1、BRITISH STANDARDBS EN 1168:2005Precast concrete products Hollow core slabsICS 91.060.30; 91.100.30g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58+A
2、3:2011National forewordThis British Standard is the UK implementation of EN 1168:2005+A3:2011. It supersedes BS EN 1168:2005+A2:2009,The start and finish of text introduced or altered by amendment is indicated in the text by tags. Tags indicating changes to CEN text carry the number of the CEN amend
3、ment. For example, text altered by CEN amendment A1 is indicated by !“.EN 1168 is a candidate “harmonized” European standard and fully takes in-to account the requirements of the European Commission mandate M/100, Precast concrete products, given under the EU Construction Products Directive (89/106/
4、EEC), and is intended to lead to CE marking. The date of applicability of EN 1168 as a harmonized European Standard, i.e. the date after which this standard may be used for CE marking purposes, is subject to an announcement in the Official Journal of the European Communities.The Commission in consul
5、ation with Member States has agreed a transition period for the co-existence of harmonized European Standards and their corresponding national standard(s). It is intended that this period will comprise a period, usually nine months, after the date of availability of the European Standard, during whi
6、ch any required changes to national regulations are to be made, followed by a further period, usually of 12 months, for the implementation of CE marking. At the end of this co-ex-istence period, the national standard(s) will be withdrawn. In the UK, there are no corresponding national standards.The
7、UK participation in its preparation was entrusted to Technical Committee B/524, Precast concrete products.In the opinion of the UK national committee, this product standard does not provide a satisfactory link between product design and building/project design. The design of the bearing support deta
8、ils is likely to include ho-rizontal forces at the support from restraint effects (shrinkage, temperature, creep, etc.) and these forces need to be considered in the plank design. Reference should be made to Design of Hybrid Contrete Buildings published by The Concrete Centre (2009).Subclause 4.3.3.
9、2.2.1 of this Product Standard provides an alternate method of design of Hollowcore Units for shear to that given in EN 1992-1-1:2004, subclause 6.2.2, in regions uncracked in bending. Therefore, use of this method could result in a design that does not conform to the Eurocode EN 1992-1-1:2004.Pract
10、ice in the UK has been for the engineer responsible for the overall stability of the structure to ensure the compatibility of the design and details of parts and components, even when some or all of the design and details of those parts are not made by this engineer.A list of organizations represent
11、ed on this committee can be obtained on request to its secretary.This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application.Compliance with a British Standard cannot confer immunity from legal obligations.BS EN 1168:2005
12、+A3:2011This British Standard was published under the authority of the Standards Policy and Strategy Committee on 9 August 2005 BSI 2011Amendments/corrigenda issued since publicationDate Comments 28 February 2011 Implementation of CEN consolidated amendments A1:2008 and A2:2009ISBN 978 0 580 73137 2
13、which is withdrawn.30 November 2011 Implementation of CEN consolidated amendmentA3:2011EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 1168:2005+A3 October 2011 ICS 91.060.30; 91.100.30 Supersedes EN 1168:2005+A2:2009 English Version Precast concrete products - Hollow core slabs Produits prfabr
14、iqus en bton - Dalles alvoles Betonfertigteile - Hohlplatten This European Standard was approved by CEN on 1 July 2004 and includes Amendment 1 approved by CEN on 14 January 2008, Amendment 2 approved by CEN on 4 January 2009 and Amendment 3 approved by CEN on 11 August 2011. CEN members are bound t
15、o 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 CEN-C
16、ENELEC Management Centre 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 CEN-CENELEC Management Centre has
17、the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Pol
18、and, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: Avenue Marnix 17, B-1000 Brussels 2011 CEN All rights of exploitation in any form and by
19、any means reserved worldwide for CEN national Members. Ref. No. EN 1168:2005+A3:2011: EEN 1168:2005+A3:2011 (E) 2 Contents The numbering of clauses is strictly related to EN 13369: Common rules for precast concrete products, at least for the first three digits. When a clause of EN 13369 is not relev
20、ant or included in a more general reference of this standard, its number is omitted and this may result in a gap on numbering. Foreword 4Introduction .61 Scope 72 Normative references 73 Terms and definitions .83.1 Definitions 84 Requirements .94.1 Material requirements .94.1.1 Prestressing steel .
21、104.2 Production requirements . 104.2.1 Structural reinforcement 104.3 Finished product requirements . 114.3.1 Geometrical properties 114.3.2 Surface characteristics 144.3.3 Mechanical resistance 144.3.4 Resistance and reaction to fire . 234.3.5 Acoustic properties 234.3.6 Thermal properties . 234.3
22、.7 Durability . 244.3.8 Other requirements. 245 Test methods . 245.1 Tests on concrete . 245.2 %Tests on pre-stressing steel #however, concrete properties adopted as input for calculation of shear resistance depend on the proper functioning of the production machine; therefore a full scale test meth
23、od to confirm both the shear resistance obtained by calculation and the proper functioning of the production machine, is given in Annex J (normative).$ Special rules for structures with hollow core elements are presented in annexes about load distribution (Annex C), diaphragm action (Annex D), negat
24、ive moments (Annex E), shear capacity of composite members (Annex F) and design of connections (Annex H). %Special rules for pre-stressing by means of thermal pre-stressing are given in Annex K. for special use in walls and other applications, see the relevant product standards for possible addition
25、al requirements. %The elements have lateral edges with a grooved profile in order to make a shear key to transfer shear through joints contiguous elements. Class 2: Elements with thermal pre-stressed bars with a maximum of 16 mm. The use of pre-stressing bars is only allowed in accordance with Annex
26、 K. b) the maximum centre to centre distance between two bars shall not exceed 300 mm; % c) in the outermost webs there shall be at least one bar, for solid slabs, the equivalent position shall be considered; vertically : dg, 10 mm and . 4.2.1.1.2 Transversal bars Transverse reinforcement is not req
27、uired in slabs up to 1 200 mm wide. Slabs having a width greater than 1 200 mm must have transverse reinforcement designed to suit the loading requirements. The minimum transverse reinforcement shall be 5 mm diameter bars at 500 mm centres. BS EN 1168:2005+A3:2011EN 1168:2005+A3:2011 (E) 11 4.2.1.2
28、Tensioning and prestressing 4.2.1.2.1 Common requirements for the distribution of prestressing tendons The following requirements shall be fulfilled: a) the tendons shall be distributed uniformly across the width of the elements; b) in every width of 1,20 m at least four tendons shall be applied; c)
29、 in every element of a width greater than 0,60 m and less than 1,20 m, at least three tendons shall be applied; d) in every element with a width of 0,60 m or less at least two tendons shall be applied; e) the minimum clear spacing between tendons shall be: horizontally : (dg+ 5 mm), 20 mm and ; vert
30、ically : dg, 10 mm and . 4.2.1.2.2 Transfer of prestress Clause 8.10.2.2 of EN 1992-1-1:2004 shall apply: NOTE “Good” bond conditions are obtained for extruded and slip-formed elements. For the description of “good” and “poor” bond conditions, see Figure 8.2 of EN 1992-1-1:2004. 4.3 Finished product
31、 requirements 4.3.1 Geometrical properties 4.3.1.1 Production tolerances 4.3.1.1.1 Dimensional tolerances related to structural safety The maximum deviations, measured in accordance with 5.2, on the specified nominal dimensions shall satisfy the following requirements: a) slab depth: h 150 mm: 5 mm,
32、 + 10 mm; h 250: 15 mm; 150 mm YptYptis the height of the position of considered tendon layer 4.3.3.2.2.3 Simplified expression As an alternative to the above equation, the following simplified equation may be applied ()ctdcp2ctdwRdcffSIbVl+= where I is the second moment of area; S is the first mome
33、nt of area above and about the centroidal axis bwis the width of the cross-section at the centroidal axis, = lx/ lpt2is the degree of prestressing transmission (I 1,0); lxis the distance of the considered section from the starting point of transmission length; lpt2upper value of transmission length
34、(see EN 1992-1-1:2004, Expression (8.18); cp= NEd/A is the full concrete compressive stress at the centroidal axis, BS EN 1168:2005+A3:2011EN 1168:2005+A3:2011 (E) 18 fctd= fctk0,05/cis the design value of tensile strength of concrete; = 0,8 reducing factor; = 0,9 reducing factor referred to transmi
35、ssion length. Sections between the edge of the support and the section at a distance 0,5h from this edge (where h is the depth of the section), need not to be checked. VRd,cis the design value of shear resistance according to 6.2.2 of EN 1992-1-1:2004, in newtons; VETdis the design value of acting s
36、hear force taking into account the torsional moment, in newtons; TEdis the design value of the torsional moment in the considered section, in newtons millimetres; bwis the width of the outermost web at the level of the centroidal axis (see Figure 4), in millimeters; bwis the sum of width of the webs
37、 at the level of the centroidal axis, in millimeters. BS EN 1168:2005+A3:2011EN 1168:2005+A3:2011 (E) 19 Figure 4 Eccentric shear force fctdjis the design value of the tensile strength of the concrete in the joints; fctdtis the design value of the tensile strength of the concrete of the topping; hfi
38、s the sum of the smallest thicknesses of the upper and lower flange and the scaled thickness of the topping (see %Figure 5 !where this scaled thickness is the nominal thickness of the topping multiplied by the ratio between the tensile strength of the topping and the tensile strength of the slabs;“
39、hjis the net height of the joint (see %Figure 5 htis the thickness of the topping (see %Figure 5 a is the length of the load parallel to the joint ; asis the distance between the centre of the load and the centre of the joint. 4.3.3.2.4 Punching shear capacity In the absence of particular justificat
40、ions, the punching shear capacity of slabs without topping VRd, in newtons, expressed as resisting point load, shall be calculated as follows: +=ctdcpctdefRd30 1f,h fbVf BS EN 1168:2005+A3:2011EN 1168:2005+A3:2011 (E) 21 with bpdxll= 1 according to 6.2.2 of EN 1992-1-1:2004 where beffis the effectiv
41、e width of the webs according to %Figure 6&; cpis the concrete compressive stress at the centroidal axis due to prestressing. beff= bw1+ bw2+ bw3a) General situation beff= bw1+ bw2+ bw3c) General situation with structural topping beff = bw1+ bw2b) Free edge of floor-bay beff= bw1+ bw2d) Free edge of
42、 floor-bay with structural topping %Figure 6 Wltis the minimum section modulus in transverse direction per unit length related to the top fibre; Wlis the smaller of Wlbor Wlt. If the elements are designed by assuming load distribution according to the elastic theory, which means that a part of the l
43、oads acting on one element are distributed to adjacent elements, the limiting value of the tensile stress is fctdin the ultimate limit state. The capacities for concentrated loads in this case, in the ultimate limit state, may be derived from the same equation, but in which qk, Fkand fctk 0,05shall
44、be replaced by qd, Fdand fctd. 4.3.3.2.6 Load capacity of elements supported on three edges Distributed imposed loads on an element of the floor with one supported longitudinal edge will cause torsional moments. The resulting support reaction due to this torsion shall be ignored in the design in the
45、 ultimate limit state. The shear stresses due to these torsional moments shall be limited to fctk 0,05/1,5 in the serviceability limit state. %The load capacity qk, in newtons per millimeter, for imposed load per unit area which is the total load minus the load due to the self weight of the elements
46、, shall be calculated, in the serviceability limit state, as follows: 2tctk0,05k06,0 lWfq = in which Wtis the lower value of Wt= 2t (h - hf)(b - bw) BS EN 1168:2005+A3:2011EN 1168:2005+A3:2011 (E) 23 and Wt= )/8,13(2hbhb+, where Wtis the torsional section modulus of an element according to the elast
47、ic theory, in cubic millimetres; t is the smallest of the values of hfand bw, in millimetres; hfis the smallest value of the upper or lower thickness of the flange; bwis the thickness of the outermost web, in millimeters; L is the length of the element. h is the total height of the elements, in metr
48、es. 4.3.7 Durability Clause 4.3.7 of EN 13369:2004 shall apply. 4.3.8 Other requirements Clause 4.3.8 of EN 13369:2004 shall apply. 5 Test methods 5.1 Tests on concrete Clause 5.1 of EN 13369:2004 shall apply. 5.2 %Tests on pre-stressing steel In case of thermal pre-stressing, all additional tests d
49、escribed in Annex K shall apply. a new production facility to confirm the proper functioning of the production machine(s). Initial type testing shall be carried out for each singular cross section or if the sections are grouped into families (see 6.2.1), for a single section of each family. For each cross section to be tested: the prestressing or reinforcement level shall be at least 75 % of the m
