BS PD CEN TS 14418-2014 Geosynthetic Barriers Test method for the determination of the influence of freezing-thawing cycles on the permeability of clay geosynthetic barrie.pdf

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1、BSI Standards Publication PD CEN/TS 14418:2014 Geosynthetic Barriers Test method for the determination of the influence of freezing-thawing cycles on the permeability of clay geosynthetic barriersPD CEN/TS 14418:2014 PUBLISHED DOCUMENT National foreword This Published Document is the UK implementati

2、on of CEN/ TS 14418:2014. It supersedes DD CEN/TS 14418:2005 which is withdrawn. The UK participation in its preparation was entrusted to Technical Committee B/553, Geotextiles and geomembranes. A list of organizations represented on this committee can be obtained on request to its secretary. This p

3、ublication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. The British Standards Institution 2014. Published by BSI Standards Limited 2014 ISBN 978 0 580 85550 4 ICS 59.080.70 Compliance with a British Standard cannot confer

4、immunity from legal obligations. This Published Document was published under the authority of the Standards Policy and Strategy Committee on 31 October 2014. Amendments issued since publication Date Text affectedPD CEN/TS 14418:2014TECHNICAL SPECIFICATION SPCIFICATION TECHNIQUE TECHNISCHE SPEZIFIKAT

5、ION CEN/TS 14418 October 2014 ICS 59.080.70 Supersedes CEN/TS 14418:2005 English Version Geosynthetic Barriers - Test method for the determination of the influence of freezing-thawing cycles on the permeability of clay geosynthetic barriers Gosynthtiques bentonitiques - Mthode dessai pour la dtermin

6、ation de linfluence de cycles gel/dgel sur la permabilit des gosynthtiques bentonitiques Geosynthetische Dichtungsbahnen - Prfverfahren zur Bestimmung des Einflusses von Frost-Tau-Zyklen auf die Wasserdurchlssigkeit von geosynthetischen Tondichtungsbahnen This Technical Specification (CEN/TS) was ap

7、proved by CEN on 21 July 2014 for provisional application. The period of validity of this CEN/TS is limited initially to three years. After two years the members of CEN will be requested to submit their comments, particularly on the question whether the CEN/TS can be converted into a European Standa

8、rd. CEN members are required to announce the existence of this CEN/TS in the same way as for an EN and to make the CEN/TS available promptly at national level in an appropriate form. It is permissible to keep conflicting national standards in force (in parallel to the CEN/TS) until the final decisio

9、n about the possible conversion of the CEN/TS into an EN is reached. CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Ita

10、ly, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG CEN-CENELEC Management Centre: Ave

11、nue Marnix 17, B-1000 Brussels 2014 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. CEN/TS 14418:2014 EPD CEN/TS 14418:2014 CEN/TS 14418:2014 (E) 2 Contents Page Foreword 3 Introduction .4 1 Scope 5 2 Normative references 5 3 Terms an

12、d definitions .5 4 Principle 5 5 Apparatus .5 6 Reagent .6 7 Procedure .6 7.1 Specimen preparation .6 7.2 Specimen hydration 6 7.3 Specimen freezing .7 7.4 Specimen thawing .7 7.5 Repetition .7 7.6 Preparation of specimen for flux testing .7 8 Calculation and expression of results .8 8.1 Recording o

13、f data 8 8.2 Calculation and expression of results .8 9 Test Report .8 PD CEN/TS 14418:2014 CEN/TS 14418:2014 (E) 3 Foreword This document (CEN/TS 14418:2014) has been prepared by Technical Committee CEN/TC 189 “Geosynthetics”, the secretariat of which is held by NBN. Attention is drawn to the possi

14、bility 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 supersedes CEN/TS 14418:2005. According to the CEN-CENELEC Internal Regulations, the national standards

15、 organizations of the following countries are bound to announce this Technical Specification: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, L

16、uxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. PD CEN/TS 14418:2014 CEN/TS 14418:2014 (E) 4 Introduction This Technical Specification defines a method for testing the influence of freezing-thawing cycle

17、s on the flux of clay geosynthetic barriers. Such resistance is a requirement for many uses of these products. The influence ratio is an indication of the behaviour of the product when exposed to repeated freezing and thawing cycles in earth constructions. The flux of saturated clay geosynthetic bar

18、riers may increase in consequence of repeated freezing-thawing cycles. The Technical Specification does not purport to address all of the safety problems, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and t

19、o comply with any regulations or legislation regardless of the wording in the technical specification. The flux determined using this test method is not considered to be representative of the in-service flux of GBR-Cs. This test determines the influence of freezing-thawing cycles in the absence of a

20、ny other phenomena, for example cation exchange. PD CEN/TS 14418:2014 CEN/TS 14418:2014 (E) 5 1 Scope This Technical Specification describes an index test to determine the influence ratio of freezing-thawing cycles on the flux through saturated clay geosynthetic barriers. This test method is applica

21、ble to GBR-C products with no additional sealing layers attached. 2 Normative references The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references,

22、the latest edition of the referenced document (including any amendments) applies. EN 16416, Geosynthetic clay barriers Determination of water flux index Flexible wall permeameter method at constant head EN ISO 3696, Water for analytical laboratory use Specification and test methods (ISO 3696) EN ISO

23、 10320, Geotextiles and geotextile-related products - Identification on site (ISO 10320) ISO 554, Standard atmospheres for conditioning and/or testing Specifications 3 Terms and definitions For the purposes of this document, the following term and definition applies. 3.1 influence ratio ratio of the

24、 flux of a specimen exposed to freezing-thawing cycles to that of the flux through an unexposed reference specimen, expressed in percent 4 Principle The flux through 100 mm diameter clay geosynthetic barrier specimens is determined with a flexible wall permeameter both on specimens exposed to freezi

25、ng-thawing cycles and on unexposed reference specimens. A specimen either square with an edge length not less than 200 mm or circular with a diameter not less than 200 mm to a tolerance of 0,5 % is hydrated under a pressure of (4 0,2) kPa for 48 h at constant room temperature. After hydration, the s

26、pecimen is stored in the freezer under a pressure of (4 0,2) kPa at 5 C for 24 h. After the freezing period the specimen is allowed to thaw under a pressure of (4 0,2) kPa at room temperature for 24 h. Then the specimen is hydrated again for 24 h at room temperature. This freezing- thawing cycle is

27、performed four times before cutting the test specimen. Eventually the test specimen and the unexposed reference specimen are tested in accordance with EN 16416. 5 Apparatus The apparatus shall consist of the following: a template of known dimensions to a tolerance of 0,5 % either square with an edge

28、 length not less than 200 mm or circular with a diameter not less than 200 mm, a waterproof box large enough to accommodate the specimen, PD CEN/TS 14418:2014 CEN/TS 14418:2014 (E) 6 a rigid chemically inert pressure plate of the same dimensions as the specimen, and not less than 10 mm thick, suffic

29、ient weights to exert a pressure of (4 0,2) kPa on the specimen (allowing for the weight of the pressure plate), a mechanically bonded nonwoven geotextile with a mass per unit area of (250 50) g/m 2 , a freezer capable to maintain a temperature of (5 2) C. 6 Reagent De-ionized water in accordance wi

30、th EN ISO 3696, grade 3. 7 Procedure 7.1 Specimen preparation Inspect the bulk clay geosynthetic barrier specimen to be tested and record any disturbance, irregularity or damage. Choose two representative sections of the specimen for testing, one for the reference specimen and one for the test speci

31、men to be submitted to the freezing-thawing cycles. Place the template on the selected section. Cut the specimens to the exact size of the template with a sharp knife or any other suitable instrument. Remove the specimens carefully to avoid loss of bentonite. The specimen size may be limited by safe

32、ty restrictions on the total mass of the weights where these are to be transported manually. Seal the edges of the clay geosynthetic barrier specimens with waterproof tape or self-adhesive aluminium foil to prevent bentonite loss during further handling. 7.2 Specimen hydration Fill a waterproof box

33、with water. Place a piece of mechanically bonded nonwoven geotextile with a mass per unit area of (250 50) g/m 2on the bottom of the box and manually remove any air bubbles. Place the GBR-C sample on the nonwoven and then put a further piece of similar nonwoven geotextile on top of the GBR-C and man

34、ually remove any air bubbles. Place a pressure plate on the “sandwich” of specimens. Place weights on the pressure plate to obtain a required pressure of (4 0,2) kPa. PD CEN/TS 14418:2014 CEN/TS 14418:2014 (E) 7 Key 1 dead load 2 pressure plate 3 GBR-C sample 4 mechanically bonded nonwoven geotextil

35、e 5 waterproof box Figure 1 GBR-C hydration setup NOTE The use of drainage mats instead of nonwoven geotextile results in unevenness in the surface of GBR-Cs. This could lead to incorrect measurements. Add de-ionized water to the box so that the water level is not above the top of the pressure plate

36、. In order to maintain the GBR-C specimen submerged, add water at the rate it is absorbed by the GBR-C specimen. Keep the specimen submerged at room temperature selected according to ISO 554 and at a pressure of (4 0,2) kPa. 7.3 Specimen freezing After 48 h, remove the excess water from the box. Pre

37、set the freezer to a temperature of (5 2) C prior to placing specimen inside it. Move the box containing the test specimen with the weights and the pressure plate to the freezer. Allow the test specimen to freeze for 24 h. The freezer temperature shall be (5 2) C. 7.4 Specimen thawing After the free

38、zing period allow the specimen to thaw for 24 h at room temperature selected according to ISO 554 without adding any water. Then add water again according to the procedure described in 7.2. Submerge the specimen again for a minimum of 24 h at room temperature selected according to ISO 554 without ad

39、ding any water unless it can be shown that omitting this point has no influence on the test result. 7.5 Repetition Repeat steps from 7.2 to 7.4 a further three times. 7.6 Preparation of specimen for flux testing Remove the weights and the nonwoven geotextile pieces and the clay geosynthetic barrier

40、specimen from the box and carefully place the specimen on a flat smooth surface. PD CEN/TS 14418:2014 CEN/TS 14418:2014 (E) 8 Take a (100 2) mm diameter specimen and perform the test in accordance with EN 16416. Perform the test in accordance with EN 16416 on an unexposed reference specimen. 8 Calcu

41、lation and expression of results 8.1 Recording of data The following data shall be recorded for each test: a) the duration of the different conditioning periods (saturation, freezing, thawing); b) the freezer temperature; c) all flux values determined and the corresponding time periods. 8.2 Calculat

42、ion and expression of results Calculate the influence ratio R of freezing-thawing cycles as follows: 100 test reference () q R q = where q testis the flux value (in m 3 /(m 2 .s) of the test specimen after exposure to the wetting-drying cycles; q referenceis the flux value in (m 3 /(m 2 .s) of the r

43、eference specimen. 9 Test Report The test report shall include the following particulars: a) number and date of this standard; b) identification of the sample in accordance with EN ISO 10320, date of receipt and date of testing; c) conditioning atmosphere; d) the results obtained, expressed in accor

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