Preview Leas Chemistry of Cement and Concrete 5th Edition 2019 by Peter Hewlett, Martin Liska (2019)

Preview Leas Chemistry of Cement and Concrete 5th Edition 2019 by Peter Hewlett, Martin Liska (2019) Preview Leas Chemistry of Cement and Concrete 5th Edition 2019 by Peter Hewlett, Martin Liska (2019) Preview Leas Chemistry of Cement and Concrete 5th Edition 2019 by Peter Hewlett, Martin Liska (2019) Preview Leas Chemistry of Cement and Concrete 5th Edition 2019 by Peter Hewlett, Martin Liska (2019) Preview Leas Chemistry of Cement and Concrete 5th Edition 2019 by Peter Hewlett, Martin Liska (2019)

Lea’s Chemistry of Cement and Concrete Fifth Edition Edited by Peter C Hewlett PhD, LLD, BSc, CChem, CSci, FRSC, FIMM, FInstConcTech, FConcSoc Martin Liska PhD (Cantab), MSc, A.M.I.C.T Butterworth-Heinemann is an imprint of Elsevier The Boulevard, Langford Lane, Kidlington, Oxford OX5 1GB, United Kingdom 50 Hampshire Street, 5th Floor, Cambridge, MA 02139, United States © 2019 Elsevier Ltd 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 and retrieval system, without permission in writing from the publisher Details on how to seek permission, further information about the Publisher’s permissions policies and our arrangements with organizations such as the Copyright Clearance Center and the Copyright Licensing Agency, can be found at our website: www.elsevier.com/permissions This book and the individual contributions contained in it are protected under copyright by the Publisher (other than as may be noted herein) Notices Knowledge and best practice in this field are constantly changing As new research and experience broaden our understanding, changes in research methods, professional practices, or medical treatment may become necessary Practitioners and researchers must always rely on their own experience and knowledge in evaluating and using any information, methods, compounds, or experiments described herein In using such information or methods they should be mindful of their own safety and the safety of others, including parties for whom they have a professional responsibility To the fullest extent of the law, neither the Publisher nor the authors, contributors, or editors, assume any liability for any injury and/or damage to persons or property as a matter of products liability, negligence or otherwise, or from any use or operation of any methods, products, instructions, or ideas contained in the material herein Library of Congress Cataloging-in-Publication Data A catalog record for this book is available from the Library of Congress British Library Cataloguing-in-Publication Data A catalogue record for this book is available from the British Library ISBN: 978-0-08-100773-0 For information on all Butterworth-Heinemann publications visit our website at https://www.elsevier.com/books-and-journals Publisher: Mathew Deans Acquisition Editor: Ken McCombs Editorial Project Manager: Peter Jardim and Charlotte Cockle Production Project Manager: Surya Narayanan Jayachandran Cover Designer: Greg Harris Typeset by SPi Global, India Author Biographies Peter Clive Hewlett is a chartered chemist and scientist turned materials scientist He is a Fellow of the Royal Society of Chemistry, Institute of Materials, Minerals and Mining, Institute of Concrete Technology and the UK Concrete Society He combines commercial research in the construction materials sector with academe and has done so for over 50 years He has lectured and published extensively and has several patents He has held a visiting industrial professorship at the University of Dundee for over 30 years and has an honorary Doctor of Laws degree (Honoris Causa) for work on concrete durability and surface characteristics He holds the UK Concrete Society Gold medal (2006) and is Chairman of the Editorial Board of the Magazine of Concrete Research A past President of the UK Concrete Society and Institute of Concrete Technology He spent some 25 years as researcher and Director of Cementation Research Ltd before joining the British Board of Agrement as Chief Executive Officer in 1988 dealing with innovative construction products Past president of the European Union of Agrement and the European Organisation for Technical Approvals He was Editor and an author of the fourth edition of Lea’s book and is co-editor of the fifth edition Martin Liska graduated at VSB Technical University of Ostrava, Czech Republic with an MSc in Mineral Resources He obtained a PhD degree in the Department of Engineering at the University of Cambridge, where he studied the fundamental properties and applications of reactive magnesia cements Martin then continued at the same institution as a PostDoctoral Research Associate to study novel cementitious binders, their fundamental and engineering properties in a number of geotechnical and geo-environmental applications He then moved into the construction industry to work closely with Professor Peter Hewlett at the David Ball Group, as Research and Development Manager, on alternative binder concrete systems based on alkali-activation This fruitful collaboration has resulted in a patented technology which is being currently exploited commercially Martin currently works as Research and Development Manager at Sika UK He is responsible for the development and deployment of admixtures for concrete and a broad range of cementitious and hybrid systems, addressing fundamental as well as engineering performance, economics and sustainability criteria Martin is the author/co-author of 29 scientific publications and patents He is a member of the Technical and Educational Committee of the Institute of Concrete Technology and is a Board member of the Magazine of Concrete Research xix xx Author Biographies Pierre-Claude Aătcin is a Professor Emeritus at the Department of Civil Engineering of the Faculty of Engineering of the Universite of Sherbrooke, P Que., Canada He is honorary member of the American Concrete Institute He received from the American Concrete Institute the Artur Anderson Award in recognition of outstanding laboratory and field research on the composition, structure and properties of HPC, superplasticisers and silica fume From 1990 to 1998 he was scientific director of the Canadian network of centres of excellence on high performance concrete In 1998 he participated to the construction of the cyclo-pedestrian bikeway of Sherbrooke, the first structure built with a Ultra High Strength Concrete He is the author of several technical books on concrete technology     High Performance Concrete (translated in French, Portuguese, Spanish and Check) Binders for Durable and Sustainable Concrete Sustainability of Concrete The Science and Technology of Concrete Admixtures James J Beaudoin has been involved in cement and concrete research at the Institute for Research in Construction (IRC), National Research Council (NRC) of Canada since 1972 He was elected a Fellow of the Royal Society of Canada in 1999 and received an honorary doctorate (LLD) from the University of Windsor in 2000 He was awarded a Gold Medal and appointed Researcher Emeritus by Dr Arthur Carty (former National Science Advisor to the Prime Minister) in 2003 He was Head of the Materials Laboratory at IRC from 1989 to 1997 He was a Principal Researcher for the Ottawa Centre of the Canadian Network of Centers of Excellence on High Performance Concrete (1990–1998) known as Concrete Canada He has served as an adjunct Professor of Civil Engineering at the University of Ottawa and the Universite Laval since 1987 He led the cement-based nanotechnology research team at IRC starting in 2003 He was instrumental in bringing the 12th International Congress on the Chemistry of Cement to Canada in 2007.Dr Beaudoin continues to have a significant impact on NRC research pertaining to the nanoscience of cements with his work on the metamorphosis of C-S-H nanostructure, the development of C-S-H-based nanocomposites and the evolution of composition-based models for C-S-H nanostructure A tribute symposium was held in his honor in 2014 at the American Concrete Institute meeting in Washington He received the ‘Della Roy Lecture Award’ in 2005 at the American Ceramic Society Annual Meeting He was also awarded the Copeland Award of the American Ceramic Society in 1998.Dr Beaudoin is the author or co-author of five books and numerous book chapters, encyclopaedia contributions, research journal papers and patents John Bensted read Chemistry for his BSc and PhD degrees at the University of London, before joining Blue Circle Cement at its research division in Greenhithe, Kent Here he spent over 17 years in research, development, quality control and technical troubleshooting worldwide for the group’s entire range of cement types He rose to become a principal scientist, and was awarded the DSc degree of the University of London for his cement research work In 1985 he joined British Petroleum at their Sunbury Research Centre, initially as a senior drilling engineer before becoming a research associate He directed research programmes on oilwell cement and functioned as an internal consultant for all aspects of cement technology for the different BP businesses worldwide Since 1992 John has become more involved with academic research in cement and concrete technology as a visiting professor at the University of Keele, Greenwich and London (Birkbeck College) He acts as a consultant in cement technology, operating internationally Author Biographies xxi Jannie S.J van Deventer completed doctorates in chemical engineering, mineral processing and business economics in South Africa, where he was Head of Chemical Engineering at the University of Stellenbosch In 1995 he became Professor of Mineral and Process Engineering at the University of Melbourne From 2003 to 2007 he served as Dean of Engineering Since 2010 he is an Honorary Professorial Fellow and continues research into chemically activated cement and mineral processing Since 2006 Jannie has been the CEO of Zeobond, which has commercialised low CO2 concrete using activation chemistry He previously commercialised computer vision technology in the mineral industry, and continues to be involved in the commercialisation of metal extraction processes His publication record of more than 700 papers includes more than 300 journal papers, many of which are highly cited He has received many awards for his research in both mineral processing and concrete science, and continues to serve on several editorial boards Thomas Daniel Dyer is a materials scientist working in the field of civil engineering He is senior lecturer within the Discipline of Civil Engineering at the University of Dundee in Scotland and a member of the Concrete Technology Unit at Dundee His research interests centre around the chemistry of cementitious materials, with particular emphasis on their role in controlling the durability of concrete Areas of research have included an examination of the influence of fly ash on the mass transport and chloride binding properties of concrete, the use of pozzolanic materials to control alkali-silica reaction He has published widely in academic journals, contributed towards chapters in books, and written two books: ‘Concrete Durability’ and ‘Biodeterioration of Concrete’ Rodney M Edmeades graduated in Chemistry in 1953 and, following an intensive technical training course, worked in the cement industry (Blue Circle Group) for 11 years Joining Cementation Research in 1964, he was appointed a Director in 1977 in charge of the Materials Technology Section His work at the time encompassed the investigation of cement hydration mechanisms and the interaction of admixtures, together with the development of materials used in civil engineering, concrete repair, ground engineering and mining He co-authored a number of papers and was elected a Member of the Institute of Concrete Technology in 1988 In that year as a result of a company reorganisation he became an Associate Director of Trafalgar House Technology, responsible for Construction Materials, and acted as Senior Consultant to various group units prior to retirement in May 1995 xxii Author Biographies James I Ferrari is an experienced geomaterials scientist with the Materials and Structures department at RSK Environment, where he leads the petrography team He graduated with a degree in Geology from Keele University in 2008 and joined STATS Limited (now part of RSK Environment) in the same year James specialises in the petrographic examination and consultancy of a wide range of geomaterials used in the built environment including aggregates, stone and slate, concrete and other cementitious materials In addition, he has experience in a wide range of physical/chemical testing methods applied to the evaluation of constructions materials James has authored a wide range of unpublished commercial reports addressing subjects including aggregate quality and suitability, AAR assessments of aggregates and concrete, fire-damaged concrete and many other forms of concrete deterioration He is an active member of the Applied Petrography Group (affiliated with the Engineering Group of the Geological Society), and since 2014, has been involved in British Standard Institute committees for the development of aggregate testing standards James is expecting to gain his chartered geologist status in early 2018 Per Fidjestøl graduated from Norwegian Technical University in 1973 with a degree in Civil Engineering He joined Det Norske Veritas working in the area of offshore and marine structures, including cold climate technology His main role, however, concerned concrete technology In 1986 he joined Elkem Materials and has been engaged in a variety of capacities, mainly related to R&D, marketing and technical support in the area of microsilica for concrete Per was a fellow of ACI and a member of several technical and board-appointed committees, including Chairman of the International Activities Committee He has published about 50 technical papers mainly on corrosion and/or microsilica He was a member of CEN groups related to microsilica, and was a member of ASTM C-9 on Concrete and D-18 on Geotechnics Herve Fryda studied material science at Universite Pierre et Marie Curie, Paris, and received a PhD from Ecole Superieur de Physique Chimie Industrielle in Paris in 1995 on the use of calcium aluminates cement for nuclear waste trapping After 18 months at Imperial College, London, he joined the Lafarge group in 1995 to conduct upstream research on calcium aluminates He joined Kerneos in 2000 where he has been in charge to develop new products for different applications (refractory concrete, construction … ) until 2012 From 2012 to 2016 he took the lead of a research group on more fundamental research on calcium aluminates (hydration, mineralogy, bio deterioration …) Since 2016 he is Director of Kerneos Research Center in Vaulx-Milieu, France Author Biographies xxiii Thomas (Tom) Harrison is an independent consultant and Visiting Industrial Professor at the University of Dundee After a period working for contractors in the United Kingdom and then for a small design office in Canada, he joined the Cement & Concrete Association in its Construction Research Department During this time he achieved a PhD on formwork pressures He became the Head of Construction and Technology in 1987 when the C&CA became the British Cement Association and then its standards manager In 1993 he was head-hunted to become the Technical Director of the British Ready-Mixed Concrete Association where he remained until reaching retirement age He was chairman of the European Ready-Mixed Concrete Organisation’s technical and environmental committee for 14 years, chairman of the BSI Concrete committee for 19 years and actively involved in European and International standardization While in the process of reducing his CEN activities, he still convenes two working groups and one task group His other activities including writing publications, acting as an expert witness and being a member of the Board of the Magazine of Concrete Research Arthur Michael Harrisson graduated in geology from the University College of Wales, Aberystwyth in 1974 and worked for a period with the Institute of Geological Sciences, now the British Geological Survey, managing drilling programmes and publishing reports on the assessment of industrial minerals In 1979 he joined Blue Circle Cement’s Research Department, where he began a long standing interest in clinker microscopy During this period he established and managed a scanning electron microscopy laboratory which carried out innovative work on clinker mineralogy and cement hydration mechanisms Since then he has worked with a number of cement manufacturers both in the United Kingdom and in several other countries including New Zealand, Malaysia, Australia, Ireland, South Africa and Spain, either as an employee or as a consultant His work has included five years as plant chemist and a similar period as Chief Chemist for Rugby Cement He has also spent time as a consultant with Mott MacDonald consulting engineers writing specifications for high performance concrete and acting as expert witness He now specialises in the assessment of mineral deposits for use as cement clinker raw materials as well as quality and environmental issues He currently operates a consultancy from a base in North Wales carrying out a range of construction industry related projects, primarily raw materials assessments and clinker microscopy He has published widely over the years and is a regular contributor to the International Cement Review Duncan Herfort is Chief Scientist at Cementir Holding and Aalborg Portland with global responsibilities for R&D, quality and technical services As a geologist and geochemist, with 30 years’ experience in the cement industry, he has developed a special interest in applying high temperature mineralogy and thermodynamics to the challenges faced by the cement industry Additional, longstanding activities and responsibilities include regular lectures for the European Cement Research Academy and the University of Toronto’s course in Cement Chemistry, industrial advisor to Nanocem, member of the Board of Editors for Cement and Concrete Research, Guest Professor at the Chinese Building Materials Academy He was awarded the fourth Klaus Dyckerhoff prize in 2014 xxiv Author Biographies Jason Henry Ideker is an Associate Professor at Oregon State University and Co-Director of the Green Building Materials Laboratory He holds a BS in Civil Engineering from The Georgia Institute of Technology and an MSE and PhD from The University of Texas at Austin Dr Ideker’s main research areas are in service-life of concrete with a focus on early-age behaviour of high performance cementitious materials, mitigation and test methods for alkali-silica reaction and durability of calcium aluminate cements Dr Ideker and his group transformational research where fundamental results are implemented into improved test methods and specification development Dr Ideker is a member of ACI Committees 201, 231 and 236 Ideker is a co-author of ACI 201.2R-16 Guide to Durable Concrete He is a recipient of the ACI Young Member Award for Professional Achievement He is a member of ASTM C01 and C09, and serves on the Executive Board of C09 He chairs ASTM Subcommittee C09.50—Risk Management for Alkali-Aggregate Reactions He is also a member of the RILEM TC258 Avoiding Alkali Aggregate Reaction (AAR) in Concrete—Performance Based Concept Dr Ideker is a three-time recipient of the PCA Education Foundation Fellowship Along with Professor Karen Scrivener their International ‘Corvallis Workshops’ has brought together industry, practitioners and academic researchers to improve concrete performance in three meetings since 2011 Ideker has authored over 80 publications including peer-reviewed journal articles, research reports, conference proceedings and book chapters Martyn Roderick Jones is Professor of Civil Engineering at the University of Dundee, Scotland He is a Charted Civil Engineer and member of the Institution of Civil Engineers He serves on CEN committee TC51/104 WG 12 TG5 and is a Board member of the Construction Scotland Innovation Centre He is an active researcher in the field of cement science and concrete technology and publishes widely His work tackles issues of sustainable concrete construction, durability and performance, with a particular focus on establishing materials appropriate for practical industrial applications Harald Justnes is Chief Scientist at SINTEF Building and Infrastructure, Department of Architecture, Building Materials and Structures He has been with the Foundation for Scientific and Industrial Research (SINTEF) since 1985 His field of interest covers the chemistry of cement, concrete, admixtures and additives (including polymers) from production, through reactivity, to durability He was educated at the Institute of Inorganic Chemistry, Norwegian University of Science and Technology (NTNU), and is now Adjunct Professor in ‘Cement and Concrete Chemistry’ at Institute of Materials Technology, Section for Inorganic Chemistry, NTNU Justnes has been visiting Professor at China Building Materials Academy (CBMA), Beijing, China, and was appointed Honorary Professor at Xian University of Architecture and Technology, Xian, China, in 2007 Related to his contribution to this book, he was award for Outstanding Contributions in the Development of Chemical Admixtures for Use in Concrete presented at the Sixth CANMET/ACI International Conference on Superplasticizers and Other Chemical Admixtures in Concrete, Nice, France, 2000 Justnes has authored or co-authored more than 330 papers in journals and conference proceedings and has been member of the Editorial board of the International Journal Cement and Concrete Composites, Elsevier, since 2003 Author Biographies xxv Siham Kamali-Bernard is graduated in Civil Engineering from the Ecole Nationale des Travaux Publics de l’Etat (ENTPE) in 1998 and from the Ecole Normale Superieure de Cachan (ENS Cachan) in 2003 in France In 1999, she joined the research team of Professor Micheline Moranville-Regourd at the LMT-Cachan to prepare her PhD thesis on the leaching of cementitious materials (experiments and modelling) with the support and the collaboration of Electricity of France (EDF) From the end of 2003 to 2006, she worked with Professor Denis Damidot at the Ecole des Mines de Douai, now Institut Mines Telecom Lille-Douai, on thermodynamical modelling of cementitious systems She is currently Associate Professor at the National Institute of Applied Sciences of Rennes where she continues to develop research on the microstructure characterisation, mechanical and transport properties as well as durability of cementitious materials using both experimental and multiscale modelling approaches She has supervised several PhD thesis and has published about 45 international papers on cementitious materials She is a regular contributor to the International Cement Review John Lay is Product Quality Director for CEMEX UK Cement and Building Products He is a Chartered Chemist and has worked in technical roles for ready mixed concrete, aggregates, asphalt, cement and building products He has been involved in British and European standardization for many years and is a former chairman of the CEN Technical Committee 154 for Aggregates and its BSI mirror committee His professional career began with work on the alkali–silica reactivity of aggregates, progressed through measuring and controlling swelling clays in sands, the thaumasite form of sulphate attack, the increased use of recycled and secondary aggregates, and innovative asphalt mixtures and asphalt/cementitious composites His current interests include the effects of alternative fuels and alternative raw materials in cement manufacture, alkali-activated cements, and the development of lower carbon multi-component cements Robert Lewis was the Technical Marketing Manager at Elkem Silicon Materials He began his career as a field technician in 1978 for Tarmac Topmix, Southern Region in the UK He immediately took on the City and Guilds courses in Concrete Practice and Technology, passing them with distinction and credit In 1986 he moved to Elkem Materials, joining the technical services of concrete operations in the UK, eventually becoming the Technical Marketing Manager In 1999 he was made a Fellow of the Concrete Society, in 2013 a Fellow of the American Concrete Institute and in 2017 a Fellow of the Institute of Concrete Technology In 2017 he was elected to Chair the British Standards Committee B/517/4 dealing with Pozzolans and it was also in that year he was elected as Vice President of the Institute of Concrete Technology and will take over the Presidency in 2019 In August 2018 he joined Ferroglobe PLC as the Technical Marketing Manager for Silica Fume for the European and International (non-US) regions He is the UK expert to the CEN (European Standards) committee for Silica Fume, and has written, co-authored and presented numerous papers on microsilica and its use in concrete He is currently on committees of the American Concrete Institute, including the International Advisory Committee, dealing with Cementitious Grouting and Fire Resistance, and is currently the Chair of ACI committee 234 ‘Silica Fume’ xxvi Author Biographies Donald E Macphee is a Professor of Chemistry at the University of Aberdeen His interest in cement chemistry, and in phase diagrams, began when he joined Professor FP Glasser’s group in 1984 He later took up a position at CSIRO in Australia in 1989, where he led the Cement and Concrete Technology Group at the Division of Building, Construction and Engineering, gaining experience in the application of cement chemistry in concrete technology, before returning to a faculty position at Aberdeen in 1992 He research on cementiteous systems has included phase equilibria studies, novel binders, processing and nondestructive characterisation methodologies, and more recently, cements and concretes as photocatalyst supports He has published over 100 journal and conference papers, is a member of the editorial boards of Cement and Concrete Research and Materiales de Construccio´n and he is a Fellow of the Royal Society of Chemistry (CChem FRSC) Michael J McCarthy is Reader in Civil Engineering in the School of Science and Engineering at the University of Dundee, Scotland, UK, where he also obtained his bachelor and doctoral degrees He has carried out research on a range of topics in the cement and concrete materials, and construction technology areas over the past 25 years Much of this has addressed practical issues and has been in collaboration with industry His work on fly ash in concrete has included the use of material, (i) covering a range of properties to EN 450-1, (ii) following wet storage in stockpiles and lagoons, including processing, (iii) in ternary blends for optimum durability performance, (iv) at high volumes in cement and (v) produced from modern power stations, e.g., using co-combustion or supercritical technology He has also investigated fly ash in cementitious grouts and in lime stabilisation of soil, for reducing expansive effects caused by sulfate He has given several invited lectures on his research and is the author of more than 100 publications Sidney Mindess is an Emeritus Professor in the Department of Civil Engineering, University of British Columbia, Vancouver, Canada, where he taught from 1969 till his retirement in 2005 He is the author or co-author of more than 300 publications on civil engineering materials, primarily dealing with cement and concrete He is a fellow of the American Ceramic Society, the Canadian Society for Civil Engineering, the American Concrete Institute, and RILEM He has lectured on cement and concrete worldwide, and was at various times a Marine Technology Visiting Fellow at Imperial College, United Kingdom, and a Lady Davis Fellow at the Technion, Israel He was also one of the original researchers in the Canadian Network of Centres of Excellence dealing with high performance concrete His current research interests include fibre reinforced concrete, durability of concrete, sustainability of cement and concrete, and service life prediction Constitution and Specification of Portland Cement 141 If either blastfurnace slags or steel slags are quenched as they are removed from the furnace a glassy product will result This is commonly carried out for blastfurnace slag which then has cementitious properties when activated For steel slags this is not normally done because the higher viscosity can easily trap cooling water with the potential for explosions The composition of granulated blastfurnace slag is similar to clinker in that four main oxides are SiO2, FeO, Al2O3 and CaO The proportions are however, different and, more significantly, the oxides are not arranged in crystalline form known to be reactive with water, but are predominantly present as glass, a disordered arrangement of oxides Glass has its own special properties A glass is a disordered arrangement of molecules which have not had time to form crystals as they cooled from the random arrangement of a liquid The glassy phase of blastfurnace slag has a composition different to either of the main clinker compounds but, because of the reactive nature of the glass, is able to combine with lime released from cement to form calcium silicate hydrates and to perform the function of a binder in concrete The use of blastfurnace slag in concrete is most commonly as a latent hydraulic cement Its reactivity depends predominantly on two properties, its chemical composition and its glass content Granulation of the slag as it emerges from the blastfurnace is achieved by quenching with high pressure jets of water, which produces a sand-like material of which some 95% can be glassy The chemistry is classified on the basis of the ratios of the main oxides such as CaO/SiO2 or (CaO + MgO + Al2O3)/SiO2 In general higher values for this ratio are considered to be more reactive for a similar proportion of glass The term ‘latent hydraulic’ means that adding pure water to the slag will not result in the formation of hydrated calcium silicate minerals as in the case of Portland cement However, all that is required is that the alkalinity of the water is raised to create an environment in which the slag will begin to dissolve into the water to be reprecipitated as hydrated phases This means that slag can perform without Portland cement, but the overall composition of the slag presents some problems to which the most satisfactory solution is to combine it with Portland cement clinker Fig 4.40 shows the composition of a typical blastfurnace slag in relation to the ternary phase diagram CaO–Al2O3–SiO2 The use of phase diagrams is discussed in Chapter but in essence this diagram can be visualised as being viewed from above a solidifying liquid The viewpoint is at a very high temperature at which everything is liquid The lines below are valleys between the white highlands As a liquid of any composition in the triangle descends in temperature it hits the ‘solidus’ at which point some mineral crystallises out The remaining liquid is deficient in whatever crystallised out and moves downhill within the triangle to a new composition As it continues to cool and change composition it hits the valleys and moves along them Eventually a suite of minerals has been formed as the whole material becomes solid The blastfurnace slag is effectively a frozen liquid and so sits above the solidus despite being of low temperature From the relationship of the slag composition to that of C2S and C3S it is evident that the slag is deficient in CaO compared to these minerals The ratio of CaO to SiO2 in C-S-H, the hydrated phase which is responsible for the strength of hydrated cement, is close to 2:1, that is, close to that of C2S in Fig 4.40 Most Portland cements, however, contain over 50% C3S, mainly because these crystals react more quickly than C2S and give faster strength development They also produce surplus CaO hydrate known as calcium hydroxide Thus the addition of slag to Portland cement clinker, as well as raising the alkalinity of the mixing water and encouraging slag to hydrate, provides the surplus calcium hydroxide which is needed by the slag to produce sufficient C-S-H to make a significant contribution to cement strength FIG 4.40 Composition of blastfurnace slag 142 Lea’s Chemistry of Cement and Concrete 4.12.3 Cement Hydration with Fly Ash and Blastfurnace Slag 4.12.3.1 Reaction of Fly Ash With Portland Cement When examined as a polished section in a scanning electron microscope (SEM) after 28 days curing irregular shaped clinker grains are observed with white centres still unreacted Light grey hydration rims of C-S-H can be seen around the grains Unreacted fly ash grains are round particles as seen in Fig 4.41 At this stage very little hydration of the fly ash will be seen However, some reaction of the ash will have occurred and will have affected the composition of the rims surrounding the cement clinker grains During examination in an SEM equipped with an energy dispersive X-ray analysis detector it is possible to hold the electron beam steady over a particular point on the specimen If this is done over the hydration rims of the clinker grains the excited X-rays which are generated can be collected and the chemistry of a very small area of hydration product determined Fig 4.42 shows the result of taking a number of such analyses and as described in Section 4.12.1, plotting the ratio of silicon to calcium against the ratio of aluminium to calcium in a cement paste with no fly ash The cluster of points around 0.5 FIG 4.41 Rounded unreacted fly ash particles 0.70 0.60 AFm Al/Ca 0.50 0.40 Ettringite AFm + C-S-H 0.30 0.20 0.10 C-S-H CH/ 0.00 0.00 0.20 0.40 0.60 Si/Ca FIG 4.42 Atom ratios in a plain Portland cement paste at 28 days 0.80 Constitution and Specification of Portland Cement 143 0.7 0.6 AFm 0.5 Al/Ca 0.4 Ettringite 0.3 AFm + C-S-H 0.2 C-S-H 0.1 CH 0 0.2 0.4 0.6 0.8 Si/Ca FIG 4.43 Atom ratios in paste with 25% fly ash at 28 days on the x-axis indicates a C:S ratio of approximately 2:1 It is evident that the composition is a little variable and also that a small proportion of aluminium is also present, with the cluster of points collecting at about 0.05 on the y-axis The positions of the other cement hydrated phases, CH, AFm and AFt are also indicated In Fig 4.43 is shown the result of the same exercise carried out on a cement paste containing 25% fly ash The C-S-H analysed is still that in the reaction rims surrounding the clinker grains The composition of the C-S-H has moved towards a more siliceous position on the x-axis and to a slightly higher aluminium content on the y-axis Evidently the different C:S ratio of the C-S-H in the presence of the ash alters the amount of ash which can be combined with the available CH The above describes in simple terms the basis of the reactions between cement and fly ash In practice C-S-H is not a crystalline material with a fixed chemical composition and the presence of fly ash can alter the composition of the various components in the cement paste The reaction products of Portland cement and water are not confined to C-S-H As described above there is also the production of calcium hydroxide and the C3A part of cement reacts with gypsum added at the cement mill to form compounds known as AFt (indicating the presence of aluminium oxide and iron oxide, combined with three radicals of SO3) and AFm containing a single radical of SO3 4.12.3.2 Reaction of ggbs With Portland Cement Fig 4.44 shows the results of a similar exercise, this time with a cement paste containing 50% replacement of Portland cement with ggbs The composition of the C-S-H in this case has changed to an even greater extent with higher silica and higher alumina contents than either the plain Portland cement paste or the fly ash blend Harrisson et al.77 describe the presence of additional phases which include a hydrotalcite-type phase As discussed above the chemistry of blastfurnace slags is deficient in CaO relative to cement and the maximum hydration of the glassy phase requires the addition of further lime, most conveniently provided by a high Lime Saturation Factor Portland cement The chemistry of blastfurnace slags can vary significantly depending of the particular iron smelting plant, the composition of the raw materials used for steel production and also the nature of the refractory in the furnace The composition of the slag has a number of impacts on the quality of the ground product in cement In general the reactivity with water when activated is related to the basicity which can be measured simply as the ratio of CaO to SiO2 or by other ratios such as (CaO + MgO)/SiO2 or (CaO + MgO + Al2O3)/SiO2 The quantity of Al2O3 also has an influence, higher alumina contents producing better strengths However, as discussed below there are other factors which must be taken into account in relation to Al2O3 content of slag The other major influence is the glass content of the slag, the faster cooling of the molten slag giving a glassier, more reactive product Fig 4.45 shows a relationship of the basicity measurement CaO/SiO2 of some German slags with the compressive strength of mortars tested with a standard Portland cement.78 The improvement with increased basicity is evident 144 Lea’s Chemistry of Cement and Concrete 0.70 0.60 0.50 AFm Al/Ca 0.40 Ettringite 0.30 C-S-H 0.20 0.10 CH 0.00 0.00 0.20 0.40 0.80 0.60 1.00 1.20 Si/Ca FIG 4.44 Atom ratios in paste with 50% ggbs at 28 days 55 Compressive strength (N/mm2) 50 45 40 35 30 25 20 15 10 day day Basicity CaO/SiO2 28 day 1.06 1.16 91 day 1.27 FIG 4.45 Influence of slag basicity (CaO/SiO2) on compressive strength, EN 197 mortar prisms Fig 4.46 shows the relationship between strength of mortar prisms and a range of levels of TiO2 in slags with the same CaO/SiO2 The fall in strength with increasing TiO2 is the most marked at the earlier ages and continued tests to 91 days suggested that the strengths would by then be recovered TiO2 is added to the blastfurnace, often as the mineral ilmenite, with the burden and works into the refractory where it improves the wear properties and therefore the increases the time before relining is necessary This is normally carried out towards the end of a campaign so the presence of TiO2 in the slag is usually only of concern to quality of ggbs properties at these times Fig 4.47 shows an example of the increased Al2O3 content of a ggbs being associated with higher strengths from a steel plant in the Ruhr region of Germany The CaO to SiO2 ratio of each ggbs was the same and so was the TiO2 content at 0.6% Although the higher Al2O3 content would appear to be beneficial it has implications for the durability of concrete made using the ggbs Constitution and Specification of Portland Cement 145 50 Compressive strength (N/mm2) 45 40 35 30 25 20 15 10 0 0.5 1.5 % TiO2 in GGBS day day 2.5 28 day FIG 4.46 Influence of TiO2 content of slag on compressive strength, EN 197 mortar prisms 55 Compressive strength (N/mm2) 50 45 40 35 30 25 20 15 10 day day % Al2O3 28 day 10.8% 91 day 14.4% FIG 4.47 Influence of the Al2O3 content of GGBS on compressive strength The potential issue when using ggbs with a high Al2O3 content relates to the sulfate resisting properties of slag/cement blends In general the presence of slag is regarded as beneficial because sulfate attack is caused by the reaction of the calcium aluminate hydrate phase from cement hydration and calcium hydroxide reacting with sulfate and water and forming expansive ettringite, (a calcium aluminate sulfate hydrate) By replacing cement with ggbs the quantity of aluminate phase in the cement is restricted and the sulfate resistance is achieved This, however, only applies to a certain limit of Al2O3 in ggbs.79 When the Al2O3 content of a blastfurnace slag is over 14%, UK concrete codes80 require that the cement used in combination with the ggbs should contain no more than 10% C3A as calculated by the Bogue calculation in order to maintain sulfate resistance While many cements conform routinely to this restriction it is not universally the case 146 Lea’s Chemistry of Cement and Concrete 4.13 SPECIFICATION OF PORTLAND CEMENT While Portland cement is essentially much the same around the world, different countries use different standards to regulate the quality of cement used These standards are used as the specifications for cement properties for the mixing of mortars or concrete and the approach adopted in modern standards to specifying what characteristics of Portland cement must be present varies from prescriptive, defining carefully what should be the chemical and physical properties of the cement, to performance based, relying on satisfactory performance in specified tests to determine its suitability for use The various specifications for cements in different countries not always use the same terminology with regard to Portland cement The European standard EN 197-1:2011 is titled ‘Composition, specifications and conformity criteria for common cements’.1 The clinker used to make these cements is referred to as Portland cement clinker and two cement types containing predominantly this clinker are called Portland cement (CEM I) and Portland-composite cements (CEM II), but the many other combinations not contain the designation ‘Portland’ The American standard ASTM C150/C150M-15 ‘Standard Specification for Portland Cement’81 refers only to cements containing Portland cement clinker, a sulfate source and up to 5% limestone as main constituents, cements containing other materials are in separate documents In Australia AS 3972-2010 concerns ‘General purpose and blended cements’.82 Portland cement is defined as a homogeneous product made by grinding together Portland cement clinker and calcium sulfate This Portland cement is then considered as a component of other cements which are produced by adding further constituents Historically Portland cement has been specified in terms of its chemistry and physical properties The chemical requirements relate to what is required in the product, such as C3S, C2S, C3A etc and what is not to be present above certain limits such as sulfate, magnesium oxide or alkalis In the case of cement for particular applications further restrictions may be specified For example, for sulfate resistance the amount of C3A as determined by the Bogue calculation (see Section 4.3) will be limited The physical requirements relate to fineness, setting times, soundness and strength An alternative approach is to rely on the performance of the cement in practice regardless of its chemical or physical make up There are evidently dangers inherent in this approach, for example the testing would need to cover every eventuality and use of the cement Most of the standards not go to one extreme or the other but use a combination of prescriptive testing of chemistry and fineness together with performance requirements in carefully controlled testing regimes As described below, the American approach is to offer alternative standards, one wholly performance based and the alternative a mixture of performance and prescription The three examples below, from Europe, Australia and America illustrate various degrees of prescription or the importance of performance in attitudes to cement acceptability Section 4.11.1 considers the properties and applications relevant to the main types of cement specified in the European standards, which adopt an essentially prescriptive approach 4.13.1 European Cement Standards Portland cement specification in Europe is governed by EN 197-1, of which the latest revision to date is EN 197-1 2011.1 There are five main types of cement as set out in Table 4.27 Within these types the standard defines 27 distinct common cements, sulfate resisting common cements as well as distinct low early strength blastfurnace cements and sulfate resisting low early strength blastfurnace cements In common with the other standards EN 197 defines the various materials which may be used in the cements The material common to all the cements covered by the standard is Portland cement clinker which is defined as consisting of at least twothirds by mass of calcium silicates (3CaOÁSiO2 + 2CaOÁSiO2) the remainder consisting of aluminium and iron-containing TABLE 4.27 The Main Types of Cement Defined in EN 197-1 Main Types CEM I CEM II CEM III CEM IV CEM V Clinker (%) Portland cement Portland-composite cement Blastfurnace cement Pozzolanic cement Composite cement 95–100 65–94 5–64 45–89 20–64 Constitution and Specification of Portland Cement 147 TABLE 4.28 Identification of the Main Constituents of European Cements, Other Than Portland Cement Clinker Notation Designation S D P Q V w T L M Granulated blastfurnace slag Silica fume Pozzolana, natural Pozzolana, industrial Fly ash, siliceous Fly ash, calcareous Burnt shale Limestone Composite, two or more of the above clinker phases and other compounds and with the ratio CaO/SiO2 being not less than 2.0 The maximum permitted MgO level is 5% in Portland cement clinker There are extra restrictions on the quantity of tricalcium aluminate to be present in the clinker if it is used for sulfate resisting Portland cement (CEM I) or sulfate resisting pozzolanic cements (CEM IV) The five main types relate to the quantity of Portland cement clinker present and the nature of the additional materials being used The range of materials permitted and their designation in the codes in EN 197 are listed in Table 4.28 As well as being specified by the composition of the cements in terms of the constituent materials, EN 197 has mechanical, physical, chemical and durability requirements The mechanical requirements refer to compressive strengths which are specified in EN 197-1 and are measured according to BS EN 196-1: 2016.83 Each of the cements can be obtained in three strength classes, being the characteristic compressive strength after 28 days hydration in Megapascals (32.5, 42.5 and 52.5), which may be high early strength (R) or ordinary (N) A further category of low (L) applies to CEM III cements Crushing strength is measured using mortar prisms, 40 Â 40 Â 160 mm in dimension, in accordance with the specification set out in BS EN 196-1: 2016 The physical requirements consist of initial setting time, soundness and heat of hydration The permitted initial setting time (BS EN 196-3:2005 + A1:2008)84 is not less than 60 in general, and not less than 45 for cement strength classes 52.5N and 52.5R The expansion determined in the test for unsoundness should not exceed 10 mm The heat of hydration of low heat common cements must be at or below the characteristic value of 270 J/g, determined in accordance with either EN 196-885 at days or in accordance with EN 196-986 at 41 h Low heat common cements are identified by the notation ‘LH’ The chemical requirements applying to the whole cement as opposed to its constituents cover loss on ignition ( 5.0%), insoluble residue ( 5.0%), sulfate content as SO3 ( 3.5% for 32.5 N, 32.5 R and 42.5 N and 4.0 % for 42.5 R, 52.5 N and 52.5 R) and chloride ( 0.10%) For sulfate resisting cements the SO3 limits are lower at 3.0% for the lower strength classes and 3.5% for the higher strength cements Other exceptions are for cements containing burnt shale at greater than 20%, which are allowed up to 4.5% SO3 The durability requirements in EN 197 refer to sulfate resistance of the sulfate resisting cements in which, apart from the SO3 restrictions above, the C3A content is specified for different classes of the cement and the cement must pass a pozzolanicity test as specified in EN 196-5.87 4.13.1.1 EN 197 CEM I CEM I is ground cement clinker with a proportion of a gypsum and anhydrite mix or an alternative sulfate source (the amount limited by the SO3 content of the cement) and is allowed to contain up to 5% of a Minor Additional Constituent (MAC) A MAC is defined in EN 197 as, ‘Specially selected, inorganic natural mineral materials, inorganic mineral materials derived from the clinker process or constituents as specified in 5.2 unless they are included as main constituents in the cement’ Section 5.2 of the Standard defined the main constituents allowable as in Table 4.28 The MAC may therefore take many possible forms but is most commonly either ground limestone or a combination of this with cement kiln dust (CKD) from the final filter of the kiln or bypass dust both of which qualify as inorganic materials derived from the clinker process Within the definition of CEM I is white cement, manufactured from especially pure chalk or limestone, with china clay (low in iron) and white sand as sources of silica Such an unreactive mix requires power-consuming sand grinding, and very high clinkering temperatures ($1600°C) In terms of properties, CEM I cement produces the best combination of early (2 days) and late (28 days) strengths with a typical setting time of up to h The colour of the product varies depending primarily on the quantity of iron present in the cement clinker 148 Lea’s Chemistry of Cement and Concrete In terms of workability and flowability, CEM I is susceptible to false set if the mill temperatures have been high and a high proportion of gypsum to anhydrite has been used in the mill Water demand is dependent on the fineness and the sulfate type in the finished cement In terms of durability, CEM I is susceptible to sulfate attack unless the C3A component is kept within the limits set out for sulfate resisting cement In the United Kingdom it is considered susceptible to alkali aggregate reaction with reactive aggregates if the alkali content is sufficiently high to produce more than the quantity of alkali per cubic metre of concrete prescribed in Concrete Society report TR30,88 BRE IP1/0289 and BRE Digest 33090 which is 3.5 kg/m3 for most cements and 3.0 kg/m3 for high alkali cements (Na2O equivalent > 0.75%) It is generally susceptible to chloride ion penetration, with consequent potential for corrosion of reinforcement steel 4.13.1.2 EN 197 CEM II CEM II comprises ground cement clinker together with a sulfate source and a MAC if required with the addition, either through intergrinding or blending, of other main constituents which are defined as blastfurnace slag, silica fume, pozzolana (natural or calcined) fly ash (siliceous or calcareous), burnt shale or limestone The limestone is also subdivided into two qualities depending on the total organic carbon (TOC) content The lower quality may contain up to 0.5% by mass and the higher quality up to 0.2% Each of the main constituents may also be present in two ranges of proportions in the cement, for example fly ash present in the proportions between 6% and 20% has one designation and between 21% and 35% will have a different designation As an example a cement with 25% siliceous fly ash has the designation CEM II/B-V The ‘B’ refers to the proportion of fly ash present and the ‘V’ informs that the addition to clinker was siliceous fly ash In total 19 different constituent combinations are defined by composition under the term CEM II Fly ash is the most commonly used second component of CEM II cements and the effects of the fly ash addition can be summarised as follows: The early strengths and 28 day strengths for similar cement contents to a CEM I cement from the same clinker source are reduced Cementitious contents in concrete therefore need to be higher for similar performance to CEM I concrete UK cement CEM I 28 day strengths tested according to EN 196-1: 2005 average about 60 MPa With CEM II this drops by about 10 MPa for the same mill throughput Customers also lose the flexibility to add ash to the cement to moderate the strengths To some extent the strength reduction is offset in practice by a reduction in water demand for similar workability which is not seen in EN 196 testing because these tests are carried out at constant water content This is one of the chief advantages of the use of fly ash and it means that workability of fly ash CEM II is generally good and the water to cement ratio can be reduced with consequent partial recovery of concrete strengths Setting times tend to be longer than for CEM I by about 20 CEM II cement is usually darker in colour than CEM I due to the carbon content of the fly ash measured as the loss on ignition (LOI) however, with some methods of fly ash recovery from lagoons, the beneficiation processes used to maintain the cementitious qualities remove most of the carbon and the fly ash may therefore be lighter than the cement The presence of about 25% fly ash gives advantages in durability for sulfate attack, chloride ion penetration, alkali silica reaction and carbonation These benefits are partly due to lower water to cement ratios which reduce the permeability of the cement paste within concrete and partly due to the chemical effect of binding penetrating ions Resistance to alkali silica reaction is due to the ash providing a source of reactive silica which can react with alkalis before the concrete has matured This effectively moves a concrete’s soluble silica content away from the pessimum value91 which brings on degradation of the concrete The prerequisite to obtaining the advantages above is that proper curing of the concrete is essential to reap the benefits Poorly cured CEM II/B-V concrete, especially with ambient temperatures above 25°C, will not mature effectively and could easily suffer surface degradation and loss of reinforcement cover 4.13.1.3 EN 197 CEM III CEM III compositions are limited to mixtures, interground or blended, of cement clinker with blastfurnace slag Three ranges of blastfurnace slag content are specified, between 26% and 65% designated ‘A’, between 66% and 80% designated ‘B’ and between 81% and 95% designated ‘C’ The characteristics of CEM III will vary depending on the method of manufacture, for example clinker is easier to mill than blastfurnace slag so slag interground with clinker tends to lead to undergrinding of the slag and overgrinding of the clinker component for a given degree of fineness A result of this is that water demand is increased due to the extra fineness of slag and its poor shape for workability characteristics and strengths are lower than would be for a CEM I Through separate grinding it is possible to optimise both the slag fineness and the clinker fineness to produce a mix which will give adequate 28 day strengths and good workability 50% replacement of CEM I with suitably graded blastfurnace slag produces a drop in day strength but usually recovery by 28 days for a similar mix to CEM I Constitution and Specification of Portland Cement 149 Because of the fineness of the slag component and (if interground) the clinker component, bleeding can be a problem giving difficulties in pumping concrete Setting times will typically be about h for initial set for a blended product When interground there is a high probability of shorter setting times if the sulfate source contains a high ratio of gypsum to anhydrite due to the higher temperatures generated in the mill CEM III cements are lighter in colour than CEM I or most CEM II/B-V cements Blastfurnace slag provides durability benefits in all respects Permeability is reduced, thus reducing carbonation rates and chloride diffusion, the potential for sulfate attack is reduced by diluting the proportion of C3A available for attack and alkali levels in the cement are reduced minimising the possibility of alkali silica reaction 4.13.1.4 EN 197 CEM IV CEM IV is specifically a pozzolanic cement; comprising Portland cement and higher proportions of pozzolana than in a CEM II cement This provides added resistance to sulfate attack and reduces the heat of hydration in concrete 4.13.1.5 EN 197 CEM V CEM V is a composite cement; comprising Portland cement and combinations of blastfurnace slag and pozzolana or fly ash This can be beneficial where more than one type of potential attack on concrete is present such as sulfate attack and chloride attack combined with a need to be pumpable and low heat and the various properties of the components can be combined 4.13.2 Australian Cement Standards In contrast to the quite prescriptive European standard, the Australian standard for general purpose and blended cements, AS 3972,82 defines Portland and blended cements in terms of their performance characteristics The Australian approach is that as the raw materials used to produce cements can vary widely between localities, the chemical composition of cements can also vary quite widely However, through knowledge and experience of the use of the materials it is possible to produce cements from different localities which have similar physical characteristics With this as a philosophy, AS 3972 only specifies restrictions on chemical composition which are necessary to ensure satisfactory performance, these are upper limits on the MgO and SO3 contents to guard against excessive long-term volumetric expansion of the hydrated cement paste and an upper limit on chloride content to protect steel reinforcement in concrete AS 3972-2010 allows up to 7.5% of mineral additions in a General Purpose (Type GP) cement, higher than either the European or the American standards allow for the equivalent cement type Mineral additions are defined as limestone, fly ash or ground granulated iron blastfurnace slag or combinations of these materials There is also permission to incorporate a proportion of minor additional constituents which comprise specially selected inorganic natural mineral materials or inorganic mineral materials derived from the clinker production process, essentially final filter dust or bypass dust Of the permitted 7.5% mineral additions up to 5% may be minor additional constituents The cements covered by AS 3972 are summarised in Table 4.29 There are three general purpose cements and four specialised cements Of the general purpose cements GP contains just Portland cement as defined in AS 3972 plus up to 7.5% mineral additions (5% of which may be minor additional constituents) General purpose Limestone cement (Type GL) contains Portland cement with the addition at the discretion of the manufacturer of 8%–20% limestone alone or in combination with minor additional constituents to a maximum of 5% General purpose Blended cement (Type GB) contains greater than TABLE 4.29 Types of Cement Covered by AS 3972 Designation Characteristics Type GP—general purpose cement Cement containing Portland cement clinker, calcium sulfate and mineral additions up to 7.5% of which 5% may be minor additional constituents Cement containing Portland cement clinker, calcium sulfate, limestone between and 20% and minor additional constituents up to 5% Cement containing Type GP cement plus greater than 7.5% fly ash or slag or up to 10% amorphous silica Type GL—general purpose limestone cement Type GB—general purpose blended cement Type HE—high early strength cement Type LH—low heat cement Type SR—sulfate resisting cement Type SL—shrinkage limited cement General purpose or blended cement fulfilling the performance requirements for high early strength General purpose or blended cement fulfilling the performance requirements for low heat development General purpose or blended cement fulfilling the performance requirements for sulfate resistance General purpose or blended cement fulfilling the performance requirements low shrinkage 150 Lea’s Chemistry of Cement and Concrete 7.5% of fly ash or ground granulated iron blastfurnace slag or up to 10% amorphous silica These very broad requirements cover the range of cements based on Portland cement clinker in the Australian standard The specialised cements comprise any of these types which fulfil more stringent performance requirements and are classed as HE (high early strength), LH (low heat), SR (sulfate resisting) and SL (shrinkage limited) The performance requirements for all the cements are based on five key performance parameters Soundness and strength are requirements for all cements then temperature rise/heat of hydration, shrinkage and sulfate resistance which are specific requirements for special purpose cements The chemical requirements are limited to restricting MgO in cement clinker to less than 4.5%, having a maximum chlorine content of 0.1% in all cements and a maximum of 3.5% SO3 in all cements 4.13.3 American Cement Standards In the United States ASTM C1157/C1157M-1192 is a performance specification for hydraulic cement The performance specification places no restrictions on the composition of the cement or its constituents but classifies cements based on specific requirements for general use, high early strength, resistance to sulfate attack and heat of hydration An alternative ASTM route for specification of cementitious materials relates to Portland cement in ASTM C150/ C150M-1581 and blended cements are covered in ASTM C595-15.93 These standards contain both performance and prescriptive elements In ASTM C150 five main types of Portland cement are defined Types, I, II and III are subdivided to give IA, IIA and IIIA, making eight A further subdivision of II and IIA was made in the 2015 edition to give II(MH) and II(MH)A Table 4.30 describes their specified uses The chemical specifications for these types are set out in Table 4.31 The American Standards make extensive use of the chemical composition of cements and set out the Bogue calculation for compound content in great detail (ASTM C 150/C150M-15) TABLE 4.30 Types of Cement in ASTM C150/C150M-15 Type I Type IA Type II Type IIA Type II(MH) Type II(MH)A Type III Type IIIA Type IV Type V For use when the special properties specified for any other type are not required Air entraining cement for the same uses as Type I, where air entrainment is desired For general use, more especially when moderate sulfate resistance is desired Air entraining cement for the same uses as Type II, where air entrainment is desired For general use, more especially when moderate heat of hydration and moderate sulfate resistance is required Air-entraining cement for the same uses as Type II(MH), where air-entrainment is desired For use when high early strength is desired Air entraining cement for the same uses as Type III, where air entrainment is desired For use when a low heat of hydration is desired For use when high sulfate resistance is desired TABLE 4.31 Chemical Specifications for Portland Cements, ASTM C 150/C150M-15 Cement Type Al2O3 maximum (%) Fe2O3 maximum (%) MgO maximum (%) SO3 maximum (%) when C3A is 8% or less SO3 maximum (%) when C3A is >8% Loss on ignition (%) Insoluble residue (%) C3S maximum (%) C2S minimum (%) C3A maximum (%) (C3A + C4AF) maximum or solid solution (C4AF + C2F) maximum, whichever is appropriate (%) I and IA II and IIA II(MH) and II (MH)A III and III A IV V — — 6.0 3.0 3.5 3.0 0.75 — — — — 6.0 6.0 6.0 3.0 — 3.0 0.75 — — — 6.0 6.0 6.0 3.0 — 3.0 0.75 — — — — 6.0 3.5 4.5 3.0 0.75 — — 15 — — 6.5 6.0 2.3 — 2.5 0.75 35 40 — — — 6.0 2.3 — 3.0 0.75 — — 25 — Constitution and Specification of Portland Cement 151 In addition, there are ASTM methods (ASTM C 265-0894) for determining the amount of water-soluble sulfur trioxide in a cement paste at appropriate times after mixing, and for the approximation of the optimum SO3 content for highest strength (ASTM C563-1595) Neither of these tests is a specification requirement The physical tests relating to these cement types concern air content, fineness, expansion, strength and setting times The blended cements covered by ASTM C 595 are in five primary classes as in Table 4.32: As well as specification by the National body, an additional standard is produced in America by the American Petroleum Institute (API) concerning the use of cements in oil wells API specification 10A96 defines classes of cement suitable for various conditions, classes A, B and C are similar to cements defined in ASTM C150, while classes G and H contain more specialised performance requirements These cements are discussed further in Chapter 14 4.13.4 Comparison of Equivalent Cements Of the many types of cement described in the three standards which concern Portland cement with a minor additional constituent but no addition of other supplementary materials, Table 4.33 gives a comparison of four One is from AS 3972, one from ASTM 150 and two from EN 197, which contains a number of overlaps in requirements for different strength grades 4.13.5 Other Cementitious Constituents All of the above country standards allow for the use of other materials in cement whether in the main standard in the case of EN 197 and AS 3972 or in a separate standard as in ASTM C595 There is also always the opportunity for concrete producers to add these other materials, most commonly fly ash, ground granulated blastfurnace slag or amorphous silica at the concrete plant in combination with Portland cement In each case the additions are also specified individually TABLE 4.32 TABLE 4.33 Types of Blended Cements in ASTM C595 Type Blended Ingredients Type IP and Type P Portland-pozzolan cement Type IS Portland blastfurnace slag cement Type I(SM) Slag-modified Portland cement Type S Slag cement 15%–40% by weight of pozzolan (fly ash) 25%–70% by weight of blastfurnace slag 0%–25% by weight of blastfurnace slag (modified) 70%–100% by weight of blastfurnace slag Comparison of the Specified Requirements for Cements From Three Standards Property Units Type GP (AS 3972) Mineral addition Minor additional constituents Initial setting time Final setting time Soundness MgO Chloride ion content SO3 content % % h mm % % % 7.5 max % of mineral addition maximum !45