1、PUBLISHED DOCUMENT PD CEN/TR 14862:2004 Precast concrete products Full-scale testing requirements in standards on precast concrete products ICS 91.100.30 PD CEN TR 14862:2004 This Published Document was published under the authority of the Standards Policy and Strategy Committee on 22 February 2005
2、BSI 22 February 2005 ISBN 0 580 45519 X National foreword This Published Document is the official English lanuage version of CEN/TR 14862:2004. The UK participation in its preparation was entrusted to Technical Committee B/524, Precast concrete products, which has the responsibility to: A list of or
3、ganizations represented on this committee can be obtained on request to its secretary. Cross-references The British Standards which implement international or European publications referred to in this document may be found in the BSI Catalogue under the section entitled “International Standards Corr
4、espondence Index”, or by using the “Search” facility of the BSI Electronic Catalogue or of British Standards Online. aid enquirers to understand the text; present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep the UK interes
5、ts informed; monitor related international and European developments and promulgate them in the UK. Summary of pages This document comprises a front cover, an inside front cover, the CEN/TR title page, pages 2 to 25 and a back cover. The BSI copyright notice displayed in this document indicates when
6、 the document was last issued. Amendments issued since publication Amd. No. Date CommentsTECHNICALREPORT RAPPORTTECHNIQUE TECHNISCHERBERICHT CEN/TR14862 September2004 ICS91.100.30 Englishversion PrecastconcreteproductsFullscaletestingrequirementsin standardsonprecastconcreteproducts Produitsprfabriq
7、usenbtonExigencespourlesessais envraiegrandeurdanslesnormessurlesproduits prfabriqusenbton BetonfertigteileAnforderungenanPrfungenanBauteilen inOriginalgrbeindenNormenfrBetonfertigteile ThisTechnicalReportwasapprovedbyCENon19April2004.IthasbeendrawnupbytheTechnicalCommitteeCEN/TC229. CENmembersareth
8、enationalstandardsbodiesofAustria,Belgium,Cyprus,CzechRepublic,Denmark,Estonia,Finland,France, Germany,Greece,Hungary,Iceland,Ireland,Italy,Latvia,Lithuania,Luxembourg,Malta,Netherlands,Norway,Poland,Portugal, Slovakia, Slovenia,Spain,Sweden,SwitzerlandandUnitedKingdom. EUROPEANCOMMITTEEFORSTANDARDI
9、ZATION COMITEUROPENDENORMALISATION EUROPISCHESKOMITEEFRNORMUNG ManagementCentre:ruedeStassart,36B1050Brussels 2004CEN Allrightsofexploitationinanyformandbyanymeansreserved worldwideforCENnationalMembers. Ref.No.CEN/TR14862:2004:ECEN/TR 14862:2004 (E) 2 Contents Page Foreword3 Introduction .4 1 Scope
10、 5 2 References5 3 Terms and definitions .5 4 The role of full-scale testing.6 4.1 Design using existing calculation models 6 4.2 Design assisted by testing .7 5 Specification of full-scale testing requirements.7 6 Objectives.8 6.1 Option or requirement in initial type testing.8 6.2 Part of producti
11、on control 8 6.3 Further type testing .8 6.4 Technical questions to be clarified9 7 Planning9 7.1 Groups in the product family9 7.2 Sampling techniques.10 7.3 Accompanying tests10 8 Interpretation based on prior knowledge10 Annex A (informative) Statistic determination of resistance model 12 A.1 Sta
12、tistical background 12 A.1.1 Introduction12 A.1.2 Procedure for initial type testing12 A.1.3 Observed principal result of the procedure13 A.1.4 Procedure for additional testing during production 14 A.2 Case study of “design assisted by testing” .15 A.2.1 Test data .15 A.2.2 Resistance models 15 A.2.
13、3 Determination of characteristic values and design values .17 A.2.4 Determination of declared values. .18 A.2.5 Comments on the test plan and the data interpretation20 Annex B (informative) Provisions for full-scale testing in CEN/TC 229 product standards21 B.1 General21 B.2 Provisions.21 B.2.1 Obj
14、ectives.21 B.2.2 Specification and selection of specimens 21 B.2.3 Loading conditions22 B.2.4 Measurements23 B.2.5 Test frequency .24 B.2.6 Statistical evaluation .24 B.2.7 Test report 24 B.2.8 Consequences .25 CEN/TR 14862:2004 (E) 3 Foreword This document (CEN/TR 14862:2004) has been prepared by T
15、echnical Committee CEN/TC 229 “Precast concrete products”, the secretariat of which is held by AFNOR. CEN/TR 14862:2004 (E) 4 Introduction Any product standard will require a certain amount of testing as part of the evaluation of conformity. The tests may be part of initial type testing or part of p
16、roduction control. It may be tests on materials, dimensions etc. Or it may be tests on the finished product. The following types of testing may be involved as a part of either initial type testing or production control, 1: a) tests to establish directly the ultimate resistance or serviceability prop
17、erties of structural parts. Test results are treated as absolute values valid for the group from which the sample was taken; b) tests to obtain specific material properties using specified testing procedures; c) tests to reduce uncertainties in parameters in load or load effect models; d) tests to r
18、educe uncertainties in parameters used in resistance models. Test results are defined as the ratio between measured and calculated values and statistical rules are applied to the ratio; e) control tests to check the identity or quality of delivered products or the consistency of the production chara
19、cteristics; f) tests carried out during execution in order to obtain information needed for part of the execution; g) control tests to check the behaviour of an actual structure or of structural members after completion. Testing of full-scale products may be involved in all types of test except type
20、 (b). Testing methods may or may not leave the tested product fit for further use (non-destructive or destructive testing). However, apart from checks on geometrical properties, full-scale testing will usually damage the tested product so that it cannot be used in a structure. Tests of type (a) do n
21、ot take into account prior knowledge as easily as type (d) tests. It means that the most effective use of full-scale testing will be (effectively destructive) tests of type (d). The aim of the report is to assist the standard writers in CEN/TC 229 regime in preparing requirements on full- scale test
22、ing in product standards. Initial type testing of a product requires the producer to establish relevant properties of the product. This is often done by means of calculation models given in a standard, but in some cases full-scale testing may be used effectively to reduce uncertainties in these calc
23、ulation models, maintaining the intended reliability. The main statistical rules to be followed in this process are given in Eurocode Basis of structural design (prEN 1990). The report illustrates how these rules may be applied in a product standard. A practical example concerning hollow core slabs
24、is also given. The test results used in this example were made available from Spenncon AS Hnefoss, Norway. CEN/TR 14862:2004 (E) 5 1 Scope This document gives guidelines on how full-scale tests may be incorporated in product standards as a tool to reduce incertainties in resistance models. This docu
25、ment also gives guidelines to designers setting up a proper test programme as part of the initial design of a component. 2 References The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated reference
26、s, the latest edition of the referenced document (including any amendments) applies. EN 1168, Precast concrete products - Hollow core slabs for floors. EN 1990:2002, Eurocode - Basis of structural design. EN 1992-1-1, Eurocode 2: Design of concrete structures - Part 1 - 1: General rules and rules fo
27、r buildings. EN 13369, Common rules for precast concrete structures. ISO 12491:1997, Statistical methods for quality control of building materials and components. RILEM TC40-TPC3:1985, Flexural and shearing tests on prefabricated concrete elements, Materials and structures, Vol. 18, No 108. 3 Terms
28、and definitions For the purposes of this document, the following terms and definitions apply. 3.1 accompanying test test to determine a material property by direct or indirect methods 3.2 biased sampling a selection of units, taken from a lot according to a selection plan 3.3 full-scale test test pe
29、rformed on a finished product to determine directly the properties of the product. Properties may include behaviour, stiffness, strengths etc. of the product subjected to relevant actions 3.4 initial type testing a procedure to demonstrate compliance of a product with the requirements applying to th
30、e product. The procedure may utilise calculation and standard materials testing and it may be assisted by full-scale tests on the product 3.5 random sampling a selection of units, taken at random from a lot. Each unit of the lot has the same chance of being selected CEN/TR 14862:2004 (E) 6 3.6 resis
31、tance model a formula used for calculation of a product property 3.7 prior knowledge existing knowledge about the properties of a product and their dependence on geometry, materials, production process etc 3.8 product family a type of product usually corresponding to one product standard, e.g. prest
32、ressed hollow core floor slabs 3.9 product group a collection of products with such characteristics that all products can be attributed the same value of a chosen property. The grouping may depend on the property. Hollow core floor slabs with the same dimensions and concrete strength may be a group
33、with respect to shear strength 3.10 production control a production control system is a quality system to ensure that the product put on the market meets the requirements of the relevant standard and complies with the specified or declared values 4 The role of full-scale testing 4.1 Design using exi
34、sting calculation models Design of products according to Eurocode 2 (EN 1992-1-1), is normally based on resistance models giving the product properties as a function of the geometry and the properties of the material used in the product. The resistance model normally expresses the mean value of the
35、property when the mean values of the parameters are inserted in the model. It is usually assumed that the same model express the characteristic value or the design value of the property if characteristic values or design values of the parameters are inserted in the model. The design strength paramet
36、ers for the materials are normally found by reducing the characteristic strength obtained from materials testing by a partial safety factor. In the initial type testing of a product, these design strength parameters are used together with nominal dimensions of the product in the resistance model to
37、determine the design value of the property. The producer can then declare a design property less than or equal to the calculated design value. It is noted that partial safety factors may change from country to country. The design value of a property for a specific product may therefore also be diffe
38、rent from one country to the next. Following initial type testing, the continuous production is monitored by production control to make sure that the declaration (and its assumptions) is fulfilled. The production control relies primarily on checking the process, including tests on materials etc. The
39、 finished product is checked for geometry, appearance etc. The resistance model used in initial type testing is usually taken for granted. CEN/TR 14862:2004 (E) 7 4.2 Design assisted by testing The resistance models available in Eurocode 2 (EN 1992-1-1), may not be adequate for initial type testing
40、of a number of products within the regime of CEN/TC 229. A model may intend to cover a large spectrum of products, and the model should be safe for the whole spectrum. The model may therefore become conservative for some of the products within that spectrum. In other cases the uncertainty on the mod
41、el may in general be large. Full-scale testing may in such cases support the initial type testing in two different ways: tests (of type (a) may be used to determine directly the property of a specific product (“single property determination”), e.g. the shear strength of a hollow core floor slab with
42、 specified dimensions and materials. The tests may yield a number kN/m for the mean value and a number for the characteristic value. These properties will be different for different variants of a product family. Although the approach may sometimes be useful, it often becomes economically unfeasible
43、because the product family may contain so many variants, that the cost of testing is prohibitive. Furthermore, the design value of the property depends on a partial safety factor that is not known, unless the property depends on the strength of only one material. Declaration of a design value for th
44、e property may therefore not be easy; tests (of type (d) may be used to improve inadequate resistance models (“determination of resistance model”). The result is a revised resistance model to determine the mean values of the property for a product family. For example, an improved formula to determin
45、e the mean value of the shear strength of hollow core floor slabs as a function of the actual dimensions and actual material strengths of the test specimens. When a revised resistance model is found, initial type testing continues in the same way as if the resistance model was taken from Eurocode 2.
46、 It means that design properties are calculated by the revised formula (using nominal values for dimensions and design values for material strengths). The producer can declare properties less than the calculated design values. Different declarations will appear due to variations in the partial safet
47、y factors. The production control procedures will contain the same items as if calculation by Eurocode 2 was used in initial type testing. New items may have to be added, if the revised resistance model is sensitive to parameters that are not monitored as part of the normal production control. 5 Spe
48、cification of full-scale testing requirements. A product standard may include requirements on full-scale testing and such requirements should be specified with the same degree of stringency as is normally used when calculations are specified. It means that the following three subjects shall be dealt
49、 with: why are full-scale testing to be considered (Objectives and planning); how can a relevant full-scale test be performed (Test method); what are the consequences of the results of the test (Interpretation). These subjects are interrelated. A test method is relevant only if it produces information about the objectives. The planni
