DOCSLIB.ORG

Elements of the Durability of Ettringite

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Elements of the Durability of Ettringite Lecture 1: Options for sustainable development of concrete Professor Karen Scrivener Cement Chemistry for Engineers, Cape Town 31st January 2013 Karen Scrivener • English • 1979 Materials Science, University of Cambridge • 1984 PhD Imperial College, London • 1995 Lafarge, Central Research Laboratory, France • 2001 EPFL, Lausanne, Switzerland • 2002 Creation of Nanocem – Industrial Academic Partnership for Fundamental Research on Cementitious Materials • 2004 Editor in Chief: Cement and Concrete Research 2 Outline The reality about concrete and environmental impact What options do we have Choices for Cement Choices for Concrete 3 Concrete and sustainable development There are a lot of misconceptions about cement and concrete with respect to sustainable development. If we want to improve things we have to start from a correct assessment of the situation We hear a lot about the fact that cement and concrete account for some 5-8% of man-made CO2 What we don’t realise is that this is amazingly good for a material which makes up around half of everything produced. The importance of concrete: Global figures (2005) (a) 34 GT of products (b) 30 GT of CO2e Material Per year A = % of CO2e / yr B = % of a b Concrete 17.1 GT 50.2% 2.6 GT 8.5% Steel* 0.74 GT 2.4% 2.3 GT 8.1% Timber 2.2 GT 6.5% 5.1 GT** 17%** (a) Resource consumption minus: major wastes (agricultural waste, mine tailings); grazed crops; fossil fuels – Krausmann et al Ecol Econ 68 (2009) 2696. (b) Estimate derived from various sources. *Virgin steel not including rebar. **IPCC estimate of emissions owing to forestry operations & thus upper bound. Full details of calculations & data sources available on request. Slide Phil Purnell, University Leeds 5 Concrete is an environmentally friendly material Best able to satisfy the demands of the world population Material MJ/kg kgCO2/kg Cement 4.6 0.83 2 Concrete 0.95 0.13 Masonry 3.0 0.22 Wood 8.5 0.46 Wood: multilayer 15 0.81 Steel: Virgin 35 2.8 Steel: Recycled 9.5 0.43 Aluminium: virgin 218 11.46 Aluminium 28.8 1.69 recycled CO energy, Relative Glass fibre 100 8.1 composites Glass 15.7 0.85 ICE version 1.6a Hammond G.P. and Jones C.I 2008 Proc Instn Civil Engineers www.bath.ac.uk/mech-eng/sert/embodied/ Given these low figures, local supply is key to avoid transport costs 6 Concrete is the only viable solution From these slides we can also see that there is no possible substitute for concrete to satisfy the needs of the worlds population for buildings and infrastructure. For example the amount of wood used per year is about 1/10th the amount of concrete and this level is already judged to be unsustainable – we are cutting down forests faster than we are replanting them. Compressed earth is still used in rural situations, but due to the low strength you need to use much greater quantities than concrete for the same application. Real danger of depleting soil in heavily populated rural areas. Now more the half the people in the world live in urban areas 7 Demand is forecast to rise: to meet the demands of a growing world population more than half of demand is currently in China 8 Concrete and sustainable development So I hope you now believe me that concrete is a very good option from an environment standpoint. But we need to see if we can continue to reduce the environmental footprint AND satisfy the growing demand We need to look at where the associated CO2 emissions are coming from: Origins of CO2 emissions in cement production 1 tonne of cement leads to the emission of 650 – 900 kg CO2 This large range reflects efficiencies of The production process different plants is highly optimised Around 80% of CaCO3 thermodynamic limit. decomposition 40 it is estimated that < 2% (CHEMICAL) further savings can be Fuel made here 60 Use of waste fuels, which can be > 80% reduces the demand CaCO3 CaO + CO2 for fossil fuels NB, importance of being local – sea transport Australia to Europe would add >500 kg /tonne 10 “Chemical CO2” Most of the CO2 emission associated with cement production comes form the decomposition of limestone This situation is particular to cement (and steel) Alternative energy sources will not help, as with most other industrial processes. If we lower this chemical CO2, we will inevitably change the chemistry of the cement And so the way it reacts and performs To introduce low carbon solutions, engineers will have to understand and deal with different cement chemistries. 11 Lets look a bit more at possibilities for low carbon chemistries 12 The resources of the earth mean we do not have a lot of options! S rest Na Mg <2% K rest K Mg Na Ca Fe O Al O ReduceCa Ca Si Si Portland Fe Al earth’s crust cement The composition of the Earth’s Crust limits the possible chemistries But the limited range mean we can explore all options 13 What about the different oxides oxide hydrates geology CaO Good mobility, hydrates can fill space Limestone, widely distributed SiO2 Less soluble but hydrates fill space Most common oxide, everywhere Al2O3 Variable solubility, hydrates fill space With silica in feldspars, clays also / bauxites ? Fe2O3 Low mobility / solubility in alkaline ? Very widely distributed solutions, poor contribution to space filling MgO Low mobility / solubility in alkaline ? More local distribution as major ? solutions, poor contribution to space filling component, wide distribution as minor component Na2O Very soluble, hydrates don’t precipitate Widely distributed as minor - component. K2O Very soluble hydrates don’t precipitate Widely distributed as minor - component. Reaction between water and cement: Increasing solid volume, replaces water Transformation from fluid paste to solid Cement grain hydrates water What about the different oxides oxide hydrates geology CaO Good mobility, hydrates can fill space Limestone,30 year widely old distributed Less soluble but hydrates fill space Most common oxide, everywhere SiO2 concrete Al2O3 Variable solubility, hydrates fill space With silica in feldspars, clays also / bauxites ? Fe2O3 Low mobility / solubility in alkaline ? Very widely distributed solutions, poor contribution to space filling Slag cement MgO Low mobility / solubility in alkaline ? More local distribution as major ? solutions, poor contribution to space filling component, wide distribution as minor component Na2O Very soluble, hydrates don’t precipitate Widely distributed as minor - component. K2O Very soluble hydrates don’t precipitate Widely distributed as minor - component. What about the different oxides oxide hydrates geology CaO Good mobility, hydrates can fill space Limestone, widely distributed SiO2 Less soluble but hydrates fill space Most common oxide, everywhere Al2O3 Variable solubility, hydrates fill space With silica in feldspars, clays also / bauxites ? Fe2O3 Low mobility / solubility in alkaline ? Very widely distributed solutions, poor contribution to space filling MgO Low mobility / solubility in alkaline ? More local distribution as major ? solutions, poor contribution to space filling component, wide distribution as minor component Na2O Very soluble, hydrates don’t precipitate Widely distributed as minor - component. K2O Very soluble hydrates don’t precipitate Widely distributed as minor - component. Most important system CaO-SiO2-Al2O3 SiO2 Silica Fume Natural pozzolan F Fly Ash C Metakaolin Slag Portland Cement Limestone CaO Al2O3 18 Other hydraulic minerals SiO2 C3S 74% CaO (proportional to CO2) C2S 65% CaO CA 35% CaO C4A3$ 37% CaO ? (3CA + C$) - Here we see real potential to reduce CO2 BUT, what sources of minerals are there which contain Al2O3 >> SiO2 ? Bauxite – localised, under Calcium aluminate / increasing demand for Portland calcium sulfo aluminate Aluminium production, Cement EXPENSIVE CaO Al2O3 19 Most promising approach – reducing the clinker factor ↓ CO2 Process optimisation ↓ clinker factor Clinker Gypsum Cement SCMs – Supplementary Cementitious Materials Limestone Fly ash Slag Natural pozzolan Often by-products or wastes from other industries Typical reductions in clinker factor Source: HOLCIM 21 But increasing substitution is reaching a limit due to: - technical performance - uniformity Figures from ~2000 - availability - cost Metakaolin Calcined clays Rice husk ash Silica fume Burnt shale Used in cement Reserve Natural pozzolana Blast furnace slag Fly ash Fly ash: significant volumes with low performance Cement 0 500 1000 1500 2000 2500 Limestone Mill. tons/year 22 So what . Portland cement clinker, blended with SCMs is likely to be best solution for sustainable cements for foreseeable future . Limited supplies of currently widely used SCMs (notably slag and fly ash) . Need solutions adapted to local resources (consequences: broader and more complex products) . Need to find or manufacture new SCMs . Need to better exploit existing materials: . Alumina - limestone synergy . Multiple blends – combining several SCMs . Questions of standards . Issues of variability will increase – need better basic knowledge to handle this 23 EXAMPLE: High substitution possible with combination of metakaolin and limestone Antoni et al, CCR, 2012 • For 45% of substitution, higher mechanical properties from 7 days • For 60% of substitution, mechanical properties still >90% of pure cement • Sulfate optimisation is key, example with B45 shows one day strength can increase by 50%! 24 There is no single magic solution We need to master a diverse range of solutions: optimised according to LOCAL raw materials and applications emissions 2 CO 1990 2000
Load more

Recommended publications
  • Construction Engineering Australia • June/July 2017
    PROUDLY SUPPORTED BY PROUD MEDIA PARTNER CONCRETE INSTITUTE of AUSTRALIA CONSTRUCTION ENGINEERING OFFICIAL PUBLICATION AUSTRALIA JUNE/JULY 2017 V3.03 CONSTRUCTION CIVIL WORKS CIVIL ENGINEERING PRINT POST APPROVED - 100001889 Keynote Speakers Professor Tim Ibell Professor Karen Scrivener Ms Louise Adams Professor Doug Hooton Mr Peter McBean Professor Des Bull Invited Speakers Mr Mike Schneider Dr Stuart Matthews Conference Registration Now Open Concrete 2017 includes • Quality Technical Program REGISTER TODAY AT: • Cement and Durability Workshops www.concrete2017.com.au • Huge Trade Exhibition • Gala “Awards for Excellence in Concrete” Dinner • Social and Networking Events 28th Biennial Conference hosted by Conference Partner www.concrete2017.com.au JUNE/JULY 2017 contents Volume 3 Number3 Published by: 2 Editorial Editorial and Publishing Consultants Pty Ltd ABN 85 007 693 138 PO Box 510, Broadford 4 Industry News Victoria 3658 Australia Phone: 1300 EPCGROUP (1300 372 476) Int’l: +61 3 5784 3438 Fax: +61 3 5784 2210 10 Cover Feature: City of Gold Coast www.epcgroup.com Publisher and Managing Editor Anthony T Schmidt 14 Product Focus: MetaMax 10 Phone: 1300 EPCGROUP (1300 372 476) Mobile: 0414 788 900 Email: [email protected] 14 Product Focus: Aussie Pumps Deputy Editor Rex Pannell Tsurumi Piling Pump Mobile: 0433 300 106 Email: [email protected] 16 Case Study: Modular Walls National Advertising Sales Manager Yuri Mamistvalov Phone: 1300 EPCGROUP (1300 372 476) Mobile: 0419 339 865 18 Lift and Shift Email: [email protected] 16 Advertising Sales - SA Jodie Chester - G Advertising 22 Innovative Solutions Mobile: 0439 749 993 Email: [email protected] 26 Materials Handling Advertising Sales - WA Licia Salomone - OKeeffe Media Mobile: 0412 080 600 Email: [email protected] 30 Concrete Institute News Graphic Design Annette Epifanidis 38 National Precast Feature 38 Mobile: 0416 087 412 TERMS AND CONDITIONS 46 Equipment Feature This publication is published by Editorial and Publishing Consultants Pty Ltd (the “Publisher”).
    [Show full text]
  • Strategic Energy Technology Plan
    STRATEGIC ENERGY TECHNOLOGY PLAN Scientific Assessment in support of the Materials Roadmap enabling Low Carbon Energy Technologies Energy efficient materials for buildings Authors: M. Van Holm, L. Simões da Silva, G. M. Revel, M. Sansom, H. Koukkari, H. Eek JRC Coordination: P. Bertoldi, E. Tzimas EUR 25173 EN - 2011 The mission of the JRC-IET is to provide support to Community policies related to both nuclear and non-nuclear energy in order to ensure sustainable, secure and efficient energy production, distribution and use. European Commission Joint Research Centre Institute for Energy and Transport Contact information Address: Via Enrico Fermi, 2749 I-21027 Ispra (VA) E-mail: [email protected] Tel.: +39 (0332) 78 9299 Fax: +39 (0332) 78 5869 http://iet.jrc.ec.europa.eu/ http://www.jrc.ec.europa.eu/ Legal Notice Neither the European Commission nor any person acting on behalf of the Commission is responsible for the use which might be made of this publication. Europe Direct is a service to help you find answers to your questions about the European Union Freephone number (*): 00 800 6 7 8 9 10 11 (*) Certain mobile telephone operators do not allow access to 00 800 numbers or these calls may be billed. A great deal of additional information on the European Union is available on the Internet. It can be accessed through the Europa server http://europa.eu/ JRC68158 EUR 25173 EN ISBN 978-92-79-22790-5 (pdf) ISBN 978-92-79-22789-9 (print) ISSN 1831-9424 (online) ISSN 1018-5593 (print) doi:10.2788/64929 Luxembourg: Publications Office of the European Union,2011 © European Union, 2011 Reproduction is authorised provided the source is acknowledged Printed in Italy Preamble This scientific assessment serves as the basis for a materials research roadmap for Energy efficient materials for buildings technology, itself an integral element of an overall "Materials Roadmap Enabling Low Carbon Technologies", a Commission Staff Working Document published in December 2011.
    [Show full text]
  • CSI/ECRA Technology Papers 2017 Can Again Serve As Important Reference Documents for Developing Further Technology Roadmaps in the Cement Sector
    European Cement Research European Cement Research Academy Academy GmbH Tannenstrasse 2 40476 Duesseldorf, GERMANY Phone: +49-211-23 98 38-0 Fax: +49-211-23 98 38-500 [email protected] www.ecra-online.org Chairman of the advisory board: Daniel Gauthier Managing director: Martin Schneider Registration office: Duesseldorf Court of registration: Duesseldorf Commercial registration no.: 47580 A-2016/2305 CSI/ECRA-Technology Papers 2017 Development of State of the Art Techniques in Cement Manufacturing: Trying to Look Ahead Dusseldorf, Geneva, 20 March 2017 2 / 190 Development of State of the Art-Techniques in Cement Manufacturing: Trying to Look Ahead, Revision 2017 Cement Sustainability Initiative (CSI) European Cement Research Academy GmbH WBCSD, Maison de la Paix, Chemin Eugène-Rigot 2B CP 2075, 1211 Geneva 1 Tannenstrasse 2 Switzerland 40476 Duesseldorf Germany www.wbcsdcement.org Phone: +49-211-23 98 38-0 [email protected] Fax: +49-211-23 98 38-500 Managing director: Philippe Fonta www.ecra-online.org [email protected] Project officer: Cristiana Ciaraldi Chairman of the advisory board: Daniel Gauthier Managing director: Martin Schneider Project manager: Volker Hoenig Person in charge: Johannes Ruppert Registration office: Duesseldorf Court of registration: Duesseldorf Commercial registration no.: 47580 This study was commissioned by the Cement Sustainability Initiative (CSI), a member-led programme of the World Business Council for Sustainable Development (WBCSD). The re- port represents the independent research efforts of the European Cement Research Acade- my (ECRA) to identify, describe and evaluate technologies which may contribute to increas- ing energy efficiency and reducing greenhouse gas emissions from global cement production today as well as in the medium and long-term future.
    [Show full text]
  • Laboratory Investigation of the Fracture Properties of Nanoclay-Modified Asphalt Materials Under Direct Tensile Test
    Laboratory Investigation of the Fracture Properties of Nanoclay-Modified Asphalt Materials under Direct Tensile Test Mohammad Hossein Esfahani1, Ali Asadollahi baboli2, Sunil Deshpande3 & Amir Asadollahi Baboli4 1Dept of Civil Engineering, Imam Khomeini International University, Qazvin, Iran 2&3Dept of Civil Engineering, Bharati Vidyapeeth University, Pune, India 4Dept of Civil Engineering, Islamic Azad University Qaemshahr, Gaemshahr,Iran E-mail : [email protected], [email protected], [email protected], [email protected] they contain carbon, hydrogen, nitrogen, sulfur, oxygen, Abstract – Increasing traffic loads and traffic volume, combined with the rising cost of asphalt, have led to an etc. Researchers have been trying to use different kinds urgent need to improve the durability, safety and efficiency of additives to modify the base asphalt in order to of asphalt pavements through asphalt modification. In this increase the resistance to pavement distress. In general, research, we have tried to use a kind of additives to modify fibers and polymers are two main materials used in the the base asphalt in order to increase the resistance to asphalt modification [1–5]. Fiber was one of the most pavement distress. The objective of this study is to review widely used additives to enhance the bonding between existing literature in the area of nano-modification of asphalt and aggregates or within asphalt since 4000 asphalt and proceed to apply nano-materials to asphalt to years old ago [6–12]. In addition, scientist and engineers improve the performance. This study integrates literature tried to use the polymer Styrene Butadiene Styrene review, preparation, and characterization of nano- modified asphalt materials.
    [Show full text]
  • Cements for the Future
    The meeting will be held at the Village Hotel Leeds. Address: The Village Hotel Leeds 186 Otley Road Headingley Leeds, LS16 5PR United Kingdom Tel: +44 113 278 1000 th Fax: +44 113 278 1111 5 OPEN MEETING http://www.village-hotels.co.uk/hotels/leeds/ The Village Hotel, Leeds, UK Cements for the Future Tuesday, April 28, 2009 The Village Hotel Headingley Leeds, United Kingdom http://www.nanocem.org/leeds2009 Nanocem is a network of European academic and industrial partners, all Invited speakers: interested in fundamental research on cement and concrete. The consortium is Peter Robery, Technical Director, Halcrow Group Ltd, Visiting Professor, entirely financed by its industrial partners. Academic partners contribute in kind the University of Leeds, Immediate Past President, The Concrete Society, UK through their projects. Pal Chana, Chief Executive (Acting), British Cement Association, UK Since its foundation in 2002, the network has constantly grown and consists and speakers from Nanocem network: now of 24 academic partners and 15 industry partners from all over Europe. More Leon Black, University of Leeds, UK than 120 academic researchers are managing some 60 PhD and PostDoctoral Jesper Sand Damtoft, Aalborg Portland, DK research projects in the area of fundamental research. Peter McDonald, University of Surrey, UK Donald Macphee, University of Aberdeen, Scotland, UK Nanocem’s main activities are: Phil Purnell, University of Leeds, UK • organizing workshops and seminars, Ian Richardson, University of Leeds, UK • sponsoring research in multi-partner projects, Karen Scrivener, Coordinator Nanocem, Ecole Polytechnique Fédérale de • acting as a recruitment base for researchers in cementitious materials, Lausanne, Switzerland • highlighting the importance of R&D on cementitious materials at the European level.
    [Show full text]
  • ANNUAL REPORT 2016 PERFORMANCE INDICATORS Pictured on the Front Cover (Top to Bottom)
    ANNUAL REPORT 2016 PERFORMANCE INDICATORS Pictured on the front cover (top to bottom): Professor Craig Simmons is the Scientific Director of the Translational Biology and Engineering Program (TBEP). TBEP is the University of Toronto’s component of the Ted Rogers Centre for Heart Research (TRCHR) and brings together faculty members and their students from U of T Dentistry, Engineering and Medicine. Together, these researchers are advancing heart research, diagnostics, and regeneration using a comprehensive approach that includes systems and developmental biology, technology innovation and clinical translation. On May 13, 2016 more than 1,400 students and teachers from across the Greater Toronto Area converged on U of T Engineering for Innovate U. The one-day workshop was Canada’s largest science, technology, engineering and math (STEM) event for children in Grades 3 to 8. Innovate U was run in partnership with Google Canada and Actua, a national STEM charity. Two students from U of T Engineering work on the Formula SAE racing car. Students can choose from more than 90 engineering clubs and teams, from design and competition groups such as the Human-Powered Vehicle Team to cultural and arts groups such as Skule™ Orchestra, as well as national organizations such as Engineers Without Borders. Currently under construction, the Centre for Engineering Innovation & Entrepreneurship (CEIE) will set a new standard for engineering education and research. When the CEIE opens in 2017, it will provide a new home for some of our world-leading institutes, such as the Centre for Global Engineering and the Institute for Sustainable Energy. Its design/meet rooms and fabrication facilities will enable students, faculty and industry partners to collaborate across disciplines on complex global challenges and launch new companies to bring their innovations to market.
    [Show full text]
  • CONCRETE INSTITUTE of AUSTRALIA
    CONCRETE IN AUSTRALIA CONCRETE INSTITUTE of AUSTRALIA Volume 41 Issue 2 June 2015 $9.95 Inc. GST www.concreteinstitute.com.au SPECIAL FEATURES n POST TENSION DESIGN & CONSTRUCTION SEMINAR n MITIGATING ALKALI AGGREGATE REACTIONS VOL 41, NO 2 JUNE 2015 UHPFRC AS A MATERIAL FOR BRIDGE CONSTRUCTION Are we making the most of our opportunities? FROM THE PRESIDENT Engineering and the Einstein Test My favourite quote from Th e Concrete Institute’s national and state based that famous engineer, seminars are one of the key ways in which we can help Albert Einstein, states engineers to develop their practical design skills, but I that everything should would here like to focus on three other, perhaps lesser be simplifi ed as far as known, sources of information available to Institute possible, but no further. members: Th is is a good summary As one of the benefi ts of membership of the international of the task of the fi b the Concrete Institute has access to online copies of the engineer at all stages of fi b “technical bulletins”. Th e bulletins are now available to their work from analysis members for free download on the Institute website, with Douglas Jenkins and design, through to a total of 68 documents currently available. Th e name construction, monitoring “bulletin” perhaps suggests a brief summary document, and remediation. Th ere are many great examples of but this is not the case; each bulletin is of textbook length, simple and elegant design from ancient structures such as and the series includes works on all aspects of concrete the Roman Pont du Garde to the modern Millau Viaduct, engineering, including a four volume manual of concrete but the history of structures is also literally littered with design, and the fi b model concrete code.
    [Show full text]
  • Making Concrete Change: Innovation in Low-Carbon Cement and Concrete 
    Chatham House Report Johanna Lehne and Felix Preston Making Concrete Change Innovation in Low-carbon Cement and Concrete #ConcreteChange Chatham House Report Johanna Lehne and Felix Preston Energy, Environment and Resources Department | June 2018 Making Concrete Change Innovation in Low-carbon Cement and Concrete The Royal Institute of International Affairs Chatham House 10 St James’s Square London SW1Y 4LE T: +44 (0) 20 7957 5700 F: + 44 (0) 20 7957 5710 www.chathamhouse.org Charity Registration No. 208223 Copyright © The Royal Institute of International Affairs, 2018 Chatham House, the Royal Institute of International Affairs, does not express opinions of its own. The opinions expressed in this publication are the responsibility of the author(s). All rights reserved. No part of this publication may be reproduced or transmitted in any form or by any means, electronic or mechanical including photocopying, recording or any information storage or retrieval system, without the prior written permission of the copyright holder. Please direct all enquiries to the publishers. ISBN 978 1 78413 272 9 A catalogue record for this title is available from the British Library. Printed and bound in Great Britain by Latimer Trend. The material selected for the printing of this report is manufactured from 100% genuine de-inked post-consumer waste by an ISO 14001 certified mill and is Process Chlorine Free. Typeset by Soapbox, www.soapbox.co.uk Cover image: Staircase, Benesse Museum House, Naoshima, Japan. Copyright © Education Images/UIG via Getty Images
    [Show full text]
  • Karen Scrivener
    Not logged in Talk Contributions Create account Log in Article Talk Read Edit View history Search Wikipedia Karen Scrivener From Wikipedia, the free encyclopedia Main page Karen Louise Scrivener is a material chemist known for her pioneering works in cementitious materials. She is the head of Karen Louise Scrivener Contents Laboratory of Construction Materials at Ecole Polytechnique Fédérale de Lausanne[1] and served as the Editor-in Chief of Current events the Cement and Concrete Research journal for 15 years. Random article About Wikipedia Contents [hide] Contact us 1 Early life and education Donate 2 Career Contribute 3 Honours and awards Help 4 References Learn to edit 5 External links Community portal Recent changes Upload file Early life and education [ edit ] Born 21 August 1958 (age 62) Tools In 1980, she graduated from the Cambridge University in Material Sciences. She earned her PhD in Materials Science from England [2] What links here the Imperial College London in 1983 on the development of microstructure during the hydration of Portland cement under Nationality British Related changes the supervision of Professor P. L. Pratt. Alma mater Cambridge University, Imperial Special pages College London Permanent link Career [ edit ] Known for Cement, Construction Materials Page information Awards Klaus Dyckerhoff Prize (2007) Cite this page Scrivener worked at the Imperial College of London in the Department of Materials science until 1995 as a post-doctoral (2007) [3] Wikidata item research assistant, Warren research fellow of the Royal Society and lecturer. In 1995 she decided to leave academia and Kroll Medal (2010) joined the Central Research Laboratory of Lafarge near Lyon in France where she was a Senior Scientist and then Head of Della Roy Lecture (2011) Print/export Calcium Aluminates Department.
    [Show full text]
  • Micromechanical Multiscale Fracture Model for Compressive Strength of Blended Cement Pastes
    Cement and Concrete Research 83 (2016) 188–202 Contents lists available at ScienceDirect Cement and Concrete Research journal homepage: www.elsevier.com/locate/cemconres Micromechanical multiscale fracture model for compressive strength of blended cement pastes Michal Hlobil a,b,⁎,VítŠmilauer a, Gilles Chanvillard c,1 a Department of Mechanics, Faculty of Civil Engineering, CTU in Prague, Thákurova 7, 166 29 Prague 6, Czech Republic b Institute for Mechanics of Materials and Structures (IMWS), Vienna University of Technology (TU Wien), Karlsplatz 13/202, A-1040 Wien, Austria c Lafarge Centre de Recherche, 95 Rue du Montmurier, 38290 Saint-Quentin Fallavier, France article info abstract Article history: The evolution of compressive strength belongs to the most fundamental properties of cement paste. Driven by an Received 19 June 2015 increasing demand for clinker substitution, the paper presents a new four-level micromechanical model for the Accepted 8 December 2015 prediction of compressive strength of blended cement pastes. The model assumes that the paste compressive Available online 9 March 2016 strength is governed by apparent tensile strength of the C-S-H globule. The multiscale model takes into account the volume fractions of relevant chemical phases and encompasses a spatial gradient of C-S-H between individual Keywords: grains. The presence of capillary pores, the C-S-H spatial gradient, clinker minerals, SCMs, other hydration prod- Compressive strength (C) Calcium-Silicate-Hydrate (C-S-H) (B) ucts, and air further decrease compressive strength. Calibration on 95 experimental compressive strength values Microstructure (B) shows that the apparent tensile strength of the C-S-H globule yields approx.
    [Show full text]
  • SGS INTRON INVESTS in the Measurement of the HEAT
    Volume 14 | June 2013 | Number 18 IN T LLE INTRON U SGS B FORENSIC INVESTIGATION REVEALS CONCRETE SECRETS COLLABORATION WITH ZUYD UNIVERSITY SGSINTRON BULLETIN 1 In these difficult economic times, companies which in the past invested in innovation are often in a better competitive position and are even showing growth despite the strong headwind. Over the past decade, the Netherlands only invested moderately in R&D – less than 2% of GDP. This is considerably less than countries such COLLABORATION WITH as Germany and the US which have devoted 3% or more of GDP in R&D. The differences are even greater in the construction industry. A typical example is nano concrete. This offers unprecedented ZUYD UNIVERSITY opportunities to give (far too) inexpensive concrete (only 3 eurocents per kg!) exceptional performance and wider applications, and there- FOR MORE INFORMATION: GERT VAN DER WEGEN [email protected] fore added value. The US has been conducting a major strategic and practical programme in this area for several years, with several commercial applications as a result. With regard to nano concrete Europe has, as far as we know, only one significant activity: the Nanocem project, where scientific research is conducted on the usinesses benefit from For instance, SGS INTRON will nano structure and properties of hydrated cement. The Netherlands quality vocational training teach the subject of concrete tech- only plays an indirect role in this. since it provides them with no logy in the materials science part B future qualified employees. of the Chemistry and Chemical This is not self-evident. Businesses Engineering course.
    [Show full text]
  • Opportunities for Using Bauxite Residue in Portland Cement Clinker Production
    Opportunities for using bauxite residue in Portland cement clinker production Opportunities for using bauxite residue in Portland cement clinker production International Aluminium Institute: www.world‐aluminium.org Current IAI membership represents over 60 % of global bauxite, alumina and aluminium production. Since its foundation in 1972 (as the International Primary Aluminium Institute), the members of the IAI have been companies engaged in the production of bauxite, alumina, aluminium, the recycling of aluminium, or fabrication of aluminium or as joint venture partners in such. The global objectives of the Institute are: In 2016 the International Aluminium Institute undertook a review of opportunities for bauxite residue in all aspects of cement production and usage. This paper addresses the background to using bauxite residue in the production of Portland cement clinker, separate papers cover possible usage in calcium sulfoaluminate/special/sulfobelite cements and in supplementary cementious materials. 2 Opportunities for using bauxite residue in Portland cement clinker production Summary The prospects for using bauxite residue in Portland cement has been explored for over 80 years with many promising technical studies and several successful large scale commercial initiatives. The iron and aluminium compounds contained in the bauxite residue provide valuable additions in the production of Portland cement at a low cost. The best estimates are that between 1,000,000 to 1,500,000 tonnes of bauxite residue are currently used annually in the production of Portland Cement clinker. The cement plants currently utilising the bauxite residue in clinker production are based in China, Ukraine, India, Russia, Georgia, Moldova, Cyprus and Greece. From the evidence from the cement plants that are already using bauxite residue on an industrial scale, it is clear that bauxite residue can satisfactorily be used in cement clinker manufacture with only slight changes to their operating process.
    [Show full text]