leading French companies in the production of UHPC: Bouygues (was RPC is now Ductal) and Quillery (was BSI is now Ceracem) including new industrial partners are reformulating their original developments and are concentrated on self compacting multifibre


mixes. The products are mainly used for prefab applications like beams, panels and bridges and architectural applications like façades panels, bus shelters, street furniture and flower pots. Besides the well known suppliers of UHPC, many new players are expecting to enter the UHPC market in the next 10 year, especially when specialized applications are developed in the next years. Due too the involvement of several specialized companies in the nearly future it will be more and more difficult to get patent rights on material compositions, it will than thus be more necessary to get patent rights on applications in combination with a material composition. 3

Applications of UHPC

After the development of the UHPC it was necessary to find applications where will be full benefit of the properties. The success of a specialized small material supplier is depending on innovative employees with a very good commercial, technical and theoretical know-how including a high dosage of persistence since practical failures and damages are also a part of the development and learning process. The different applications for the HPC, UHPC and HRUHPC which I present are based on the Danish experience in general and the authors experience during the last 19 years.

3.1

Wear protection

Because of the connection Aalborg Portland had with the FLS Group, who is designing, building and supplying cement factories worldwide and there own cement plant in Aalborg Denmark, the first applications of UHPC were protection against wear of their different installations and transport systems. UHPC is used for more than 25 years as wear protection in hydraulic- and pneumatic transport and storage systems of abrasive materials like coal, fly ash, cement, steel, silica sand and chemicals.

Photo 7: Replaceable part of scoop feeder.

Photo 8: Parts mounted together.

The scoop feeder (design Knud Lund Eriksen, 1981) for a cement mill (photo’s 7 and 8) is usually made of cast steel and has a total service life of max. 6 months due too the heavy wear. The six replaceable sections are made of reinforced UHPC with about 10% V/V main rein-


forcement and steel fibers to give ductility, in fact already a CRC structure, and had an Fc 250 MPa. The service life of 15 – 20 year is a large extension compared to the original scoop feeder. The UHPC has the following advantages in wear protection: •

Application: casting, shotcrete, handpatch.

•

Wear resistance: equal to that of melted basalt, special steel and high tech ceramic materials.

•

Wear resistance can be designed.

•

To cast in-situ and jointless or prefab.

•

Impact resistance: high – very high, especially compared to wear resistance tiles.

•

Temperature range: - 50°C till +1250 °C (special binder and aggregates).

3.2

Concrete repair

One of the first large applications was the rehabilitation of the Kinzua Dam Stilling Basin in October and November 1983. This basin had, despite earlier repairs in 1973 – 1974, due to cavitation erosion, holes until 1.10 m dept in the 1.50 thick concrete slab. The specified unreinforced 1.540 m3 DSP concrete with a thickness of 30 cm and with an fc of 90 MPa was placed in sections.

Photo 9: Damaged stilling basin.

Photo 10: Kinzua dam.

Despite several problems, most of them related to the lack of sufficient knowledge with HPC, like cracks, autogenous shrinkage, applicability and workability the overlay is working according the expectations. With the present knowledge it would be better to place a reinforced HPC concrete as levelling layer with a high wear resistant topping from 5 cm UHPC.


In Venezuela various tests are made to repair large damages in the Raúl Leoni Dam (“Guri”). Very large damage due too cavitation erosion occurred in the inlet/ outlet, the toe and the spillways. Repairs in the outlet with small bended high strength steel plates (accessibility is only possible through a manhole) fixed with drilled in anchors and welded together didn’t function.

Photo 11: The Raúl Leoni Dam (“Guri”).

Photo 12: Equipment ASTM C 1138-97 test.

The ASTM C 1138-97 test, developed by U. S. Army Engineer Waterways Experiment Station (WES), Vicksburg, MS. to simulate extreme cavitation erosion like in hydraulic structures, showed large abrasion-erosion from the grinding balls but no wear of the UHPC. In the Netherlands various repairs are made with UHPC since 1988 and 1989 in locks and sluices with abrasion-erosion. The damage were large holes with a depth until 30 cm till the lean concrete and a wear over the whole surface a wear of 7 – 10 cm.

Photo 13: Complex Sambeek.

Photo 14: Repair with UHPC underwater.

The emergency repairs underwater were done by divers, they simply casted the premixed UHPC which was let down by hand in a bucket, in the large holes. The large repair on the floor in the basin was done with only a minimum of leak water. After high pressure cleaning, the placPlenary Session International Symposium on UHPC September 13 - 15, 2004, Kassel, Germany. Peter Buitelaar

ing of reinforcement anchored to the sub concrete and a filling out layer of underwater concrete C 25 a topping of 25 mm UHPC was placed with a double vibration screed on guiding rails. Until the last inspections in 2003 no wear to measure but new wear occurs at the unprotected concrete.

Photo 15: Reinforcement for the levelling concrete.

Photo 16: Placing 25 mm UHPC topping.

In the Netherlands a solution was made for the repair of several foundation piles of a small bridge in the Zaan river in 1990 and this solution was demonstrated to different consultants and engineers by the author by placing a large concrete pile in a transparent plastic form filled with water. The protective layer of the pile was cast with UHPC what was simply filled in from above through the water. In the actual repair job a concrete pump was used to fill the formwork with UHPC. Due too the very positive experience of the consultant, the same repair system with UHPC was tested further and finally described in the tender for the repair of the jetty of Venterminales in Venezuela. The 254 hollow pre-stressed foundation piles, with a diameter of 50 cm and a wall thickness of 10 cm, were seriously damaged in the splash-down zone (4 m under- and 2 m above the water level) by chloride initiated corrosion. A fast repair was thus necessary to extend the service life of the jetty.

Photo 17: Damage at the piles.

Photo 18: Jetty with scaffolding.

The repairs method was as follow: Plenary Session International Symposium on UHPC September 13 - 15, 2004, Kassel, Germany. Peter Buitelaar

•

Removal of not sound concrete, cleaning and sandblasting under and above water.

•

If necessary placing new or extra reinforcement.

•

Placing and connecting moulds with diameter of 56 cm.

•

Pumping UHPC reinforced with steelfibers in the mould from the bottom of the mould.

•

Demoulding after 36 hours.

Photo 19, 20, 21 and 22: Placing moulds, casting with pump and repaired piles.

After 13 years no damage visible and no chloride penetration to measure, while similar repairs with cement based products in Venezuela with concrete showed damage again after 2 - 5 years.

Photo 23: Shotcreting UHPC.

Photo 24: UHPC Shotcrete with dense reinforcement

Shotcreting with UHPC is done for repairs of deteriorated concrete in very thin covers, for wear protection and for re-strengthening of structures according the HRUHPC principles. The advantages are: •

Constant high quality of the UHPC.

•

Less demand on skills nozzle man.

•

Minimum rebound and dust.

•

Can be sprayed in very dense reinforcement.

•

Fast strength development.

•

Can be finished with a smooth surface.


• 3.3

Both wet and dry methods are possible. Offshore

The first jobs for the hydro carbon industry were based on the very positive experience with the rehabilitation of the jetty from Venterminales in Pto. Cabello, Edo. Carabobo in Venezuela and were done in a similar way as that job to place a UHPC lining around the piles. After the first rehabilitation of foundation piles in both steel- and concrete of oil production platforms for the PDVSA (Petróleos de Venezuela,S.A.) in the lake of Maracaibo in Venezuela in 1992 and 1993 for corrosion protection and rehabilitation, UHPC is used to upgrade the platforms of the Ekofisk field, a solution developed by Norwegian consultants in co-operation with the owners of the platforms, in the North sea in 1995 and to rehabilitate various other platforms later. The use of grouts for the filling of members of offshore platforms is not a new application since it is done for more than 30 years but the properties of the UHPC are resulting in a much higher bearing capacity and an extreme good corrosion protection. A lining around piles or members and/or the filling of them is necessary in existing structures due to subsidence of the seabed, unforeseen topside load, increased wave load or weakening of the structure by corrosion, fatigue or accidents. The UHPC is to use for: •

Strengthening individual intact members by local- or complete filling.

•

Placing additional members which will be filled to restrength selected areas.

•

Increasing the load bearing capacity: filling up to 4 times and with special CRC solutions much more.

•

Filling under dimensioned and/or damaged members for additional strength.

•

Solving fatigue problems in local area’s with CRC solutions.

Also for new constructions UHPC and HRUHPC can be used for strengthening and by that the constructions can be made much more slender and thus reducing wave loads, the dead load of the platform and the steel dimensions. With special CRC solutions it is possible to reinforce fatigue sensitive areas and to replace steel in corrosive sensitive area’s like in the splash-down zone and the deck structure.


Due to the positive effect on the environment and the savings on traditional fuels for power plants there is a great interest in offshore windmill parks. Due to the extreme wave – and wind loads an extreme good fixation in the sea bed is important. UHPC for offshore windmills: Foundations: the UHPC is grouted in the bedrock and the casing to create a maximum fixation. Connections: the UHPC is grouted in the connection between the mono-pile and the transition part.

Advantages: •

Ultra high strength and stiffness.

•

Fast strength development.

•

Extreme fatigue strength.

•

Possible to correct pile intolerance to ensure a vertical tower.

For the offshore special HRHPC braces cast in-situ can be developed to restrength fatigue critical areas like jackets and tubular from offshore platforms and offshore windmills. Practical tests are already made to restrength and to protect platform jackets made from concrete as well as Plenary Session International Symposium on UHPC September 13 - 15, 2004, Kassel, Germany. Peter Buitelaar

made from steel. Decks of offshore platforms and supply vessels can be restrength and protected against corrosion and impact with an HRUHPC overlay bonded to the original deck plate. Very large offshore windmills with a high fatigue resistance and a large service life can be built in HRUHPC.

3.4

Security industry

Since the beginning of our history we are trying to protect our valuable belongings against burglary and fire. For more than 20 years structures are designed for high-strength, lightweight security barriers for use in the manufacturing of classified safes, vaults and ATMs. Security barriers are tested according standards, made by insurance institutes in cooperation with test institutes, based on RU values (Resistance Units), each type of barrier needs a minimum of RU to be accepted to store a certain amount of valuables.

Photo 25: The use of an oxyacetylene torch.

Photo 26: Tougher than the rest!

During the tests different specified tools are used to try to create an opening with clearly specified dimensions in the wall of the specific construction. UHPC and HRUHPC barrier materials are continuously tested and approved by the leading test institutes in Europe, Africa, Asia and the USA - classified in medium-end and high-end classes. UHPC security products are used all around the globe due to the fact that barrier solutions are sold to some of the world’s leading manufacturers of safes, vaults and ATMs. Small barriers like ATMs and safes are made with a double steel wall, often in combination with special designed and patented reinforcement and/or profiles, which is filled with UHPC of different compositions (depending on the necessary RU required).


Photo 27: Casting of door for vault.

Figure 6: A prefab made strong room.

Large vaults and the so called strong rooms are build from prefabricated HRUHPC in combination with special connection systems. With this prefab system is it possible to create large vaults and strong rooms in different locations and on different floors in a building. Since the last years various security products made in UHPC/ HRUHPC, or in combination with other materials, are also developed for the protection of humans and other valuables against ballistic and blast impact. 3.5

Prefab structures

The use of HRUHPC makes it possible to construct gigantic but non brittle structures, extremely slender, elegant and sometimes daringly designed. The new concept with a new philosophy and new principles for structural design as recent developed by Bache must be a new challenge for architects to design structures which are very visual very attractive. Until today however HRUHPC is mainly used to make prefab structures like balconies, galleries and stairs thus the properties of the HRUHPC are still, unfortunately, not used in the most significant way. As Professor Man-Chung Tang from T.Y. Lin International said several times during his presentation: we have to think "out of the Box". He also wrote in his proceeding: "Let us be more innovative! It appears to be a good idea to think of UHPC not as concrete as we know it now. We should try to develop new structural concepts that can utilize the strength and superb performance of this material. With time, this will happen!" Well, thinking out of the box is already possible and we are now able to use the new concept as recent developed by Bache which will make it possible to create new giant structures.


Photo 28: Gallery made in HRUHPC.

Photo 29: Slender stair made in HRUHPC.

A very good example of the use and the potential possibilities of the HRUHPC principles are the prefab panels placed on the bascule bridges in the motorway N 44 in the Netherlands. To replace the existing wooden bridge decks different alternative solutions were investigated by the Civil Engineering Division of the Ministry of Transport, Public Works and Water Management in the Netherlands. A solution with HRUHPC prefab panels was chosen as the best solution concerning costs, maintenance and durability within the maximum weight tolerance of the operating machinery. Testing of two small panels in the lab from TNO Building and Construction Research resulted in amazement by the engineers present: “If you want to see concrete flutter look to this” and “Amazing how flexible a plate with these dimensions can be, you see the plate clearly bulge under the load”. This project demonstrates on a small scale what is possible to reach with the HRUHPC: light, thin and ductile constructions with strength possible as that from structural steel.

Photo 30: Testing panels in TNO.

Photo 31: Placing panels on the bascule bridge.

An example how successful a simple idea can be are the so called prefab in UHPC cast Mushrooms, these thin (edge 18 mm, middle 78 mm and ø 1100 mm) Mushrooms are, after coldmilling a circle out of the asphalt, placed in the asphalt to form a road bump. Ambulances,


fireworkers and busses are able to pass easy while normal cars are lifting their wheels one by one.

Photo 32: Surface of the Mushroom.

3.6

Photo 33: Mushrooms placed.

Industrial floors, - pavements and Ultra Thin White toppings

For more than 20 years HPC, UHPC and HRUHPC are used as toppings in the food-, the food processing- and the heavy industry. The qualities of the material like very high early- and final strength, high wear resistance, not sensitive for placing on wet sub base and environment friendly makes it an excellent flooring product. Making good quality floors is not only depending on materials, almost each material from well known suppliers is of good quality, but is also depending on a combination of technical know how and good workmanship. Especially in the case of thin toppings success, or failure, are depending on factors as bonding, workability, placing conditions, finishing and curing. The preparations have to start with an examination of the existing sub base. Also the purpose, the loads (mechanical, thermical and chemical), aesthetics and other relevant aspects of the floor have to be checked with the owners and users of the floor. Especially in de food processing industry details are very important to avoid damage and contamination of food and/ or installations with bacteria’s. After the examination it is possible to make a good solution and a choice for a topping system.

Photo 34: UHPC topping in the heavy industry.

Photo 35: HPC topping in the food industry.


Various types of HPC and UHPC toppings are developed during these 20 years and a wide range of products are available. The compressive strength is still the parameter for HPC and UHPC, the difference between a HPC and an UHPC is thus than most of the time only the quality/ type of the aggregates.

Photo 36: Placing self levelling UHPC.

Photo 37: Powerfloating granolithic UHPC.

One of the first large applications of the HRHPC/ HRUHPC overlay is as a white topping on damaged pavements and industrial floors and in cargo ships. The unique properties of the HRHPC/ HRUHPC makes it possible to place the overlay as an “independent” topping (industrial floors) or wearing course (ultra thin white topping) on a cracked and/ or polluted sub base or even on an under dimensioned sub base made from different materials like asphalt concrete, concrete, wood, ceramics or steel. The concrete overlay contains one or more layers of welded mesh reinforcement (bar diameter 6 – 20 mm and bar spacing 15 – 50 mm). The concrete mixture contains both steel fibers and acrylic fibers and is based on a special composite of pre-blended materials. The HPC/ UHPC can be mixed at the building site or in a batching plant and can be transported with dumpers or truck mixers. The flow and workability are such that the material is easy to compact with the use of a laser screed or a double vibration screed. A large research project in the Netherlands is executed during the last 6 years to develop a new revolutionary HPC concrete wearing course on orthotropic steel bridges which is also extending the service life of the total construction by solving fatigue problems in specific deck details.


Photo 38: Caland bridge in the Netherlands.

Photo 39: Placing tent.

After the large test period a Pilot project is executed on the Caland bridge to test the method on an actual project. The application phases were as follow: •

Removing existing asphalt wearing course and placing tent.

•

Inspection deck and repair of cracks.

•

Placing profiles with dowels at sides and ends.

•

Shot blasting deck plate for good adhesion.

•

Applying sprinkled in epoxy interface layer.

Photo 40: Placing the interface layer.

Photo 41: Reinforcement principle.

•

After hardening of the epoxy unbonded aggregates are removed.

•

Placing distance keeper ø8 mm with on top 3 layers ø8 mm spaced at 50 mm.

•

A mobile concrete plant was used to mix the HPC.

•

A double vibration screed compacted en levelled the HPC.

•

After setting the surface was floated and polished to obtain a dense smooth surface.

•

Hereafter the surface was protected for 24 hours with wet burlap.

•

The surface of the HPC was shotblasted to obtain a high skid resistance.

•

The whole Pilot project from the first step until re-use took less than 120 hours!


Photo 42: Casting HPC.

Photo 43: In use again.

Fatigue cracks are a large problem for orthotropic steel bridge decks, especially cracks in the steel deck plate are of great concern due to their effect on traffic safety. Much is learned from the pilot project and this experience and know-how will be very useful for larger projects which will be executed in the following years. Strain measurements on the re-surfaced Caland Bridge show a stress reduction with a factor 4 5 in the fatigue critical structural details. This equals the reduction factor measured on the small test samples in the Adhesion Institute of the Delft University of Technology and the computer simulations. Further investigations on a part of an orthotropic steel deck plate with fatigue cracks and a HRHPC overlay show also a significant stress reduction in the trough wall (stiffeners). It could thus be possible to leave certain fatigue cracks un-repaired when the HRHPC overlay will be placed what will result in a shorter shutdown time and additional savings on repair costs. The pilot project demonstrated that it is also practically possible to place the HRHPC overlay on an orthotropic steel bridge deck even when traffic, including heavy loaded freight trains, is allowed to use a part of the bridge deck. Much more detailed specifications can now be made based on information obtained during the execution and evaluation of the pilot project. Preparations are started for the restrengthening of large orthotropic steel bridge decks. The planning is to resurface the Moerdijk Bridge (32,000 m2) and the Hagestein Bridge (7,500 m2) in the summer of 2005. Other orthotropic steel bridge decks will follow soon after. Fatigue problems in with orthotropic steel bridge decks are not an unique problem for the Netherlands alone, several similar problems are known in other countries and therefore a lot of international attention and interest have been received for the RHPC overlay as a rehabilitation and restrengthening method. 4

New applications

By combining the HRUHPC with other materials large ceramic/ metal-based hybride structures can be made that exhibit unique combinations of great strength in all directions; great hardness and extremely great fracture toughness. This make it not only possible to design and build gigantic structures and extremely slender, elegant and daringly designed structures but also to Plenary Session International Symposium on UHPC September 13 - 15, 2004, Kassel, Germany. Peter Buitelaar

make non-brittle ceramics for medical (implants and bone replacements) and industrial applications (tooling, pumps, engines). In nearly future the use of HRHPC will not be focused only on applications in civil engineering because the composite is also offering new solutions for other fields of application. Especially when the HRHPC is used in combination with other materials to produce new composite materials there are interesting solutions and applications possible.

Figure 7 and 8: Large thin, non brittle, CRC structures designed by Arch. Anja Bache

Other possible and very interesting application of UHPC and HRUHPC is the replacement of the sliding steel gates in the Eastern Scheldt Storm Surge Barrier in the Netherlands. The 62 sliding steel gates are composed of a vertical plate construction, a main girder system and a vertical girder system and have a width of 41,0 m¹ and a height (depending on the location of the piers) between 5,9 and 11,9 m¹.

Photo 44: The Storm Surge Barrier.

Photo 45: Corroded steel gates.

The replacement of the sliding steel gates will maybe be necessary in the nearly future because of the very high maintenance costs and the repeated application under special conditions of a special coating to avoid corrosion.


An internal research project initiated by the Civil Engineering Division of the Ministry of Transport, Public Works and Water Management in the Netherlands shows that it is possible to replace the existing sliding steel gates with HPC/HRUHPC gates within the maximum weight tolerance of the existing gate-operating machinery. The present design for the HPC/HRUHPC sliding gates consists of a HPC concrete for the girders and a HRUHPC for the plate construction (75 mm thick and reinforced with 3 layers ø8 - 50mm). Possible more weight reduction and additional strength can be reached by the use of high strength steel and/ or the use of carbon fibre- or other fibre reinforcement in the plate construction. Because the expected service life of the HPC/HRUHPC sliding gates will exceed the 100 years without additional maintenance it seems both practical and economical a very interesting solution.

Figure 9: Details concrete gate.

Figure 10: Concrete gate.

UHPC and HRUHPC can replace many existing structures made from other materials or new to build structures. Complete UHPC bascule bridges can be build with a shot blasted HRUHPC deck, the whole structure can be cast in prefab and on-site the prefab parts can than be connected together with UHPC joints. Gates and hatches in sluices and locks can be precasted and connected in the same way with a joint. Critical areas with possible impact can be cast in HRUHPC. refab

5

New material developments

The strength and properties of an UHPC will go in an upwards direction in the nearly future, 200 – 500 MPa will be possible within the next 20 years. For this it will also be necessary to produce Plenary Session International Symposium on UHPC September 13 - 15, 2004, Kassel, Germany. Peter Buitelaar

more artificial made aggregates to be able to reach these high strengths. With the much better available research equipment and computer modelling the microstructure can be investigated much better than before what will result in new developments including the incorporation of much more additives to control and to influence the properties of the matrix. New types of additives will be developed and they don’t have to be special developed for concrete. The use of special polymers like in MDF (Macro Defect Free) concrete will be interesting again to produce new types of UHPC. Heavy reinforcement in different materials and different forms will be used on all material levels thus also to reinforce the nano- and microstructure of the matrix. Future HRUHPC will thus incorporate a wide range of materials from different sources in both the binder part and the reinforcement part. 6

Conclusion

Although UHPC is much earlier developed than is known by many engineers and that there are several applications were UHPC is used for 25 years it is in general still an unknown material. During the last 10 years new applications are found for the use of heavy reinforced ultra high performance concrete and it seems that the C.R.C. concept starts to find its way between other composite materials and composite structures. HRUHPC offers new and sometimes exiting possibilities: lighter structures, larger structures, hybride structures, new design and new products with a potential for a better economy and resource consumption than with more traditional concrete, steel and other building materials. When designers, architects, engineers and structural engineers are more open for the “new concrete” and the “new technology” and are more willing to investigate and to innovate with the existing knowledge than much more can be achieved. To make use of the large potential for HRUHPC there must be a change of direction and a break with conventional practice to be able to understand the material properties and possibilities. For this it will be necessary that the industry will cooperate in a much better way with Technical Universities, institutes, governments and end-users and that knowledge and practical experience will be much more exchanged between those parties. 7

Acknowledgements

I especially like to thank Hans Henrik Bache, a great engineer and scientist but also a good motivator and a visionary, for his interesting lessons during all those years and his inspiring comments and advice, it is a great honour for me that I’m able to help to make some of his more than 25 years old dreams come true. I like to thank Niek Kaptijn from the Civil Engineering Division of the Ministry of Transport, Public Works and Watermanagement in the Netherlands and René Braam and all the employees from the Stevin lab of the Delft University of Technology in the Netherlands for their support and help


with the different projects in the Netherlands and for their contributions in the different proceedings. I like to thank Professor Michael Schmidt and the Scientific Committee for the kind invitation to present this paper as part of the plenary session at the International Symposium on Ultra High Performance Concrete 2004 in Kassel. 8

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