1、BRITISH STANDARDBS ISO 16938-1:2008Building construction Determination of the staining of porous substrates by sealants used in joints Part 1: Test with compressionICS 91.100.50g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54
2、g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58BS ISO 16938-1:2008This British Standard was published under the authority of the Standards Policy and Strategy Committee on 30 April 2008 BSI 2008ISBN 978 0 580 53260 3National forewordThis British Standard is the UK imple
3、mentation of ISO 16938-1:2008.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 all
4、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 CommentsINTERNATIONALSTANDARDISO16938-1First edition2008-03-01Reference number
5、ISO 16938-1:2008(E)Building construction Determination of the staining of porous substrates by sealants used in joints Part 1:Test with compressionConstruction immobilire Dtermination du tachage des supports poreux par les mastics utiliss dans les joints Partie 1: Essai avec compressionBS ISO 16938-
6、1:2008ii 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 subject for
7、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) on all m
8、atters 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 circul
9、ated 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 responsible
10、for identifying any or all such patent rights.ISO 16938-1 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 substrat
11、es by sealants used in joints: Part 1: Test with compression Part 2: Test without compressionBS ISO 16938-1:2008blank1Building construction Determination of the staining of porous substrates by sealants used in joints Part 1:Test with compression1ScopeThis part of ISO 16938 specifies a method for de
12、termining 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 the test is
13、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 discolour the tes
14、ted poroussubstrate over a longer time period. Experience in various countries with similar test methods has shown thatthe compression of test specimens further accelerates the occurrence of staining.2 Normative referencesThe following referenced documents are indispensable for the application of th
15、is document. For datedreferences, only the edition cited applies. For undated references, the latest edition of the referenced document(including any amendments) applies.ISO 4892-1, Plastics Methods of exposure to laboratory light sources Part 1: General guidanceISO 4892-2:2006, Plastics Methods of
16、exposure to laboratory light sources Part 2: Xenon-arc lampsISO 4892-3, Plastics Methods of exposure to laboratory light sources Part 3: Fluorescent UV lampsISO 6927, Building construction Jointing products Sealants VocabularyISO 11431:2002, Building construction Jointing products Determination of a
17、dhesion/cohesion propertiesof sealants after exposure to heat, water and artificial light through glass3 Terms and definitionsFor the purposes of this document, the terms and definitions given in ISO 6927 apply.4 PrincipleThis method measures the visible staining attributed to joint sealants on poro
18、us substrates that is a result of theconditioning specified.A sealant is applied and cured between two pieces of porous substrate. The test specimens are compressedand then subjected to heat aging and/or cold aging and/or aging in actinic radiation accelerated weatheringequipment. After aging, the t
19、est specimens are evaluated and visible staining is recorded on the exterior surfaceand in the interior of the substrate after visual inspection of changes in surface appearance and measurementsof maximum and minimum stain width and stain penetration.BS ISO 16938-1:200825 Apparatus5.1 Substrate mate
20、rials, 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 preparation of the test specimens, of cross-section , with non-adherentsurface (see Figure 1).NOTE If the spacers are made of a material t
21、o 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 specimens, e.g. polyethylene (PE) film, preferably onthe advice of the sealant manufacturer.5.4 Masking tape, suitable for covering the tested su
22、rface of the substrates (see Figure 1) to prevent sealantcontamination during specimen preparation.5.5 Ventilated convection-type oven, capable of being maintained at .5.6 Refrigerated enclosure, capable of being maintained at .5.7 Clamps or other device, for maintaining the specimen under compressi
23、on (see Table 1).5.8 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 differ between the exposure to fluorescent ultraviole
24、t 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 8.2.4.5.8.1 Fluorescent ultraviolet radiation/condensation test apparatus, fitted with fluorescent UVA-340lamps having the
25、ir 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 are described in ISO 4892-1. Thetarget value
26、for irradiance at shall be at .5.8.2 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 of ISO 4892-2:2006, Table 3, Method A (cycle 1
27、 or 2). Irradiance at the surface of the testspecimens between the wavelength of and shall be . Irradiance belowshall not exceed .5.9 Black standard thermometer, complying with the requirements of ISO 4892-1. All temperatures reportedin this part of ISO 16938 for the UV exposure apparatus are measur
28、ed 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 on the test temperature, but can be up to .5.
29、10 Measuring device, scaled in half millimetres.12 mm 12 mm(70 2)C(20 2)C343 nm340 nm (0,77 0,02) W/m260C290 nm 800 nm (550 75) W/m2300 nm 1 W/m210CBS ISO 16938-1:200836 Preparation of test specimensFour test specimens for each sealant and each aging method shall be prepared.For each test specimen,
30、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 procedure for multi-component sealants, shall be fo
31、llowed.Dimensions in millimetresKey1substrate2sealnt3spacer4 tested surface5 tooled surfaceFigure 1 Test specimen assemblyBS ISO 16938-1:20084The following procedure shall be used for specimen preparation:a) the sealant and the substrate materials (5.1) shall be brought to ;b) the tested surface of
32、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 preparation;d) the hollow volume formed by the substr
33、ate 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 masking tapes on the faces of the substratemat
34、erials 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; the specimens shall remain in this position wi
35、th 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 Test procedure8.1 CompressionAll test specimens shall be compressed by a percentage equal to the movement capability for the sealan
36、t undertest. This compression shall be , , or or any other compression as agreed by theconcerned parties. The sealant shall be held at this compression (see Table 1) using suitable clamps (5.7).8.2 Aging procedures8.2.1 GeneralOne or more of the following aging procedures (8.2.2, 8.2.3, 8.2.4) shall
37、 be carried out as agreed between theconcerned parties.8.2.2 Heat agingFour of the compressed specimens shall be placed in an oven (5.5) at . Remove two specimensafter and the other two specimens after .Table 1 Correspondence of movement capability, compression and joint width after compressionMovem
38、ent capability Compression Joint width after compression() () (mm)7,5 7,5 11,112,5 12,5 10,520 20 9,625 25 9,0(23 2)C48 h28 d (23 2)C (50 5) %7,5 % 12,5 % 20 % 25 % %(70 2)C14 d 28 dBS ISO 16938-1:200858.2.3 Cold agingFour of the compressed specimens shall be placed in a refrigerated enclosure (5.6)
39、 at . Removetwo specimens after and the other two specimens after .8.2.4 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 (5.8.1)
40、 with wet exposure condition see a); xenon lamp test apparatus (5.8.2) with wet exposure condition see b); UV fluorescent radiation condensation apparatus (5.8.1) with dry exposure condition see c); xenon lamp test apparatus (5.8.2) with dry exposure condition see d).Four of the compressed specimens
41、 shall be placed in the actinic radiation exposure apparatus, with the testedsurface perpendicularly facing the radiation source. Two specimens shall be removed after and the othertwo specimens after .Wet exposure.a) In the UV fluorescent radiation/condensation test apparatus the sealant surface sha
42、ll 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 of dry periods with radiationfollowed by wet periods (water s
43、pray 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. The UV fluorescent radiation/condensation test apparatus shall
44、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 (5.9).9 Detection of staining9.1 GeneralAfter aging, the compression on the test specimens shall be released
45、 and the specimens shall be conditionedat and relative humidity for one day.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 stain wi
46、dth on the tested surface ofthe substrate shall be measured to the nearest , using the measurement device (5.10) (see Figure 2),and recorded.(20 2)C14 d 28 d14 d28 d50 mm8h (60 2)C 4h (50 2)C50 mm(60 2)C500 h(65 2)C(23 2)C (50 5) %0,5 mmBS ISO 16938-1:200869.3 Detection in the depth of the substrate
47、The 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 half. The bulk of thesubstrate shall be examined to determine if the sealant has caused any discoloration
48、 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 the measurement device (5.10).9.4 Expression of resultsThe minimum and maximum measurements of stain wi
49、dth and penetration of each of the two specimens shallbe determined for each of the test conditions (see Figure 4 for an example worksheet).For 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 length UV lamp.Sometimes the detection of hydrophobic staining may be improved by wetting t
