1、BRITISH STANDARD BS3712-1: 1991 Building and construction sealants Part 1: Methods of test for homogeneity, relative density and penetrationBS3712-1:1991 This British Standard, having been prepared under the directionof the Elements and Components (of Diverse Materials)for Buildings Standards Policy
2、 Committee, waspublished under the authorityof the Standards Boardand comes into effect on 30 August1991 BSI07-1999 First published April1964 Second edition January1974 Third edition August1985 Fourth edition August1991 The following BSI references relate to the work on this standard: Committee refe
3、rence ECB/3 Special announcement in BSINews August1991 ISBN 0 580 19921 5 Committees responsible for this British Standard The preparation of this British Standard was entrusted by the Elements and Components (of Diverse Materials) for Buildings Standards Policy Committee (ECB/-) to Technical Commit
4、tee ECB/3, upon which the following bodies were represented: Aluminium Window Association Association of Sealant Applicators British Adhesives and Sealants Association Building Employers Confederation Department of the Environment (Building Research Establishment) Department of the Environment (Prop
5、erty Services Agency) Flat Glass Manufacturers Association Glass and Glazing Federation Institution of Civil Engineers Refined Bitumen Association Ltd. Society of Architectural and Associated Technicians Society of Chemical Industry Water Services Association of England and Wales Amendments issued s
6、ince publication Amd. No. Date CommentsBS3712-1:1991 BSI 07-1999 i Contents Page Committees responsible Inside front cover Foreword ii 1 Scope 1 2 Definition 1 3 Sampling 1 4 Homogeneity 1 5 Relative density 1 6 Penetration 2 Figure 1 Penetration needles 3 Figure 2 Penetration cones 4 Table 1 Penetr
7、ation determinations 7 Publication(s) referred to Inside back coverBS3712-1:1991 ii BSI 07-1999 Foreword This Part of BS3712, prepared under the direction of the Elements and Components (of Diverse Materials) for Buildings Standards Policy Committee, is a new edition of and supersedes BS3712-1:1985
8、which is withdrawn. This new edition has been necessitated by the need to delete the methods of test for extrudability (which has been published as BS EN28394) and slump (which has been published as BS EN27390). Attention is also drawn to BS EN29048. No review of or technical amendment to the remain
9、ing methods of test in this Part of BS3712 has been made. BS3712 provides a body of test methods suitable for the wide range of sealants of different types and properties now available on the market. The primary aim of these test methods is to enable the properties of sealants to be assessed and for
10、 their quality to be controlled, particularly in relation to their compatibility with other materials and to their suitability for application to building joints. Methods of test are included in other Parts of this British Standard for the following sealant properties: Part 2: Methods of test for se
11、epage, staining, shrinkage, shelf life and paintability; Part 3: Methods of test for application life, skinning properties and tack-free time; Part 4: Method of test for adhesion in peel. It is recognized that the movement capability of a joint sealant is a cardinal property when specifying a materi
12、al for a specific application. However, there are no generally applicable test methods for the assessment of this property within British Standards, since the withdrawal of DD69:1980 in November1989. Two new test methods for movement capability have been developed by ISO Technical Sub-Committee TC59
13、/SC8, which are to be adopted as European and BritishStandards. These are ISO9046:1987 (BS EN29046) “Building construction Sealants Determination of adhesion/cohesion properties at constant temperature”, which is appropriate for the assessment of sealants of predominantly plastic properties; and ISO
14、9047:1989 “Building construction Sealants Determination of adhesion/cohesion properties at variable temperature”, which is suitable for elastomeric sealants. Further work is in progress by the ISO Technical Sub-Committee to develop a test method for the assessment of the movement capability of high-
15、performance elastomeric sealants capable of withstanding total movement of amplitudes greater than25% of the joint width. It is likely that in due course the resulting international standard will be adopted as a European Standard and as a British Standard. Test methods to allow the assessment of dur
16、ability of sealants in service are also needed, though progress in this field is likely to be gradual. At present the following British Standard specifications for sealants are available: BS2499, Specification for hot applied joint sealants for concrete pavements. BS4254, Specification for two-part
17、polysulphide-based sealants. BS5212, Cold applied joint sealant systems for concrete pavements. BS5215, Specification for one-part gun grade polysulphide-based sealants. BS5889, Specification for one-part gun grade silicone-based sealants. Although it is expected that in due course these prescriptiv
18、e specifications will be superseded by appropriate performance specifications, they contain some methods of test appertaining to performance in service which are not at present included in BS3712.BS3712-1:1991 BSI 07-1999 iii A British Standard does not purport to include all the necessary provision
19、s 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 legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pagesi toiv, pages1 to8, an inside b
20、ack cover and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover.iv blankBS3712-1:1991 BSI 07-1999 1 1 Scope This Part of BS3712 describes test methods for the following p
21、roperties of building and construction sealants: a) homogeneity; b) relative density; c) penetration. NOTEThe titles of the publications referred to in this standard are listed on the inside back cover. 2 Definition For the purposes of this Part of BS3712 the following definition applies. building s
22、ealant a joint sealant for building and construction, applied by hand, gun, knife, or trowel, or in strip form, or by pouring, and intended to maintain a seal between the sides of a joint which is subject to some degree of movement NOTEThe strip form materials covered by this definition are plastic
23、at the time of application, i.e.readily deformable but not capable of reverting to their original shape. 3 Sampling Take samples of building sealants as described in eithera),b) orc): a) select at random sufficient unopened packages to provide material for the tests; b) select sufficient material at
24、 random from the bulk supply; c) take single samples from a gun for specific tests. 4 Homogeneity NOTEThe homogeneity of a building sealant, i.e.the uniform dispersion of the ingredients, is an important property which is best assessed by inspection. 4.1 Preparation of sample Condition the sample in
25、 closed containers at25 1 C for16h prior to inspection. 4.2 Test procedure Inspect the samples for separation of components, skin formation or foreign matter. 4.3 Test report The report shall include the following information: a) the type of sealant; b) the manufacturers batch number (if known); c)
26、the method of sampling; d) whether there was any separation of components and, if so, whether the sealant could be restored to a condition suitable for use by normal agitation appropriate to the sealant and its package; e) whether there was any skin formation; f) the presence of any foreign matter.
27、5 Relative density 5.1 General Methods for measuring the relative density of pouring grade sealants and sealants which do not flow are described in5.2 to5.5. 5.2 Apparatus 5.2.1 Balance, capable of weighing up to200g to an accuracy of0.01g. 5.2.2 Relative density cup 1) , having a nominal capacity o
28、f100mL, complete with a cover and a suitable overflow orifice. 5.2.3 Constant temperature enclosure, maintained at25 1 C. 5.3 Preparation of sample and water Inspect the sample for separation of components, skin formation or foreign matter. Remove any skin. Condition the sample and the relative dens
29、ity cup(5.2.2) in the constant temperature enclosure(5.2.3) for not less than4h or until the constant temperature is achieved. At the same time, condition an adequate quantity of deionized or distilled water to the same temperature. 5.4 Test procedure 5.4.1 Stage one Weigh the empty relative density
30、 cup, complete with cover, then fill with conditioned deionized or distilled water. Fit the cover and wipe off any excess water which overflows, ensuring that the container is full to the top of the overflow orifice. Reweigh and record the difference in grams between the mass of the container and th
31、e mass of the container filled with water. Empty and dry the cup. 5.4.2 Stage two 5.4.2.1 Pouring grade sealants Fill the cup with sealant, taking care to avoid entrapped air. Fit the cover and wipe off excess sealant, making sure the cup is full to the top of the orifice. Weigh the full cup complet
32、e with cover. Record the difference in grams between this mass and the mass of the empty cup complete with cover. 1) Commonly known as a “weight per gallon” cup.BS3712-1:1991 2 BSI 07-1999 5.4.2.2 Non-sag and strip sealants Place in the cup a volume of sealant not less than15mL. NOTENon-sag gun-grad
33、e sealant can be extruded directly from the cartridge. Preformed strip can be cut from an extruded length. Trowelling grades of sealant can be transferred in the form of a single blob, using a spatula. Replace the cup lid and reweigh. Completely fill the cup with conditioned deionized or distilled w
34、ater. During the filling operation, brush the surface of the sealant lightly to remove any air bubbles. Fit the cover and wipe off any excess water which overflows, ensuring that the container is full to the top of the overflow orifice. Weigh the cup and sealant and water. 5.5 Expression of results
35、Calculate the relative density, r, to an accuracy of 0.05 using the following formulae: for pouring grade sealants for non-sag sealants where 5.6 Test report The report shall include the following information: a) the type of sealant; b) the manufacturers batch number (if known); c) the method of sam
36、pling; d) whether there was any separation of components and, if so, whether the sealant could be restored to a condition suitable for use by normal agitation appropriate to the sealant and its package; e) whether there was any skin formation; f) the presence of any foreign matter; g) the relative d
37、ensity to an accuracy of 0.05. 6 Penetration 6.1 General The object of the penetration test is to make an assessment of a property usually referred to as the consistency. It is not suitable for sealants which contain coarse lumps, show visible signs of separation or caking, or show any lack of unifo
38、rmity within the sample. The penetration is the distance in tenths of a millimetre which a specified needle (see6.2.1) or cone (see6.2.2) penetrates vertically into a specimen under specified conditions of loading, time and temperature. 6.2 Apparatus NOTEEach piece of apparatus adopted for use in th
39、e penetration test originated from various sources in the UK or elsewhere and was manufactured in accordance with the specification from which it was taken. For this reason it is not always possible to describe all apparatus in rounded off metric dimensions, e.g.as the ball-ended needle and penetrat
40、ion cones are manufactured in imperial sizes, they are described in metric equivalents to the original imperial units. 6.2.1 Penetration needles 6.2.1.1 General. Use one of the types of polished stainless steel needle described in6.2.1.2 to6.2.1.4. 6.2.1.2 Needle,50.8mm long and1.6mm diameter, termi
41、nating at one end in a4.8mm diameter stainless steel ball and at the other end in a brass shank25.4mm long and3.175mm diameter seeFigure 1(a). 6.2.1.3 Flat-ended cylindrical needle,2mm diameter. 6.2.1.4 Needle, as shown inFigure 1(b) of1.00mm to1.02mm diameter, symmetrically tapered at one end to a
42、cone approximately6.35mm in height. The angle of the cone is within the range8409 and9409. After tapering, the needle is “blunted” by grinding to a truncated cone, the smaller base of which is0.14mm to0.16mm in diameter. The length of the frustrum is4.8mm to5.8mm. The finished needle is mounted in a
43、 brass shank not more than3.2mm in diameter,20mm to25mm long. The total length of the needle protruding from the shank is approximately50mm. The mass of the needle and shank is1.5g to2.0g. m 0 is the mass of the container; m 1 is the mass of the container plus sealant; m 2 is the mass of the contain
44、er filled with water; m 3 is the mass of the container filled with sealant and water. r m 1 m 0 m 2 m 0 - = r m 1 m 0 m 2 m 0 ()m 3 m 1 () - =BS3712-1:1991 BSI 07-1999 3 6.2.2 Penetration cones 6.2.2.1 General. Use one of the types of cone described in6.2.2.2 and6.2.2.3. 6.2.2.2 Cone, consisting of
45、brass or corrosion resistant steel with a detachable hardened steel or stainless steel tip, of the external dimensions shown inFigure 2(a). The outside surface of the cone and tip are given a very smooth finish. The total moving mass is150g. NOTEThe internal construction and dimensions are intended
46、as suggestions only and may be modified as desired. 6.2.2.3 Cone, of magnesium or other suitable material with a detachable hardened steel tip, of the dimensions shown inFigure 2(b). The total mass of the cone is102.5 0.05g and of the shaft, collet and stop rings47.5 0.05g. The shaft is a rigid, smo
47、oth rod having a stop at its upper end and a suitable means for engaging the cone at its lower end. The outer surface is polished to a smooth finish. NOTEThe interior construction may be modified to achieve the specified mass, provided the general contour and mass distribution are not altered. Figur
48、e 1 Penetration needlesBS3712-1:1991 4 BSI 07-1999 Figure 2 Penetration conesBS3712-1:1991 BSI 07-1999 5 NOTETolerances on all dimensions1.6min. (b) All dimensions are in millimetres.Figure 2 Penetration cones (concluded)BS3712-1:1991 6 BSI 07-1999 6.2.3 Penetrometer, which permits the needle holder
49、 to move vertically in the guide without appreciable friction and which is capable of indicating the depth of penetration to the nearest0.1mm. The sides of the guide are vertical. When used with a needle, the total moving mass (needle, holder and superimposed weight) is50 0.25g, and is adjustable to give total moving masses such as25g (by removing superimposed weights),100g (by adding more weights), or any intermediate loading. Whe
