1、BRITISH STANDARD BS 6579-8: 1987 Safety fences and barriers for highways Part 8: Specification for concrete safety barriers UDC625.738+692.88BS6579-8:1987 This British Standard, having been prepared under the directionof the Road EngineeringStandards Committee, was published underthe authority of th
2、e BoardofBSI and comes intoeffecton 30 November 1987 BSI 03-1999 First published February1985 First revision November1987 The following BSI references relate to the work on this standard: Committee reference RDB/18 Draft for comment86/15254DC ISBN0580162249 Committees responsible for this British St
3、andard The preparation of this British Standard was entrusted by the Road Engineering Standards Committee (RDB/-) to Technical Committee RDB/18upon which the following bodies were represented: Aluminium Federation Association of Consulting Engineers British Railways Board British Steel Industry Ceme
4、nt and Concrete Association Convention of Scottish Local Authorities County Surveyors Society Department of Transport (Highways) Institution of British Engineers Institution of Civil Engineers Institution of Highways and Transportation Royal Automobile Club Royal Society for the Prevention of Accide
5、nts The following bodies were also represented in the drafting of the standard, through subcommittees and panels: Department of Transport (Transport and Road Research Laboratory) Fencing Contractors Association Amendments issued since publication Amd. No. Date of issue CommentsBS 6579-8:1987 BSI 03-
6、1999 i Contents Page Committees responsible Inside front cover Foreword ii 0 Introduction 1 1 Scope 1 2 Definitions 1 3 Construction 2 4 Materials 2 5 Manufacture and handling of precast units 3 6 Marking of precast units 4 Appendix A Vehicle safety fences and barriers for highways: type characteris
7、tics 5 Appendix B Information to be supplied by the purchaser 6 Figure 1 Profile type1: in-situ 7 Figure 2 Profile type2: in-situ 8 Figure 3 Profile type3: in-situ split level 9 Figure 4 Profile type4: precast units installed 10 Figure 5 Profile type5: precast units installed 11 Figure 6 Profile typ
8、e4: precast unit 12 Figure 7 Profile type5: precast unit 13 Figure 8 Precast3m standard length unit 14 Figure 9 Precast1m long make-up unit 15 Figure 10 Details of base and end fixings for precast units 16 Figure 11 Precast termination unit 17 Figure 12 Precast transition unit: type1(for transition
9、to double sided open box beam safety fence) 18 Figure 13 Connector for precast transition unit: type1to single sided open box beam safety fence 19 Figure 14 Connector for precast transition unit: type1to doublesidedopenbox beam safety fence 20 Figure 15 Precast transition unit: type2(for transition
10、to200mm100mm tensioned rectangular hollow section beam safety fence) 21 Figure 16 Connector for precast transition unit: type2 (for transition to tensioned rectangular hollow section beam safety fence) 22 Figure 17 Precast transition unit: type3(for transition to single sided open box beam safety fe
11、nce) 23 Figure 18 Precast transition unit: type4(for transition to200mm 100mm tensioned rectangular hollow section beam safety fence) 24 Figure 19 Connector for precast transition unit: type4(for transition totensioned rectangular hollow section beam safety fence) 25 Figure 20 Diagramatical represen
12、tation of fences and barriers 26 Table 1 Safety fences and barriers: type characteristics 5 Publications referred to Inside back coverBS 6579-8:1987 ii BSI 03-1999 Foreword This Part of BS6579has been prepared under the direction of the Road Engineering Standards Committee. The other Parts of BS6579
13、either published or in preparation are: Part 1: Specification for components for tensioned corrugated beam safety fence on Z posts; Part 2: Specification for tensioned corrugated beam safety fence on offset brackets; Part 3: Specification for tensioned rectangular hollow section beam safety fence (1
14、00mm 100mm); Part 4: Specification for tensioned rectangular hollow section beam safety fence (200mm 100mm); Part 5: Specification for open box beam safety fence (single height); Part 6: Specification for open box beam safety fence (double height); Part 7: Specification for untensioned corrugated be
15、am safety fences. In this revision of the1985edition of BS6579-8the principal changes are as follows. a) Additional figures have been included to cover extra types of transition unit (types3and4). b) Most of the existing figures have had minor modifications incorporated. c) The references to CP110“T
16、he structural use of concrete” Part1“Design, materials and workmanship” (now withdrawn) have been replaced by appropriate references to BS8110-1. This revision of BS6579supersedes the1985edition which is withdrawn. BS6579is being produced at the request of users and manufacturers in order to cover t
17、he various types of safety fences and barriers available. Fences detailed in Parts1to7have been developed already and approved for use in roads in the United Kingdom. The designs are based on the results of static and dynamic tests carried out in the past on components and complete systems under the
18、 direction of the Transport and Road Research Laboratory. The safety barrier detailed in this Part is for use only on certain roads at the date of publication of this Part of BS6579. If further types are developed, BS6579will be revised and increased in scope to cover additions and variations. A Bri
19、tish Standard does not purport to include all the necessary provisions 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 fro
20、nt cover, an inside front cover, pagesiandii, pages1to26,an inside back 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 theinside front cover.BS 6579-8:1987 BSI 03-1999 1 0 Introduc
21、tion 0.1 The objective of providing safety fences and safety barriers adjacent to a highway is to reduce the consequences of vehicles leaving the carriageway and entering areas where it would be unsafe for them to travel. Safety fences are intended to absorb some of the energy of impact and to redir
22、ect the errant vehicle, so that it follows, within a narrow angle, the line of the fence in the direction of the traffic and does not overturn. Safety barriers are intended to provide containment without significant deflection or deformation under impact, and to re-direct errant vehicles along the l
23、ine of the barrier in the direction of traffic. 0.2 The safety fences and barriers for ground mounting which are the subject of BS6579are for use in conjunction with parapets on bridges and other structures, which are the subject of BS6779. Although definitions in both standards have been chosen so
24、as to align as closely as possible, there are some cases where the definition is applicable only to a particular Part of BS6579and does not apply generally. 0.3 No direct guidance is given in BS6579on the situations where safety fences and barriers should be erected or on the choice of the types des
25、cribed in the various parts, but information pertaining to general characteristics of different types of safety fences and barriers is given inAppendix A. 0.4 There are various situations and various methods by which transition between a safety fence or safety barrier and a vehicle containment parap
26、et can be assured without impairing the overall protection afforded to the users of the highway. Guidance is provided in Figure 12, Figure 15, Figure 17 andFigure 18 on means for connecting the concrete barrier to two types of safety fence. 1 Scope This Part of BS6579specifies the methods and materi
27、als to be used for the construction of concrete safety barriers and the manufacture of precast units. Basic installation details are included on the figures. NOTEThe titles of the publications referred to in this standard are listed on the inside back cover. 2 Definitions For the purposes of this Pa
28、rt of BS6579the following definitions apply. 2.1 safety fence an installation provided for the protection of users of the highway consisting of horizontal members mounted on posts 2.2 safety barrier an installation provided for the protection of users of the highway which is continuously in contact
29、with its supporting foundation 2.3 concrete safety barrier a non-yielding concrete barrier the traffic face of which may be so contoured as to assist the redirection of an errant vehicle along the line of the installation 2.4 profile the cross-sectional outline of the barrier 2.5 traffic face the fa
30、ce of a safety fence or barrier that is nearer to the vehicular traffic flow 2.6 impacting vehicle a vehicle striking a safety fence or barrier whether or not it is redirected 2.7 base fixing the method of fixing the base of the barrier to or into the underlying surface or foundation for stability o
31、f the installation 2.8 end fixing the method of securing adjacent sections one to another for stability of the installation 2.9 transition the transition from a concrete safety barrier to a safety fence 2.10 termination the ramped end of a safety barrier installationBS 6579-8:1987 2 BSI 03-1999 3 Co
32、nstruction 3.1 Methods Concrete safety barriers shall be constructed by one of the following methods: a) in-situ between fixed forms (see3.2); b) in-situ between sliding forms (see3.3); c) in precast units (see3.4). NOTEThe choice of method of construction should be stated when making an enquiry or
33、order (see Appendix B). 3.2 In-situ between fixed forms 3.2.1 Barriers constructed in-situ between fixed forms shall be either type1,2or3and shall conform to the required profiles, dimensions, tolerances and reinforcement details as follows: a) profile type1in conformity with Figure 1; b) profile ty
34、pe2in conformity with Figure 2; c) profile type3in conformity with Figure 3. 3.2.2 Reinforcement shall be provided and fixed in accordance with section7of BS8110-1:1985. 3.2.3 Barriers constructed between fixed forms shall have a type C finish as described in6.10.3 of BS8110-1:1985,formwork shall be
35、 in accordance with6.9 of BS8110-1:1985,transporting, placing and compacting shall be in accordance with6.5 of BS8110-1:1985and curing shall be in accordance with6.6 of BS8110-1:1985. 3.2.4 The terminations of an in-situ installation or the transition of a concrete safety barrier to a safety fence s
36、hall be constructed in precast units as shown in Figure 11, Figure 12, Figure 15, Figure 17 or Figure 18 as applicable. 3.2.5 Dowelled base fixings for type1in-situ barriers shall be provided to conform to the details shown inFigure 1. 3.2.6 Connection between an in-situ section of barrier and preca
37、st termination or transition units shall be no less efficient than the method of end fixing at vertical joints between precast units as shown inFigure 10. 3.3 In-situ between sliding forms 3.3.1 Barriers constructed in-situ by slip form machines between sliding forms shall be either type1or2and conf
38、orm to the profiles, dimensions, tolerances and reinforcement details as follows: a) profile type1in conformity with Figure 1; b) profile type2in conformity with Figure 2. 3.3.2 Slip-form machines shall have the characteristics described inA.2 of BS5931:1980. The workability of the concrete and the
39、method of construction shall be in accordance with8.4 and8.5 of BS5931:1980respectively. 3.3.3 The type of surface finish required shall be in accordance with6.10.3 of BS8110-1:1985. 3.3.4 The terminations of a concrete safety barrier constructed with slip form machines, or the transition to a safet
40、y fence shall be constructed in precast units as shown in Figure 11, Figure 12, Figure 15, Figure 17 or Figure 18 as applicable. 3.3.5 Connections between a slip-formed section of barrier and precast termination or transition units shall be no less efficient than the method of end fixing at vertical
41、 joints between precast units that is shown in Figure 10. 3.3.6 Dowelled base fixings for type1barriers shall be provided to conform to the details shown in Figure 1. 3.4 In precast units 3.4.1 Concrete safety barriers which comprise precast units installed on a regulating/bedding layer of low moist
42、ure content cement-sand mortar shall be constructed to the profiles, dimensions and tolerances shown in Figure 4, Figure 5 and Figure 7. 3.4.2 Precast units for use in the construction of concrete safety barriers shall be manufactured, handled, transported and stored in accordance with clause5. 3.5
43、Joints Provision shall be made to accommodate contraction movement in in-situ installations at intervals which are appropriate to the amount of reinforcement that is used in the section. NOTE 1No additional measures will normally need to be taken to accommodate contraction movement in precast instal
44、lations. In all cases joints shall be provided to coincide with expansion or contraction joints in an underlying pavement or structure. NOTE 2 No provision will normally be necessary to accommodate expansion movement in either precast or in-situ installations. 4 Materials 4.1 Concrete 4.1.1 Air entr
45、ainment and mix design. Concrete which is used for the construction of in-situ and precast safety barriers shall be air-entrained, and comply with the requirements of BS5328and shall be either: a) a designed mix, or b) a special prescribed mix. 4.1.2 Strength and durability. The concrete shall be C4
46、0 grade in accordance with Table 3 of BS5328:1981. 4.1.3 Cement content. The minimum cement content shall be330kg/m 3of fully compacted concrete.BS 6579-8:1987 BSI 03-1999 3 4.1.4 Water/cement ratio. The ratio of free water to cement shall be a maximum of0.5. 4.1.5 Air content. The air content of th
47、e concrete shall be5 1.5% by volume. 4.1.6 Lightweight concrete. Where it is required to reduce dead-loading on structures, lightweight aggregate concrete with a density of at least1800kg/m 3shall be used. 4.2 Cement The cement shall be either ordinary Portland or Portland-blastfurnace cement comply
48、ing with the requirements of BS12or BS146,respectively. Coloured Portland cement shall comply with the physical requirements of BS12. 4.3 Aggregates 4.3.1 Quality. Fine and coarse aggregates shall consist of either: a) crushed or uncrushed materials complying with the requirements of BS882or BS1047,
49、 or b) lightweight (see4.1.6) coarse aggregate complying with the requirements of BS877 or BS3797. 4.3.2 Maximum size. The maximum size of the coarse aggregate shall be20mm. 4.4 Admixtures and pigments 4.4.1 Air-entraining admixtures. Concrete shall be air-entrained with an admixture which complies with the requirements of BS5075-2. 4.4.2 Accelerating admixtures. Accelerating admixtures containing calcium chloride shall not be used. 4.4.3 Water-reducing admixtures. If water-reducing admixtures are used they shall comp
