1、BRITISH STANDARD Tests for chemical properties of aggregates Part 3: Preparation of eluates by leaching of aggregates The European Standard EN 1744-3:2002 has the status of a British Standard ICs 91.100.15 BS EN 1744-3 :2002 British Standards NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY
2、COPYRIGHT LAW BS EN 1744-3 12002 National foreword This British Standard is the official English language version of EN 1744-3:2002, which is included in a package of new European Standards being prepared by CEN/TC 154 relating to aggregates. Although the English text versions of these European Stan
3、dards will be adopted as British Standards as they become available, the existing British Standards for aggregates will be retained, but only until such a time that the completed package of European Standards becomes available. The original group of British Standards will then be withdrawn and this
4、will be noted in BSI Standards Update. The UKparticipation in its preparation was entrusted by Technical Committee B/502, Aggregates, to Subcommittee B/502/6, Test methods, which has the responsibility to: - - aid enquirers to understand the text; present to the responsible international/European co
5、mmittee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; monitor related international and European developments and promulgate them in the UK. - A list of organizations represented on this subcommittee can be obtained on request to its secretary. Cro
6、ss-references The British Standards which implement international or European publications referred to in this document may be found in the BSI Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Search”faci1ity ofthe BSI Electronic Catalogue or ofBr
7、itish Stan dards Online. This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. Compliance with a British Standard does not ofitself confer immunity from legal obligations. This British Standard, having been prepare
8、d under the This document comprises a front cover, an inside front cover, the EN title page, direction of the Building and Civil Engineering Sector Policy and Strategy Committee, was The BSI copyright date displayed in this document indicates when the published under the authority of the Standards P
9、olicy and Strategy Committee on 9 August 2002 Summary of pages pages 2 to 9 and a back cover. document was last issued. Amendments issued since publication Amd.No. I Date I Comments O BSI 9 August 2002 ISBN O58040248 7 EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 1744-3 July 2002 ICs 91.100.
10、15 English version Tests for chemical properties of aggregates - Part 3: Preparation of eluates by leaching of aggregates Essais pour dterminer les proprits chimiques des granulats - Partie 3: Prparation dluats par lixiviation des granulats Prfverfahren fr chemische Eigenschaften von Gesteinskrnunge
11、n - Teil 3: Herstellung von Eluaten durch Auslaugung von Gesteinskrnungen This European Standard was approved by CEN on 5 March 2002 CEN members are bound to comply with the CENKENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national stan
12、dard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the Management Centre or to any CEN member. This European Standard exists in three official versions (English, French, German). A version in any other lan
13、guage made by translation under the responsibility of a CEN member into its own language and notified to the Management Centre has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, I
14、celand, Ireland, Italy, Luxembourg, Malta, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION EUROPISCHES KOMITEE FR NORMUNG COMIT EUROPEN DE NORMALISATION Management Centre: rue de Stassart, 36 B-1050 Brussels O 2002 CEN All rights o
15、f exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 1744-3:2002 E EN 1744-3:2002 (E) Contents page Foreword 3 1 Scope 4 2 Normative references . 4 3 Terms and definitions 4 4 Principle 5 5 Reagents . 6 6 Apparatus 6 7 Sampling . 6 8 Preparation of tes
16、t portions . 6 9 Procedure . 7 10 Bibliography 9 Test rep0 rt . 8 2 EN 1744-3:2002 (E) Foreword This document EN 1744-3:2002 has been prepared by Technical Committee CEN/TC 154 “Aggregates“, the secretariat of which is held by BSI. This European Standard shall be given the status of a national stand
17、ard, either by publication of an identical text or by endorsement, at the latest by January 2003, and conflicting national standards shall be withdrawn at the latest by January 2003. This standard forms part of a series of tests for chemical properties of aggregates. Test methods for other propertie
18、s of aggregates will be covered by Parts of the following European Standards: EN 932 EN 933 EN 1097 EN 1367 EN 13179 Tests for general properties of aggregates Tests for geometrical properties of aggregates Tests for mechanical and physical properties of aggregates Tests for thermal and weathering p
19、roperties of aggregates Tests for filler aggregate used in bituminous mixtures The other parts of EN 1744 are, or will be: Part 1 : Chemical analysis Part 2: Part 4: Determination of resistance to alkali reaction Water susceptibility of fillers for bituminous mixtures According to the CENKENELEC Int
20、ernal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands, Norway, Portugal, Spain, Sweden, Swi
21、tzerland and the United Kingdom. 3 EN 1744-3:2002 (E) 1 Scope This European Standard specifies a method for the preparation of eluates, by leaching of aggregates, for subsequent investigation of physical and chemical properties by existing standard methods for the purpose of compliance testing. It a
22、pplies to unbound aggregates that have a particle size below 32 mm with or without size reduction (see clause 8). 2 Normative references This European Standard incorporates by dated or undated reference, provisions from other publications. These normative references are cited at the appropriate plac
23、es in the text, and the publications are listed hereafter. For dated references, subsequent amendments to or revisions of any of these publications apply to this European Standard only when incorporated in it by amendment or revision. For undated references the latest edition of the publication refe
24、rred to applies (including amendments). EN 932-1, Tests for general properties of aggregates - Part I: Methods for sampling. EN 932-2, Tests for general properties of aggregates - Part 2: Methods for reducing laboratory samples. EN 932-5, Tests for general properties of aggregates - Part 5: Common e
25、quipment and calibration. EN 933-2, Tests for geometrical properties of aggregates - Part 2: Determination of particle size distribution - Test sieves, nominal size of apertures. EN 1097-5, Tests for mechanical and physical properties of aggregates - Part 5: Determination of the water content by dry
26、ing in a ventilated oven. EN IS0 3696, Water for analytical laboratory use - Specification and test methods (IS0 3696: 1987). 3 Terms and definitions For the purposes of this European Standard, the following terms and definitions apply. 3.1 leachant liquid used in a laboratory leaching procedure 3.2
27、 eluate solution remaining after the laboratory leaching procedure of a solid material in contact with a leachant 3.3 constant mass successive weighings after drying at least 1 h apart not differing by more than 0,l %. NOTE specified oven at (1 10 f 5) “C. Test laboratories can determine the time re
28、quired to achieve constant mass for specific types and sizes of sample dependent upon the drying capacity of the oven used. In many cases constant mass can be achieved after a test portion has been dried for a pre-determined period in a 3.4 laboratory sample sample intended for laboratory testing 3.
29、5 test portion sample used as a whole in a single test 4 EN 1744-3:2002 (E) 4 Principle The aggregate to be examined is placed on a screen insert and leached in a tank (see Figure 1). The liquid solid ratio is 1O:l (in mass proportion) and the leaching time is 24 h. The water is agitated by a motor
30、driven dip stirrer. NOTE During the test procedure the leachant is agitated but the solid material is not. The method is based on the assumption that equilibrium or near-equilibrium is achieved between the liquid and solid phases during the test period. The solid residue is drawn off. The properties
31、 of the eluate are measured using methods developed for water analysis adapted to analysis of eluates. O +I O 7 3 Dimensions in millimetres 3 1 2 3 4 5 NOTE Drawing not to scale. 1 Motor driven dip stirrer 2 Cover 3 Tank 4 Screen support 5 6 Test portion 7 Stopcock Screen insert (mesh size 2 mm) Fig
32、ure 1 - Example of tank with screen support 5 EN 1744-3:2002 (E) 5 Reagents 5.1 Distilled water, demineralized water, deionized water or water of an equivalent purity (5 conductivity less than 0,5 mS/m conforming to grade 3 of EN IS0 3696. pH 73) with a 5.2 0,l mol/l nitric acid, analytical grade. 6
33、 Apparatus 6.1 All apparatus, unless otherwise stated, shall conform to the general requirements of EN 932-5. 6.2 Balance, capable of weighing 2 kg with an accuracy of 0,l g. 6.3 Thermometer, range O “C to 50 “C and accurate to 1 “C for air and leachant temperature measurement. 6.4 Centrifuge, opera
34、ting at 3 O00 m/s2 to 4 O00 m/s2. 6.5 pH meter, readable to 0,l pH units. 6.6 Electrical conductivity meter. 6.7 Filtering apparatus, either a vacuum filtering device (between 2,5 Pa to 4,O Pa) or a high pressure filtration apparatus ( 500 kPa), capable of rinsing. 6.8 Pre-rinsed 0,45 pm membrane fi
35、lters, for filtration (rinsed with nitric acid, 0,l mol/l (5.2) and water (5.1). 6.9 Tank for leaching. A one piece glass tank of external dimensions, height (400 f IO) mm and diameter (300 f IO) mm, with the following: a) cover; b) screen support, made of PTFE or glass (or stainless steel for the d
36、etermination of organic parameters only or polypropylene for the determination of inorganic parameters only) with a screen mesh size 2 mm, dimensions of height (50 f IO) mm and diameter such that the support is (20 f 2) mm from the edge of the tank. The distance between the base of the screen and th
37、e base of the tank should be (50 f 5) mm. For lightweight aggregates, the test portion shall be covered by a second screen; c) motor driven dip stirrer with a stirring rod and propeller diameter (60 f IO) mm made of PTFE or PTFE- covered material that is inserted through a small hole in the cover of
38、 the tank. 6.10 Crushing equipment, jaw crusher or a cutting device, for particles retained on the 32 mm sieve. 6.11 Sieves, of nominal sizes 16 mm and 32 mm conforming to EN 933-2, for sieving recrushed or cut particles. 7 Sampling Sampling shall be carried out in accordance with EN 932-1. 8 Prepar
39、ation of test portions Aggregates shall be tested in the particle size distribution in which they are normally delivered. Particles retained on the 32 mm sieve shall be crushed and the fraction 16/32 mm sieved out. This material is returned to the sample under preparation in the percentage in which
40、the fraction larger than 32 mm was present in the original sample. 6 EN 1744-3:2002 (E) If the sample is wet it shall be air dried at room temperature (e 40 OC) to constant mass to allow dividing and screening. The water content of the sample used for leaching shall be determined on a parallel sampl
41、e by drying at 11 O OC in accordance with EN 1097-5. Reduce the size of the laboratory sample in accordance with the procedures specified in EN 932-2 to give a test portion with a mass of about 2 kg and weigh the test portion to the nearest 0,l g. For lightweight aggregates, the mass of the test por
42、tion shall be reduced in proportion to the density of the aggregate. It may also be necessary to increase the liquid/solid ratio in 9.2 in order that a lightweight aggregate test portion is covered with water. NOTE 1 Contamination of the sample can occur to an extent, which affects the leaching of s
43、ome constituents of concern, for example from tungsten carbide equipment or stainless steel apparatus. Care should be taken to ensure that such contamination of samples is minimised. NOTE 2 should be reduced to 500 g. In the case of lightweight aggregates with a bulk density less than 200 kg/m3 (0,2
44、 Mg/m3), the mass of the sample 9 Procedure 9.1 Testing conditions The leaching shall be carried out at room temperature (20 OC to 25 OC) 9.2 Test procedure After filling the tank with a mass of leachant equal to 10 times the dry mass of the test portion, place the appropriate screen into the tank i
45、n such a way that it is completely covered with water. Slowly distribute the test portion, which is to undergo leaching, uniformly over the screen so that as much air as possible is removed from the test portion. When the test portion is arranged on the screen, the water cover shall be at least at 2
46、0 mm. Then lower the screen support to the bottom of the tank. Place the screen insert in the leaching tank in such a way that a uniform distance from the walls of the vessel is maintained. Cover the leaching tank. Insert the motor-driven dip stirrer through the small hole in the cover of the tank a
47、nd fix it in such a way that the propeller is closely above the test portion. Set the motor-driven dip stirrer to a rotational speed of (500 f 20) min-. After 24 h f 10 min switch off the stirrer and draw off the required quantity of eluate, as specified in 9.3, for analysis. NOTE should be equal to
48、 forty times the dry mass of the sample. In the case of lightweight aggregates with a bulk density less than 200 kg/m3 (0,2 Mg/m3), the amount of leachant 9.3 Further preparation of the eluate for analysis Immediately after the test, allow the coarse particles suspended in the leachant to settle for
49、 10 min and then draw off the eluate from the tank. If inorganic parameters together with the pH value and electrical conductivity are to be determined, filter the eluate through a membrane filter of pore size 0,45 pm. If organic parameters are to be determined (e.g. phenol index), centrifuge the liquid. Care shall be taken to ensure that the material of the centrifuge does not influence the results of the analysis. During the centrifuging operation, remove the suspended particulate matter from the eluate for 10 min at a relative centrifugal acceleration of 3 500 m/s2. NOTE
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