ICOLD Bulletin **: The Specification and Quality Control of Concrete for Dams I C O L D COMMITTEE ON CONCRETE DAMS THE SPECIFICATION AND QUALITY CONTROL OF CONCRETE FOR DAMS MARCH 2006 Revision 7.2 March 15, 2006 ICOLD Bulletin **: The Specification and Quality Control of Concrete for Dams AVERTISSEMENT – EXONÉRATION DE RESPONSABILITÉ : Les informations, analyses et conclusions contenues dans cet ouvrage n'ont pas force de Loi et ne doivent pas être considérées comme un substitut aux réglementations officielles imposées par la Loi. Elles sont uniquement destinées à un public de Professionnels Avertis, seuls aptes à en apprécier et à en déterminer la valeur et la portée et à en appliquer avec précision les recommandations à chaque cas particulier. Malgré tout le soin apporté à la rédaction de cet ouvrage, compte tenu de l'évolution des techniques et de la science, nous ne pouvons en garantir l'exhaustivité. Nous déclinons expressément toute responsabilité quant à l'interprétation et l'application éventuelles (y compris les dommages éventuels en résultant ou liés) du contenu de cet ouvrage. En poursuivant la lecture de cet ouvrage, vous acceptez de façon expresse cette condition. NOTICE – DISCLAIMER : The information, analyses and conclusions in this document have no legal force and must not be considered as substituting for legally-enforceable official regulations. They are intended for the use of experienced professionals who are alone equipped to judge their pertinence and applicability and to apply accurately the recommendations to any particular case. This document has been drafted with the greatest care but, in view of the pace of change in science and technology, we cannot guarantee that it covers all aspects of the topics discussed. We decline all responsibility whatsoever for how the information herein is interpreted and used and will accept no liability for any loss or damage arising therefrom. Do not read on unless you accept this disclaimer without reservation. Revision 7.2 March 15, 2006 ICOLD Bulletin **: The Specification and Quality Control of Concrete for Dams COMMITTEE ON CONCRETE DAMS COMITÉ DES BARRAGES EN BÉTON * (1997-2006) Chairman/Président Canada/Canada/ USA/Etats-Unis R.G. Charlwood (since 1997) Vice Chairman/Vice Président France/France J. Launay (since 1997) Members/Membres Australia/Australie M. Pegg (to 1996) B. Forbes (since 1997) Austria/Autriche H. Ludescher (to 1995) H. Huber (since 1996) W Pichler (since 2001) Brazil/Brésil F.R. Andriolo (1996-2001) J. Marques Filho (since 2002) Canada/Canada R. Charlwood (since 1995) China/Chine Shen Chonggang (to 1998) Jia Jinsheng (since 1999) Croatia/Croatie V. Ukrainczyk France/France J. Launay (to 1999) M. Guerinet (since 2000) Great Britain/Grande-Bretagne M.R.H. Dunstan India/Inde B.J. Parmar Iran/Iran M.E. Omran (to 1997) A.A. Ramazanianpour (since 1998) Italy/Italie M. Berra Japan/Japon S. Nagataki (to 1997) O. Arai (1998-2002) Revision 7.2 March 15, 2006 ICOLD Bulletin **: The Specification and Quality Control of Concrete for Dams T. Uesaka (since 2002) Norway/Norvège O.J. Berthelsen Portugal/Portugal A. Camelo Russia/Russie A.D. Osipov (to 1999) G. Kostyrya (since 2000) South Africa/Afrique du Sud J. Kroon (to 2004) J. Geringer (since 2005) Spain/Espagne J.M. Gaztanaga (to 1998) J. Buil Sanz (since 1999) Sweden/Suède J. Alemo Switzerland/Suisse H. Kreuzer (since 1999) USA/Etats-Unis V. Zipparro (1998-2000) R.G Charlwood (since 2001) Revision 7.2 March 15, 2006 ICOLD Bulletin **: The Specification and Quality Control of Concrete for Dams ACKNOWLEDGEMENTS This Bulletin was drafted under the auspices of the ICOLD Committee for Concrete Dams and the Chairmanship of R.G. Charlwood (Canada/USA). The lead author of the Bulletin was O.J. Berthelsen (Norway). The first draft of the Bulletin in its current form was assembled by O.J. Berthelsen utilising a previous draft by J.M. Gaztanaga (Spain) in 2000. Contributions and reviews were provided by B. Forbes (Australia), H. Kreuzer (Switzerland), B. J. Parmar (India), Malcolm Dunstan (United Kingdom) and J. Launay (France). The case histories were provided by B. J. Parmar (India) for Sardar Sarovar, Bruce Bennett and James Stiady (United States) for Olivenhain Dam), and A. Camelo (Portugal) for Alqueva Dam. Revision 7.2 March 15, 2006 ICOLD Bulletin **: The Specification and Quality Control of Concrete for Dams FOREWORD This Bulletin on the 'The Specification and Quality Control of Concrete for Dams' follows more than two decades of advances in the construction of concrete dams. The purpose of this Bulletin is to make available a summary of current practice in the specification and quality control of concrete for dams. This Bulletin supersedes ICOLD Bulletin Nº47 'Quality Control of Concrete' published in 1983. In 1991, the International Commission on Large Dams (ICOLD) directed that its technical Committee on Concrete for Dams, then under the Chairmanship of J.R. Graham (USA), undertake the preparation of an update of the existing Bulletin. A sub-Committee of the ICOLD Committee on Concrete for Dams, chaired by J. Gaztenaga (Spain), prepared a preliminary version of a new Bulletin. In 1999 the Committee, then under the Chairmanship of R.G. Charlwood (Canada) agreed to major revisions to the terms of reference proposed by O.J. Berthelsen (Norway) who was appointed to lead the sub-Committee and proceeded to prepare a new draft. The new draft was wider in scope and addressed the specification of concrete as well as practices for quality control. This Bulletin addresses all aspects of the relationship between the specification of concrete for dams of all sizes, construction procedures, the properties of the hardened concrete and how quality control is used. The development of concrete for dams from the conceptual stage to finished product is described. It presents a holistic approach, recognizing the interrelatedness of the design and construction process and the roles of both Designers and Constructors in the production of functional, durable and economic concrete. Both method and performance approaches to specifications are recognised as well as current options in contracting for construction including conventional design, bid and construct as well as design-build approaches (turnkey and EPC). Case histories are presented for a gravity dam of conventional vibrated concrete (CVC), a roller compacted concrete (RCC) dam, and a CVC arch dam. Appendices give tables of typical test frequencies, a sample table of contents listing for a complete specification plus a listing of specific requirements for control of thermal cracking are given as possible checklists. This Bulletin presents the present “State of the Art” and does not intend to limit any further developments. Robin G. Charlwood Chairman Committee on Concrete Dams March 2006 Revision 7.2 March 15, 2006 ICOLD Bulletin **: The Specification and Quality Control of Concrete for Dams THE SPECIFICATION AND QUALITY CONTROL OF CONCRETE FOR DAMS Table of contents Section Page 1 Introduction...........................................................................................................................1 1.1 Objectives............................................................................................................................1 1.2 The Contents of the Bulletin................................................................................................1 1.3 Quality Control and Quality Assurance..............................................................................2 1.4 Definitions...........................................................................................................................2 1.5 Related ICOLD Bulletins....................................................................................................2 2 The specification and quality control process.....................................................................3 2.1 The Content of Specifications..............................................................................................3 2.2 Purpose of Quality Control.................................................................................................4 2.3 Purpose of Quality Assurance.............................................................................................4 2.4 Development of Specifications from Feasibility Stage to Construction..............................4 2.5 Approaches to Specification of Concrete............................................................................6 2.6 Approaches to Quality Control, Division of Responsibilities.............................................8 2.7 Requirements for Effective Quality Control........................................................................9 3 Concrete constituents and concrete manufacture............................................................13 3.1 Material specification and control....................................................................................13 3.1.1 Introduction...........................................................................................................13 3.1.2 Aggregate..............................................................................................................13 3.1.3 Cementitious materials..........................................................................................16 3.1.4 Mineral Admixtures..............................................................................................17 3.1.5 Chemical Admixtures............................................................................................18 3.1.6 Water and ice.........................................................................................................18 3.2 Trial mix programmes.......................................................................................................19 3.3 Full scale trials..................................................................................................................20 3.4 Process specification and control.....................................................................................20 3.4.1 Stockpiles and silo storage....................................................................................20 3.4.2 Quality of manufacturing facility..........................................................................21 3.4.3 Batching, charging and mixing, Process equipment.............................................21 3.4.4 Control of water content........................................................................................23 3.4.5 Fresh concrete properties and verification............................................................23 4 Control of concrete transport and placement...................................................................24 4.1 Transport...........................................................................................................................24 Revision 7.2 March 15, 2006 ICOLD Bulletin **: The Specification and Quality Control of Concrete for Dams 4.1.1 Specification..........................................................................................................24 4.1.2 Quality control.......................................................................................................24 4.2 Delivery and placement.....................................................................................................24 4.2.1 Specification..........................................................................................................24 4.2.2 Inspection..............................................................................................................25 4.2.3 Testing at time of placement.................................................................................25 5 Control of strength..............................................................................................................27 5.1 The basis for approving dam concrete..............................................................................27 5.2 Variations in strength and statistics..................................................................................27 5.3 Other approaches to evaluating acceptable variation......................................................29 5.4 Establishment of acceptable failure rate...........................................................................30 5.5 Strength development over time........................................................................................31 5.6 Dealing with under strength concrete...............................................................................31 6 Control of cracking.............................................................................................................33 6.1 Introduction.......................................................................................................................33 6.2 Design of crack control measures.....................................................................................33 6.3 Specification......................................................................................................................36 6.4 Principal quality control activities....................................................................................36 7 Concrete in contact with high velocity water flows..........................................................37 7.1 Specification of properties................................................................................................37 7.1.1 Strength.................................................................................................................37 7.1.2 Properties of fresh concrete...................................................................................37 7.1.3 Surface finish.........................................................................................................37 7.1.4 Concrete for sediment-laden flows.......................................................................37 7.2 Specification of placement and finishing..........................................................................38 7.3 Quality control..................................................................................................................39 8 Case histories.......................................................................................................................40 8.1 SARDAR SAROVAR DAM................................................................................................40 8.1.1 Introduction:..........................................................................................................40 8.1.2 Evaluation of Aggregates......................................................................................40 8.1.3 Cement and Pozzolan............................................................................................41 8.1.4 Concrete Properties:..............................................................................................42 8.1.5 Concrete Production and Placement.....................................................................42 8.1.6 Quality Control System during Dam Construction:..............................................42 8.1.7 Concrete Mix design.............................................................................................43 8.1.8 Documentation......................................................................................................44 8.1.9 Process Control.....................................................................................................44 8.1.10 Tests and Inspection:.............................................................................................47 Revision 7.2 March 15, 2006 ICOLD Bulletin **: The Specification and Quality Control of Concrete for Dams 8.1.11 Non Conformity Control and Statistical Techniques............................................47 8.1.12 Test Equipment Control........................................................................................47 8.1.13 Statistical Analysis of field compressive strength of concrete..............................47 8.1.14 References.............................................................................................................49 8.2 OLIVENHAIN ROLLER COMPACTED CONCRETE DAM............................................50 8.2.1 Introduction...........................................................................................................50 8.2.2 Specification of concrete.......................................................................................50 8.2.3 Project delivery system.........................................................................................52 8.2.4 Quality control system..........................................................................................52 8.2.5 Official reporting...................................................................................................56 8.2.6 Tracking of concrete strength................................................................................56 8.2.7 References.............................................................................................................56 8.3 ALQUEVA DAM...............................................................................................................58 8.3.1 Introduction...........................................................................................................58 8.3.2 Aggregate evaluation.............................................................................................58 8.3.3 Mix design and specification of concrete.............................................................60 8.3.4 Concrete production..............................................................................................61 8.3.5 Project delivery system.........................................................................................62 8.3.6 Quality Control System during dam construction.................................................63 8.3.7 Organization and responsibilities (communication).............................................63 8.3.8 Quality Control planning.......................................................................................64 8.3.9 Process control (concrete production, placement and cure)..................................65 8.3.10 Tests and inspection..............................................................................................65 8.3.11 Non conformity control.........................................................................................65 8.3.12 Test equipment control..........................................................................................68 8.3.13 Quality control reports and statistical analyses.....................................................68 8.3.14 Activity reports......................................................................................................68 9 References............................................................................................................................69 FIGURES FIGURE 1 TYPICAL QC SYSTEM FOR A CONVENTIONAL CONSTRUCTION CONTRACT...............................................9 FIGURE 2 TYPICAL QC SYSTEM FOR AN EPC CONSTRUCTION CONTRACT.............................................................10 FIGURE 3 QUALITY CONTROL OF AGGREGATE PRODUCTION.................................................................................14 FIGURE 4 SCHEMATIC DIAGRAM OF QUALITY CONTROL OF CEMENT.....................................................................17 FIGURE 5 INFLUENCE OF QUALITY CONTROL ON REQUIRED MEAN STRENGTH.......................................................28 FIGURE 6 QUALITY CONTROL CHART FOR THE INTERIOR CONCRETE OF AN ARCH-GRAVITY DAM WITH RATHER POOR STANDARD OF CONTROL...............................................................................................................30 TABLES TABLE 1 TYPICAL TESTS FOR AGGREGATE..............................................................................................................14 TABLE 2 TYPICAL QUALITY CONTROL ACTIVITIES AT CONCRETE BATCHING STATIONS...........................................22 TABLE 3 TYPICAL QUALITY CONTROL ACTIVITIES AT THE CONCRETE MIXING PLANT.............................................22 TABLE 4 STANDARDS FOR CONCRETE CONTROL (ACI 214)...................................................................................29 TABLE 5 MAXIMUM ALLOWABLE TEMPERATURE DROPS AS A FUNCTION OF BLOCK SIZE AND LOCATION IN DAM...34 Revision 7.2 March 15, 2006 ICOLD Bulletin **: The Specification and Quality Control of Concrete for Dams APPENDICES APPENDIX 1 TABLES OF TYPICAL TEST FREQUENCIES TABLE A1-1 TYPICAL QUALITY CONTGROL TESTS TABLE A1-2 TYPICAL TEST FREQUENCIES FOR MEDIUM SIZE RCC DAM TABLE A1-3 TYPICAL TESTING STANDARDS FOR A LARGE RCC DAM TABLE A1-4 TYPICAL TEST FREQUENCIES FOR LARGE RCC DAM TABLE A1-5 TESTING STANDARDS AND FREQUENCIES FOR A CONVENTIONAL MASS CONCRETE DAM APPENDIX 2 EXAMPLE OF OUTLINE SPECIFICATION FOR CONCRETE WORK APPENDIX 3 REDUCTION OF RISK OF THERMAL CRACKING: ITEMS WHICH MAY BE SPECIFIED APPENDIX 4 REDUCTION OF RISK OF THERMAL CRACKING: PRINCIPAL QUALITY CONTROL ACTIVITIES Revision 7.2 March 15, 2006