SIST EN 12878:2005
(Main)Pigments for the colouring of building materials based on cement and/or lime - Specifications and methods of test
Pigments for the colouring of building materials based on cement and/or lime - Specifications and methods of test
This European Standard specifies the requirements and the test methods for pigments for use in the colouring of building materials based on cement and cement/lime combinations.
Pigments covered by this European Standard can also be used in pure lime mortar. For this application see
EN 459-1 and EN 459-2.
Pigments for this purpose can be single pigments, blends of pigments, or blends of pigments and extenders, in powder or granular form, or aqueous preparations.
Pigments typically belong to one of the following classes of compounds:
- synthetic or natural oxides and hydroxides of iron;
- oxides of chromium, titanium and manganese;
- complex inorganic pigments, for example combinations of the above mentioned metal oxides and hydroxides with cobalt, aluminium, nickel and antimony oxides and hydroxides;
- ultramarine pigments;
- phthalocyanine blue and green;
- elemental carbon (should be regarded as an inorganic pigment);
- blends of the above materials (which may also include extenders).
Pigmente zum Einfärben von zement- und/oder kalkgebundenen Baustoffen - Anforderungen und Prüfverfahren
Diese Europäische Norm legt die Anforderungen und Prüfverfahren für Pigmente fest, die zum Einfärben von
Baustoffen aus Zement und Zement-/Kalkmischungen verwendet werden.
Pigmente nach dieser Europäischen Norm dürfen auch in reinem Kalkmörtel verwendet werden. Für diese
Anwendung siehe EN 459-1 und EN 459-2.
Pigmente für diese Anwendung dürfen Einzelpigmente, Pigment-Mischungen oder Pigment/Füllstoff-Mischungen in
pulveriger oder granulierter Form oder wässrige Präparationen sein.
Die Hauptbestandteile der Pigmente gehören üblicherweise zu einer der folgenden Klassen von Stoffen:
. synthetische oder natürliche Oxide und Hydroxide des Eisens;
. Oxide von Chrom, Titan und Mangan;
. komplexe anorganische Oxide und Hydroxide, z. B. Kombinationen aus den o. g. Oxiden und Hydroxiden mit
Kobalt-, Aluminium-, Nickel- und Antimonoxiden und -hydroxiden;
. Ultramarine;
. Phthalocyaninblau und -grün;
. Kohlenstoff (ist als anorganisch zu betrachten);
. Mischungen der o. g. Materialien (die auch Füllstoffe enthalten können).
Pigments de coloration des matériaux de construction a base de ciment et/ou de chaux - Spécifications et méthodes d'essai
Pigmenti za obarvanje gradbenih materialov na osnovi cementa in/ali apna - Specifikacije in metode preskušanja
General Information
Relations
Standards Content (Sample)
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Pigments for the colouring of building materials based on cement and/or lime - Specifications and methods of testPigmenti za obarvanje gradbenih materialov na osnovi cementa in/ali apna - Specifikacije in metode preskušanjaPigments de coloration des matériaux de construction a base de ciment et/ou de chaux - Spécifications et méthodes d'essaiPigmente zum Einfärben von zement- und/oder kalkgebundenen Baustoffen - Anforderungen und Prüfverfahren91.100.10Cement. Mavec. Apno. MaltaCement. Gypsum. Lime. Mortar87.060.10Pigmenti in polnilaPigments and extendersICS:SIST EN 12878:2005enTa slovenski standard je istoveten z:EN 12878:200501-julij-2005SIST EN 12878:2005SLOVENSKI
STANDARDSIST EN 12878:20001DGRPHãþD
EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM
EN 12878
May 2005 ICS 87.060.10; 91.100.10
Supersedes EN 12878:1999
English version
Pigments for the colouring of building materials based on cement and/or lime - Specifications and methods of test
Pigments de coloration des matériaux de construction à base de ciment et/ou de chaux - Spécifications et méthodes d'essai
Pigmente zum Einfärben von zement- und/oder kalkgebundenen Baustoffen - Anforderungen und Prüfverfahren This European Standard was approved by CEN on 25 March 2005.
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 any 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 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, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION COMITÉ EUROPÉEN DE NORMALISATION EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: rue de Stassart, 36
B-1050 Brussels © 2005 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 12878:2005: E
EN 12878:2005 (E) 2 Contents Foreword.3 1 Scope.4 2 Normative references.4 3 Terms and definitions.5 4 Requirements.6 5 Test methods.8 6 Evaluation of conformity.15 Annex A (informative) Further information regarding test methods.21 Annex ZA (informative) Clauses of this European Standard addressing the provisions of the EU Construction Products Directive.22 Bibliography.29
EN 12878:2005 (E) 3 Foreword This document (EN 12878:2005) has been prepared by Technical Committee CEN/TC 298 “Pigments and extenders”, the secretariat of which is held by DIN. 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 November 2005, and conflicting national standards shall be withdrawn at the latest by February 2007. This document supersedes EN 12878:1999. Annex A gives further information regarding the test methods. This document has been prepared under a mandate given to CEN by the European Commission and the European Free Trade Association, and supports essential requirements of EU Directive(s). For relationship with EU Directive(s), see informative Annex ZA which is an integral part of this document. This document includes a Bibliography with currently existing International Standards for particular pigments suitable for use in building materials based on cement and/or lime. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.
EN 12878:2005 (E) 4
1 Scope This European Standard specifies the requirements and the test methods for pigments for use in the colouring of building materials based on cement and cement/lime combinations.
Pigments covered by this European Standard can also be used in pure lime mortar. For this application see EN 459-1 and EN 459-2. Pigments for this purpose can be single pigments, blends of pigments, or blends of pigments and extenders, in powder or granular form, or aqueous preparations. Pigments typically belong to one of the following classes of compounds: - synthetic or natural oxides and hydroxides of iron; - oxides of chromium, titanium and manganese; - complex inorganic pigments, for example combinations of the above mentioned metal oxides and hydroxides with cobalt, aluminium, nickel and antimony oxides and hydroxides; - ultramarine pigments; - phthalocyanine blue and green; - elemental carbon (should be regarded as an inorganic pigment); - blends of the above materials (which may also include extenders). 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. EN 196-1:2005, Methods of testing cement — Part 1: Determination of strength EN 196-3, Methods of testing cement — Part 3: Determination of setting times and soundness EN 197-1, Cement — Part 1: Composition, specifications and conformity criteria for common cements EN 934-2, Admixtures for concrete, mortar and grout — Part 2: Concrete admixtures – Definitions, requirements, conformity, marking and labelling EN ISO 787-3, General methods of test for pigments and extenders - Part 3: Determination of matter soluble in water - Hot extraction method (ISO 787-3:2000) EN ISO 787-9, General methods of test for pigments and extenders — Part 9: Determination of pH value of aqueous suspension (ISO 787-9:1981) EN ISO 787-13, General methods of test for pigments and extenders - Part 13: Determination of water-soluble sulfates, chlorides and nitrates (ISO 787-13:2002) EN ISO 1158, Plastics - Vinyl chloride homopolymers and copolymers - Determination of chlorine content (ISO 1158:1998) EN ISO 15528, Paints, varnishes and raw materials for paints and varnishes — Sampling (ISO 15528:2000)
EN 12878:2005 (E) 5 ISO 787-7, General methods of test for pigments and extenders — Part 7: Determination of residue on sieve — Water method — Manual procedure ISO 3310-1, Test sieves — Technical requirements and testing — Part 1: Test sieves of metal wire cloth ISO 7724-1, Paints and varnishes — Colorimetry — Part 1: Principles ISO 9277, Determination of the specific surface area of solids by gas adsorption using the BET method 3 Terms and definitions For the purposes of this European Standard, the following terms and definitions apply. 3.1 pigment substance, generally in the form of fine particles, which is insoluble in the application medium and whose sole purpose is to colour cement- and/or lime-based building materials 3.2 single pigment pigment of singular (chemical) composition containing no substances other than those originating from the pigment manufacturing process NOTE
Surface treatment of the primary pigment particles is considered as a part of the pigment manufacturing process. 3.3 pigment blend blend of at least two single pigments, or at least one single pigment and an extender 3.4 aqueous pigment preparation preparation in which a pigment (single pigment or pigment blend) is dispersed in water, with or without a dispersion or other agent NOTE
Examples of agents are:
- dispersants;
- binding agents (resins);
- solvents;
- wetting agents;
or combinations thereof. 3.5 pigment in granular form preparation in which a pigment (single pigment or pigment blend) is converted into granules, by the use of a binding agent which retains the integrity of the granule 3.6 reference sample standard pigment sample of a single pigment or a blend (powder, or preparation) retained by the interested parties for comparison for the evaluation of the product properties
3.7 extender inorganic substance, generally a material in granular or powder form, which is insoluble in the application medium and has no inherent colour properties
EN 12878:2005 (E) 6 4 Requirements 4.1 Effects on concrete properties 4.1.1 General In addition to all other requirements, pigments for steel reinforced concrete shall meet the Category B requirements given in 4.1.3, 4.2.3 to 4.2.5.
The inorganic pigment dosage shall be 5,0 % solids, carbon black and organic pigment dosage of 2,0 % solids, by mass, based on the cement amount for testing according to 5.1.
If a higher dosage of pigment is recommended the tests shall be carried out with that dosage. The dosage in percent by mass shall be specified by the manufacturer. 4.1.2 Setting time 4.1.2.1 Initial setting time The initial setting time of cement with the single pigment or a blend (both as powder, granulate or preparation), determined in accordance with 5.1.1, shall not be less than 60 min. The maximum difference between the initial setting time of mixes with and without the single pigment or a blend (both as powder, granulate or preparation) shall not be greater than 60 min. 4.1.2.2 Final setting time The final setting time of cement with the single pigment or a blend (both as powder, granulate or preparation), determined in accordance with 5.1.1, shall not be longer than 720 min. 4.1.3 Compressive strength The 28 day compressive strength of mixes with the single pigment or a blend (both as powder, granulate or preparation), determined in accordance with 5.1.2, shall not be reduced in comparison with the mix without pigment more than
Category A: the manufacturer’s declared value
Category B: 8 %. 4.2 Composition 4.2.1 General Where dispersion agents, binding agents and/or grinding aids are used, their total content shall be equal to or less than 5,0 % by mass, based on pigment solids. If admixtures are used for the preparation of single pigments or blends in the form of granulates or preparations they shall conform to EN 934-2. Admixture type according to EN 934-2 shall be reported. The stability of a pigment with respect to colour shall be linked to the intended end use conditions. The solids content, as a percentage (%) of aqueous preparations, shall be declared by the manufacturer. 4.2.2 Composition of the pigment The main constituents of the pigments are determined in accordance with 5.2.2.
EN 12878:2005 (E) 7 4.2.3 Water soluble substances The content of water soluble substances, determined in accordance with 5.2.3, shall not be greater than
Category A: the manufacturer's declared value
Category B: 0,5 % by mass. For pigment blends in powder form, evidence of compliance may be calculated from data recorded for constituent single pigments. 4.2.4 Soluble chloride The soluble chloride content of a single pigment or a blend (powder, granulate or preparation), determined in accordance with 5.2.4, shall not be greater than
Category A: the manufacturer's declared value
Category B: 0,10 % by mass. For pigment blends in powder form, evidence of compliance may be calculated from data recorded for constituent single pigments. NOTE Where pigment blends, pigment/extender mixtures, or granulates or aqueous preparations thereof, are used in excess of 5 % based on cement, the total content of halides and of anions precipitated by Ag+ which are admitted into the concrete should not exceed 0,005 % based on the cement. 4.2.5 Total chlorine The total chlorine content of a single pigment or a blend (powder, granulate or preparation), determined in accordance with 5.2.5, shall not be greater than
Category A: the manufacturer's declared value
Category B: 0,10 % by mass. For pigment blends in powder form, evidence of compliance may be calculated from data recorded for constituent single pigments. 4.3 Loss on ignition The loss on ignition of a single pigment or a blend (powder, granulate or preparation), determined in accordance with 5.3, shall be declared by the manufacturer. 4.4 Emission of radioactivity Where subject to regulatory requirements, the emission of radioactivity by the pigment shall be declared. NOTE
See Annex ZA. 4.5 Release of dangerous substances Where subject to regulatory requirements, the release of dangerous substances by the pigment shall be declared. NOTE
See Annex ZA. 4.6 Relative colour strength The relative colour strength in comparison with the standard pigment, determined in accordance with 5.6, shall be 100 % ± 5 %.
EN 12878:2005 (E) 8 4.7 Residue on sieve The residue on the sieve of pigment in powder form, determined in accordance with 5.7, shall be declared by the manufacturer. 4.8 pH value The pH value, determined in accordance with 5.8, shall conform with the manufacturer's specified value ± 2. 4.9 Alkali stability The manufacturer shall declare that the pigment, tested in accordance with 5.9, is alkali stable. 4.10 Resistance to weathering The manufacturer shall declare that the pigment, tested in accordance with 5.10, is resistant to weathering. 4.11 Thermal stability The manufacturer shall declare that the pigment, tested in accordance with 5.11, is thermally stable. 4.12 Colour comparison against standard pigment The manufacturer shall declare the ûE value, compared against the standard pigment, tested in accordance with 5.12. NOTE Research into the repeatability and reproducibility of this test method has shown that samples prepared using the same pigments at five separate laboratories produced results within a ûE range of 0,5. 5 Test methods 5.1 Effect on concrete properties 5.1.1 Setting time The influence on the setting time of cement shall be tested using the test method described in EN 196-3, using a paste made with Portland cement CEM I 42,5 R conforming to EN 197-1, with and without the addition of pigment. 5.1.2 Compressive strength The influence of a pigment on the 28-day compressive strength of the mortar shall be tested in accordance with EN 196-1. The mortar shall be made with Portland cement CEM I 42,5 R conforming to EN 197-1 (same cement as in 5.1.1) with and without the addition of pigment. The water content of aqueous pigment preparations shall be taken into account. 5.2 Composition 5.2.1 General Any physical effects are determined by way of comparative tests on pigmented and unpigmented cement paste, mortar or concrete mixes, as appropriate. When using pigment preparations (3.4 and 3.5), the pigment solids content shall be taken into consideration in the mix composition.
Generally, an amount of not more than 10,0 % pigment should be added to cement or lime.
Sampling shall be in accordance with 6.2.
EN 12878:2005 (E) 9 5.2.2 Composition of the pigments Determine the chemical composition of the pigments (4.2.2) in accordance with the relevant standard (see Bibliography). Where no standard exists, appropriate up-to-date analytical procedures shall be used. 5.2.3 Water soluble substances The determination of the water soluble content shall be performed in accordance with EN ISO 787-3. In pigment preparations (3.4 and 3.5) the quantity to be used is chosen so that it contains the amount of solids indicated in EN ISO 787-3. 5.2.4 Soluble chloride Conduct the test for water-soluble chloride in accordance with EN ISO 787-13. For pigment preparations (3.4 and 3.5), the quantity to be used is chosen so that it contains the amount of solids indicated in EN ISO 787-3. 5.2.5 Total chlorine The test shall be carried out in accordance with the test procedure of EN ISO 1158 except that the accurately weighed sample shall be approximately 0,25 g of the dry material and that the silver nitrate and ammonium thiocyanate solutions are 0,01 mol/l (0,01 N). 5.3 Loss on ignition Weigh 2 g to 5 g (to an accuracy of 1 mg) of pigment (m1) that has been dried to constant mass at 105 °C ± 5 °C and calcine it to constant mass at 1000 °C ± 50 °C. Cool in a dessicator to room temperature and weigh again (m2). Calculate the loss on ignition L as a percentage by mass using the following equation: 100121×−=mmmL (1) where m1 mass, in gram, of the pigment under test; m2 mass, in gram, of the residue after ignition and cooling. 5.4 Emission of radioactivity Where required a relevant test method should be used. NOTE
See Annex ZA. 5.5 Release of dangerous substances Where required a relevant test method should be used. NOTE
See Annex ZA. 5.6 Relative colour strength 5.6.1 General remarks The relative colour strength attained in coloured cement or cement/lime bound construction materials is determined by means of the following special test methods: Pigments in powder form shall be tested by dry mixing with a white material in fine powder form, in accordance with 5.6.2, or by wet mixing, in accordance with 5.6.3 or 5.6.4. The relative colour strength of aqueous pigment
EN 12878:2005 (E) 10 preparations and granulates shall be tested in accordance with 5.6.3 or in a wet mix with cement in accordance with 5.6.4. Testing may be carried out in accordance with alternative test methods with a proven correlation to the standard methods. The test method 5.6.4 shall be the reference method. The measurement of colour strength shall be carried out well below the point of colour saturation in a given formulation. This is the point at which an increase in pigment loading produces no noticeable change in colour intensity. 5.6.2 Relative colour strength in barytes or white Portland cement CEM I (dry mix) 5.6.2.1 Equipment and test materials 5.6.2.1.1 Analytical balance, capable of weighing to the nearest 0,1 mg. 5.6.2.1.2 200 ml jars, thick-walled, for shaking the mix. 5.6.2.1.3 Stainless steel balls, 5 mm ± 0,5 mm in diameter. 5.6.2.1.4 Stopwatch. 5.6.2.1.5 Sieve, for separating the stainless steel balls. 5.6.2.1.6 Spatula. 5.6.2.1.7 Paper with rough surface texture. 5.6.2.1.8 Barytes of 1 m2/g to 2 m2/g specific surface area measured by the BET method as described in ISO 9277, or white Portland cement CEM I.
5.6.2.1.9 Pigment in powder form, to be used as a reference sample. 5.6.2.1.10 Mechanical sieve machine or shaker. 5.6.2.2 Test procedure The pigment sample (0,1 g to 0,5 g weighed to the nearest 0,1 mg) and 10,00 g of the white material are weighed into the shaker jar. After adding 200 stainless steel balls, mix for 3 min with either the mechanical sieve machine or shaker. If a suitable machine is not available the jar may be hand-shaken until a thorough mix is obtained. Abraded glass shaking jars and corroded steel balls shall be discarded. Sieve the contents of the jar to remove the stainless steel balls. The resultant dry powder mix has to appear without streaks when spread and smoothed out with the spatula on the rough paper. If streaks are apparent the test shall be repeated using a longer shaking time. Prepare a mix of the reference sample in a similar manner. To determine the colour strength, place the mixes alongside each other on the paper and draw down with the spatula, so that the mixes touch but do not intermix. Compare the drawdowns visually and, if different, adjust the amount of pigment in the test mix and repeat until parity with the reference sample mix is achieved.
EN 12878:2005 (E) 11
5.6.2.3 Calculation of result The relative colour strength F, in %, of the pigment tested is calculated using the equation: 100×=TRmmF (2) where mR is the mass of the reference sample, in g, in the mix; mT is the mass, in g, of the test pigment, in the mix. NOTE
In this equation a stronger pigment relative to the reference sample will give a value exceeding 100 %. 5.6.3 Determination of relative colour strength in barytes (wet mix) 5.6.3.1 Equipment and test material 5.6.3.1.1 General As indicated in 5.6.2.1, together with 5.6.3.1.2 Film applicator or drawdown bar, giving a wet film thickness of 500 µm 5.6.3.1.3 Glass plates 5.6.3.1.4 Forced-air drying oven 5.6.3.1.5 Aqueous preparation (or pigment in powder or granular form) and a reference sample 5.6.3.1.6 Tap water 5.6.3.2 Test procedure The pigment sample (0,3 g to 1,5 g weighed to the nearest 0,1 mg) and 30,00 g of barytes are weighed into the shaker jar. Add 300 stainless steel balls and sufficient water to produce a free flowing suspension. The suspension shall separate easily from the stainless steel balls and be easily drawn down. Shake the jar as described in 5.6.2.2. Sieve the aqueous suspension directly after the shake cycle. Draw out the aqueous suspension on a glass plate, using the film applicator, and dry in the oven at 105 °C ± 5 °C for 15 min. Scrape the dried mixture from the glass plate and follow the dry mix procedure in accordance with 5.6.2.2; mix for 1 min to pulverize the mix. Prepare a mix using the reference sample in similar manner and compare. Compare the drawdowns visually and, if different, adjust the amount of pigment in the test mix and repeat until parity with the reference sample mix is achieved. Calculate the test results in accordance with 5.6.2.3. NOTE
For further details see Annex A.
EN 12878:2005 (E) 12 5.6.4 Determination of relative colour strength in white Portland cement mortar (wet mix) 5.6.4.1 Test procedure Mortar test pieces are made using the pigment to be tested and the reference sample. After curing, the test pieces are split and their split faces are compared. 5.6.4.2 Preparation of test pieces The making of the mortar mix and the preparation, compaction and storage of the test pieces are all performed in accordance with EN 196-1. Cement from the same batch shall be used for the pigment to be tested and for the reference sample. The following deviations from EN 196-1 are permitted: - The prescribed work area climate need not be adhered to. - Smaller test mixes may be used provided that they have the same ratio of ingredients. - The amount of pigment to be used will normally lie between 1,0 % and 5,0 % by mass of dry solids on the basis of the cement. - The norm sand may be substituted by clean sand passing a 2 mm sieve and retained on a 63 µm sieve, both in accordance with ISO 3310-1. - To optimise dispersion of the pigment, whether a powder, granule or a liquid preparation, it is recommended that the sand and the pigment should be dispersed first and mixed for 20 s. Then add the water, mix for 20 s, add the cement, and continue mixing for a further 30 s to 60 s; the same procedure shall be used for the reference sample. - The water content of liquid preparations shall be taken into account in the mix design. - The mould should provide a cross-sectional area of not less than 30 mm by 30 mm. Other suitable moulds may be used instead of the steel mould. - If a vibration-table or shock-table is not available, the effect may be simulated by repeatedly tapping the mould on a hard surface. To deaerate the mix, the mould should be filled and compacted in stages. - If an humidified air chamber is not available for curing the test pieces, they may be stored for up to 48 h at ambient temperature in a desiccator filled to just below the support plate with water. - The test sample and the reference sample shall be compacted and cured under identical conditions. 5.6.4.3 Evaluation of test After curing for an additional 24 h under ambient conditions, split the test and the reference pieces and visually assess the colour strength of the split faces. If different, adjust the amount of pigment in the test mix and repeat 5.6.4.2 (with a new reference sample) until parity with the reference sample mix is achieved. Calculate the test result in accordance with 5.6.2.3. NOTE
For further details see Annex A. 5.7 Residue on sieve For pigments in powder form determine the residue on a 90 µm sieve in accordance with ISO 787-7. For pigment blends, evidence of compliance is calculated from data recorded for constituent single pigments. 5.8 pH value Determine the pH-value in accordance with EN ISO 787-9.
EN 12878:2005 (E) 13 5.9 Alkali stability 5.9.1 General remarks The test assesses the stability of pigments against the alkalinity of cement- and/or lime-based materials without the influence of outdoor weathering. 5.9.2 Preparation of test pieces Prepare the test pieces in accordance with 5.6.4.2 using cement as specified in 5.1.1. 5.9.3 Test procedure Take the test pieces out of the mould after 24 h curing, place them in a desiccator filled with water to just below the supporting plate, and store for 6 days. Store for a further 6 days in a covered glass or plastic container completely filled with water; replace the water after 2 days and after 4 days. Allow the test pieces to dry for 3 days at room temperature in air, avoiding exposure to direct sunlight. At the same time prepare fresh reference pieces for comparison purposes. Cure under the same conditions for 24 h, take out of the mould and allow to dry for 2 days in air at room temperature, avoiding exposure to direct sunlight.
Test and reference pieces are split and compared visually, both on the split face and the smooth surfaces. If necessary, remove efflorescence by washing with diluted (approximately 5,0 %) hydrochloric or formic acid, thoroughly rewash with water and dry. The pigment is regarded as being alkali stable if the test sample has remained similar to the reference sample.
Different cements can lead to a lightening of the split faces of the specimen as a result of the ongoing hydration process. Should testing point to unsatisfactory colour stability of the pigment in the cement, the test shall be repeated using a pigment with established colour stability to determine whether the lightening of the split face is traceable to the hydration of the cement. NOTE
For further details see Annex A. 5.10 Resistance to weathering Resistance to weathering is evaluated by comparing a weathered specimen with an unweathered reference specimen; the test method shall be agreed between the interested parties. Outdoor weathering shall be the reference method. The following basic rules apply: - The test shall be conducted in the same building material to be coloured by the pigment. - If several pigments are tested in relation to each other the test specimen shall be produced in an identical manner. - Test specimen shall be free of coatings on their weather-exposed surfaces; for example pigmented or transparent acrylate coatings, mould release oils, water repellent impregnation's (e.g. silicones), etc. - Reference specimen used for comparison shall be stored dry and in the dark. During the course of time a small degree of efflorescence may occur. This should be taken into account when comparing test and reference specimens. - The test specimen shall be exposed at an angle of 45°, facing south. - To avoid misinterpretation of the results, the first evaluation of the test specimen shall not take place until the unavoidable efflorescence has been removed by weathering. Experience demonstrates that this is usually the case after two years. This is recommended as the minimum exposure period subject to the agreement by the two parties.
EN 12878:2005 (E) 14 - Exposure in one weathering location allows a reliable statement with respect to the resistance to weathering for that location only. If results are to be generalized, then test specimen shall be placed in different climatic and environmental conditions. If admixtures are added this shall be mentioned in the test report. NOTE
For further details see Annex A. 5.11 Thermal stability The evaluation of the thermal stability of a pigment is only required if it is to be exposed to a temperature exceeding 80 °C during the manufacture of the building material.
The thermal stability of a pigment can play a role during the manufacture of building materials by a production process involving elevated temperature (e.g. autoclave curing). Such processes cannot be simulated by simple laboratory tests. A test method shall be agreed between the interested parties. 5.12 Colour comparison against the standard pigment 5.12.1 General The total colour difference attained in coloured cement or cement/lime bound construction
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