12.07 Testing
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Introduction
The nature of the testing employed to investigate or confirm the potential durability of a material for a given situation depends on the material being used. For natural materials such as stone the material properties are fixed and it is necessary to carry out tests on samples of the material to establish its likely durability performance. However for manufactured materials, such as concrete, it is possible to vary the material properties, which determine its durability, by varying the proportions of the constituents. The required properties of the material can therefore be chosen and the mix proportions varied to give those properties. Testing may then be carried out to confirm that the required properties have been achieved or that the specified mix proportions have been used. With concrete and mortar the specifier may have sufficient knowledge to choose the mix proportions of the material himself but for many materials, such as polymers, this will require specialist knowledge.
Purpose of testing
Tests for durability may be carried out for various reasons as follows:
- As part of a research programme.
- To check compliance with a specification.
- To check suitability of a product for a particular use
Research is required to establish the durability characteristics of currently available materials and in the development of new materials or new formulations of existing materials. These tests may be used to establish specification criteria for the suitability for use of the material in different exposure conditions.
For many materials sufficient research has been carried out to give a good understanding of the behaviour of the material. Testing may then only be required to check that the material being produced has been formulated correctly.
When a material is to be used in a situation where there is no satisfactory evidence from previous research or experience it may be necessary to carry out specific tests to evaluate its suitability.
Types of test
The most reliable test for durability is long term exposure to the service conditions for the proposed service life of the component. In most cases this is not practical and durability tests have been devised to provide an assessment of durability in a much shorter timescale. These tests must then be correlated with the results of long term natural exposure tests. For research and development purposes test regimes lasting several years may be acceptable but for project specific tests a timescale of days or possibly weeks is required.
A large number of tests has been devised in an attempt to assess the durability of materials used in the cladding industry. These are have been listed at the end of this Section for different material groups.
Test methods take several forms as follows:
- Simulation of aggressive agents such as freeze thaw cycling and exposure to UV.
- Screening tests for impurities that may affect durability such as petrographic examination and chemical analysis.
- Measurement of properties known to be related to durability such as strength, water absorption and paint film thickness.
- Determination of material composition.
Interpretation of results
Tests can provide useful comparative information when the same test is carried out on different products and where there is sufficient data from previous experience they may give a reasonable prediction of the likely service life. However they suffer from the following problems:
- To provide results in a sufficiently short timescale the test regime may employ more aggressive conditions than those experienced in normal service and the deterioration mechanisms may not be the same.
- The interpretation of the results requires knowledge of the correlation between the measured parameter and durability. The correlation may not be very good or may be insufficiently well established.
- Many British Standard Specifications refer to tests with a simple pass/fail criterion. For example BS 7413 has a requirement for retention of impact strength of pvc-u after artificial ageing. The specifications do not give guidance on the life expectancy to be expected for materials complying with the specification, or the effect on life expectancy of exceeding or failing to meet the test criteria.
- There are apparent inconsistencies between similar standards. For example BS 4842, BS 6496 and BS 6497 all relate to organic coatings for metal components and all include an acetic acid/salt spray test. The test procedures are similar except that the exposure times are 240 hours, 1000 hours and 500 hours respectively. A possible explanation is that the standard requirements relate to what was thought to be achievable rather than objective requirements in terms of a particular service life. Using the same performance criteria in all cases would aid comparison of performance of different materials.
British Standards are changing rapidly due to the adoption of European Standards. This may reduce some of the variations in test details, as there is a trend to separating the test methods from the material standards so that the same test method can be adopted by several related material standards. However, although the basic test method may be standardised, the period of exposure may be specified in the material standard. The range of tests is also becoming more comprehensive as European Standards cover areas not traditionally covered by British Standards. However the main obstacle to the use of durability tests is information on how to interpret the results.
Test procedures
The test methods given below are generally limited to those given in British Standards but where no British Standard method exists, other commonly used procedures have been included.
BS 7479:1991 ( ISO 9227:1990) Method for salt spray corrosion tests in artificial atmospheres.
BS 6161-4:1981 ( ISO 2932-1981) Methods of test for anodic oxidation coatings on aluminium and its alloys. Assessment of sealing quality by measurement of the loss of mass after immersion in acid solution.BS 6161-7:1984 Methods of test for anodic oxidation coatings on aluminium and its alloys. Accelerated determination of light fastness of coloured anodic oxidation coatings using artificial light.
BS 6161-16:1990 ( ISO 8993:1989) Methods of test for anodic oxidation coatings on aluminium and its alloys. Rating system for the evaluation of pitting corrosion Chart method.
BS 6161-17:1990 ( ISO 8994:1989) Methods of test for anodic oxidation coatings on aluminium and its alloys. Rating system for the evaluation of pitting corrosion Grid method.
BS 6161-18:1991 Methods of test for anodic oxidation coatings on aluminium and its alloys. Determination of surface abrasion resistance.
BS EN ISO 12944-6:1998 Paints and varnishes. Corrosion protection of steel structures by protective paint systems. Laboratory performance test methods.
BS 7352:1990 Specification for strength and durability performance of metal hinges for side hanging applications and dimensional requirements for template drilled hinges.BS EN 179:1998 Building hardware. Emergency exit devices operated by a lever handle or push pad. Requirements and test methods.
BS EN 1125:1997 Building hardware. Panic exit devices operated by a horizontal bar. Requirements and test methods.
BS EN 1154:1997 Building hardware. Controlled door closing devices. Requirements and test methods.
BS EN 1155:1997 Building hardware. Electrically powered hold-open devices for swing doors. Requirements and test method.
BS EN 1158:1997 Building hardware. Door coordinator devices. Requirements and test method.
BS EN 1303:1998 Building hardware. Cylinders for locks. Requirements and test methods.
BS EN 1527:1998 Building hardware. Hardware for sliding doors and folding doors. Requirements and test methods.
BS EN 1670:1998 Building hardware. Corrosion resistance. Requirements and test methods.
BS 5666-1:1987 ( EN 212:1986) Methods of analysis of wood preservatives and treated timber. Guide to sampling and preparation of wood preservatives and treated timber for analysis.BS 5666-2:1980 Methods of analysis of wood preservatives and treated timber. Qualitative analysis.
BS 5666-3:1991 Methods of analysis of wood preservatives and treated timber. Quantitative analysis of preservatives and treated timber containing copper/chromium/arsenic formulations.
BS 5666-4:1979 Methods of analysis of wood preservatives and treated timber. Quantitative analysis of preservatives and treated timber containing copper naphthenate.
BS 5666-5:1986 Methods of analysis of wood preservatives and treated timber. Determination of zinc naphthenate in preservative solutions and treated timber.
BS 5666-6:1983 Methods of analysis of wood preservatives and treated timber. Quantitative analysis of preservative solutions and treated timber containing pentachlorophenol, pentachlorophenyl laurate, -hexachlorocyclohexane and dieldrin.
BS 5666-7:1991 Methods of analysis of wood preservatives and treated timber. Quantitative analysis of preservatives containing bis(tri-nn-butyltin)oxide : determination of total tin.
BS 6559:1985 ( HD 1/160) Guide. General introductory document on European (or CEN) methods of test for wood preservatives.
BS 6948:1989 Methods of test for mechanically fastened joints in timber and wood-based materials.
BS 7066-1:1990 ( EN 152-1:1988) Wood preservatives. Laboratory method for determining the protective effectiveness of a preservative treatment against blue stain in service. Brushing procedure.
BS 7066-2:1990 ( EN 152-2:1988) Wood preservatives. Laboratory method for determining the protective effectiveness of a preservative treatment against blue stain in service. Application by methods other than brushing.
BS 7282:1990 Field test method for determining the relative protective effectiveness of a wood preservative in ground contact.
BS EN 302-3:1992 Adhesives for load-bearing timber structures: test methods. Determination of the effect of acid damage to wood fibres by temperature and humidity cycling on the transverse tensile strength.
BS EN 302-4:1992 Adhesives for load-bearing timber structures: test methods. Determination of the effects of wood shrinkage on the shear strength.
BS EN 1311:1997 Round and sawn timber. Method of measurement of biological degrade.
DD ENV 12404:1997 Durability of wood and wood-based products. Assessment of the effectiveness of a masonry fungicide to prevent growth into wood of dry rot Serpula lacrymans (Schumacher ex Fries) S. F. Gray. Laboratory method.
BS 6206:1981 Specification for impact performance requirements for flat safety glass and safety plastics for use in buildings.BS EN ISO 12543-4:1998 Glass in building. Laminated glass and laminated safety glass. Test methods for durability.
Manufacturers may carry out their own tests for various properties of glass including abrasion resistance and artificial weathering of coatings.
BS EN ISO 10545-7:1999 Ceramic tiles. Determination of resistance to surface abrasion for glazed tiles.BS EN ISO 10545-9:1996 Ceramic tiles. Determination of resistance to thermal shock.
BS EN ISO 10545-10:1997 Ceramic tiles. Determination of moisture expansion.
BS EN ISO 10545-11:1996 Ceramic tiles. Determination of crazing resistance for glazed tiles.
BS EN ISO 10545-12:1997 Ceramic tiles. Determination of frost resistance.
BS EN ISO 10545-14:1997 Ceramic tiles. Determination of resistance to stains.
BS 1217:1997 Specification for cast stone.BS 1881-122:1983 Testing concrete. Method for determination of water absorption.
BS 1881-124:1988 Testing concrete. Methods for analysis of hardened concrete.
BS 1881-208:1996 Testing concrete. Recommendations for the determination of the initial surface absorption of concrete.
BS 4551-1:1998 Methods of testing mortars, screeds and plasters. Physical testing.
BS 4551-2:1998 Methods of testing mortars, screeds and plasters. Chemical analysis and aggregate grading.
BS 5328-4:1990 Concrete. Specification for the procedures to be used in sampling, testing and assessing compliance of concrete.
DD 216:1993 Method for determination of chloride content of fresh concrete.
DD 249:1999 Testing aggregates. Method for the assessment of alkali-silica reactivity. Potential accelerated mortar-bar method.
BS EN 990:1996 Test methods for verification of corrosion protection of reinforcement in autoclaved aerated concrete and lightweight aggregate concrete with open structure.
DD ENV 1170-8:1997 Test method for glass-fibre reinforced cement. Cyclic weathering type test.
BS 187:1978 Specification for calcium silicate (sandlime and flintlime) bricks.BS 3921:1985 Specification for clay bricks.
BS EN 772-4:1998 Methods of test for masonry units. Determination of real and bulk density and of total and open porosity for natural stone masonry units.BS EN 1925:1999 Natural stone test methods. Determination of water absorption coefficient by capillarity.
BS EN 1926:1999 Natural stone test methods. Determination of compressive strength.
BS EN 12370:1999 Natural stone test methods. Determination of resistance to salt crystallization.
ASTM C 97-90 1990 Test methods for absorption and bulk specific gravity of dimensional stone.
ASTM C 295-90 1990 Guide to petrographic examination of aggregates for concrete.
BS 3900-C5:1997 ( ISO 2808:1997) Methods of test for paints. Determination of film thickness.BS 3900-C9:1982 ( ISO 4627-1981) Methods of test for paints. Tests associated with paint film formation. Methods for evaluation of the compatibility of a product with a surface to be painted.
BS EN ISO 2409:1995 ( BS 3900-E6:1992) Paints and varnishes. Cross-cut test.
BS 3900-E7:1974 Methods of test for paints. Resistance to impact (falling ball test).
BS 3900-E8:1974 Methods of test for paints. Resistance to impact (pendulum test).
BS EN ISO 2815:1998 ( BS 3900-E9:1976) Paints and varnishes. Buchholz indentation test.
BS 3900-E12:1986 ( ISO 6441-1984) Methods of test for paints. Mechanical tests on paint films. Indentation test (spherical or pyramidal).
BS 3900-E14:1997 ( ISO 7784-1:1997) Methods of test for paints. Determination of resistance to abrasion (Rotating abrasive-paper-covered wheel).
BS 3900-E15:1997 ( ISO 7784-2:1997) Methods of test for paints. Determination of resistance to abrasion (Rotating abrasive rubber wheel).
BS 3900-E17:1997 ( ISO 12137-1:1997) Methods of test for paints. Determination of mar resistance using a curved stylus.
BS 3900-E18:1997 ( ISO 12137-2:1997) Methods of test for paints. Determination of mar resistance using a pointed stylus.
BS 3900-E19:1999 ( ISO 15184:1998) Methods of test for paints. Determination of film hardness by pencil test.
BS 3900-F2:1973 Methods of test for paint. Durability tests on paint films. Determination of resistance to humidity (cyclic condensation).
BS 3900-F4:1968 Methods of test for paints. Resistance to continuous salt spray.
BS 3900-F6:1976 Methods of test for paint. Durability tests on paint films. Notes for guidance on the conduct of natural weathering test.
BS EN ISO 3231:1998 ( BS 3900-F8:1993) Paints and varnishes. Determination of resistance to humid atmospheres containing sulfur dioxide.
BS EN ISO 6270:1995 ( BS 3900-F9:1982) Paints and varnishes. Determination of resistance to humidity (continuous condensation).
BS 3900-F12:1997 ( ISO 7253:1996) Methods of test for paint. Durability tests on paint films. Determination of resistance to neutral salt spray (fog).
BS EN ISO 4623:1995 ( BS 3900-F13:1986) Paints and varnishes. Filiform corrosion test on steel.
BS EN ISO 11341:1998 ( BS 3900-F14:1995) Paints and varnishes. Artificial weathering and exposure to artificial radiation. Exposure to filtered xenon-arc radiation.
BS 3900-F15:1995 ( ISO 11503:1995) Methods of test for paints. Determination of resistance to humidity (intermittent condensation).
BS 3900-F16:1997 ( ISO 11507:1997) Methods of test for paint. Durability tests on paint films. Resistance to artificial weathering (UV radiation and water).
BS 3900-F17:1998 ( ISO 11998:1998) Methods of test for paint. Durability tests on paint films. Determination of wet-scrub resistance and cleanability of coatings.
BS 3900-F18:1998 ( ISO 11997-1:1998) Methods of test for paint. Durability tests on paint films. Determination of resistance to corrosion under a wet (salt fog)/dry/humidity cycle.
BS EN ISO 2812-1:1995 ( BS 3900-G5:1993) Paints and varnishes. Determination of resistance to liquids. General methods.
BS 3900-G6:1989 Methods of test for paints. Assessment of resistance to fungal growth.
BS 3900-G7:1998 ( ISO 3248:1998) Methods of test for paints. Determination of the effect of heat.
BS EN ISO 2812-2:1995 ( BS 3900-G8:1993) Paints and varnishes. Determination of resistance to liquids. Water immersion method.
BS 3900-G9:1996 ( ISO 7783-1:1996) Methods of test for paints. Determination of water-vapour transmission rate of free films (dish method).
BS 4842:1984 Specification for liquid organic coatings for application to aluminium alloy extrusions, sheet and preformed sections for external architectural purposes, and for the finish on aluminium alloy extrusions, sheet and preformed sections coated with liquid organic coatings Appendix D method for assessing the effect of mortar, Appendix E Method for determination of resistance to acetic acid/salt spray, Appendix F Method for determination of resistance to artificial weathering.
BS 6496:1984 Specification for powder organic coatings for application and stoving to aluminium alloy extrusions, sheet and preformed sections for external architectural purposes, and for the finish on aluminium alloy extrusions, sheet and preformed sections coated with powder organic coatings. Includes tests for resistance to mortar, acetic acid/salt spray, permeability, artificial weathering and natural weathering.
BS 6497:1984 Specification for powder organic coatings for application and stoving to hot-dip galvanized hot-rolled steel sections and preformed steel sheet for windows and associated external architectural purposes, and for the finish on galvanized steel sections and preformed sheet coated with powder organic coatings. Includes tests for resistance to mortar, acetic acid/salt spray, permeability, artificial weathering and natural weathering.
BS 903-A37:1997 ( ISO 6505:1997) Physical testing of rubber. Determination of tendency to adhere to and to corrode metals.BS 903-A40:1988 ( ISO 5600-1986) Physical testing of rubber. Determination of adhesion to rigid materials using conical shaped parts.
BS 903-A42:1992 ( ISO 3384:1991) Physical testing of rubber. Method for determination of stress relaxation in compression at ambient and at elevated temperatures.
BS 903-A43:1990 ( ISO 1431/1:1989) Physical testing of rubber. Method for determination of resistance to ozone cracking (static strain test).
BS 903-A44:1995 ( ISO 1431-2:1994) Physical testing of rubber. Method of determination of resistance to ozone cracking (dynamic strain test).
BS 903-A52:1986 ( ISO 6914-1985) Physical testing of rubber. Determination of ageing characteristics by measurement of stress at a given elongation.
BS 903-A53:1989 ( ISO 4665-2:1985) Physical testing of rubber. Methods for exposure to natural weathering, for use in determining resistance to weathering.
BS 903-A54:1989 ( ISO 4665-3:1987) Physical testing of rubber. Methods for exposure to artificial light, for use in determining resistance to weathering.
BS 903-A55:1989 ( ISO 4665-1:1985) Physical testing of rubber. Methods for assessment of changes in properties after exposure to natural weathering or artificial light, for use in determining resistance to weathering.
BS 2782-0:1995 Methods of testing plastics. Introduction. BS 2782 describes a very large number of tests for plastic some of which are relevant to durability. The tests are listed in appendix B to BS 2780-0.BS 2782-5:Method 551A:1988 ( ISO 4611:1987) Methods of testing plastics. Optical and colour properties, weathering. Determination of the effects of exposure to damp heat, water spray and salt mist.
BS 7412:1991 Specification for plastics windows made from PVC-U extruded hollow profiles. Appendix A Measurement of deflection recovery of weatherstrips and glazing gaskets, Appendix B Migration and staining tests of weatherstrips and glazing gaskets, Appendix C Heat shrinkage or reversion test for weatherstrips and glazing gaskets, Appendix D Colour fastness test.
BS 7413:1991 Specification for white PVC-U extruded hollow profiles with heat welded corner joints for plastics windows: materials type A. Appendix C Retention of impact after artificial ageing, Appendix E Heat reversion test Appendix F Heat ageing test, Appendix H Colour fastness test.
BS 7414:1991 Specification for white PVC-U extruded hollow profiles with heat welded corner joints for plastics windows: materials type B. Appendix C Retention of impact after artificial ageing, Appendix E Heat reversion test Appendix F Heat ageing test, Appendix H Colour fastness test.
BS ISO 1163-2:1995 Plastics. Unplasticized polyvinyl chloride (PVC-U) moulding and extrusion materials. Preparation of test specimens and determination of properties.
BS EN 478:1999 Unplasticized polyvinylchloride (PVC-U) profiles for the fabrication of windows and doors. Appearance after exposure at 150°C. Test method.
BS EN 479:1999 Unplasticized polyvinylchloride (PVC-U) profiles for the fabrication of windows and doors. Determination of heat reversion.
BS EN 607:1996 Eaves gutters and fittings made of PVC-U. Definitions, requirements and testing.
BS EN ISO 877:1997 ( BS 2782-5:Method 550B:1996) Plastics. Methods of exposure to direct weathering, to weathering using glass-filtered daylight, and to intensified weathering by daylight using Fresnel mirrors.
BS EN ISO 4600:1998 Plastics. Determination of environmental stress cracking (ESC). Ball or pin impression method.
BS EN ISO 6252:1998 Plastics. Determination of environmental stress cracking (ESC). Constant-tensile-stress method.
BS 3712-1:1991 Building and construction sealants. Methods of test for homogeneity, relative density and penetration.BS 3712-2:1973 Building and construction sealants. Methods of test for seepage, staining, shrinkage, shelf life and paintability.
BS 3712-4:1991 Building and construction sealants. Method of test for adhesion in peel.
BS 4254:1983 Specification for two-part polysulphide-based sealants.
BS 5215:1986 Specification for one-part gun grade polysulphide-based sealants.
BS 5889:1989 Specification for one-part gun grade silicone-based sealants. Includes some test methods for durability which are now covered by European testing standards.
BS EN ISO 9047:1998 Building construction. Sealants. Determination of adhesion/cohesion properties at variable temperatures.
BS EN ISO 10590:1998 Building construction. Sealants. Determination of adhesion/cohesion properties at maintained extension after immersion in water.
BS EN ISO 10591:1998 Building construction. Sealants. Determination of adhesion/cohesion properties after immersion in water.
BS ISO 11431:1993 Building construction. Sealants. Determination of adhesion/cohesion properties after exposure to artificial light through glass.
BS ISO 11600:1993 Building construction. Sealants. Classification and requirements.
BS EN ISO 10563:1998 Building construction. Sealants for joints. Determination of change in mass and volume.
BS EN ISO 11432:1998 Building construction. Sealants. Determination of resistance to compression.
BS EN 27389:1991 ( ISO 7389:1987) Building construction. Jointing products. Determination of elastic recovery.
BS EN 27390:1991 ( ISO 7390:1987) Building construction. Jointing products. Determination of resistance to flow.
BS EN 28339:1991 ( ISO 8339:1984) Building construction. Jointing products. Sealants. Determination of tensile properties.
BS EN 28340:1991 ( ISO 8340:1984) Building construction. Jointing products. Sealants. Determination of tensile properties at maintained extension.
BS EN 28394:1991 ( ISO 8394:1988) Building construction. Jointing products. Determination of extrudability of one-component sealants.
BS EN 29046:1991 ( ISO 9046:1987) Building construction. Sealants. Determination of adhesion/cohesion properties at constant temperature.