BS EN 12224-2000 Geotextiles and geotextile-related products - Determination of the resistance to weathering《土工织物及其相关产品 耐气候老化性能测定》.pdf

《BS EN 12224-2000 Geotextiles and geotextile-related products - Determination of the resistance to weathering《土工织物及其相关产品 耐气候老化性能测定》.pdf》由会员分享，可在线阅读，更多相关《BS EN 12224-2000 Geotextiles and geotextile-related products - Determination of the resistance to weathering《土工织物及其相关产品 耐气候老化性能测定》.pdf（12页珍藏版）》请在麦多课文档分享上搜索。

1、| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | BRITISH STANDARD BS EN 12224:2000 The Euro

2、pean Standard EN 12224:2000 has the status of a British Standard ICS 59.080.70 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW Geotextiles and geotextile-related products Determination of the resistance to weatheringThis British Standard, having been prepared under the directi

3、on of the Sector Committee for Building and Civil Engineering, was published under the authority of the Standards Committee and comes into effect on 15 November 2000 BSI 11-2000 ISBN 0 580 36551 4 BS EN 12224:2000 Amendments issued since publication Amd. No. Date Comments National foreword This Brit

4、ish Standard is the official English language version of EN 12224:2000. It supersedes DD ENV 12224:1997 which is withdrawn. The UK participation in its preparation was entrusted to Technical Committee B/553, Geomembranes and geotextiles, which has the responsibility to: aid enquirers to understand t

5、he text; present to the responsible European committee 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 committee can be

6、 obtained on request to its secretary. Cross-references The British Standards which implement international or European publications referred to in this document may be found in the BSI Standards Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Fi

7、nd” facility of the BSI Standards Electronic Catalogue. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from lega

8、l obligations. Summary of pages This document comprises a front cover, an inside front cover, the EN title page, pages 2 to 9 and a back cover. The BSI copyright notice displayed in this document indicates when the document was last issued.EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 12224 S

9、eptember 2000 ICS 59.080.70 Supersedes ENV 12224:1996 English version Geotextiles and geotextile-related products - Determination of the resistance to weathering Gotextiles et produits apparents - Dtermination de la rsistance au vieilissement d aux conditions climatiques Geotextilien und geotextilve

10、rwandte Produkte - Bestimmung der Witterungsbestndigkeit This European Standard was approved by CEN on 15 July 2000. 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 an

11、y alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the Central Secretariat or to any CEN member. This European Standard exists in three official versions (English, French, German). A version in any other language made by

12、 translation under the responsibility of a CEN member into its own language and notified to the Central Secretariat 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, Iceland, Ire

13、land, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Central Secretariat: rue de Stassart, 36 B-1050 Brussels 2000 CEN All rights of exploitation in

14、any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 12224:2000 EPage 2 EN 12224:2000 BSI 11-2000 Foreword This European Standard has been prepared by Technical Committee CEN/TC 189, Geotextiles and geotextiles-related products, the Secretariat of which is held by IBN.

15、This European Standard supersedes ENV 12224:1996. 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 March 2001, and conflicting national standards shall be withdrawn at the latest by March 2001. Acc

16、ording to the CEN/CENELEC Internal 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, Netherlands, Norway, Portug

17、al, Spain, Sweden, Switzerland and the United Kingdom.Page 3 EN 12224:2000 BSI 11-2000 Introduction The effect of weathering on the properties of geotextiles and geotextile-related products is of technical importance for many of their applications. Since natural weathering requires testing at long d

18、urations, there is a need to obtain information more rapidly and reproducibly by accelerated procedures. For this purpose weathering devices with specific artificial light sources are used. NOTE: For further information see CR ISO 13434. 1 Scope This European Standard describes a method for determin

19、ing the resistance of geotextiles and geotextile-related products to weathering conditions more intense than those of natural weathering. This is an index test to differentiate between products with little or no resistance to weathering and those which do have this resistance. 2 Normative references

20、 This European Standard incorporates by dated or undated reference, provisions from other publications. These normative references are cited at the appropriate places in the text and the publications are listed hereafter. For dated references, subsequent amendments to or revisions of any of these pu

21、blications apply to this European Standard only when incorporated in it by amendment or revision. For undated references the latest edition of the publication referred to applies (including amendments). EN 12226:2000 Geotextiles and geotextile-related products - General tests for evaluation followin

22、g durability testing ISO 4892-1 Plastics - Methods of exposure to laboratory light sources - Part 1: General guidance ISO 4892-3 Plastics - Methods of exposure to laboratory light sources - Part 3: Fluorescent UV lamps 3 Principle Specimens of the material to be tested are exposed to a light source

23、for a defined radiant exposure or exposure time and at recommended temperature and moisture conditions. After this exposure the change in performance of these specimens is determined.Page 4 EN 12224:2000 BSI 11-2000 4 Apparatus 4.1 Laboratory light sources The light sources used shall be fluorescent

24、 UV lamps in accordance with ISO 4892-3. To improve the correlation with outdoor exposure the spectrum of the light source shall be as near as possible to that of solar global radiation, particularly in the ultraviolet region, because polymers are generally very sensitive to changes in this spectral

25、 region. NOTE: Fluorescent tubes can be selected to have a spectral output corresponding to that of the actinic ultraviolet region in solar global radiation. The spectral irradiance of the fluorescent lamps in the UV-region shall be as given in Table 1. Table 1 - Fluorescent UV lamps - spectral irra

26、diance Irradiance in the band (in W/m ) a) Wavelength band ( ) (in nm) Type I (340 nm) Combination of different types of lamps 290 to 320 3,1 3,3 320 to 360 25,1 22,0 360 to 400 11,0 18,0 a) Tolerances on all irradiances are 10 %. As the characteristics of lamps and filters change in use due to agei

27、ng, they shall be replaced at appropriate intervals as recommended by the manufacturer of the lamp. 4.2 Temperature monitoring system As the temperature of the specimen influences the result of the exposure test, the ambient temperature shall be controlled. To this purpose a black standard thermomet

28、er in accordance with ISO 4892-1 shall be used, mounted instead of a specimen holder with the blackened metal side facing the lamp. NOTE 1: Fluorescent tubes produce little infrared radiation and there is generally no heat problem. As degradation processes generally run faster with increasing temper

29、ature, the surface temperature of specimens however remains an essential test parameter. NOTE 2: The temperature is controlled by a black panel thermometer or black standard thermometer, since it is not practical to monitor the individual specimen temperatures. The black standard temperature may be

30、controlled by adjustment of the cooling air circulation. Readings should only be taken after sufficient time for the temperature to become steady.Page 5 EN 12224:2000 BSI 11-2000 4.3 Means of determining radiant exposure (optional) When appropriate, a radiation meter, in accordance with ISO 4892-1,

31、may be included to measure the radiance (E) at the face of the specimen and the total radiant exposure (H). NOTE: A direct comparison of the UV radiant exposure measured in the weathering apparatus with that measured during natural weathering is possible if, in both cases a radiation meter as descri

32、bed above is used. If, for the natural weathering, there are only data for the total radiant exposure, the radiant exposure value obtained in the wavelength range from 280 nm to 400 nm is multiplied by the appropriate factor specific to the apparatus by which the portion of the global radiation of w

33、avelength from 400 nm to 2 450 nm is also taken into account. 4.4 Specimen holders Specimen holders shall be made of two stainless steel grids of mesh size 15 mm to 20 mm and wire diameter of about 1 mm (transmitting area 87 % to 90 % of total area). NOTE: If desired, a portion of each test specimen

34、 may be shielded by an opaque cover throughout the test. This gives an unexposed area adjacent to the exposed area for comparison. 5 Test conditions Materials shall be exposed to continuous radiation according to Table 1 with the following wet/dry cycle: - 5 h dry interval at a black standard temper

35、ature of (50 3) C; - 1 h water spray at a black standard temperature of (25 3) C. If required by the equipment, the fluorescent lamps shall be turned off during the spray interval. If the equipment allows, a cycle with a narrower variation of temperature of (50 1) C and a controlled relative humidit

36、y of (10 5) % during the dry interval should be used. NOTE 1: The photodegradation of geotextiles, especially those made from polyolefines and polyamides, may be strongly influenced by changes of temperature and relative humidity, e.g. the rate of photo-oxidation of polyethylene may increase by 8 %

37、if the temperature increases by 1 C. The radiant exposure shall be 50 MJ/m. NOTE 2: The durations required to reach a radiant exposure of 50 MJ/m have been shown to be approximately: - 320 h for devices with a combination of fluorescent UV lamps; - 350 h for devices with type I (340 nm) fluorescent

38、lamps if the lamps are left on during the water spray; - 430 h for devices with type I (340 nm) fluorescent lamps if the lamps are turned off during the water spray.Page 6 EN 12224:2000 BSI 11-2000 6 Specimens for determination of change in properties Prepare test and control specimens in accordance

39、 with EN 12226:2000. 7 Test procedure 7.1 Mounting of specimens Attach the specimens to the specimen holders in the equipment in such a manner that the specimens are not subject to any mechanical stress. Identify each test specimen by suitable indelible marking, but not on areas to be used in testin

40、g. As a check, retain a plan of the mounting positions. If an opaque cover is used (see 4.4), the data reported shall also be based on a comparison with control specimens stored separately in the dark. NOTE: If desired, a portion of each test specimen may be shielded by an opaque cover throughout th

41、e test. This gives an unexposed area adjacent to the exposed area for comparison. This is useful for checking the progress of exposure. 7.2 Exposure to light sources Before placing the specimens in the test chamber, ensure that the apparatus is operating at the agreed specified conditions. Maintain

42、these conditions throughout the exposure. Expose the mounted specimens for the specified period of exposure (see Clause 5). NOTE: The position of the specimens in the apparatus should be varied from time to time to reduce any local inequalities of exposure conditions. If the position of the specimen

43、s is adjusted, ensure that they remain the same way up. 7.3 Measurement of radiant exposure If the radiant exposure (H) is to be measured, mount an instrument for measuring radiation so that the radiometer indicates the UV irradiance at the test specimens exposed surface. Mount the radiation meter o

44、n a support for a test panel in such a way that it receives the same radiation as a flat specimen on the same support would receive, and locate it either at the specimen distance or where it has a sufficient field of view with the detector calibrated for irradiance (for the calibration procedure: se

45、e ISO 4892-1). Express the exposure interval in terms of radiant exposure in J/m for the UV range. The irradiance (E) in the UV-wavelength range 300 nm to 400 nm or at a specific wavelength in UV (for example at 340 nm) shall be stated in the test report.Page 7 EN 12224:2000 BSI 11-2000 8 Determinat

46、ion of the change in performance of exposed samples The properties of the exposed specimens and controls shall be determined in accordance with EN 12226:2000. 9 Test report The test report shall include the following information: a the number and date of this European Standard; b) the material teste

47、d; c) full record of the exposure conditions, including the following: 1) type and model number of the exposure apparatus; 2) type and age of light source and wattage; 3) type and age of filters, if applied; 4) if applicable, details of the radiant exposure and radiance at the specimen surfaces and

48、the total number of cycles 5) elapsed exposure time (in hours); 6) spray cycle; 7) the black standard temperature; 8) the relative humidity; d) the change in properties of the exposed specimens.Page 8 EN 12224:2000 BSI 11-2000 Annex A (informative) Solar and artificial radiation A.1 General The qual

49、ity and intensity of solar global radiation at the earths surface vary with climate, location and time. Besides solar radiation there are other important factors that affect natural weathering and ageing process such as temperature, temperature cycling, humidity, etc. Therefore a maximum outdoor exposure of six summer months, as a basis of this index test, can cause a broad variability of results. A minimum of two years of natural exposure at a particular location may be required to minimize the variability among results from repeat