1、July 2009DEUTSCHE NORM English price group 7No part of this standard may be reproduced without prior permission ofDIN Deutsches Institut fr Normung e. V., Berlin. Beuth Verlag GmbH, 10772 Berlin, Germany,has the exclusive right of sale for German Standards (DIN-Normen).ICS 75.140; 91.100.50!$Xlt“153
2、7381www.din.deDDIN EN 12850Bitumen and bituminous binders Determination of the pH value of bituminous emulsionsEnglish version of DIN EN 12850:2009-07Bitumen und bitumenhaltige Bindemittel Bestimmung des pH-Wertes von BitumenemulsionenEnglische Fassung DIN EN 12850:2009-07SupersedesDIN EN 12850:2002
3、-08www.beuth.deDocument comprises 9 pagesDIN EN 12850:2009-07 2 National foreword This standard has been prepared by Technical Committee CEN/TC 336 “Bituminous binders” (Secretariat: AFNOR, France). The responsible German bodies involved in its preparation were the Normenausschuss Materialprfung (Ma
4、terials Testing Standards Committee) and the Normenausschuss Bauwesen (Building and Civil Engineering Standards Committee), Joint Technical Committee NA 062-03-32 GA Bitumen; Prfverfahren und Anforderungen fr die Bindemittel. Amendments This standard differs from DIN EN 12850:2002-08 as follows: a)
5、The use of any cleaning agent instead of xylene or toluene is now specified. b) The use of any cleaning agent instead of propan-2-ol or ethanol is now specifed. c) The standard has been editorially revised. Previous editions DIN EN 12850: 2002-08 EUROPEAN STANDARDNORME EUROPENNEEUROPISCHE NORMEN 128
6、50March 2009ICS 75.140; 91.100.50 Supersedes EN 12850:2002 English VersionBitumen and bituminous binders - Determination of the pH valueof bituminous emulsionsBitumes et liants bitumineux - Dtermination du pH desmulsions de bitumeBitumen und bitumenhaltige Bindemittel - Bestimmung despH-Wertes von B
7、itumenemulsionenThis European Standard was approved by CEN on 17 February 2009.CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this EuropeanStandard the status of a national standard without any alteration. Up-to-date lists and bibl
8、iographical references concerning such nationalstandards 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 translationunder the responsibility of
9、 a CEN member into its own language and notified to the CEN Management Centre has the same status as theofficial versions.CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland,France, Germany, Greece, Hungary, Iceland, Ireland,
10、 Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMIT EUROPEN DE NORMALISATIONEUROPISCHES KOMITEE FR NORMUNGManagement Centre: Avenue Marnix 17, B-1000
11、 Brussels 2009 CEN All rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN 12850:2009: EEN 12850:2009 (E) 2 Contents Page Foreword 3 1 Scope 4 2 Normative references 4 3 Terms and definitions .4 4 Principle 4 5 Reagents and materials 4 6 Apparat
12、us .5 7 Sampling .5 8 Procedure .5 9 Expression of results 6 10 Precision .6 11 Test report 6 Bibliography 7 DIN EN 12850:2009-07 EN 12850:2009 (E) 3 Foreword This document (EN 12850:2009) has been prepared by Technical Committee CEN/TC 336 “Bituminous binders”, the secretariat of which is held by A
13、FNOR. 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 2009, and conflicting national standards shall be withdrawn at the latest by September 2009. Attention is drawn to the possibility t
14、hat 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 supersedes EN 12850:2002. From the previous edition, use of any cleaning agent enabling the dissolution of bitu
15、men is now specified. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Ice
16、land, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. DIN EN 12850:2009-07 EN 12850:2009 (E) 4 1 Scope This European Standard specifies a method for measuring the pH value of
17、bituminous emulsions. It is applicable to anionic, cationic bituminous emulsions and bituminous emulsions prepared by means of non ionic surfactant. NOTE In certain circumstances, the pH value can provide an indication of the ionic character of a bitumen emulsion. However, this indication should be
18、confirmed by a particle polarity test conforming to EN 1430 1. WARNING The use of this standard can involve hazardous materials, operations and equipment. This standard does not purport to address all of the safety problems associated with its use. It is the responsibility of the user of this standa
19、rd to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For
20、undated references, the latest edition of the referenced document (including any amendments) applies. EN 58, Bitumen and bituminous binders Sampling bituminous binders EN 12594, Bitumen and bituminous binders Preparation of test samples EN ISO 3696, Water for analytical laboratory use Specification
21、and test methods (ISO 3696:1987) ISO 756-1, Propan-2-ol for industrial use Methods of test - Part 1: General ISO 1388-1, Ethanol for industrial use Methods of test - Part 1: General ISO 5272, Toluene for industrial use Specifications ISO 5280, Xylene for industrial use Specification 3 Terms and defi
22、nitions For the purposes of this document, the following terms and definitions apply. 3.1 pH value negative logarithm to the base of 10 of the concentration of hydrogen ions in moles per litre of solution 4 Principle A pH meter and electrode are calibrated using standard buffer solutions. The pH val
23、ue of the test solution is then determined. 5 Reagents and materials Use only reagents of recognised analytical grade and water conforming to grade 3 of EN ISO 3696. 5.1 Xylene or toluene, conforming respectively to ISO 5280 and ISO 5272, or any cleaning agent enabling the dissolution of the bitumen
24、. DIN EN 12850:2009-07 EN 12850:2009 (E) 5 5.2 Propan-2-ol or preferably ethanol, conforming respectively to ISO 756-1 and ISO 1388-1. NOTE If possible, the use of ethanol is preferable. It is however permissible to use other cleaning agent providing their effectiveness is established. Reference to
25、this shall be made in the test report as appropriate. 5.3 Standard buffer solutions, two, one buffer solution with a pH equal to 7,0 (for neutral electric balance), and an other solution getting closer to the expected pH. 5.4 Potassium chloride solution, 3 mol/l. 6 Apparatus Usual laboratory apparat
26、us and glassware, together with a pH meter, with pH electrodes (combined or not). 7 Sampling The material under test shall be sampled in accordance with EN 58 and prepared in accordance with EN 12594. 8 Procedure Calibrate the pH meter and electrode according to the manufacturers instructions using
27、the standard buffer solutions (5.3). Gently stir the emulsion test sample and pour a sufficient quantity into a 250 ml glass beaker. Adjust the temperature of the emulsion test sample to (25 5) C, if necessary by cooling the sample. Rinse the electrode with water, wipe it and immerse it in the emuls
28、ion test sample to the minimum depth recommended by the manufacturer. Read the indicated pH value when this becomes constant. If the pH value is not constant after 1 min, include this information in the test report. It is possible to indicate the approximate pH. Remove the electrode from the emulsio
29、n test sample and clean it, using the following sequence of operations: wash with the aqueous phase of the emulsion if there is some; wash with water; wash with propan-2-ol or ethanol (5.2); wash with xylene or toluene (5.1 or any cleaning agent enabling the dissolution of the bitumen; wash with pro
30、pan-2-ol or ethanol (5.2); wash with water. Store the electrode in the potassium chloride solution (5.4). NOTE The instructions concerning electrode cleaning and storage are applied if there is no manufacturers information. DIN EN 12850:2009-07 EN 12850:2009 (E) 6 9 Expression of results Express the
31、 pH value to the nearest 0,1 pH unit. If the pH value is not constant after 1 min, report this information in the test report. 10 Precision NOTE The precision of this method has been estimated on the basis of experience. It may be necessary to modify the precision figures when the results of a stati
32、stically correct series of tests become available. 10.1 Repeatability The difference between two successive test results, obtained by the same operator with the same apparatus under constant operating conditions on identical test material would, in the long run, in the normal and correct operation o
33、f the test method, exceed 0,3 pH unit in only one case in twenty. 10.2 Reproducibility The difference between two single and independent results obtained by different operators working in different laboratories on identical test material would, in the long run, in the normal and correct operation of
34、 the test method, exceed 0,5 pH unit in only one case in twenty. 11 Test report The test report shall contain at least the following information: a) type and complete identification of the sample under test; b) reference to this European Standard; c) any deviation, when use of other cleaning agent d
35、ifferent than those recommended (see Clause 5); d) any variability of pH if it is not stable after one minute (see Clause 9); e) result of the test (see Clause 9); f) any deviation, by agreement or otherwise, from the procedure specified; g) date of sampling, date of sample preparation and date of the test. DIN EN 12850:2009-07 EN 12850:2009 (E) 7 Bibliography 1 EN 1430, Bitumen and bituminous binders - Determination of particle polarity of bituminous emulsions DIN EN 12850:2009-07
