1、BS EN 196-8:2010ICS 91.100.10NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBRITISH STANDARDMethods of testingcementPart 8: Heat of hydration SolutionmethodThis British Standardwas published under theauthority of the StandardsPolicy and StrategyCommittee on 31 May2010. BSI 201
2、0ISBN 978 0 580 68243 8Amendments/corrigenda issued since publicationDate CommentsBS EN 196-8:2010National forewordThis British Standard is the UK implementation of EN 196-8:2010. Itsupersedes BS EN 196-8:2003 which is withdrawn.The UK participation in its preparation was entrusted to TechnicalCommi
3、ttee B/516/12, Sampling and testing.A list of organizations represented on this committee can be obtained onrequest to its secretary.This publication does not purport to include all the necessary provisionsof a contract. Users are responsible for its correct application.Compliance with a British Sta
4、ndard cannot confer immunityfrom legal obligations.BS EN 196-8:2010EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 196-8 March 2010 ICS 91.100.10 Supersedes EN 196-8:2003English Version Methods of testing cement - Part 8: Heat of hydration - Solution method Prfverfahren fr Zement - Teil 8: Hydr
5、atationswrme - Lsungsverfahren This European Standard was approved by CEN on 21 February 2010. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-da
6、te lists and bibliographical references concerning such national standards may be obtained on application to the CEN Management Centre or to any CEN member. This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under t
7、he responsibility of a CEN member into its own language and notified to the CEN Management Centre has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Gr
8、eece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Manage
9、ment Centre: Avenue Marnix 17, B-1000 Brussels 2010 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 196-8:2010: EBS EN 196-8:2010EN 196-8:2010 (E) 2 Contents Page Foreword 31 Scope 42 Normative references 43 Principle 44 Materials
10、. 44.1 Acid mixture . 44.2 Zinc oxide (ZnO) . 54.3 Anhydrous cement 54.4 Hydrated cement 55 Apparatus . 56 Calorimeter calibration 76.1 Principle 76.2 Procedure . 76.3 Calculation of calibration characteristics . 86.3.1 Corrected temperature increase, Tc. 86.3.2 Thermal leakage coefficient, K . 86.3
11、.3 Thermal capacity, C . 87 Determination of heat of solution 97.1 Heat of solution of anhydrous cement 97.1.1 Procedure . 97.1.2 Calculation 107.1.3 Expression of results 107.2 Heat of solution of hydrated cement . 117.2.1 Procedure . 117.2.2 Correction for bound water 117.2.3 Calculation 117.2.4 E
12、xpression of results 128 Heat of hydration . 138.1 Calculation of results 138.2 Reporting of results . 138.3 Precision . 138.3.1 Repeatability . 138.3.2 Reproducibility . 13Bibliography 14BS EN 196-8:2010EN 196-8:2010 (E) 3 Foreword This document (EN 196-8:2010) has been prepared by Technical Commit
13、tee CEN/TC 51, “Cement and building limes“, the secretariat of which is held by NBN. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by September 2010, and conflicting national standards shall be wit
14、hdrawn at the latest by September 2010. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN and/or CENELEC shall not be held responsible for identifying any or all such patent rights. This document has been prepared under a mandat
15、e given to CEN by the European Commission and the European Free Trade Association, and supports essential requirements of EU Directive(s). This document supersedes EN 196-8:2003. EN 196, Methods of testing cement, consists of the following parts: Part 1: Determination of strength Part 2: Chemical an
16、alysis of cement Part 3: Determination of setting times and soundness Part 5: Pozzolanicity test for pozzolanic cement Part 6: Determination of fineness Part 7: Methods of taking and preparing samples of cement Part 8: Heat of hydration Solution method Part 9: Heat of hydration Semi-adiabatic method
17、 Part 10: Determination of the water-soluble chromium (VI) content of cement CEN/TR 196-4, Methods of testing cement Part 4: Quantitative determination of constituents According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to impl
18、ement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Sw
19、itzerland and the United Kingdom. BS EN 196-8:2010EN 196-8:2010 (E) 4 1 Scope This European Standard describes a method of determining the heat of hydration of cements by means of solution calorimetry, also known as the solution method. The heat of hydration is expressed in joules per gram of cement
20、. This standard is applicable to cements and hydraulic binders whatever their chemical composition. NOTE 1 Another procedure, called the semi-adiabatic method, is described in EN 196-9. Either procedure can be used independently. NOTE 2 It has been demonstrated that the best correlation between the
21、two methods is obtained at seven days for the solution method (EN 196-8) compared with 41 h for the semi-adiabatic method (EN 196-9). 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies
22、. For undated references, the latest edition of the referenced document (including any amendments) applies. EN 197-1:2000, Cement Part 1: Composition, specifications and conformity criteria for common cements 3 Principle The method consists in measuring the heats of solution, in an acid mixture, of
23、anhydrous cement and cement hydrated under standardized conditions for a predetermined period of time, e.g. seven days. These standardized hydration conditions are as follows: water/cement ratio 0,40; use of neat cement paste; storage at constant temperature of (20,0 0,2) C during the whole hydratio
24、n process. The heat of hydration for each period, Hi, is obtained from the difference between the heat of solution of anhydrous cement, Qa, and that of hydrated cement, Qi. 4 Materials 4.1 Acid mixture Analytical reagent quality acid mixture, obtained by adding 2,760 g of 40 % hydrofluoric acid (HF)
25、 for every 100,0 g of (2,00 0,01) mol/l nitric acid (HNO3), or 2,600 ml of hydrofluoric acid for every 100,0 ml of nitric acid. WARNING Hydrofluoric acid can cause painful skin burns which heal only with difficulty and precautions in handling this very corrosive substance should be strictly observed
26、. The quantity (mass or volume) of acid to be used, which is common to all tests, shall be measured to 0,2 %. BS EN 196-8:2010EN 196-8:2010 (E) 5 4.2 Zinc oxide (ZnO) Use zinc oxide of analytical quality to determine the thermal capacity of the calorimeter. Weigh 40 g to 50 g. Ignite at (950 25) C f
27、or 1 h. Cool in a desiccator. Grind to pass a 125 m sieve. Store in a desiccator. 4.3 Anhydrous cement Store anhydrous cement, from which metallic iron has been removed with a magnet, in a sealed container to avoid absorption of water or carbon dioxide. Bring the test sample to ambient temperature a
28、nd carefully homogenize it before use. 4.4 Hydrated cement Prepare the hydrated cement test sample by vigorously mixing, either manually or mechanically, (100,0 0,1) g of anhydrous cement with (40,0 0,1) g of distilled or deionised water for 3 min at ambient temperature. Place the resulting paste in
29、 plastics or glass cylindrical vials (three for each hydration period to be tested) so that each vial contains 15 g to 20 g of material. Seal the vials by means of a stopper and, if necessary, with paraffin wax or similar material and store them horizontally in a thermostatic bath maintained at a te
30、mperature of (20,0 0,2) C. 5 Apparatus 5.1 Calorimeter. NOTE The method does not deal with the standardization of the calorimetric apparatus, or the measuring instruments. Insulated flasks with a volume of about 650 ml have proved to be suitable. A suitable calorimeter (see Figure 1) comprises the f
31、ollowing: a) Dissolution vessel, consisting of: an insulated flask (e.g. Dewar flask), placed either in a heat insulated container set inside a box constructed of insulating material (e.g. wood, plastics), or immersed in a thermostatic water bath regulated to 0,2 C; and an insulated stopper (made of
32、 cork or plastics) through which holes are provided for the thermometer, the stirrer and the funnel used for introducing the sample. The insulation of the calorimeter shall ensure that the thermal leakage coefficient, K (determined in accordance with 6.3), is less than 0,06 K per 15 min for each Kel
33、vin above ambient temperature. The internal surface of the flask, that part of the thermometer immersed in the acid mixture and the lower part of the stopper, shall be acid mixture resistant. b) Thermometer, either a Beckmann thermometer with a 5 C to 6 C scale and subdivisions every 0,01 C or other
34、 measurement apparatus of an equal or higher accuracy such as a thermistor or platinum resistance thermometer, positioned such that the end of the thermometer is at least 4 cm below the level of the liquid surface. Express temperature readings with a resolution of 0,002 C. Adjust the zero of the Bec
35、kmann thermometer so that the upper limit of the scale is approximately the ambient, or water bath, temperature. Calibrate the thermometer in a thermostatic bath against a 0,01 C graduated and calibrated thermometer. c) Funnel, of acid mixture resistant plastics, through which the sample is introduc
36、ed into the flask and which extends below the lower part of the stopper by 5 mm to 6 mm and is sealed during the test. d) Stirrer, of acid mixture resistant plastics, positioned such that the blades are as close as possible to the bottom of the flask and rotated by a motor at a speed of (450 50) min
37、-1. The motor shall be low power rated (e.g. a motor of a few watts) so as to prevent any excessive heat emission from affecting measurements. BS EN 196-8:2010EN 196-8:2010 (E) 6 125749610832111Key 1 flask 5 thermometer 9 insulating material 2 container 6 stirrer 10 flask support 3 box 7 funnel 11 a
38、mbient thermometer 4 stopper 8 support 12 stirrer motor Figure 1 Typical heat of solution calorimeter apparatus BS EN 196-8:2010EN 196-8:2010 (E) 7 5.2 Thermostatic bath, e.g. water bath, for storing the hydrated samples at a temperature of (20,0 0,2)C. 5.3 Mortar or electric grinder, for crushing t
39、he hydrated samples. 5.4 Plastics or glass vials, of capacity approximately 20 ml, for storing the hydrated paste. 5.5 Sieve, of mesh size 125 m. 5.6 Sieve, of mesh size 600 m. 5.7 Chronometer, graduated in seconds, for timing the temperature readings. 5.8 Two platinum crucibles, of capacity approxi
40、mately 20 ml, for ignition of samples. 5.9 Electric furnace, naturally ventilated, capable of operating at (950 25) C, for ignition of samples. 5.10 Analytical balance, capable of weighing to an accuracy of 0,000 1 g. 5.11 Balance, of capacity 2 kg, capable of weighing to an accuracy of 0,2 g. 6 Cal
41、orimeter calibration 6.1 Principle Calibration of the calorimeter is carried out in order to determine its thermal capacity and thermal leakage coefficient. These characteristics are determined by dissolving the ignited zinc oxide (4.2) in the acid mixture (4.1) and measuring the temperature of the
42、calorimeter at fixed intervals of time. The temperature of acid mixture shall be so set that after the dissolution reaction the calorimeter temperature is at least 0,5 C below the ambient temperature. Where a water bath is used the temperature of the bath is considered to be the ambient temperature
43、for the calorimeter. 6.2 Procedure Measure a quantity of acid mixture (4.1) by mass or volume to 0,2 % such that the liquid level will be approximately 2 cm below the calorimeter stopper. Place the acid mixture in the flask. Immediately before the determination of the thermal capacity, ignite the zi
44、nc oxide at (950 25) C for a maximum of 5 min and cool in a desiccator to room temperature. The quantity of zinc oxide to be used, weighed to 0,000 1 g, is that required to satisfy Equation (1): 160 =oxidezincofMassmixtureacidofMass(1) Carry out the procedure as follows: a) Preliminary period Stir t
45、he acid mixture for 40 min to 50 min. b) Pre-period When the rate of temperature increase is constant, start the timing using the chronometer (5.7) and record the initial temperature, 15Tc) Sample introduction After 15 min record the temperature, T0, and immediately add the zinc oxide sample to the
46、acid mixture, taking not more than 1 min. BS EN 196-8:2010EN 196-8:2010 (E) 8 d) Dissolution period Stir the mixture for 30 min, after which the dissolution is considered as being complete, and then record the temperature, 30T . Record the ambient temperature, Ta. If the difference between Taand 30T
47、 is less than 0,5 C then repeat the test. e) Post-period Record the final temperature 45T after a further 15 min. In order to reduce reading errors, determine temperatures ,15T 30T and 45T as the average of five different readings recorded at intervals of 1 min over the period 2 min before to 2 min
48、after the prescribed time, Ti(i.e. Ti-2, Ti-l, Ti, Ti+l, Ti+2). Determine the value of T0by extrapolation of the function of temperature against time in the period T-4to T-1. If the extrapolated value differs from the T0reading by more than 0,002 C then replace T0by the extrapolated value. If more t
49、han a trace of zinc oxide is found adhering to the tip of the funnel or to the stopper when the calorimeter is opened, repeat the calibration. NOTE The temperature readings will therefore effectively start 17 min before the zinc oxide sample is introduced and the last reading will take place 47 min after its introduction. The total duration
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