NANOCEM 10th Anniversary
OPEN MEETING
Tuesday, April 8, 2014
Starling Hotel Lausanne Saint Sulpice, Switzerland
Rolex Learning Center EPFL, Lausanne ©Alain Herzog
Welcome to the 10th Anniversary celebration Open meeting of the Nanocem Consortium, April 8th, 2014 in Lausanne
It is a pleasure to welcome you to our Open meeting in celebration of the 10th Anniversary of the Nanocem Consortium. Today we take the opportunity to present some of the research of the consortium which has made a difference in the field of cement and concrete: Thermodynamics, Proton Nuclear Magnetic Resonance, Admixtures and Cement, Atomistic modeling and the effects of SCMs on the microstructure of cement and concrete. Although these may sound rather fundamental topics, we hope you will see their relevance to everyday applications. We will end the meeting with a talk from Wolfgang Dienemann, head of the Industrial Advisory Board, on the perspectives of the industry for the future.
Nanocem, founded in 2004, is a consortium of twenty-three academic and eleven industrial partners who have a common interest in the nanoscale science of cement and concrete. The Nanocem partnership is unique: the industry finances a central Nanocem fund; and the academic partners contribute to the network with one of their externally funded projects, Partner Project, sharing the main results. Together, they identify gaps and plan collaborative research, our Core Projects, which get financed via the Nanocem central fund.
The fundamental aspect of the research is of utmost importance. It means that the research is done at a pre-competitive level. The aim is to understand the physical and chemical mechanisms governing the performance of cementitious materials at the nanoscale rather than to develop new products. This builds the foundation for future developments to allow for better and more sustainable cementitious materials.
To date fourteen Core Projects have been initiated, half of them have been completed. The principal results of seventy Partner Projects have been shared within the consortium. Two European Marie Skáodwoska Curie training network projects supporting some 30 researchers mostly at an early stage have been awarded to subgroups of Nanocem. Please browse our display of posters of these projects in the foyer and the conference room.
With this booklet, we have attached a folder containing five factsheets which explains who we are and what we do and a mortar USB key including a list of the publications issued from Nanocem
We take the opportunity to thank our industrial partners who have generously sponsored the event, the speakers and all our partners who have prepared posters. We hope you will enjoy your stay in Lausanne and we thank you for joining us for the celebration of the 10th Anniversary of Nanocem.
Karen Scrivener Coordinator of the Nanocem network
- 3 - - 4 - Table of contents
Nanocem Consortium ...... 6
Partners ...... 7
List of Core projects...... 8
Programme ...... 9
List of attendees ...... 10
Presentations...... 12
10 years of Nanocem research - some highlights K. Scrivener (EPFL, CH) ...... 13
Thermodynamics: from phase diagrams to predictive engineering T. Matschei (Holcim Technology Centre, CH) ...... 19
Water and cement : new insights from nuclear magnetic resonance techniques P. Mcdonald (University of Surrey, UK) ...... 23
Workability and interactions between admixtures and cement R. Flatt (ETHZ, CH) ...... 30
Atomistic modelling of cementitious materials: from crystal growth to disordered structures P. Bowen (EPFL, CH) ...... 36
Effects of supplementary cementitious materials on microstructure and performance of cements B. Lothenbach (EMPA, CH) ...... 43
An Industrial Perspectives on the future of Nanocem W. Dienemann (HeidelbergCement, DE)...... 49
- 5 - NANOCEM CONSORTIUM
Nanocem is a consortium of academic and industrial partners with a common interest in fundamental research into the nano and micro-scale of the phenomena that govern the performance of cements and concrete. Nanocem was founded in 2004 and has grown to a network of 23 academic and 11 industry partners. This unique cooperation between the industry and the academic community has lead to identify common issues and has helped map the research needs for sustainable cement and concrete.
A few of the ways that Nanocem brings added value to its members in the cement and concrete industry: x organizing workshops and seminars, x sponsoring research in multi-partner projects, x acting as a recruitment base for researchers in cementitious materials, x highlighting the importance of R&D on cementitious materials at the European level, x acting as a networking body to ensure academic research is relevant.
Aims
Research: To grow the basic knowledge needed to develop new cementitious materials, linking features and processes that take place at atomic level and their impact once used in buildings, bridges or other structures, and to disseminate the results of our work.
Education: To prepare the next generation of researchers, by educating university graduates and providing a platform for future employment in the cement and concrete industry.
Responsibility: 7R KHOS ¿QG VROXWLRQV WKDW ZLOO IXUWKHU UHGXFH WKH HQYLURQPHQWDO LPSDFW RI FHPHQW DQG concrete.
- 6 - PARTNERS
Industrial Partners 1. Aalborg Portland (Cementir Holding), Denmark 2. BASF, Germany 3. CTG Italcementi Group, Italy 4. Elkem as Silicon Materials, Norway 5. HeidelbergCement AG, Germany 6. Holcim Technology Ltd, Switzerland 7. Lafarge, France 8. SCG Cement-Building Materials, Siam Research and Innovation Co., Ltd, Thailand 9. SIKA Technology AG, Switzerland 10. VDZ, Germany 11. WR Grace, USA
Academic Partners 1. Ecole polytechnique fédérale de Lausanne, Switzerland $JHQFLD(VWDWDO&RQVHMR6XSHULRU,QYHVWLJDFLRQHV&LHQWL¿FDV6SDLQ 3. Aarhus University, Denmark 4. Bauhaus-Universität Weimar, Germany 5. Commissariat à l’énergie atomique et aux énergies alternatives, France 6. CSGI/University of Florence, Italy 7. Czech Technical University in Prague, Czech Republic 8. Danish Technological Institute, Denmark 9. Empa, Swiss Federal Laboratories for Materials Science and Technology, Switzerland 10. Eidgenossische Technische Hochschule Zurich, Switzerland 11. Institut français des sciences et technologies des transports, de l’aménagement et des réseaux (ex-LCPC), France 12. Imperial College London, United Kingdom 13. Lund University, Sweden 14. Norwegian University of Science and Technology (NTNU), Norway 15. Technical University of Denmark, Denmark 16. Technische Universität München, Germany 17. Technische Universität Wien, Austria 18. University of Aberdeen, United Kingdom 19. Université de Bourgogne, France 20. University of Leeds, United Kingdom 21. Universitat Politècnica de Catalunya-Barcelona Tech, Spain 22. University of Surrey, United Kingdom 23. ZAG, Slovenia
- 7 - LIST OF CORE PROJECTS
These are fundamental, long-term research projects carried out by two or more contractors, funded by the resources of the Nanocem Consortium. Typically 2-3 of the academic partners work together sharing a PhD student who moves between partners.
Finished Core Projects:
1. Mineralogy of Hydrated Cements University of Aberdeen, UK – Empa, CH 2. Pore Structure Characterisation by Magnetic Resonance Techniques University of Surrey, UK – Ecole Polytechique, FR 3. Organo-Aluminates Interactions Ecole Supérieure de Physique et Chimie Industrielles de Paris – ParisTech, FR 4. Hydration of Blended Cements EPFL, CH – Aarhus University, DK – University of Leeds, UK – DTU, DK 5. Alkali Activation of Aluminosilicates - An Assessment of Fundamental Mechanisms University of Aberdeen, UK – CSIC, SP 6. Atomistic Modelling on Cementitious Systems EPFL, CH 7. Fundamental Mechanisms of Cement Prehydration TUMünchen, DE – University of Leeds, UK – Lund University, SE – ZAG, SI
On-going Core Projects:
8. Non-Saturated Transport Properties of Cementitious Materials Lund University, SE - IFSTTAR, FR - CSIC, SP - Empa, CH - DTU, DK - Imperial College London, UK 9. Impact of Additions on Hydration Kinetics of Cementitious Materials EPFL, CH – University of Aberdeen, UK – Aarhus University, DK – Empa, CH 10. Micromechanical Analysis of Blended Cement-Based Composites CTU in Prague, CZ – TUWien, AT 11. Carbonation Behaviour of Low-Clinker Cements University of Leeds, UK – IFSTTAR, FR – Lund University, SE – ZAG, SI – CSIC, SP ,QÀXHQFHRIWKH)XQFWLRQDOLWLHVRI2UJDQLF0ROHFXOHVRQWKH5HDFWLYLW\DQG+\GUDWLRQ Kinetics of Cement Phases University of Bourgogne-Dijon, FR – University of Surrey, UK 13. Shrinkage and Cracking in cementitious materials Empa, CH – DTU, DK 14. Frost durability of low clinker binders Lund University, SE – NTNU, NO (to start in 2014)
- 8 - PROGRAMME
9:00 Registration and coffee
10:00 Welcome P. Gillet, Vice-president EPFL (EPFL, CH)
10:15 10 years of Nanocem research - some highlights K. Scrivener (EPFL, CH)
10:45 Thermodynamics – from phase diagrams to predictive engineering T. Matschei (Holcim Technology Centre, CH)
11:15 Water and cement – new insights from nuclear magnetic resonance techniques P. Mcdonald (University of Surrey, UK)
11:45 Workability and interactions between admixtures and cement R. Flatt (ETHZ, CH)
12:15 Buffet Lunch and Posters of projects
14:00 Atomistic modelling of cementitious materials: from crystal growth to disordered structures P. Bowen (EPFL, CH)
14:30 Effects of SCMs on microstructure and performance of cements B. Lothenbach (EMPA, CH)
15:00 An Industrial perspective on the future of Nanocem W. Dienemann (HeidelbergCement, DE)
15:30 Closure
- 9 - NANOCEM 10th Anniversary OPEN MEETING App,ril 8, 2014 , Starlin g Hotel , Saint-Sul p,pice, Switzerland Listst oof participantspa t c pa ts
LLtNast Name First name IItitt/Cnstitute/Company CCtountry
1 Antoni Mathieu EPFL CH 2 AtAvet FiFrançois EPFL CH 3 Babayan David Holcim Technology Ltd CH 4 Baquerizo Luis Holcim Technology Ltd CH 5 Ben Haha Mohsen HTC DE 6 Berodier Elise EPFL CH 7 Beuchle Günter Karlsruhe Institute of Technology KIT DE 8 Bizzozero Julien EPFL CH 9 Black Leon University of Leeds GB 10 Bowen PlPaul EPFL CH 11 Canonico Fulvio Buzzi Unicem SpaIT 12 Cepuritis Rolands NTNU NO 13 Chabrelie Aude Creabeton SE 14 Chanvillard Gilles Lafarge Centre de Recherche FR 15 Cheung Josephine Grace US 16 Chowaniec Olga CEMEX RESEARCH GROUP CH 17 Costoya Mercedes Holcim Technology Ltd CH 18 DlDalang MiAliMarie-Alix EPFL CH 19 Damtoft Jesper Sand Aalborg Portland DK 20 Deschner Florian BASF Construction Solutions GmbH DE 21 Di B ell a ClCarmelo Empa CH 22 Dienemann Wolfgang HTC DE 23 Durdzinski Pawel EPFL CH 24 Eberhardt Arnd Sika Technology AG CH 25 Elsen Jan KUleuven BE 26 ElElsenesener Bernh nhaard ETHZ CH 27 Espina Carlos Lafarge Centre de Recherche FR 28 Etzold Merlin University of Cambridge GB 29 FiFavier AéliAurélie EPFL CH 30 Fernandez-Zumel Mariano Alfonso CEMEX RESEARCH GROUP CH 31 Ferrari Lucia CHRYSO FR 32 Flatt Robert ETHZ CH 33 Forster Samir DESAX SA CH 34 Fridh Katia Lund University CH 35 Fylak Marc SCHWENK Zement KG DE 36 Gallucci Emmanuel Sika Technology AG CH 37 GtGartner Ellis LfLafarge Cen tre de Rec herc he FR 38 Geiker Mette NTNU NO 39 Goisis Marco Italcementi IT 40 Haerdtl Reiner HTC DE 41 Haniotakis Manolis Titan Cement Company GR 42 Herfort Duncan Aalborg Portland DK 43 Herterich Julia University of Leeds GB 44 Jacob Romain DESAX SA CH 45 Juill an d PtikPatrick Sika T ec hnol ogy AG CH 46 Kocaba Vanessa CHRYSO CH 47 Kunther Wolfgang Aarhus University DK
- 10 - Last Name First name Institute/Company Country
48 Le Bescop Patrick CEA Saclay FR 49 Leemann Andreas Empa CH 50 Legat Andraz ZAG SI 51 Lothenbach Barbara Empa CH 52 Lura Pietro Empa CH 53 Manzano HiHegoi UiUnivers ity o fthBf the Basque Coun try ES 54 Marchi Maurizio Iler CTG SpaIT 55 Marzari Nicola EPFL CH 566 Matschei Thomas Holhldlcim Technology Ltd CH 57 McDonald Peter University of Surrey GB 58 Moro Fabrizio Holcim Technology Ltd CH 59 Möser Bernd Bauhaus-University Weimar DE 60 Mosquet Martin Lafarge Centre de Recherche FR 61 Nicol eau Luc BASF C onst ructi on S ol uti ons Gm bH DE 62 Nonat Andre Université de Bourgggogne FR 63 Olsson Nilla Lund University SE 64 Pascu GGbilabriel CEMEX RESEARCH GROUP CH 65 Pegado Luis UUdougogniversité de Bourgogne FR 66 Pereira João CIMPOR Serviços PT 67 Provis John University of Sheffield GB 68 Radtke Frank CPMChemisch Ͳ PhysikalischeMesstechnik AG CH 69 Reiff Holger ZKG INternational CH 70 Rocha Paulo CIMPORServiços PT 71 Roessler Christiane Bauhaus- University Weimar DE 72 Romer Mic hae l HliHolcim Tec hno logy Ltd CH 73 Rossen John EPFL CH 74 Russo Alessandro CEMEX RESEARCH GROUP CH 75 Saeidpour Mahsa Lund University SE 76 Sandberg Paul Calmetrix US 77 Santa Quiteria Gomez Cristina Ruiz Aarhus University DK 78 Santos Rodrigo CIMPOR Serviços PT 79 Schmidt Thomas Holcim Technology Ltd CH 80 ShSchumach er PtPetra FIB CH 81 Schweike Uwe Karlsruhe Institute of Technology KIT DE 82 Scrivener Karen EPFL CH 838 Sealey Ben Elkem GB 84 Silva Adriano InterCement do Brasil BR 85 Snellings Ruben EPFL CH 86 Spaeth Valérie Redco NV BE 87 Stemmermann Peter Karlsruhe Institute of Technology KIT DE 88 Stoppa Riccar do WR Grace CH 89 Tajgjuelo Rodriguez Elena University of Leeds GB 90 Touzo Bruno Kerneos FR 91 ThdiTschudin MkMarkus HliHolcim Tec hno logy LdLtd CH 92 Vadeeydean der HeydenLuc Redco NV BE 93 Wattimena Johannis Nettalus Penta Chem ID 94 Wong Hong Imperial College London GB 95 Xuerun Li Nanjing Tech University CN 96 Zajac Maciej HTC DE 97 Zanders Carsten CEMEX RESEARCH GROUP CH 98 Zografou Mado University of Bath GB
updated: 3/30/2014
- 11 - PRESENTATIONS
- 12 - Background
THE INDUSTRIAL-ACADEMIC RESEARCH NETWORK ON CEMENT AND CONCRETE • Until end of 1970s large laboratories PCA, BCA, CERILH, carridied out b asi c wor k on cemen titious ma ter ia ls 10 years of Nanocem research – • Then drastic downsizing / closure of these laboratories some higgghlights • Work in Universities fragmented, small isolated groups • Duplication, reinventing the wheel, no follow through
• PhD structure – studies limited to 3 years
Karen Scrivener, LMC, EPFL • Current developments largely empirical and incremental Switzerland • Recognition that situation has to change
• MtihlltdMounting challenge to decrease envi ronment tlftitalfootprint
Creation of NANOCEM THE INDUSTRIAL -ACACEMIC RESEARCH NETWORK ON CEMENT AND CONCRETE
• May 2002: first meeting, 6 partners, Paris
• Unsuccessful bid for EU network of excellence
• March 2003: Decision to form independent consortium
• May 2004: signature of consortium agreement
Continuing activity indefinite duration
11 Industrial partners
23 Academic partners
An Industrial Academic Partnership for Fundamental Research on Cementitious Materials
- 13 - Industrial - academic dialog Areas where lack of understanding or quantitative measurement blocks progress e g ge ses owled vance ducts
€s d s n For d Partner Core ACADEMIA INDUSTRY nowle n of k erm a ew pro proce k
research t o n research d
projects of programme an into Long tegrati In
Interpretation of knowledge and clarification of possible progress areas
How to meet increase in demand Structuring effect on research
The impact of Nanocem goes way beyond funding new research:
Regular Identification Structuring scientific of key effect on debate questions research
10
Blends based on Portland clinker Typical reductions in clinker factor CO CO2
Process optimisation lik clinker fac tor
Clinker Gypsum Cement
SCMs – Supplementary Cementitious Materials
Limestone Fly ash Slag Natural pozzolan
Often by-products or wastes from other industries SHOLCIMSource: HOLCIM
12
- 14 - But increasing substitution is reaching a limit due to: - technical performance 50% Clinker: excellent mechanical properties at young ages - availability Burgess India1 Thai India3 Metakaolin Calcined clays Figures from ~2013 Kaolinite content (%) 95 80 50 20 Rice husk ash
Silica fume
Burnt shale Used in cement Calcined clay Reserve Natural pozzolana
Blast furnace slag PPC LCC
Fly ash Fly ash: significant volumes with low performance 1st International conference Cement Calcined clays for sustainable concrete 23-25 June 2015 Mill. tons/year 0 1000 2000 3000 4000 Lausanne Limestone
13
Calcined clay + limestone
100 Combined addition gives better 80 In the future sustainability can be increased by strength than OPC at 7 & 28d for Metakaolin [%] 60 replacement of 45% Limestone [%] ~90% for 60% addition 40 Cement [%] 1. Extending the use of current clinker substitutes; 20 2. The development of novel, cost-effective Fast synergetic effect between 0 supplementary cementitious materials and alternative clinkers; metakaolin and limestone OPC LS15 MK30 B45 B60 3. Optimizing the use of waste materials as substitutes for clinker and fuel;
However such developments can only be successful if we can provide the basis in understanding and performance tests for users to have confidence in the many potential solutions
There is no magic bullet solution: sustainability can only come from mastering an increasingly diverse range of cementitious materials
15
To master new solutions, The basis for user confidence we need approaches based on mechanisms
Can only come (on a reasonable timescale) through : A systematic, science-based understanding of cementitious processes and materials at the nanoscale: Composition, Extended across all the scales involved in cement and concrete Mixing, production to: Time, Provide the multidisciplinary assessment and prediction tools needed Temperature, to assess the functional and environmental performance RH, of c urrent and ne w materials . etc
- 15 - Network Resources THE INDUSTRIAL-ACACEMIC RESEARCH NETWORK ON CEMENT AND CONCRETE Nanoscience of Cementitious Materials: processes occurring at the nano / micro scale ~120 permanent research staff involved determine macroscopic performance ~65 doctoral students
Financing of core projects based on industry contribution (~ 750.000 € p. a.)
<100nm + Umbrella for European projects
Absorption of Capillary forces in partially 2006-2010: ~4 M€: Marie Curie RTN, C-S-H, superplasticiser saturated pores less than 15 PhDs + Post docs main hydrate phase: molecules on cement 100 nm controls strengg,th, grains: controls shrinkage and 2010-2014: ~4 M€: Marie Curie ITN, 15 PhDs durability, etc controls rheology cracking
Types of projectect Core projects
Partner PartnerPartner Core projects aim to bridge the gaps between the independent project Partner project research of the different academic partners. project Partner They typically fund 1-2 PhD students working across Core Core project Partner 2-4 partner institutions projectproject projectproject projjtect Core projects chosen after workshops process Partner Core projjtect projjtect Partner project PartnerPartner Partner project project
Core ppjrojects, comp leted Core ppjrojects - ongggoing CP1 (finished, early 2008): Aberdeen + EMPA CP8 (started Oct 2009): LCPC + Lund Phase Assemblages with C-S-H Ion transport in partially saturated conditions CP2 (finished, Sept 2007): Surrey + Ecole Polytechnique CP9 (started Jan 2011): EPFL, Aberdeen, Aarhus Pore structure by 1H NMR Influence of mineral additions on Kinetics of hydration CP3 (finished Feb 2009): ESPCI Paris + Dijon CP10 (started Oct 2012): CTU, TUV Organo Aluminates Micromechanical analysis of blended cement-based composites CP4 (fini sh ed Oct 2009) : EPFL, Aar hus, Lee ds, DTU CP11 (t(start tOt Oct 2012): Lee ds, LCPC Reactivity of cement and SCMs in blended pastes Carbonation Behaviour of Low-Clinker Cements CP5 (finished 2009): Aberdeen, IETCC Madrid CP12 (started Oct 2012): Dijon Phase formation in Alkali activated systems Influence of the functionalities of organic molecules on the CP6 ((g)finishing 2013): EPFL reactivity and hydration kinetics of cement phases Atomistic modelling to study hydrate formation CP13 (to start 2013): EMPA, DTU CP7 (finished 2012): TUMunich + Leeds + ZAG Early age dimensional changes and cracking “Pre-Hydration” - Reactions before mixing with liquid water
- 16 - 15 PhD an ddI Ind ust ri alD l Doct orat e P roj ect s
-cracks mm TRANSPORT concrete PREDICTION Imperial 4 wetting / didrying cyc les 3 IFSTTAR 5 FEM EPFLcement TRANSCEND MC ITN m EPSRC project UdUnderst andi ng W Wtater Transport for Concrethihite whichis Eco friendly iNnovative and Durable LB Cambridgecement Cambridge 2
HHSurreyHHHH Surrey nm O O O IC and micro-graphs MD cement for structure 1 Surrey Theme A : 5 inter-connected modelling projects.
15 PhD an ddI Ind ust ri alD l Doct orat e P roj ect s 15 PhD an ddI Ind ust ri alD l Doct orat e P roj ect s UPC Sika cracks Dry & Shrink HeidelbergNoemi characterisation 15 11 Conv. tests validate TRANSPORT Crack 14 EPFL Cracks PREDICTION 11 4 Holcim Hyst. -structure TransportEffectof RH models on non 5 TRANSPORT characterisation Cracks C-S-HEffect hydrates of RH LBFEM micro PREDICTION validate 13 7 3 4 Lund -struc Hyst. Transport 7 5 Leeds LBLB nano LBFEM micro coefficients CSH 2 3 6 morphology MD T. Coeffs 8 LBLB nano 6 1 2 Lafarge DTU LB: MD to FEM Surrey Cryoporometry CSH MD validate 12 8 1 NMR and MRI 10 Cryo. 9 MR 10 9 The experimental projects of Theme B (6-11), feeding modelling in Theme A (1-5). Theme C industrially based validation projects (12-15)
Nanocem summary Training programmes
Nanocem is a complex, dynamic and evolving research network 2 x 6 doctoral level courses in context of Marie Curie networks • Finances core proj ec ts. TiTopics: ItIntrod ucti on, W Witiriting wor khkshop an d spec imen prepara tion, • Develops European projects Characterisation techniques, Durability, Transport Processes and modelling, • Training environment Standardisation, Mechanical Behaviour and Modelling, Microstructure, Performance testing, Applications to engineering problems, Innovation • Multiple interactions between partners: • Industry – academic 4 Knowledge transfer workshops on the topics of • Academic –academic •Advances in cement hydration (2009) • Industry - Industry •Effect of SCMs on microstructure and performance of cementitious materials (()2011) •Transport Processes (2012) •Pore Structure (2013)
Numerous thematic workshops
- 17 - CreatingPhotoa description new paradigm to be changed for research in the Master slide WherePhoto is description this going to be changed in the Master slide Additional text to be changed in the Master slide Additional text to be changed in the Master slide • Prediction of solid phases present as function of: Plan (and fund) Chem is try; Time; Temperat ure; R el a tive Hum idity; Photo description to be changed in the Master slide Photo description to be changed in the Master slide Additionalcollaborative text to be changed in the Master slide Additional text to be changed in the Master slide research Better • Prediction of microstructure, pore structure and movement of “water” and more Sustainable • Appropriate tests to verify suitability of new materials and prediction of Identify gaps Research projects training new experts Cementitious their performance throughout the life of structure materials
Definition of a road map for safe and effective use of new materials
THE INDUSTRIAL-ACACEMIC RESEARCH NETWORK ON CEMENT AND CONCRETE
IndividualPhoto description observations, to be changed examples in the Master slide CollaborativePhoto description observations to be changed in the Master slide Additional text to be changed in the Master slide Additional text to be changed in the Master slide
Photo descriptionLab 1to be changed in the Master slide Photo description to be changed in the Master slide Additional text to be changed in the Master slide Additional text to be changed in the Master slide
Lab 2
Lab 3
THE INDUSTRIAL-ACADEMIC RESEARCH NETWORK ON CEMENT AND CONCRETE
- 18 - Content
• Why thermodynamics - Introduction to thermodynamic methods in cement science THE INDUSTRIAL-ACADEMIC NANOSCIENCE RESEARCH NETWORK FOR SUSTAINABLE CEMENT AND CONCRETE • Impact of limestone on cement hydration • Impact of water activity Thermodynamics: From Phase • Thermodynamics and Civil Engineering Diagrams to Predictive Engineering
Thomas Matschei
AFt + AFt + Mc + calcite Innovation R&D, Holcim Technology Ltd. Hc +Ms (ms)
MS ss (ms)+ AFt + Hc+ Mc Hc Nanocem Consortium 10th Anniversary Open Meeting lim. Ms ss H+CAH () Lausanne, 08 April 2014
Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 2
Why Thermodynamics? Fundamentals
Advantages of thermodynamic modelling approaches General modelling approach • Generic Approach: Thermodynamic calculations are solids Follows the principle of the minimisation of the Gibbs widely applicable to numerous materials free energy of a complex chemical system +H2O G(x) ; min. at given T, P • Qualitative und quantitative predictions of phase assemblages occurring in complex materials Energy-Minimization (Software e.g. ) Computes mass balances, based on equilibrium phase • Provides Understanding of the material behaviour in a assemblages and speciation in the aqueous phase, from given service environment total bulk composition ; possibility of quantification
Ca2+ CaOH+
HSiO - SO 2- • Significant reduction of laboratory work and trial and 3 4 CO 2- A comprehensive database involving all relevant phases error experiments due to simulation of complex reactions 3 Solids + aq. species including solid solutions has to be applied in all calculations
Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 3 Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 4
Fundamentals Core Project 1: Thermodynamics enabled a systematic prediction of mineral phase assemblages in hydrated cements A complete dataset is the base of any successful model
Thermodynamic database including the main thermodynamic data of cement hydrates coupled to an excess portlandite present in all assemblages ms- metastable existing standard database (incl. aq. Ions gas phase etc.) 3.5 AFt +gypsum + calcite Database 3.0 “Standard” database Cement hydrates high Carbonate content 2.5
• Aqueous phase (e.g. AFt -ratio [-] AFm hydrogarnet C-S-H 3 AFt (ettringite) + Ca2+, Ca(OH)+, etc) O 2 2.0 • Gaseous phase (e.g. AFt + monocarbonateAFt + Mc + calcite + /Al CO2 (g), etc.) 3 Hc • SO -AFm • SO -AFt • C AH • tobermorite- calcite • Minerals (e.g. calcite, 4 4 3 6 Solid Solid Solid jennite solid 1.5 +Ms (ms) Portlandite, gypsum, •solution solution solution solution model etc.) • OH-AFm • CO3-AFt • sil. Hydrogar. + thaumasite C3ASxHy • CO3-AFm 1.0 • hemicarbonate molar bulk SO bulk molar • stratlingite AFt + Hc+ Mc 0.5 MS ss (m s)+ Hc lim. Ms ss Hc + C AH (ms) 0.0 4 x 0 0.25 0.5 0.75 1 1.25 1.5 molar bulk CO2/Al2O3-ratio [-] For original data source see: Matschei et al CCR 2007 (37) 1379-1410; Lothenbach et al CCR 2008 (38) 1-18 Small amounts of carbonate may significantly change the phase Qualitative and quantitative calculation of phase assemblages in the range 1 – 99°C assemblages of hydrated cements (for database cemdata 07.3 see http://www.empa.ch/plugin/template/empa/*/62204)
Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 5 Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 6
- 19 - Core Project 1: Optimised spacefilling of hydrating cement by Core Project 1: Optimised spacefilling vs. Compressive strength controlling the carbonate content (exp. Data by D. Herfort, Aalborg cement)
100 15 estimated chemical shrinkage Example: calculated for compressive strength measured Example: calculated for SO3/Al2O3 = 0.7, 25°C SO3/Al2O3 = 0.7, 25°C m axim um specific volum e of solids 10 pore solution 75 calcite 5 increase AFt hemicarb. m s (ss) 0 50 monocarboaluminate decrease portlandite -5
25 compressive strength [%] -10
total volume [Vol.-%] total volume total porosity calculated C-S-H (Ca/Si~1.6) relative change of porosity and -15 0 0 2 4 6 8 10 12 14 16 18 20 22 0 2 4 6 8 10 12 14 16 18 20 22 amount of CaCO3 added [wt.-%] amount of added CaCO [wt.-%] 3 Matschei et al., ZKG 2006 &, CCR 2007 Good correlation between predicted changes of relative porosity and measured compressive strength Change of specific solid volume with changing CaCO3-content
Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 7 Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 8
Synergies between limestone and alumina-rich SCM’s with great potential to optimise multiple blends
Slag- limestone blends Fly ash- limestone Calcined clay - blends Limestone blends
110 CEM III B (slag 19% Al O ) 100 2 3
90 OPC strength [%] (low C3A) 80 OPC
28d relative Compressive (high C3A) 70 01020 limestone [wt.-%]
own investigations De Weerdt ea. 2011, Cost ea 2014 Herfort 2010, Damidot ea 2011, Antoni ea 2013
Thermodynamic calculations helped to understand complex phase relations which can be used as base for smarter product design.
Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 9 Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 10
Transcend industrial doctorate@Holcim Better understanding of the drying/wetting behaviour of The impact of water activity on the volume stability of hydrates cementitious materials
Annual temperature and humidity fluctuations in Weimar/Germany 100 25 Monosulfate 90 20 –sensitive- 80 15 125% 70 10 Ms Mc 60 5 120% Temperature [°C]
relative humidity relative humidity [%] 50 0 115%
40 -5 110%
105% Hygric expansion (%) 100% 012345 How do fluctuations of temperature 23% rH days 97% rH and relative humidity impact the thermodynamic and volume stability of Monocarbonate cement hydrates? –not sensitive- PhD thesis Luis Baquerizo Baquerizo, Matschei and Scrivener Ibausil 2012
Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 11 Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 12
- 20 - Improved characterisation of thermodynamic stability of hydrates Impact of temperature and RH on the thermodynamic stability of as function of water activity hydration states of monosulfoaluminate
Volume Phase diagram: Monosulfoaluminate-H O Predicted volume changes in the system 1. X-Ray diffraction (XRD) Density 2 Monosulfoaluminate-H2O at 25°C Water content *corresponding No. of total moles of H O per formula unit 2. Thermogravimetric analysis (TGA) 100 2 Ms16* 100 3. Sorption calorimeter: collaboration Transcend Project 6: Lund University Ms14* [Ca4Al2(SO4)(OH)12.10H2O] [Ca4Al2(OH)12.8H2O] 90 80 4. Sorption balance: collaboration Transcend Project 6: Lund University 80
5. Humidity buffer method Ms12* 70 Ms14 60 [Ca Al (SO )(OH) .6H O] 60 2 4 2 4 12 2 50 Ms12 Ms10.5
1 RH (%) 40 Ms10.5* 40 3 [Ca Al (SO )(OH) .4.5H O] 4 2 4 12 2 30 Volume solids (%) 1 20 20 Ms9 10
Ms 9*[Ca Al (SO )(OH) .3H O] 0 0 4 2 4 12 2 0 102030405060708090100 1009080706050403020100 5 RH (%) Temperature (°C) 4 Baquerizo et al, Transcend Conference 2013
The knowledge of different hydration states of cement hydrates allows the prediction of specific solid volume changes as function of temperature and RH Baquerizo et al. submitted to Journal of Physical Chemistry C, 2014
Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 13 Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 14
Translation of basic chemical principles into Thermodynamics and Civil engineering practical application
Calorimetry as thermodynamic fingerprint of hydration to optimise concrete performance
Development of an easy-to-use software tool Holcim ConTempTM for concrete temperature prediction with CTU Prague
Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 15 Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 16
Holcim ConTempTM Prediction of application relevant concrete Validation Example: Water lock Bolzum characteristics
70
Challenge: bottom concrete slab 65 Max Tqadiab, 7d acc. to 60 ZTV W LB 215 Tad, 7d, hydr+Tfresh concrete 56°C; 55 200x12x3m concrete slab 50 3 (~7200m ) 45 [°C] measured 5 cm from surface [°C] measured 50 cm from surface Sulfate resistance req. 40 [°C] measured 100 cm - core [°C] Ambient temperature 35 simulation 290kg CEM III B+90kg FA (Core) simulated ambient temperature 30 simulation 350kg CEM III B (core) 25
Temperature [°C] Temperature 20 15 10 • Standard approach to show compliance with temperature restrictions 5 (acc. to ZTV W LB 215 (German standard)) 0 0 24 48 72 96 120 144 168 Large scale concrete test 2mx2mx2m = 8m3 concrete time [h] Quasi-adiabatic conditions: Use of 36cm Styrofoam insulation to Development of powerful engineering tools based on thermodynamic principles simulate adiabatic conditions
Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 17 Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 18
- 21 - Summary Acknowledgements
• Present and future cementitious materials have a high degree of complexity and variability in chemical and mineralogical composition. Engineers cannot rely only on experiences gained in the past mainly from OPC systems.
Nanocem for funding of CP1 Hence generic tools are needed to establish quantitative links Prof Fred Glasser, Prof Donald Macphee between cement chemistry and mineralogy with physical and Dr Barbara Lothenbach mechanical properties of concrete. Dr Ellis Gartner, Dr Duncan Herfort, Prof Karen Scrivener and specially to Marie-Alix Holcim • Thermodynamic tools are useful to determine reaction pathways, Dr Michael Romer, Dr Markus Tschudin quantify reactions and enable new ways to optimise complex cement The whole Innovation Team compositions. They can serve as input for powerful predictive engineering tools. Transcend Prof Lars Wadsö, Mahsa, Alva (Lund University) EC for funding CTU Prague Prof Vit Smilauer
Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 19 Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 20
- 22 - Magnetic resonance imaging
Water and cement: new insighfhts from nuclear magnetic resonance techniques PJMDldPeter J McDonald
Whole Brain Atlas: Johnson and Becker
THE INDUSTRIAL-ACACEMIC RESEARCH NETWORK ON CEMENT AND CONCRETE
Advantages of NMR for cement The beginning of NMR relaxometry and cement • Non destructive & non invasive Time course studies • Water is the probe! R. Blinc et al. • Quantit a tive “NMR Relaxation Study of Learnt how to “see” all the water Adsorbed Water in Cement andCd C3SPS Past es” • Can be quick and easy J. Am. Ceram. Soc. 61, 35 • Can be rich and rewarding 37, (1978)
Robert Blinc (1933 2011)
NMR oil well logging NMR relaxometry of cements since 2004 Pore sizes from signal amplitudes & drying C S H morppgyphology, composition, water state and density DQF 1H NMR & lateral extent of pores NMR restricted diffusometry Water exchange rate between pores Permeabili ty analilysis NMR of isopropanol / water interactions in cement Portable instrumentation MD & MC simulations of NMR relaxation ((ydynamics) in q uasi 2D pores
Image: OffshoreEnergyToday.com
- 23 - Bench top apparatus Basic experiment
Free induction R.F. decay signal exciiitation pulse
T2 decay time MQC benchtop analyser: Oxford Instruments
T2 relaxation time T2 and pore size
T2 is the NMR signal lifetime Relaxation rate averages between following excitation in an 10s slllowly re laxing “bu lk” molllecules and experiment: Free water rapidly relaxing “surface” molecules. T2 1s It is very sensitive to 1H 100ms molecular motion and confinement. 10ms 1ms Water in large pores
100 s Water in small pores 10 s BdBound water 1 s Brownstein and Tarr, Phys Rev A (1979)
Key results: Pore size calibration
T2 & Pore size distribution Inter hydrate Inter hydrate spaces and spaces and Gel pores capillary pores Gel pores capillary pores C S H inter layer C S H inter layer
Water in CH & Ett Water in CH & Ett u) u) ity (a. ity (a. s s s s
White cement, Inten Inten w/c = 0.4, 7 days 2 3 0.01 0.11 10 SSA= 186 m /cm 0.01 0.11 10 seallded cure. 1 3 10 100 nm T2 Relaxation time (ms) T2 Relaxation time (ms)
- 24 - Quantification: Quantification: Xtal solid content Are we seeing all the water? NMR vs XRD vs TGA
1 g/g anhydrous @ 28 days
.) Paste mixed with 0.8 XRD & TGA NMR w/c=0.4 w/c CH Ettringite Total Solids . (a.u m m 006.6 0.32 0.218 0.062 0.280 0.29 Underwater cure 0.40 0.276 0.076 0.352 0.34 per g 040.4 0.48 0.318 0.085 0.403 0.40 28 day, cure sealed, white paste ignal 0.2 w/c = 0.463 S S
AMU CH 0 w 74 I CH AMU H 2O 0 0.2 0.4 0.6 0.8 1 mNMR c 18 CH w 1 Mass (g) c
Muller, Scrivener, Gajewicz and McDonald: JPC:C 2013; MMM: 2013 Muller, Scrivener, Gajewicz and McDonald: JPC:C 2013; MMM: 2013
Key results: Mass balance equations Pore size during hydration for C-S-H composition and density 8 Growth of DfhdtiDfDegree of hdhydration: Signa l f rac tions 7 CH & Ett from XRD
6 w w F V 1 (1 ) H I Ca(OH ) I CSH (I gel I cap )X ) Parallel growth of g f 2 . c c 5 C S H
ty (a.u 4 i 1 w Reciprocal water fractions 3 Development of uc c w Intens GelGellp porosity porositorosity 2 F I I (I I I ) V (1 ) w Ca(OH )2 CSH gel cap void cHG XW 1 uc Ca(OH )2 CSH w Consumption of 0 inter hydrate and 6 5 4 3 2 1 10 10 10 10 10 10 capillary water Relaxation time (s) Densities
Oxide conservation C-S-H composition and density x 56z 9y 51 18( 1) Ca1.53 (Si0.96+Al0.04) O3.51 (H2O)1.92 y nSi / (nSi nAl ) C f S C f S C f f Ett S I n I n z C f f Ett S 3D C3S T 2D C3S T 3D C3A C3A T CH Hyd CSH Hyd 3D C3A C3A T EC SAMU U E C SAMU U E C AAMU U 2 2x E C AAMU U 303.0 Excluding 3 2 3 3 f f C f f Ett S I n y C f f Ett S gel water C3S C3S D C3A C3A T CSH Hyd D C3A C3A T AMU AMU 2 AMU 2 AMU C3S C2S E C3A U 2x E C3A U Ett 2.5 n layers 4xfC3A fC3A y 1 /cc) (n 1) interlayer AMU g I CSH nHydC3A
sity ( 2.0 n The unknowns n Independent measurement, De Including DOH e.g . XRD gel water 1.5 Measure conventionally or, if 0.0 0.5 1.0 Shrinkage Degree of hydration underwater cure then measure the increased w/c ratio by NMR Muller, Scrivener, Gajewicz and McDonald: JPC:C 2013; MMM: 2013
- 25 - Powers model revisited Key results: 0.8 Pore size resolved desorption isotherm Voids Total water 0.6 Capillary / Inter hydrate (g/cc) Gel porosity rous d d 0.4 Gel porosity
anhy C S H m 0.2 C S H interlayers l/ g
o CH+EttCH+Ett V CH Anhydrous 0 Capillary porosity 0 0.2 0.4 0.6 0.8 1 Degree of hydration
Muller, Scrivener, Gajewicz and McDonald: JPC:C 2013; MMM: 2013 Muller, Scrivener, Gajewicz and McDonald: JPC:C 2013; MMM: 2013
Key results: A picture of the water location Pore size resolved desorption isotherm Total water
Gel porosity
C S H interlayers Insight into how CH C S H dries and In re wets Capillary porosity
Muller, Scrivener, Gajewicz and McDonald: JPC:C 2013; MMM: 2013 Muller, Scrivener, Gajewicz and McDonald: JPC:C 2013; MMM: 2013
Key results: Exchange experiments Imaging experiment
A B Measure T2 Delay Measure T2 Intensity – ld e Discrete size how much Frequency capillary structures where etic fi Magn
Gel pyporosity Position
C S H – gel pore water exchange
T2 decay rate –
McDonald, Korb, Mitchell, Monteilhet, Phys. Rev. E (2005) how mobile Monteilhet, Korb, Mitchell, McDonald, Phys. Rev. E (2006)
- 26 - Key results: Surface treatments Traditional permeability test
Treatment Darcy La w ingress & cure / / LQ K ssure ssure RH RH e e
h AP w Lo Hig w pr igh pr o o MassMass balanceba lance L H flow rate
Permeability WtWater pene tra tion through treated layer
Black, McDonald et al. J. Mat. Sci. Lett., 1995
NMR permeability test Key results: Permeability test
Darcy Law Total mobile t water / / onten LQ K( ) AP ssure ssure ater c RH RH Gel pore water e e h w W Lo Hig
w pr Water profile igh pr o o Position L H C S H interlayer water PermeabilityPermeability as a function of Capillary water saturation
Zamani, Kowalczyk, McDonald CCR 2014
Testing models of permeability Testing models of permeability
Relative vapour 21 2 permeabilitypermeability K 4 10 m Liquid Ions Inter diffusion H2O ) r k Isother Liquid mass transfer (D’Arcy type flow) Sorpti Relative liquid permeability o m og ( n
Vapour mass transfer (D’Arcy type flow) L Vapour Dry air Inter diffusion H2O Saturation Baroghel Bouny, V., Thiéry, MM&WangX. & Wang, X. Modelling of isothermal coupled moisture–ion transport in cementitious materials. Cem. Conc. Res. (2011). Zamani, Kowalczyk, McDonald CCR 2014
- 27 - Portable instrumentation Portable instrumentation
Sample Permanent magnet
N
S
Portable instrumentation The next 10 years in situ measurements Collaboration with the UK National Physical Laboratory
• Define pp/rotocols/ standards for NMR • Instrumentation • Measurements Swimming pool: • Analyses Willmo tt of cement Dixon • Reference materials Accommodation block Leadbitter
The next 10 years Why Nanocem? Dedicated, affordable instrumentation • Multidisciplinary • NMR plus … • Critical mass of groups • Continuity of support • Pre competitive, fundamental work • Shared risk • Good atmosphere
- 28 - Recent review
- NMR & Cemen ts - - 2D LaplaceAlgorithm - Luc Montheilet Y-Q Song Mike Mulheron, Jon Mitchell Schlumberger Victor Rodin, Andrea Valori Agata Gajewicz - Site- access - Willmott Dixon Arnaud Muller, Karen Scrivener Leadbitter EPFL, Switzerland - Funding - Jean-Pierre Korb, NANOCEM Surface finishing Drying Ecole Polytechnique, France The Royal Society front
1 day UK EPSRC 2 days 4 days 0 4 8 7 days 12 16
20 - Magnets - 24 28 European Community depth (mm) Peter Aptaker VlValor i, SiScrivener, MDMcDona ld. Cem. Conc. Res. 49 (2013) 65 81 LLliaplacian LLdtd
THE INDUSTRIAL-ACACEMIC RESEARCH NETWORK ON CEMENT AND CONCRETE
- 29 - Phases and Interfaces in Concrete
Solid THE INDUSTRIAL-ACADEMIC NANOSCIENCE RESEARCH NETWORK FOR SUSTAINABLE CEMENT AND CONCRETE Solid-liquid Solid-vapour S-S Agglomeration, Adsorption, Dispersion; Cohesion Dry dispersion Dissolution, Nucleation, Growth; Creep Hydration pressure; Workability and interactions Crystallization pressure; S-L-V Prehydration Creep CorrosionCarbonation between admixtures and cement Corrosion L-L SubmarineInhibitors V-V casting Not Dr. Claire Giraudeau, Schlumberger (formerly ESPCI) Oil extraction relevant Prof. Jean-Baptiste d’Espinose, ESPCI Liquid Vapour Prof. R.J. Flatt, ETHZ (formerly Sika Technology AG)* Liquid-vapour Prof. André Nonat (Uni. Burgendy) Flatt et al. Capillary pressure, Surface tension; Dr. Irene Schober, Sika Technology AG J Eur Ceram Soc (2012) ShrinkageAir entrainment reducers Dr. Martin Mosquet, Lafarge LCR Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem AirNanocem entrainers Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 2
A little bit of philosophy MgO as a model system: Temperature dependence of adsorption plateau
“Studying cement and admixtures is 0.16 like studying what can go on between PCE-1 PCA-2 a hooker and a Gigolo ” 0.12 ] PCA-1 2
“ anything can happen, you cannot 0.08 predict it and you don’t want to know [μmol/m
about it!” Polymer on MgO 0.04
– Joydeep Duta, former colleague 0.00 Flatt et al., 5 15 25 35 45 Canmet/ACI (1997) Temperature [°C] Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 3 Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 4
Competitive adsorption and superplasticizers Chemical depletion
Cement Particle
Cement Particle
Cement Particle
Cement Particle Chemical reactions with Admixtures
Flatt & Houst, Cem Concr Res (2001) ? Flatt, PhD Thesis (1999)
Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 5 Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 6
- 30 - Chronology of Superplasticizers What can go wrong and why?
Cement 1930 Particle
Na 2S2O5 Ligninsulfonate O C C C O C C C 1940 SO Na COOM 3 Cement MeO MeO Particle Gluconate H C OH
1950 HO C H
H C OH
H C OH 1960 CH2OH
CH X CH Y C 2 2 H 2 N
1970 * N N C H n 2 Naphthalene Sulfonate * N N n
NH SO3Na 1980
CH2SO3Na Melamine Sulfonate Cement Particle 1990 * CH CH CH2 CH * n Vinyl Copolymers CO COONa N CO Cement H2C 1 2 NR R R3 R4 Particle
2000 Chemical reactions
R R C C C C E C C C C E C C C C E C C C C E with Admixtures
Polycarboxylate ether CH C CH C * 2 2 * 1 1 1 1 m n
2010 COOH (PCE) CO-X-(CH2CHRO-)y R 2 2 2 2 3 3 3 3 4 4 4 4 ? 5 5 5 5 P P P P
Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 7 Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 8
Admixture consumption: A proposed process of intercalation Organoaluminates: A probable Layered Double Hydroxides
Ca2+, Al3+
2- 2- - CO3 , SO4 , OH or Organics
Ca2+, Al3+ Fernon et al., Canmet/ACI SP Conf (1997)
Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 9 Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 10
Layered Double Hydroxides: A family of compounds Intercalation in Layered Double Hydroxides
III
Al Fe Cr Co Mn Ni Sc Ga Mg X X X X NiXXXX X Fogg et al., Chem. Mater., 1998, 10, 356 Zn X X II Cu X X Co X Mn X X Fe X X Ca X
Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 11 Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 12
- 31 - Biopolymers: Alginates Plank approach
And also DNA !
F. Leroux et al., J. Solid. State. Chem. (2003) Plank et al., Mater. Lett (2006), Inorg. Chim. Acta (2006)
Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 13 Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 14
Giraudeau approach Main conclusions
Organoaluminates can form They are stable at high temperature against the formation of the cubic phase
Ca(OH)2 Ca(OH) All at 5°C to 2 enhance stability of
C4AHx polymer
C4AHx - polymer
Giraudeau et al., J. Am. Ceram Soc. (2009) Plank et al., Mater. Lett (2006), Inorg. Chim. Acta (2006)
Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 15 Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 16
Temperature stability Possible structures
T > 25°C no SP Meso-composite Nano-composite Hybrid C4AH19 Very fast rx
entanglement of hydrates exfoliation C3AH6 + SP
Inspired and adapted from cross-linking Plank et al., true intercalation Canmet/ACI Sp Conf (2006) F. Merlin et al., J. Mater. Chem. 2002, 12, 3308. A. Bonapasta, Chem. Mater. 2002, 14, 1016.
Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 17 Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 18
- 32 - Molecular scale structure: 27Al NMR Intercalation examine by XRD
Immediate addition
Delayed addition Dix5P23 immediate addition 2345678910 x5P23 delayed addition 2θ (°) Polymer-AFm Intercalated x6,4P46Ci immediate addition Immediate Delayed x6,4P46 delayed addition polymer x3,1P23 3,2 nm 3,2 nm For each polymer Without x2,3P23Bi immediate addition x2,3P23 3,4 nm 3,2 nm dimmediate = ddelayed polymer x2,3P23 delayed addition x6,4P46 3,2 nm 3,2 nm 20 18 16 14 12 10 8 6 4 2 0 δ (ppm) x5P23 2,6 nm 2,6 nm 10,2ppm 9,3ppm Polymer => Modification of the chemical x8,3P23 2,4 nm 2,2 nm environment of all the aluminum Long graft chains => Validation of intercalation x6,7P114 - - No intercalation polymer Independent of the synthesis procedure x3P23OH Not synthesized 3,1 nm
Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 19 d00l for each polymer-AFm compound Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 20
Structure at the nanometric scale TRAPDOR: TRAnsfer of Populations by Double Resonance
Immediate 1H nTr nTr addition
Delayed addition 2345678910 27 20 nm 2θ (°) Al ~ 3 nm ~ 1 nm (2θ ~ 8°) polymer spin echo sequence (influence of T2)
irradiation of 27Al during the evolution time ⇒ coupling between 27Al and 1H
OH-AFm Intercalation in both cases Polymer-AFm
Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 21 Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 22
TRAPDOR principle TRAPDOR principle
Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 23 Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 24
- 33 - Conformation: TRAPDOR Experiment Polymer conformation model
-(CH2CH2O)n- tp tp XRD at 100%RH, very small angles measured 1H 14 -OCH3 12 27 Al 27 Without Al irradiation 10 Spin echo sequence (influence of T ) : 27 2 With Al irradiation 8 Irradiation of 27Al during the evolution time Spectrum of difference: ⇒ coupling between 27Al and 1H 6 TRAPDOR effect D = 2 R 4 R AC di = 2.1 Rac + 0.6 AC 5,0 4,8 4,6 4,4 4,2 4,0 3,8 3,6 3,4 3,2 3,0 2 ppm Interlayer spacing [nm] 0 2 R AC 0.0 1.0 2.0 3.0 4.0 5.0 Polymer RAC [nm] in blobs conformation Lenain et al (2009) Flatt et al (2009)
Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 25 Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 26
Dissolution precipitation process Charge compensation and dosage
Polymer x8,3P23 c 1,0 2 g/L, delayed addition Compensation : c = n(COO-)/n(Al) in the polymer-AFm phase 0,9
0,8
0,7 No plateau :
0,6 more complicated than a simple adsorption 3+ Al 0,5 Ca2+ 0,4 0,3
0,2 COO- 0,1 Polymer x5P23 0,0 0,000 0,005 0,010 0,015 0,020 0,025 0,030 0,035 C(COO-) in solution at equilibrium (eq/L) Concentration in solution (mmol/L) Concentration in solution (mmol/L)
In good accordance with the observed Time (h) dissolution-re-precipitation mechanism Same structure whatever the synthesis procedure
Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 27 Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 28
Reactivity versus sulfates Latent period for polymer release
1SO 2-/Al O , 4mmol of Al = n(negative charges) 4 2 3 c 1SO 2-/Al O Polymer x5P23 n(Al) 4 2 3 Brought by sulfates
Quick adsorption Polymer x6,4P46 of sulfates Adsorption of sulfates Polymer x2,3P23 Release of polymer
Latent period Equilibrium in the solid phase (meq) Brought by the polymer
Negative charges brought by sulfates Time (h)
Time (h) Latent period increases when the initial compensation of positive charges increases (c) Release of polymer : not immediate / not total
Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 29 Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 30
- 34 - Giraudeau et al, J Am Ceram Soc, 2009 Summary about polymer release
XRD : monosulfoaluminate + no more patterns characteristic of the polymer intercalation
2- 2- 2- SO4 SO4 SO4 2- 1SO4 /Al2O3 2- 2- 2- SO4 SO4 SO4
Polymer at the surface of the particles
Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 31 NanocemNanNanoceNNaaanocenocnocenoceococemSm SpringSSpSpr SpringggM Meeting,Mee MMeeeeetingtitting,tininging,ngngg,, 8-108-18-1-10 1010 April Aprilpprriliill2l 2014,2 014,01014014,14144,, Lausanne, La CH ©Nanocem 32
Amount of effective dispersant consumption over time Conclusions and outlook
Superplasticizers play and essential role in modern concrete and their Added polymer importance will only grow in the future
Consumed Excess Anything that modifies the surface coverage by superplasticizers and its time Associated with solid phases Remaining in solution evolution impacts their effect in concrete
time Competitive – adsorption AND organo-aluminate reactions/interactions are important in this regard
The interaction of organic admixtures with aluminate reactions is very complex Adsorbed Reacted Involved in dispersion Precipitated, intercalated, mechanisms micellized On going research is continuing to clarify various depending effects as: Role of cement chemistry [Habbaba et al, Cem Concr Res (2014)] Change of surface coverage [Dalas, PhD Uni Burgundy (2014)] Initial surface Newly formed surfaces Adsorption extent and Consume excess polymer Reliable specific surfaces [Mantellato et al, Int. GDCh Symp.(2013)] adsorbed properties Reduce surface coverage Molecular structure role in activation of blended cements [Marchon et al, condition initial rheology Flatt, Mat. & Struct. (2004) Soft Matter (2013)]
Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 33 Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 34
- 35 - Plan of the Talk
10 years of nanocem …7 years atomistic simulations… First Atomistic Simulation workshop for nanocem - Berlin December 2007 • Kirkpatrick, Delville, Johnsson, Pellenq….. THE INDUSTRIAL-ACADEMIC RESEARCH NETWORK ON CEMENT AND CONCRETE • Conclusion of meeting – atomistic simulation ready for cement….but needed high quality student to cope with such a wide domain • PB boasted – SG was this student….Next 30 minutes will see if he was correct……Core Atomistic modelling of cementitious Project 6….. • Significant progress but a lot more effort needed….. materials: from crystal growth to • Started with crystalline product….second major component of hydrated cement disordered structures Portlandite - Effect of solution composition on growth – Ca2+ , OH- (pH) and silicates - Then moved onto….. C-S-H Sandra Galmarini, Paul Bowen Used potential sets developed for calcium silicates start looking at C-S-H structural Core Project 6 modifications of tobermorite. Often proposed but not investigated energetically …i.e. are these proposed defect structures stable….
Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 0 Nanocem1 Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 1
Global Aim of the project
Choice and optimization of force fields – calcium silicates Molecular dynamics, Energy minimisation, Metadynamics, Monte Carlo
Portlandite C-S-H
x x x xx x x x xx x x x x xx x x x x x x x xx x x x x x Ca(OH)2 xx x x x x Force Field
Simulation of possible defects in the Simulation of adsorption of different ions on tobermorite structure and at tobermorite portlandite surfaces and surface steps surfaces
How do these ions influence growth and the Can one explain the lack of three-dimensional final morphology of portlandite crystals? crystallinity even after prolonged ageing? What is the probable microstructure of C-S-H?
Integration of results into microstructural models
Nanocem2 Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 2 Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 3
Rejected Force Fields – Properties Chosen Force Field – Properties*
Adapted from TIP4P/2005 & Freeman et al. CLAYFF (Cygan Liang, Kalinichev. 2004): partial charge force field developed for • rigid water morse bond potential for OH clays and cementitious systems. • rigid ion • angle potential for O-Si-O and Si-O-Si b CH (00.1) surface is not a perfect cleavage plane. b Much too large CH dissolution energy (partial to full charge). simulation experimental a b c α β γ a b c α β γ [Å] [Å] [Å] [°] [°] [°] [Å] [Å] [Å] [°] [°] [°] Ca(OH) 3.68 3.68 4.81 90 90 120 Kerisit et al. (Kerisit et al. 2003, used by Pellenq et al.): Oxygen atom with variable 2 3.59 3.59 4.91 90 90 120 polarization due to core-shell model. alite T 11.94 14.36 14.00 105 94 90 11.64 14.2 13.6 105 95 90
14Å tob. 6.85 7.26 27.95 90 93 123 6.74 7.43 28.0 90 90 123
b Estimated error on distances: 5 % , on angles: 15 㼻 b Time step has to be chosen smaller due to shells (computationally more expensive) Reactions ∆H [kJ/mol] ∆Hexp [kJ/mol] sim- Exp b 3 Water model with a too high density (1.2 g/cm ) 3CaO + SiO → Ca SiO -123.9 -115.5 8.48.4 b Stability problem with shells when simulating 14 Å tobermorite 2 3 5 Ca(OH)2 → [(Ca) + 2(OH)]aq 21.7 -18.1 39.839.8
Ca(OH)2 + SiO2 → [CaSiO2(OH)2]aq 222.5 237.5 115.25.2
Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 4 *Galmarini& Bowen – Submitted to ActaMat (2014) Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 5
- 36 - Goals
Question: How do the solute species in cementitious systems interact with growing portlandite particles?
Ca(OH)2 Portlandite (Ca(OH) ) 2- , , 2- 2- 2 = SO4 Al(OH) SiO (OH) CaCl2 and NaOH + 0.1 M SO 2- 4 2 2 4 + 0.001 M SiO3 ߥExperimental observation of the morphology of Ca(OH)2 particles - model systems – precipitation.
ߥThermodynamic calculations to estimate the changes in solution species for the different model systems.
ߥAtomistic Simulation of Ca(OH)2 – vacuum/water interfaces - • Simulation of different crystallographic faces (100,001,101) + 0.001 M AlO2 2+ - 2- • Simulation of Ca , OH , CaSiO2(OH)2 and SiO2(OH)2
adsorption ߥMonte Carlo Simulation of ionic distribution at interfaces
Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 6 Nanocem7 Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 7
Experimental Morphology – Pure system Portlandite – Thermodynamic conditions (GEMS)
Main portlandite species in solution: Ca2+ and OH- b growth species? Precipitation by heating saturated Morphological analysis – identified Initial conc. pH Ca2+ CaOH+ OH- Other species Solid phases solution Ca(OH)2 – 65㼻C – 23 days crystallography of facettes [mol/l] [mol/l] [mol/l] [mol/l] [mol/l] [g/l]
0.1 CaCl2 + 12.6 0.02 0.004 0.04 0.2 Na+ + 0.2 Cl- 5.6 g portlandite 0.2 NaOH
0.1 CaCl2 + 12.7 0.02 0.004 0.04 0.2 Na+ + 0.2 Cl- + 5.6 g portlandite +
0.2 NaOH + 3e-5 CaSiO2(OH)2 0.2 g C-S-H 0.001 Na2SiO3 0.1 CaCl2 + 12.9 0.009 0.003 0.07 0.4 Na+ + 0.2 Cl- + 4.5 g portlandite +
0.2 NaOH + 0.005 Ca(SO4) + 0.02 3.7 g gypsum - 0.1 Na2SO4 Na(SO4) + 0.05 SO4 0.1 CaCl + 0.2 Na+ + 0.2 Cl- + 2 5.4 g portlandite + 0.2 g 0.2 NaOH + 12.6 0.02 0.004 0.04 0.003 NaOH + 1e-4 Long experiments with small yield C3AH6 0.001 Al(NO ) AlO - (theoretical yield: 0.45 g/l) [101] 3 3 2 0.1 CaCl2 + 0.4 Na+ + 0.2 Cl- + 4.3 g portlandite + 3.6 g 0.2 NaOH + 0.005 Ca(SO4) + 0.02 gypsum + 0.2 g C-S-H +
0.001 Na2SiO3 12.9 0.009 0.002 0.07 Na(SO4)- + 0.05 SO4 0.6 g SO4_CO3_AFt + + 0.1 Na2SO4+ + 3e-5 CaSiO2(OH)2 0.001 g CO3_SO4_AFt + 0.001 Al(NO3)3 + 9e-10 Al(OH)4- 0.001 g ettringite 200 μm Main Si species present: CaSiO2(OH)2
Nanocem8 Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 8 Nanocem9 Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 9
Atomistic Simulation – Surface Energies I Atomistic Simulation – Surface Energies II
Portlandite-vacuum: Energy Minimization (EM) of different cuts … • Portlandite-Vacuum: Energy minimisation (EM) Portlandite-water: Molecular Dynamics (MD) simulation at constant volume γ (EM) [00.1] [10.0] 2 Calculation of interfacial energy γ: [J/m ] vacuum (00.1) 0.1 ± 0.03 (10.0) 0.6 ± 0.06 4.9 Å vacuum (10.1) 0.74 ± 0.10 vacuum
I. Richardson, 2004
• Portlandite-Water: Molecular Dynamics (MD) Experiment [10.0] [00.1] [10.1] γA = E - 0.5 E - 0.5 E γ (MD) surf port_water water port [J/m2] EH20_ (00.1) 0.11 ± 0.06 (10.0) 0.13 ± 0.06 (10.1) 0.09 ± 0.06 Exp* 0.090 * Harutyunyan et al. 2009 200 μm Klein and Smith 1968
Nanocem10 Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 10 Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 11
- 37 - Atomistic Simulation – Molecular Dynamics and Metadynamics* Atomistic Simulation – Adsorption Sites
- 2+ • Use metadynamics - get free • Interaction of H2O, OH and Ca dependent on surface crystallography – energy landscape - estimate different terminations on each facet [10.0],[00.1],[10.1] energy of adsorption • Add a positive Gaussian potential to the real energy landscape of the system – stops it returning to this configuration system system system E Epot Epenalisation
Red – Oxygen Blue - Calcium White - Hydrogen distance portandite – Ca2+
*Laio, A.; Parrinello, M. (2002)
12 SoftCem – August 2012– Monte Verita © Nanocem Nanocem13 Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 13
Atomistic Simulation – Surface structure & Water sites – [00.1] Atomistic Simulation – Adsorption Sites - Water – [10.0]
• Terminated by a high density of OH groups surface • Terminated by OHs but lower density than [00.1] • Close to bulk positions. • Bulk OHs are parallel to surface, 50% are at surface. • Two water sites • 2 water sites observed • b1 - one with both Hs - H bond with surface O atoms • b1 same position of next OH layer in bulk structure. • b2 - only one H seems to form a H- bond. • Donate 1 or 2 H-bonds to the surface OH groups. • Density of both types relatively low. • 94 % of the sites are occupied. • From number density profile about 34 % of the surface • b2, is similar to [00.1] surface. donating a H- bond to the nd hydrogens have accepted a hydrogen bond. surface O -2 hydrogen is oriented away from the • Interaction - water and the [00.1] weak, surface - about 30-35 % of the sites occupied. • consistent with the essentially unchanged portlandite- • Interaction between H2O and [10.0] surface much stronger than [00.1] surface. Consistent with lowering of b2 water interfacial energy b1 interfacial energy by H2O
0 Å surface Å
Nanocem14 Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 14 Nanocem15 Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 15
Atomistic Simulation – Adsorption Sites Atomistic Simulation – Adsorption Sites
• Terminated by OHs and Ca ions - 50% of Ca sites occupied • Exposing OH layer - surface similar to the bulk positions. • 3 water sites distinguished. • b1 and b2 - between two OHs with 2 Hs towards O of OHs • Forming H-bonds. • b1 between two occupied calcium sites, • b2 water molecules, between two empty calcium sites • Both fully occupied throughout the simulation – • Indicates very strong interaction - consistent with • large change in surface energy (vacuum/water) Between hydroxyls Between hydroxyls but Desorbs 2 H2O’s and in - + • b3 H2O sits above the surface Ca ions with the O towards with OH i.e as CaOH crytsallographic site • Ca - weak electrostatic bonds CONCLUSION
Both [10.0] & [10.1] strong interaction with H2O - network of strongly bound water at the surfaces, - stabilize facet not only energetically but also 2+ kinetically, Equivalent site next OH OH- equivalent site weak adsorption onto Ca layer in crystal And desorbs H O No H O desorbed - Need to be desorbed before the crystal can grow... 2 2 Metadynamics calculations using Molecular Dynamics Nanocem16 Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 16 Nanocem17 Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 17
- 38 - Atomistic Simulation – Adsorption Energy Atomistic Simulation – Adsorption Sites
• If – rate limiting step desorption of water • Interaction of OH- and Ca2+ dependent on surface crystallography – • [10.0] – adosprtion of OH- need – for [10.1] adsorption of Ca2+ • Increase in pH – decrease in Ca2+ conc, (common ion effect) • For [00.1] – detailed Metadynamics simulation needed • Decrease the speed in [00.1] and [10.1] direction and • Increase the speed in [10.0] direction. • Ca2+ minimum at 8Å • Importance of the [00.1] and [10.1] surfaces compared to the [10.0] • size of hydration shell surface in the growth morphology would increase. • Difficult to approach • Berger and McGregor - addition of hydroxides (LiOH and NaOH) had a surface tendency to increase the aspect ratio L10:0 / L00:1 • Additionally this explains observations by Gray [40], - • OH easier approach • decreasing the Ca/OH to hydroxyl ratio more equiaxed particles, • elongated hexagonal prisms, dominated by [00.1] facet, • Rate limiting step – • observed at higher calcium concentrations. • Perhaps dehadyration • of calcium ion
Nanocem18 Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 18 Nanocem19 Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 19
Atomistic Simulation – Mobility of Si species Metadynamics – Adsorption Free Energies on [00.1]
25 Ca b OH and Ca-Si complex seem to be 20 O solid able to move closer to the surface H solid O water 15 H water b Ca-Si complex adsorbs more easily and is more mobile than Ca 10 density [a.u.] b Portlandite growth hindrance? b C-S-H “template”? 5
0 0.5 -2 0 2 4 6 8 10 12 14 distance form surface [Å] Ca energy 0.4 OH energy
0.3 CaSi energy Si energy 0.2
0.1 Energy [eV] b How does the ion distribution at the 0 portlandite surfaces look like? -0.1 b Link to experimental surface
-0.2 charge and zeta potential -2 0 2 4 6 8 10 12 14 b distance form surface [Å] Next step towards kinetics Nanocem20 Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 20 Nanocem21 Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 21
Portlandite Summary and Conclusions I
- Strongly bound water stabilizes higher energy portlandite surfaces - Probably botht enrgetically and kinetically - Ftrom MD –Metadynaincs – rate limiting steps for growth on different surfaces
• Dehydration and adsorption of the Ca2+ ion at the [00.1] surface. C-S-H • Desorption of strongly bound surface water and subsequent adsorption of OH- at the[00.1] surface. • Desorption of strongly bound surface water and subsequent adsorption of Ca2+ at the [10.1] surface. • Consistent with experiment
Nanocem22 Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 22 Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 23
- 39 - C-S-H - Goals C-S-H – State of the Art – “Bulk”
• Ultimate goal – how does C-S-H grow – why is it so poorly crystalline – how can Ca/Si=0.83 we effect its growth kinetics – i.e. accelerate improve early strength x x x xx x x x xx x x x x xx x x x x x x x xx x x x x x xx x x x x •The structural similarity between C-S-H and tobermorite and the retention of a high degree of (nano-) crystallinity up to a Ca/Si ratio of 1.5 – 1.7 has been well documented (Renaudin • Study of the atomistic structure of C-S-H, focus on C-S-H – water interfaces et al. 2009, Nonat 2004)
ߥExperimental state of the art: What are the conditions a good C-S-H structural •The number of bridging Si groups decreases with increasing Ca/Si, however bridging Si can model should fulfill? Starting point? still be observed at Ca/Si = 1.5 or even higher (Brunet et al. 2004, Mohan and Taylor 1982, Richardson 2009) • Existing models for C-S-H … • Experimental “hard” knowledge of the structure of C-S-H … •The percentage of Si monomers stays very low (~ 2%) and no monomer-monomer interactions can be observed by NMR (Brunet et al. 2004, Richardson 2009) • Experimental knowledge about tobermorite / C-S-H surfaces
•The number of Silanol groups decreases with increasing Ca/Si. However Silanol groups can still be observed at Ca/Si = 1.5. (Brunet et al. 2004) ߥCa/Si ratio increasing defects in 14 Å tobermorite. Which defects are likely to occur? Work done in collaboration with Steve Parker @ University of Bath •Ca-OH groups can be observed for Ca/Si > 0.9. At low Ca/Si these groups are probably in the interlayer but at Ca/Si = 1.5 their presence in the layers is possible. (Brunet et al. 2004)
Nanocem24 Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 24 Nanocem25 Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 25
C-S-H – State of the Art – Interface 14 Å Tobermorite
•The size of the C-S-H crystallites have been estimated by many authors 14 Å Tobermorite Polymorph b11m (Richardson 2009, Allen et al. 2007, Renaudin et al. 2009, Nonat 2004). The smallest dimension is generally estimated to be 3-6 nm and the largest dimension 6-x*10 nm. 4·[CaSiO2(OH)2]aq + 3.5H2O → 2+ - • Consider a small particle with dimensions 3nm, 4nm and 6nm in a, b and c [Ca2.5Si3O8(OH)·3.5H2O]tob + 1.5·[Ca ]aq + 3·[OH ]aq + [Si(OH)4]aqq direction and a large particle with dimensions 6nm, 6nm and 10nm. • Define the surface layer thickness as half the Ca-Si sheet thickness: 0.7 nm
XRD 1) DFT (by Steve Parker) Classical MD 2) Z49-73 % of the C-S-H is at the surface! ZSurface chemistry is extremely important • Early Atomistic Model (Pellenq et al. PNAS, 2009) • Probably too disorderd • Not consistent with experimental results* • No Surfaces • No water-solid interfaces ∆Hexp : -5.2 eV3) ∆HDFT : -4.6 eV ∆HMD : -3.5 eV
*I.G. Richardson, Acta Cryst. (2013). B69, 150-162 1) Bonaccorsi et al. 2005, 2) Partially minimized MD snapshot, 3) Lothenbach et al. 2006 Nanocem26 Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 26 Nanocem27 Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 27
Defect Reactions Defect Energies
Calculate the energy of the following defect reactions in the bulk e.g.: Ca/Si:Ca/Si: 1.001.00 Ca/Si: 1.25 Ca/Si: 1.25 -2.8-2.8 eeVV -0.9 eV +0.4 eV b 2 tob(0.83)ob(0.83 + [CaSiO2(OH)2]aq 2 tob(1.0)b(1.0) + [Si(OH)4]aq
Ca/Si: 1.50 Ca/Si:Caa/Si: 1.501 .50 Ca/Si: 1.75 +0.6 eV - -0.10.1 eeVV +0.7 eV
One defect within a supercel of 48 tobermorite units 3 4 Ca/Si: 1.75 C Ca/Si:a/Si: 2.2.00 Ca/Si: 2.5 +0.6 eV - -0.40.4 eeVV +0.7 eV
4
Nanocem28 Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 28 Nanocem29 Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 29
- 40 - Low Energy Defects C-S-H Polymorphism
14 Å Tobermorite Polymorph sy Ca/Si: 0.83 Ca/Si: 1.00 Ca/Si: 1.50 Ca/Si: 2.00 DFT (by Steve Parker) Classical MD 1)
sub Formula Hdft [eV] HMD [eV]
b11m Ca2.5Si3O8(OH)·3.5H2O -4.61 -3.48
sy Ca2.5Si3O8(OH)·3.5H2O -4.55 -3.46
1) Partially minimized MD snapshot Nanocem30 Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 30 Nanocem31 Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 31
C-S-H Polymorphism - Defects C-S-H – Surface Definition and Water Content
What is the surface of a C-S-H particle?
Surface position? Ca/Si sub Formula Hb11m [eV] Hsy [eV]
0.83 Ca2.5Si3O8(OH)·3.5H2O -3.480 -3.462
1.00 a Ca3Si3O9·3.5H2O -2.835 -2.865
1.00 b Ca3Si3O9·3.5H2O -2.824 -3.226
1.25 Ca2.5Si2O6(OH)·5.5H2O -0.866 -0.608 Consider C-S-H particle of 1.50 b Ca3Si2O5(OH)4·3.5H2O -0.143 -0.244 Allen, Thomas and Jennings: (surface water included) 2.00 Ca4Si2O7(OH)2·3.5H2O -0.362 0.977
C1.7SH1.8, ρ: 2.604 Mg/m3 dimensions: 3x4x6 nm
If surface water is excluded, one gets:
C1.7SH0.8, ρ: 2.4 Mg/m3
Nanocem32 Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 32 Nanocem33 Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 33
C-S-H Summary and Conclusion Summary and Conclusion b A series of likely Ca/Si raising defects mostly consistent with experimental b Atomistic Simulations have great potential for cement chemistry observations have been identified b Insights into mechanisms and near surface phenomena very very difficult to access experimentally b Sandra Galmarini was in fact an outstanding PhD student
b BUT
b Systems studied still relatively simple and small, short timescales b Polymorphism does not seem to have a big influence on defect energies b Need significant coordinated effort to bring further light on key aspects of cement chemistry b Surfaces are important b C-S-H surface chemistry and b C-S-H growth mechanisms in different complex ionic media b Warrants further investigation: b Effects of additives e.g. superplasticizers b Effect of defect concentration on defect energies b Need not 1 PhD student but 10……. b Defect energies at surfaces? b Microscopic structure of C-S-H surfaces and water interfaces included……
Nanocem34 Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 34 Nanocem35 Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 35
- 41 -
Acknowledgements • Nanocem (funding) • Steve Parker (help with atomistic simulations) • Barbara Lothenbach (help with GEMS) • Anne Aimable, Nicolas Ruffray , Amirreza Kiani, Michael Stuer, Marijana Mionic (precipitation experimental) • Karen Scrivener, Ellis Gartner, Patrick Juilland, Robert Flatt (Help and Discussions) • All the C-S-H pioneers for helping us start to see the light at the end of the tunnel…
Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 36
- 42 - Portland cement / SCM
b CaCO3 CaO + CO2 THE INDUSTRIAL-ACADEMIC NANOSCIENCE RESEARCH NETWORK FOR Production of 5% of global man SUSTAINABLE CEMENT AND CONCRETE Portland made CO2 emission cement clinker Energy
Effects of SCM on microstructure CO2 Reduction less CaO Clinker replacement by SCM Fe2O3 Other Alternative materials and performance of cements 2% 2% Al2O3 4% => Changing chemistry
SiO2 17% Barbara Lothenbach, Empa, Switzerland CaO Reduce 75%Ca
Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 2
SCM Blast furnace slag
Silica fume SiO2
silica Ground granulated blast furnace slag (GGBFS) wt% fume by-product from the steel production Mainly amorphous glass
fly ash F fly ash Grinding: irregular shape Natural pozzolans Latent hydraulic C metakaolin MgO slag Fe2O3 slag Al2O3 CaO
Portland cement limestone SiO2 Dendritic crystals of merwinite fine limestone (3CaO MgO 2SiO ) CaO 2 Typical chemical composition [V.Kocaba, 2008] Al2O3
Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 3 4 Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 4
Fly ash Silica fume
Spherical glassy particles, amorphous fraction reactive By-product of silicon and ferrosilicon production
Very fine particle, high surface area, amorphous => highly reactive pozzolan
[C.Gosselin, 2007] By-product of coal combustion
Class F (low Calcium) fly ash from burning anthracite or bituminous coal Pozzolanic [FHWA, 2006] SiO2 + Al2O3 + Fe2O3 70% MgO CaO Fe2O3
SiO2 85% SiO2 Al2O3 Mean diameter of particle: 0.1 μm Specific surface area: 15 000 m2/kg (350 m2/kg OPC)
[F. Deschner, 2012] Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 5 Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 6
- 43 - How did nanocem contribute ? 1) Effect of limestone (CaCO3)
Nanocem funding EU funding Independent / partner projects 70 +7%
ettringite 2004 CP 1: Many partner projects: 60 hydrated •SCMs – durability monosulfate cements CP 4: 50 2006 hemi- Thermo- Blended •Synergistic effect FA monocarbonate hydrotalcite carbonate dyn. data cements MC Nanocem (15) and limestone CP 5: New materials 40 calcite 2008 Activation •Phase development Durability in blended systems of SCMs /100 g 3 portlandite CP 9: 30 2010 SCMs => •SCM and alkali cm hydration aggregate reaction CP 11: CP 10: snf (4) 20 kinetics •… 2012 SCMs => SCMs => MC Transcend (15) SCMs + CP 13: carbon- micro- Water transport C-S-H C-S-H RILEM 10 ation mechanicSCMs => 2014 shrinkage TC Thermodynamic modelling: / cracking SCM 0 • Changes in hydrates 2016 012345678910• Volume maximum wt% CaCO 3
Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 7 Damidot ea 2011 CCR 41; Lothenbach ea 2008, CCRNanocem 38; Spring Matschei Meeting, 8-10 ea April 2007, 2014, CCRLausanne, 37 CH ©Nanocem 8
1) Effect of limestone (CaCO3) 1) Effect of limestone (CaCO3)
70 +7% 70 +7%
60 ettringite 60 ettringite monosulfate monosulfate 50 hemi- 50 hemi- monocarbonate monocarbonate hydrotalcite carbonate hydrotalcite carbonate calcite calcite effect of limestone40 40 /100 g /100 g
3 portlandite 3 portlandite 3monosulfate30 + 2calcite + 18water ettringite + 2monocarbonate 30 cm cm 3 C4AsH12 + 2Cc + 18H C6As3H32 + 2C4AcH11 Ettringite Monocarbonate 20 Monosulfate20 3*309 + 2*37+18*18 707 + 2*262 Hemicarbonate Ettringite C AF 1001 1231 (+23 % volume) 1 year 4 10 C-S-H 10 C-S-H 1 year C4AF calcite 7 days 0 7 days 0 012345678910 012345678910 ettringite monosulfate wt% CaCO wt% CaCO 3 monocarbonate 3 1 day 1 day 8 91110 12 8 91110 12 Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 9 Damidot eaAngles 2011 CCR2 (degrees) 41; Lothenbach CuK ea 2008, CCRNanocem 38; Spring Matschei Meeting, 8-10 eaAngles April 2007, 2014, 2 CCR Lausanne,(degrees) 37 CH ©Nanocem CuK 10
1) Effect of limestone (CaCO3) 1) PC – limestone and fly ash: synergistic effect on compressive strength
70 +7% 3% 9% 60 ettringite 53 44 monosulfate 51 OPC 43 50 OPC + FA hemi- 80 49 42 carbonate monocarbonate hydrotalcite 47 41 40 70 calcite 45 40 ] 39
[MPa] 43 /100 g 60 [MPa]
3 portlandite 30 38 41 cm 37Fly ash and limestone 50 39 36together: synergistic effects 20 37 Volume changes 40 35 35 34
Compressive strength C-S-H 0 5 10 10 15 20 25 30 35 30 Herfort 1: 5.0% Al2O3 % limestone pow der 35/0 30/5 5/30 0/35 Herfort 2: 4.2% Al2O3 25/10 20/15 15/20 10/25 % fly ash / limestone powder 0 20 Herfort 3: 4.4% Al2O3 compressive strength [MPa strength compressive 012345678910De Weerdt, 2010 10 De Weerdt, 2011a wt% CaCO 3 De Weerdt, 2011b Fly ash + limestone: synergistic effects 0 (more aluminium present) 0 5 10 15 20
Damidot ea 2011 CCR 41; Lothenbach ea 2008, CCRNanocem 38; Spring Matschei Meeting, 8-10 ea limestoneApril 2007, 2014, CCR Lausanne, [%] 37 CH ©Nanocem 11 De Weerdt et al. 2011 Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 12
- 44 - 2) Effect of fly ash 2) Effect of fly ash
PC Portlandite consumption
Slower strength development PC+35 FA
PC
PC+35 FA Less heat
Portlandite consumption => slow reaction of fly ash
De Weerdt ea 2011 Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 13 De Weerdt ea 2011, Deschner ea 2012 Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 14
2) Effect of fly ash: Influence on C-S-H (TEM)
Image analysis to determine the reaction of fly ash Foil-like OPC+FA+L Op Mc E Hc Fibrils Fibrils 140 days (Op) (Op)
90 days 25 μm Fine Ip 28 days Foil-like Ip in FA 400nm 1 day
8 9 10 11 12 13 100% WPC 5 years 70% PC + 30% fly ash 3 years 2 theta Reaction of fly ash lowers the calcium in C-S-H Changes morpholpgy
De Weerdt ea 2011, CCR 41; Ben Haha ea 2010, CCR 40; Deschner ea 2013 Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 15 John Rossen, PhD student sinergia Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 16
3) Effect of silica fume Reaction of silica fume (PC + 10% silica fume)
Al(OH) Si-NMR 60 3 Influence silica fume: • consumesgypsum portlandite monocarbonate 50 • lowers pH calcite ettringite • Low Ca C-S- H alite + C-S-H 40 hydrotalcite • AFm, ettringite belite Silica fume portlandite low calcium
/100 g 30 Experimental 3 high calcium C-(A-)S-H
cm C-S-H 20
pH pH Simulation 10
SiO 2 0 0 1020304050 wt% SiO 2 PC SF 80 % reacted 3 months
Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 17 From S. Poulsen, PhD thesis 2009 Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 18
- 45 - Distribution of water (PC + 10% SF) Reaction of silica fume (PC + 10% silica fume) H NMR PC+10SF
W/C = 0.40 PC Cap. water
alite C-S-H gel water
Silica fume => water distribution Chemically bound water less gel/interlayer more capillary water belite SF: accelerates cement reaction
Changes C-S-H composition C-S-H interlayer water
Alite 80 % reacted 1 week SF 80 % reacted 3 months
From S. Poulsen, PhD thesis 2009 Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 19 Arnauld Mueller, PhD 2014 Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 20
4) Influence of slag Microstructure compressive strength
PC PC+slag
100% PC 1year 60% PC + 40% slag 1year
Still plenty of CH regions Slag rims Slag: slower strenght devolpment Changes in C-S-H
Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 21 V. Kocaba, PhD thesis 2009 Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 22
Influence on C-S-H Influence of slag on C-S-H composition
Fibrils (Op) DecreaseCa/(Si+Al) of Ca/(Si+Al) in C-S-H
Ca/(Si+Al) ratio 2.5 Fibrils Inner C-S-H (Op) Outer C-S-H Rim of slag 2.0 Typical C/S of OPC 1.5 Fine Ip Slag 1 Slag Ip with 1.0 hydrotalcite Slag 8 400nm
0.5 100% WPC 5 years 60% PC + 40% slag 5 years 0.0 Qualitatively different appearance of C-S-H B B B B-S1 B-S1 B-S1 B-S8 B-S8 B-S8 28d 90d 1y 28d 90d 1y 28d 90d 1y
Comparison with-without slag: Ca/(Si+Al)Outer C-S-H decreases from 2 to 1.5 [V.Kocaba, 2008] John Rossen, PhD student sinergia Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 23 V. Kocaba, PhD thesis 2009 Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 24 24
- 46 - 4) Influence of slag Effect of SCM on durability: sulfate (Na2SO4 solutions)
Mercury intrusion porosimetry SCMs can increase durability (expansion tests in Na2SO4 solutions) 2 years at 20oC 0.3
PC 70% slag 0.2
SCM affect pore structure PC + 6% SF CEM I HS
0.1 PC + FA 40% slag OPC PC + 12% SF
Cumulative pore vol. (frac.) PC + slag 0 0.001 0.01 0.1 1 Intruded pore diameter (μm) Canut PhD thesis 2013
Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 25 Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 26
Conclusions Current topics: Al uptake in C-S-H
Effect of SCMs: Measurement of aluminium uptake Spectroscopic investigations • react slower than Portland cements strätlingite • can accelerate reaction of Portland cement • affects strength (can have synergistic effects) • modify cement composition/ C-S-H composition • Microstructure • Porosity/ water distribution • can enhance durability L’Hopital ea Renaudin ea 2012 Where is aluminium most stable Thermodynamic models (molecular modelling) Al(IV)
Al(VI)
Al(V) Pegado ea Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 27 Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 28
Which challenges will we face in the future Outlook
Better understanding of the role of SCMs => result of the work of many scientists / intense collaborations Reduction of CO Generic approach 2 (within and outside nanocem) => more SCM How did nanocem contribute to that? Understanding of effects • Ease collaboration / exchange of ideas at fundamental level on: New cements • Platform to present and discuss results • Kinetics C$A, celitment, … • Mechanical properties • Contributing financially to some projects • Microstructure • Update thermodynamic database for cements • Chemistry • Determination of reaction degree of SCMs (NMR/Image analysis) • Durability Interaction with environment • Influence of SCM s •…. • on hydrates • on porosity Try • distribution of water (HNMR) and • … error
Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 29 Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 30
- 47 - Thanks to
Thanks for data, slides, … • Nanocem
• Marian Canut (DTU) • Klaartje de Weerdt (NTNU) • Florian Deschner (Empa) • Mette Geiker (DTU/NTNU) • Duncan Herfort (Cementir) • Vanessa Kocaba (EPFL) • Wolfgang Kunther (Empa) • Emilie L’Hopitâl (Empa) • Arnauld Müller (EPFL/Surrey) • Soren Poulsen (Aarhus) • John Rossen (EPFL) • Karen Scrivener (EPFL) • Jorgen Skibsted (Aarhus) •…
Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 31
- 48 - Industry perspective for the future of Nanocem
THE INDUSTRIAL-ACADEMIC NANOSCIENCE RESEARCH NETWORK FOR SUSTAINABLE CEMENT AND CONCRETE
An Industrial Perspective on the future of Nanocem Agenda Wolfgang Dienemann Concrete – the backbone of sustainable construction Key trends/challenges for the industry Open Meeting at the Nanocem Consortium Needs and opportunities for research and innovation 10th Anniversary Celebration Why do we need joint research? Perspectives for Nanocem Tuesday, April 8th, 2014, 9:00 – 16:00
Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 2
Concrete – the backbone of sustainable construction Concrete – the backbone of sustainable construction
Concrete is by far the most widely-used construction material in the world. It accounts for > 50 w-% of all manufactured goods and materials SOCIETY – Towards smart cities 70% of the world´s population lives in concrete structures The concrete in a standard family house costs less than € 7000 Every €1 spent on construction output generates a total of € 3 in total economic activity (GDP increase) Concrete is a highly flexible, durable, affordable, fire resistant and The value of concrete production in Europe is €74 billion energy-efficient material that can effectively address a wide variety of needs The concrete used in the Channel Tunnel is contractually guaranteed to The concrete sector can help tackle the shortage of housings by last for 120 years providing comfortable, affordable and energy-efficient buildings The concrete industry uses over 18 times more waste, by-products and Concrete´s ability to absorb temperature variations contributes to secondary materials than it generates building comfort as well as lower costs Concrete buildings typically have a minimum service life of 50 years CtllldbtConcrete: locally sourced, robust, energy-effic ien t The durability and resilience of concrete makes it ideal for constructing buildings that provide high safety levels AnewA new Cembureau-led campaign will be launched on May 27, 2014
Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 3 Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 4
Concrete – the backbone of sustainable construction Concrete – the backbone of sustainable construction
ECONOMY – Concrete and construction – an engine for growth ENVIRONMENT – Whole life performance
CttiConstruction is the ltlargest silingle economicactivit yand thegreatttest idindus tiltrial When looked at from this life-cycle perspective, the long-term benefits of employer in Europe, with some 20 million jobs concrete become evident: its durability, its thermal mass, and the availability The European Commission estimates that one job created in the construction and abundance of its raw materials (including secondary materials) means two additional jobs are created elsewhere Concrete buildings can provide substantial energy savings during their lifetime - Concrete is a local business, employing local people - Money and investment in The high level thermal inertia of concrete buildings means that indoor construction are pumped back into the local economy tttemperatures remainreltillativelystbltable ditdespiteextlternal fluc tuati ons The components that go into making concrete – aggregates, cement, and Cement uses alternative fuels and materials derived from wastes to reduce the water – are also sourced locally; the production value also remains local industy‘s reliance on fossil fuels and ppyrimary raw materials With this heavy emphasis on the local, the concrete sector is vitally important to At the end of its life, concrete can be fully recycled, either into new concrete the strengthening of local economies and provides a stable, continuous source or into other applications such as road base of jobs and economic activity The cement iidndus try has ddldeveloped a set of priiilnciples on quarry reha bilita tion
Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 5 Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 6
- 49 - Concrete – the backbone of sustainable construction Key trends/challenges for the industry
Annual cement consumption is predicted to grow further in the Urbanisation and population growth coming decades, and to reach 4400 Mt by 2050 Between 2011 and 2050, the world population is expected to increase from 7.0 billion to 9.3 billion The urban population is expected to increase from 3.6 billion in 2011 to over 6 billion in 2050 The volume of tltravel withinurban areas is anticipated to triple by 2050
This will require
Innovative buildings to provide energy-efficient housing solutions or work spaces New tttransport soltilutions tomiiinim ise envitlironmental effect sand congestion Vertical buildings to reduce the area needed to house 9 billion people Underground construction to reduce land use Source: WBCSD - CSI
Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 7 Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 8
Key trends/challenges for the industry Key trends/challenges for the industry
Circular economy / urban mining Climate change adaption
Natural sources of valuable raw materials are Increasing temperatures will lead to: gggetting scarce or difficult to exploit Rising sea levels Disposal of construction and demolition wastes More weather extremes resulting will become very expensive and may be prohibited in strong storms, floodings, etc. Heat-island effects and excessive air pollution in Megacities
This will require This will require Increased use of alternative fuels and raw materials Durable coastal protection and harbour modernisation Full recycling of construction & demolition waste Resilient buildings and infrastructures Utiliza tion of wastestreams from other idindus titries Innovative concrete surfaces (bright, self-cleaning, air purifying,…)
Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 9 Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 10
Key trends/challenges for the industry Key trends/challenges for the industry
CO2/ Climate change CO2/ Climat echange
Source: WBCSD – CSI “Technology Roadmap“ Source: Cembureau : “ The role of CEMENT in the 2050 LOW CARBON ECONOMY“
Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 11 Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 12
- 50 - Needs and opportunities for research and innovation Needs and opportunities for research and innovation
Innovative concrete solutions for smart cities Special concretes for alternative energy supply
Concrete elements with high thermal conductivity and increased heat storage capacity High-performance concrete for off-shore wind parks Concrete surface with self-cleaning, air purifying properties Durable concrete structures for energy generation and storage, Modular, flexible concrete structures ege.g. dams, pipes, tidal structures Durable, (i.e. low maintenance) infrastructures for: • (Public) transport, often underground Special concretes for heat storage in solar power plants • Energy and water supplies • Sewer systems
Staudamm und Andasol Bilder ?
Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 13 Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 14
Needs and opportunities for research and innovation Needs and opportunities for research and innovation
Extended use of low carbon materials and wastes Replace OPC clinker by alternative concepts
Develop and optimise cements with further reduced clinker content Develop cementitious materials/concepts with low carbon footprints Ensure performance (workability, strength, ..) and robustness Utilize wider range of industrial by-products, e.g. slags, ashes Ensure durability of concrete produced with alternative cements Ensure performance (workability, strength, ..) and robustness Ensure stitric tcompliance with envitlironmental and H&S regultilations Ensure durability of concretes produced with low clinker contents Prove potential for wide range of applications Based on widely available and affordable raw materials Ensure strict compliance with environmental and H&S regulations
Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 15 Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 16
Why do we need joint research ? Why do we need joint research ?
The radica linnooatosvations dema nded fromindustry will require The inherent safety and resilience expected from concrete structures requires a fundamental understanding of the underlying mechanisms that govern concrete performance More than just a proof of concept on lab scale for radical innovations substantial resources / a critical mass, which can not be financed and managed by idiidlindividual companies or itittinstitutes Clear evidence of long-term durability based on sound scientific understanding as well as a broad experience base a coordinated long-term approach to building up the competence levels needed A common understanding and acceptance of innovative concepts by all stakeholders (academic, industry and authorities) a multidisciplinary network of scientists bridging nanoscale phenomena to mesoscale effects to macroscopic properties Clear documentation in standards and application codes
Nanocem – a network for competence development Nanocem – a basis for introduction of new cements
Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 17 Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 18
- 51 - Why do we need joint research ? Perspectives for Nanocem
The ceme n t aadnd con cr ete industries require well-educated and well-trained personnel
for today´s tasks and future innovations
with a sound scientific/technical education
mastering systems of growing complexity
with an international mindset and mobility
suited and motivated to work in international teams
with an understanding of the industrial perspective
Nanocem – a pool of talents Source: Nanocem Spring Meeting 2014
Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 19 Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 20
Perspectives for Nanocem Perspectives for Nanocem
Source: Nanocem Spring Meeting 2014 Source: Nanocem Spring Meeting 2014
Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 21 Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 22
Perspectives for Nanocem
CoCocusosnclusions aadnd Outl ook
The Nanocem network has proven its value for industry and academia
Excellent progress has been made in several research fields
The need for joint research to enable (radical) innovations continues to increase
The network is self-sustaining and has demonstrated its ability to adapt to changes
Nanocem – 10 years of success and a bright future
Nanocem Spring Meeting, 8-10 April 2014, Lausanne, CH ©Nanocem 23
- 52 - - 53 -
Thank you to our sponsors, the Nanocem industrial partners, for their special contribution to this event