This Bulletiп has Ьееп prepared bv Р. J. Маsоп (Great Britaiп) оп behalf of the British Natioпal Committee оп Large Dams for the Committee оп Materials for Coпcrete Dams Origiпal text iп Eпglish - Freпch traпslatioп Ьу R. Chadwick, revised Ьу У. Le Мау EXPOSURE OF DAM CONCRETE ТО SPECIAL AGGRESSIVE WATERS. Guidelines. Commission Internationale des Grands Barrages 151, bd Haussmann, 75008 Paris - Те!. : 40 42 67 33 - Пlех : 641320 F (ICOLD) NOTICE – DISCLAIMER : The information, analyses and conclusions referred to herein are the sole responsibility of the author(s) thereof. 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. COMM ITTEE O N MATERIALS FOR CONCRETE DAMS (*) ( 1983-1989) Chairman BERTACCHI ltaly Р. Members W. PAC ELLI DE ANDRADE Brazil J.-P. GARBE France М. W. С. WILLIAMS Great Britain J. TABATABAI Iran Т. YANAGIDA Japan С. GOMEZ-TOLEDO Mexico 1. BOERSETH Norway Е. F. PIM ENTEL MACHADO Portugal С. HALLIER South Africa Р. А. Sweden А. ENGELBREKTSON Switzerland G. TRUCCO USA J. R. GRAHAM USSR А. D. OSIPOV Yugoslavia М. С ALOGOVIC (*) Membersbip in March 1989 2 CONTENTS FOREWORD 1. INTRODUCТION 2. TYPES OF АТТАСК 3. PLACES OF HIGH RISK 4. WATER ANALYSES 5. DELETERIOUS EFFECTS 6. PREVENТIVE MEASURES 7. INVESТIGAТIONS АТ EXIST­ ING DAMS 8. REMEDIAL WORKS 9. REFERENCES APPENDIX А - Case histories APPENDIX В - Codes and standards 3 TABLE OF CONTENTS FOREWORD ........................................................................................................................ 13 1. INTRODUCТION .................................................... ...................................................... 15 1.1. Scope of the Bulletin .. .. .... ............ .......... .. .. .. .... .. ......... ....... .. .. .. .. .. .. .... .. .... .... ... ... 15 1.2. Extent and Nature of the ProЫem .. .... .. ...... .. .......... .. .. .. .. .. .. ..... ... .... .. .. .. .. ...... .. .. .. 15 1.3. Purpose of the Bul\etin .......................................................................................... 15 2. TYPES OF АТТАСК ................................ ........................................................ ............. 17 2.1. Soft Water ................................................................................................................ 17 2.2. Sulphates 19 2.3. Sulphides 21 2.4. Chlorides ..................... ............................................................................................. 21 2.5. Acids .......................................................................................................................... 23 2.6. Plant Growth .... .. .. .. .. .. .... .. .. .. ...... .... ..... ... .. .. .. .. .. .... .. .. .. .. .......... .. .. .... .. .......... .... .. .... .. .. 25 2.7. Combined Attacks ........................................................ ......................................... 25 3. PLACES OF HIGH RISK ............................................................................................ 29 3.1. General ...................................................................................................................... 29 3.2. Geographical Location ............................................................................................ 29 3.2.1. Mountain or Нigh Moorland Water ............................. ............................. 29 3.2.2. Low Moorland or Marsh Water ............................................... ................. 29 3.2.3. lgneous and Siliceous Geology .................................................................. 29 3.2.4. Natural Sulphate Rich Areas ...................................................................... 31 3.2.5. Natural Sulphide Rich Areas .............................................. ........................ 31 3.2.6. Contaminated Ground and Waste Products ... ......................................... 31 3.2.7. Seawater ........................................................................................................ 33 3.2.8. Deposits of Marine Origin .......................................................................... 33 3.3. Structural Locations ................................................................................................ 33 3.3.1. Potential Flow Paths ....................................................................... ............. 33 3.3.2. Areas with Reinforcement or Embedded Parts ........................................ 35 3.3.3. Highways .............................................................................. :......................... 37 3.3.4. Unventilated Galleries ...... ............................ .............................................. 37 3.3.5. Pump Sumps and Relief Drains ............... ................................................. 37 3.3.6. Plant Growth ................................................................................................ 39 4. WATER ANALYSES ...................................................................................................... 43 4. 1. Basic Requirements and Definitions .................................................................... 43 4.1.1. Ion Content ........ ............................ .................................... .......................... 43 4.1 .2. рН .................................................................................................. ................ 43 4.1.3. Alkalinity or Acidity ....................................................... ............................. 45 4.1 .4. Hardness ....................... ..... .......................................................... ................. 45 4.1.5. Dissolved Carbon Dioxide .......................................................................... 45 4.1.6. Total Dissolved Solids ................................................... ............................. 47 4.1 .7. Saturation Index ............ .............................................................................. 47 4. 1.8. Temperature .......... ..................... .................................................................. 47 4.1 .9. Electrical Conductivity ................................................................................ 47 5 4.2. Assessing Aggressivity due to Soft Water Leaching ............ .... ................. .. 47 4.2.1. Dissolved Carbon Dioxide .......... .......................... .. .. ............ .. .......... .. .... 4 7 4.2.2. Simple Testing ............................ .. .......... ................ .. .. ............ .. ... ... 49 4.2.3. Saturation or Langelier Index .... .............................................. ................. 49 4.3. Sulphates .......................................... .................... ...................... ..................... 51 4.4. Sampling Technique .............................. .......... .......... .. .................... ............ ............ 51 4.5. Aggression Level Classification .............................. ................... ... ........ ............ 53 5. DELETERIOUS EFFECTS ........................................ ........................................ 73 5.1. Loss of Strength . ..................................... ...................... ................. ....................... 73 5.2. Increased Drainage Flows . .. ................. ............................................ ..................... 73 5.3. Increased Uplift ...................................................................................................... 73 5.4. Reduced Cohesion .................................................................................................. 75 5.5. Corrosion of Reinforcement .................................................. ............................... 75 5.6. Hydraulic Effects .......................... ........................ ...................... ..................... 75 5.7. Appearance . ......................... ................................................................................... 77 5.8. Gas Pockets .......................... ........ .. .................. ........ ...................... .. ................ ........ 77 6. PREVENТIVE MEASURES .................................................................... .................. 79 6.1. Introduction .................. ............................ ........................ .. .. .................. .......... .. 79 6.2. Concrete Mix Design ..... ................... ... ............. .......... .. .. .... .............. .. ............ .. .. 79 6.2.1. Aggregate .................... .... .............................................. .. .............. .. ............ 79 6.2.2. Cements .......... .................... .. ................ .......................... .. .. .............. .. ............ 79 6.2.3. Water/Cement Ratio ...............................................................