BS ISO 16938-2-2008 Building construction - Determination of the staining of porous substrates by sealants used in joints - Test without compression《建筑结构 通过接缝密封胶测定多孔基板的锈蚀性 非压缩试验》.pdf

《BS ISO 16938-2-2008 Building construction - Determination of the staining of porous substrates by sealants used in joints - Test without compression《建筑结构 通过接缝密封胶测定多孔基板的锈蚀性 非压缩试验》.pdf》由会员分享，可在线阅读，更多相关《BS ISO 16938-2-2008 Building construction - Determination of the staining of porous substrates by sealants used in joints - Test without compression《建筑结构 通过接缝密封胶测定多孔基板的锈蚀性 非压缩试验》.pdf（14页珍藏版）》请在麦多课文档分享上搜索。

1、BRITISH STANDARDBS ISO 16938-2:2008Building construction Determination of the staining of porous substrates by sealants used in joints Part 2: Test without compressionICS 91.100.50g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36

2、g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58BS ISO 16938-2:2008This British Standard was published under the authority of the Standards Policy and Strategy Committee on 30 April 2008 BSI 2008ISBN 978 0 580 53261 0National forewordThis British Standard is the UK im

3、plementation of ISO 16938-2:2008.The UK participation in its preparation was entrusted to Technical Committee B/547, Sealants for building and construction.A list of organizations represented on this committee can be obtained on request to its secretary.This publication does not purport to include a

4、ll the necessary provisions of a contract. Users are responsible for its correct application.Compliance with a British Standard cannot confer immunity from legal obligations. Amendments/corrigenda issued since publicationDate CommentsINTERNATIONALSTANDARDISO16938-2First edition2008-03-01Reference nu

5、mberISO 16938-2:2008(E)Building construction Determination of the staining of porous substrates by sealants used in joints Part 2:Test without compressionConstruction immobilire Dtermination du tachage des supports poreux par les mastics utiliss dans les joints Partie 2: Essai sans compressionBS ISO

6、 16938-2:2008ii iiiForewordISO (the International Organization for Standardization) is a worldwide federation of national standards bodies(ISO member bodies). The work of preparing International Standards is normally carried out through ISOtechnical committees. Each member body interested in a subje

7、ct for which a technical committee has beenestablished has the right to be represented on that committee. International organizations, governmental andnon-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the InternationalElectrotechnical Commission (IEC) o

8、n all matters of electrotechnical standardization.International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.The main task of technical committees is to prepare International Standards. Draft International Standardsadopted by the technical committees are

9、 circulated to the member bodies for voting. Publication as anInternational Standard requires approval by at least 75 % of the member bodies casting a vote.Attention is drawn to the possibility that some of the elements of this document may be the subject of patentrights. ISO shall not be held respo

10、nsible for identifying any or all such patent rights.ISO 16938-2 was prepared by Technical Committee ISO/TC 59, Building construction, Subcommittee SC 8,Jointing products.ISO 16938 consists of the following parts, under the general title Building construction Determination of thestaining of porous s

11、ubstrates by sealants used in joints: Part 1: Test with compression Part 2: Test without compressionBS ISO 16938-2:2008blank1Building construction Determination of the staining of porous substrates by sealants used in joints Part 2:Test without compression1ScopeThis part of ISO 16938 specifies a met

12、hod for determining the staining of porous substrates (e.g. marble,limestone, sandstone, or granite) by sealants used in building construction. The method evaluates the likelihoodof a sealant causing an early stain on a porous substrate due to exudation of materials from the sealant. Theoutcome of t

13、he test is specific to the tested sealant and tested substrate and cannot be extrapolated to othersealant formulations or other porous substrates. During this accelerated test, if the sealant does not stain ordiscolour the substrates, it does not mean that the tested sealant will not stain or discol

14、our the tested poroussubstrate over a longer time period.2 Normative referencesThe following referenced documents are indispensable for the application of this document. For datedreferences, only the edition cited applies. For undated references, the latest edition of the referenced document(includi

15、ng any amendments) applies.ISO 4892-1, Plastics Methods of exposure to laboratory light sources Part 1: General guidanceISO 4892-2:2006, Plastics Methods of exposure to laboratory light sources Part 2: Xenon-arc lampsISO 4892-3, Plastics Methods of exposure to laboratory light sources Part 3: Fluore

16、scent UV lampsISO 6927, Building construction Jointing products Sealants VocabularyISO 11431:2002, Building construction Jointing products Determination of adhesion/cohesion propertiesof sealants after exposure to heat, water and artificial light through glass3 Terms and definitionsFor the purposes

17、of this document, the terms and definitions given in ISO 6927 apply.4 PrincipleThis method measures the visible staining attributed to joint sealants on porous substrates that is a result of theconditioning specified.A sealant is applied and cured between two pieces of porous substrate. The test spe

18、cimens are subjected toheat aging and/or cold aging and/or aging in actinic radiation accelerated weathering equipment. After aging,the test specimens are evaluated and visible staining is recorded on the exterior surface and in the interior of thesubstrate after visual inspection of changes in surf

19、ace appearance and measurements of maximum andminimum stain width and stain penetration.BS ISO 16938-2:200825 Apparatus5.1 Substrate materials, for the preparation of each test specimen; two substrate pieces of the samematerial are required with dimensions as shown in Figure 1.5.2 Spacers, for the p

20、reparation of the test specimens, of cross-section , with non-adherentsurface (see Figure 1).NOTE If the spacers are made of a material to which the sealant adheres, their surfaces should be made non-adherent,e.g. by a thin wax coating.5.3 Non-adherent substrate, for the preparation of test specimen

21、s, e.g. polyethylene (PE) film, preferably onthe advice of the sealant manufacturer.5.4 Masking tape, suitable for covering the tested surface of the substrates (see Figure 1) to prevent sealantcontamination during specimen preparation.5.5 Ventilated convection-type oven, capable of being maintained

22、 at .5.6 Refrigerated enclosure, capable of being maintained at .5.7 Actinic radiation accelerated aging apparatus.Fluorescent ultraviolet radiation/condensation test apparatus or xenon light test apparatus shall be employed asactinic radiation accelerated aging apparatus.NOTE Test results can diffe

23、r between the exposure to fluorescent ultraviolet radiation/condensation and xenon lightbecause of differences in the spectral power distribution of the radiation source and differences in the exposure conditionsa) to d). See 8.4.5.7.1 Fluorescent ultraviolet radiation/condensation test apparatus, f

24、itted with fluorescent UVA-340lamps having their peak emission at , capable of exposing the test specimens to radiation undercontrolled conditions of temperature and moisture or water, complying with the requirements of ISO 4892-3.Standard practices for operating such accelerated weathering chambers

25、 are described in ISO 4892-1. Thetarget value for irradiance at shall be at .5.7.2 Xenon light test apparatus, fitted with xenon light source with daylight filter, capable of exposing thetest specimens to radiation under controlled conditions of temperature and water, complying with therequirements

26、of ISO 4892-2:2006, Table 3, Method A (cycle 1 or 2). Irradiance at the surface of the testspecimens between the wavelength of and shall be . Irradiance belowshall not exceed .5.8 Black standard thermometer, complying with the requirements of ISO 4892-1. All temperatures reportedin this part of ISO

27、16938 for the UV exposure apparatus are measured with the black standard thermometer.Black panel thermometer may also be used. Under given operating conditions, they tend to indicate lowertemperatures than the black standard thermometer. The temperature difference between the measurementswill depend

28、 on the test temperature, but can be up to .5.9 Measuring device, scaled in half millimetres.12 mm 12 mm(70 2)C(20 2)C343 nm340 nm (0,77 0,02) Wm260C290 nm 800 nm (550 75) W/m2300 nm 1 W/m210CBS ISO 16938-2:200836 Preparation of test specimensFour test specimens for each sealant and each aging metho

29、d shall be prepared.For each test specimen, two substrate materials (5.1) and two spacers (5.2) shall be assembled (see Figure 1)and set up on the non-adherent substrate (5.3).The instructions of the sealant manufacturer concerning, for instance, whether a primer is to be used, and themixing procedu

30、re for multi-component sealants, shall be followed.Dimensions in millimetresKey1substrate2sealnt3spacer4 tested surface5 tooled surfaceFigure 1 Test specimen assemblyBS ISO 16938-2:20084The following procedure shall be used for specimen preparation:a) the sealant and the substrate materials (5.1) sh

31、all be brought to ;b) the tested surface of both substrate materials shall be placed in the same plane as the tooled surface of thesealant (see Figure 1).c) masking tape (5.4) shall be applied on the tested surfaces of the substrate materials to prevent sealantcontamination during specimen preparati

32、on;d) the hollow volume formed by the substrate materials and spacers (5.2) shall be filled with the sealant(avoiding the formation of air bubbles);e) the sealant shall be pressed to the inner surfaces of the substrate materials;f) the sealant surface shall be trimmed so that it is flush with the ma

33、sking tapes on the faces of the substratematerials and spacers;g) immediately following application and tooling of the sealant, the masking tape shall be removed;h) the test specimens shall be set on edge on one of the substrate materials and the non-adherent substrateremoved as soon as possible; th

34、e specimens shall remain in this position with the spacers in place foranother to allow curing or optimum drying of the sealant.7 ConditioningThe test specimens shall be conditioned for at and relative humidity.8 Aging procedures8.1 GeneralOne or more of the following aging procedures (8.2, 8.3, 8.4

35、) shall be carried out as agreed between theconcerned parties.8.2 Heat agingFour of the specimens shall be placed in an oven (5.5) at . Remove two specimens after andthe other two specimens after .8.3 Cold agingFour of the specimens shall be placed in a refrigerated enclosure (5.6) at . Remove twosp

36、ecimens after and the other two specimens after .8.4 Actinic radiation agingAs agreed between the concerned parties, the test specimens shall be exposed to actinic radiation according toone of the following aging procedures: UV fluorescent radiation condensation apparatus (5.7.1) with wet exposure c

37、ondition see a); xenon lamp test apparatus (5.7.2) with wet exposure condition see b); UV fluorescent radiation condensation apparatus (5.7.1) with dry exposure condition see c); xenon lamp test apparatus (5.7.2) with dry exposure condition see d).Four of the specimens shall be placed in the actinic

38、 radiation exposure apparatus, with the tested surfaceperpendicularly facing the radiation source. Two specimens shall be removed after and the other twospecimens after .(23 2)C48 h28 d (23 2)C (50 5) %(70 2)C 14 d28 d(20 2)C14 d 28 d14 d28 dBS ISO 16938-2:20085Wet exposure.a) In the UV fluorescent

39、radiation/condensation test apparatus the sealant surface shall be held fromthe radiation source. The cycle of the UV fluorescent radiation/condensation test apparatus shall be set toUV radiation at , and condensation at .b) In the xenon-lamp test apparatus, the specimens shall be exposed to cycles

40、of dry periods with radiationfollowed by wet periods (water spray or immersion) as defined in ISO 11431:2002 , 8.2.2 (automatic cycling)or 8.2.3 (manual cycling).Dry exposure.c) In the UV fluorescent radiation/condensation test apparatus, the sealant surface shall be held fromthe radiation source. T

41、he UV fluorescent radiation/condensation test apparatus shall be set to UV radiationat .d) In the xenon-lamp test apparatus, the specimens shall be exposed dry to radiation for a period of at atemperature of as measured on the black standard thermometer (5.8).9 Detection of staining9.1 GeneralAfter

42、aging, the test specimens shall be conditioned at and relative humidity for oneday.9.2 Detection at the surface of the substrateThe substrates shall be examined to determine if the sealant caused the tested surface to change inappearance in any way. If so, the maximum and minimum dimensions of the s

43、tain width on the tested surface ofthe substrate shall be measured to the nearest , using the measurement device (5.9) (see Figure 2), andrecorded.Key1 substrate material2 minimum stain width3 maximum stain widthFigure 2 Determination of minimum and maximum stain width50 mm8h (60 2)C 4h (50 2)C50 mm

44、(60 2)C500 h(65 2)C(23 2)C (50 5) %0,5 mmBS ISO 16938-2:200869.3 Detection in the depth of the substrateThe substrates shall be broken perpendicular to the joint within the area of maximum stain width. If no stainingcan be observed on the tested substrate surface, the substrates shall be broken in h

45、alf. The bulk of thesubstrate shall be examined to determine if the sealant has caused any discoloration of the substrate itself. Themaximum and minimum of the stain penetration into the bulk substrate (see Figure 3) at the centre of thesealant joint ( depth) shall be recorded to the nearest , using

46、 the measurement device (5.9).9.4 Expression of resultsThe minimum and maximum measurements of stain width and penetration of each of the two specimens shallbe determined for each of the test conditions (see Figure 4 for an example worksheet).Key1 minimum stain penetration2 maximum stain penetration

47、Figure 3 Determination of minimum and maximum stain penetrationExposure Specimen SubstrateDuration14 days 28 daysMinimum stain widthMaximum stain widthMinimum stain widthMaximum stain width1A28415B358 22A46910B2459Report 2 8 4 151AB2ABReportXenon (wet exposure)1AB2ABReportFigure 4 Example worksheet

48、for determination of reportable maximumand minimum stain width and penetration6mm 0,5 mm70C20CBS ISO 16938-2:20087For some sealant formulations, the ease and reliability of the detection of staining may be improved byinspecting the test specimen in a dark room under illumination with a short-wave le

49、ngth UV lamp.Sometimes the detection of hydrophobic staining may be improved by wetting the substrates with water. Somesealants may stain the substrates completely, resulting in a uniform discolouration of the substrates and makingthe detection of the stain difficult. In this situation, it may be helpful to compare the substrate surface to anunexposed control.10 Test reportThe test report shall include the