1、BRITISH STANDARD BS5931:1980 Code of practice for Machine laid in situ edge details for paved areas UDC 625.888BS5931:1980 This British Standard, having been prepared under the direction of the Road Engineering Standards Committee, was published under the authority of the Executive Board and comes i
2、nto effect on 30April1980 BSI04-1999 The following BSI references relate to the work on this standard: Committee reference RDB/31 Draft for comment77/14456 DC ISBN 0 580 11367 1 Cooperating organizations The Road Engineering Standards Committee, under whose direction this British Standard was prepar
3、ed, consists of representatives from the following Government departments and scientific and industrial organizations: Aluminium Federation Federation of Manufacturers of Asphalt and Coated Macadam Association* Construction Equipment and Cranes Association of Consulting Engineers Greater London Coun
4、cil British Quarrying and Slag Federation* Institute of Petroleum British Tar Industry Association Institute of Quarrying Cement and Concrete Association* Institution of Civil Engineers* Concrete Society Limited* Institution of Highway Engineers* Contractors Plant Association Institution of Municipa
5、l Engineers* Convention of Scottish Local Authorities Institution of Structural Engineers County Surveyors Society* Lighting Industry Federation Limited Department of the Environment (Property Ministry of Defence Services Agency) Refined Bitumen Association Limited Department of the Environment (Tra
6、nsport Road Emulsion Association Limited and Road Research Laboratory) Road Surface Dressing Association Department of Transport* Sand and Gravel Association Federation of Civil Engineering Society of Chemical Industry Contractors* Trades Union Congress The organizations marked with an asterisk in t
7、he above list, together with the following, were directly represented on the committee entrusted with the preparation of this British Standard: Cement Admixtures Association National Paving and Kerb Association Cement Makers Federation Individual expert Institute of Geological Sciences Amendments is
8、sued since publication Amd. No. Date of issue CommentsBS5931:1980 BSI 03-1999 i Contents Page Cooperating organizations Inside front cover Foreword ii 0 Introduction 1 1 Scope 1 2 References 1 3 General considerations 1 4 Machines for forming in situ edge details 1 5 Section size and tolerances 2 6
9、Trial lengths 2 7 Asphalt sections 2 8 Concrete sections 4 Appendix A Characteristics of machines for forming in situ edge details 7 Figure 1 Typical cross sections of asphalt kerbs 8 Figure 2 Typical cross sections of concrete kerbs 9 Table 1 Classification of auger powered kerb extruder machines 7
10、 Publications referred to Inside back coverBS5931:1980 ii BSI 03-1999 Foreword Extruded asphalt kerbing was introduced into the United Kingdom from the USA in1961 and concrete some years later, since which time a substantial amount of experience has been obtained with their use. Some kerbs of this t
11、ype have now been in service for over15years with satisfactory performance. These recommendations set out to give general information on such kerbs based on this experience. This code recommends good practice for the production of both asphalt and concrete edge details. Specific reference to either
12、material is made only where their individual characteristics warrant such reference. A British 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 its
13、elf confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pagesiandii, pages1 to10, 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 indic
14、ated in the amendment table on the inside front cover.BS5931:1980 BSI 03-1999 1 0 Introduction 0.1 Uses. Most forms of road-edge detail may be successfully extruded or, for concrete alone, slip formed. Raised kerbs may be formed on both rigid and flexible pavements during new construction projects.
15、The principle use of machine laid in situ sections in the United Kingdom has been at the back of hardshoulders on motorways as a drainage detail. However there are now many cases where these sections have been successfully adopted immediately adjoining carriageways on all-purpose roads and on housin
16、g estates. Other situations where this type of section may be used include surrounds to vehicle parking areas, as a means of channelling traffic (e.g.at toll booths) and for the delineation of individual parking bays. Sections may be formed on existing pavements for surface water control, to facilit
17、ate provision of footways with minimum cost or for traffic management purposes. Where an edge beam is specified as a buttress or datum for pavement construction, a machine laid in situ concrete section may be the preferred form of construction and this may include a raised kerb where required. 0.2 A
18、dvantages. Machine laid in situ sections can be laid at up to ten times the rate of laying for conventional forms of kerbs. The in situ type of kerb may be superimposed on existing kerbs thus avoiding taking up and relaying to new levels. It is particularly suitable where a simple addition to an exi
19、sting pavement is required for surface water control or traffic segregation. Even if the length to be constructed is small but speed is essential, machine laid in situ kerbs, channels or other features may be considered advantageous in spite of any possible additional cost. 0.3 Disadvantages. Line-g
20、uided machines are susceptible to inaccuracies or disturbances of line setting possibly leading to expensive remedial works on long lengths of in situ section. Conventional pre-cast kerbs are fairly easily adjusted for line and level, and conventional formwork can be checked before concrete is place
21、d. Apart from the question of cross-sectional area, the main limitation on the use of an extrusion machine is the presence of obstacles adjacent to the line of the section. For example, the machines cannot normally be operated immediately against bridge parapets, walls, etc. although, to overcome th
22、is problem, hand placing of pre-extruded section may be practicable. Machine laid in situ concrete is not readily adapted to allow for settlement or alteration to provide for accesses. Extruded asphalt is more readily adapted than concrete to provide entrances and replacement of damaged sections. Ae
23、sthetically, asphalt sections are vulnerable to damage from heavy traffic particularly in the first few weeks of life and they may soften in extremely hot weather. 1 Scope This code gives information and recommendations about the use of extruded-asphalt or extruded-concrete, and slip-formed concrete
24、 road-edge features such as kerbs or channels. Details of asphalt and concrete mixes that are suitable for the processes are given together with construction details. This code does not provide recommendations for the forming of such edge features monolithically with paved areas nor on the forming o
25、f safety barriers. 2 References The titles of the publications referred to in this code are listed on the inside back cover. 3 General considerations In general, the case for or against the adoption of a machine laid in situ section is one of economics. Where a kerb is to be formed on the surface of
26、 a new pavement the cost of that portion of the pavement should be added to that of the kerb. Because the mechanized construction of in situ edge details is a specialized process, it is recommended that experienced machine operators be employed. Continuity of experience is also desirable. Constructi
27、on should be a continuous process and it is recommended that the supply of materials should be co-ordinated with the output of the particular machine. Where line-guided machines are used, care should be taken to ensure that the line is not displaced. 4 Machines for forming in situ edge details 4.1 G
28、eneral considerations. There are two basic types of machine commonly referred to as: a) extrusion machines; b) slip-form machines. Further details of the characteristics of both types are given in Appendix A.BS5931:1980 2 BSI 03-1999 The selection of a machine for a particular project should take ac
29、count of: a) the material to be laid; b) the section dimensions; c) in the case of concrete, whether dowels or reinforcement are to be included. Asphalt may be laid by only certain of the extrusion machines. Plain concrete may be laid by either extrusion or slip forming machines. Reinforced concrete
30、 or that containing vertical dowels, may be laid by most slip forming machines but not by extrusion machines. 4.2 Auger powered extrusion machines. To achieve the correct density there is a critical relationship between machine mass, auger size and number of augers to the cross-sectional area of the
31、 mould. The density of the extruded section is a direct result of the resistance of the machine to forward movement. Hence a machine of a mass appropriate to the section dimensions should be selected (see Appendix A). 5 Section size and tolerances 5.1 General. A wide variety of kerb, kerb and gulley
32、, channel, edge beams and ditch liners can be achieved. There are some physical limitations, however, that affect the choice of machine as indicated in4.1 and Appendix A. Most slip-form machines will accept moulds for almost any section from120mm 120mm chamfered kerb upwards. Many can place structur
33、es, such as kerb and footpath combined, up to1.5m to2m wide and a few will accept moulds up to3m wide. The auger powered extruding machines are more limited. Whilst machine laid kerbs are preferably laid to straight line or gentle curves, it is possible for them to be satisfactorily laid to radii as
34、 sharp as5m. Abrupt changes in kerb-line and level, e.g.at gulley outlets or at dropped kerbs, should receive special attention as indicated in7.3.6 and8.5.6. 5.2 Dimensional tolerances on cross section of moulds. The tolerance on the cross section of the mould should be 3mm. 5.3 Finished tolerances
35、 on alignment. Except in the case of line-guided machines the regularity of asphalt kerbs with respect to level depends on the accuracy of finish of the surface on which it is laid. In the case of line-guided machines the surface regularity of the top of the kerb should be within 3mm of the theoreti
36、cal line. The horizontal alignment should not depart from the intended line by more than 13mm nor deviate from the straight by more than3mm in3m. Where false falls have been provided in the pavement surfacing to assist drainage in the channels, except where a line-guided machine is used, special mea
37、sures are usually necessary to ensure that the kerb level follows the true road level rather than that of the falls. It may simply require adjustments to be made to the height of the wheels of the extrusion machine or it may be necessary to run the machine on a short length of suitably supported tra
38、ck or board, placed at the required datum. Alternatively, consideration should be given to the use of pre-extruded kerbs laid on an in situ bed such as would normally be laid for conventional kerbs. 6 Trial lengths Before commencing any contract it is recommended that the contractor, having selected
39、 a mix, should demonstrate, by laying a trial length, that this mix, the plant, equipment and method of construction will produce an acceptable end product. Such trial lengths should be assessed for the required degree of compaction, a uniform surface finish free from blemishes, accurate cross-secti
40、onal dimensions and longitudinal alignment. The capability of the machine to do the curve and gradient work required in the contract should be checked during the trial. Consideration should be given to the siting of the trial length so that, if successful, it can form part of the main work. Once the
41、 mix details, plant and method of construction have been chosen, these should not be varied without the prior approval of the engineer. 7 Asphalt sections 7.1 General. Experience in the United Kingdom has shown that rolled asphalt mixes of the type described in BS594are most suitable for extrusion.
42、Recommended recipe mixes are detailed as follows.BS5931:1980 BSI 03-1999 3 7.2 Materials. A nominal coarse aggregate content within the range20% to 30% is recommended, although other stone contents have been successfully used. The nominal size of the coarse aggregate should not exceed20mm and will n
43、ormally be10mm. The aggregate type and other properties should comply with the requirements of BS594. The binder content of the asphalt mix should normally lie within the range6% to9% although some aggregates may require0.5% to1% more binder. It is recommended that the binder be50,70 or100penetratio
44、n grade. In general the upper range of binder content and the lower range of penetration will lead to a more durable kerb. In situations where the kerbs will be immediately adjoining a carriageway and where there is a high risk of mechanical damage from vehicle impact, a harder grade of binder (e.g.
45、35-pen), coupled with the upper range of coarse aggregate content may be considered more appropriate. The final mix composition will depend on the type of machine, the profile specified and the nature of the coarse aggregate. The normal tolerances specified in BS594with respect to composition of the
46、 mixture apply to asphalt mixes to be used for extruded kerbing. 7.3 Construction 7.3.1 Setting out. Asphalt kerb extrusion does not necessarily require the setting of rails or guide wires and it is common practice simply to work to a string or chalk guide line on the surface on which the kerbs are
47、to be placed. 7.3.2 Preparation of foundation. Asphalt kerbs may be extruded on to the basecourse or wearing course of a flexible construction or, in the case of a rigid construction, on the finished concrete. The surface on which the kerbs are to be laid should be dry and cleaned of loose or delete
48、rious material. 7.3.3 Bond. Except in the case of freshly laid bituminous pavements, a tackcoat of either bitumen emulsion complying with the requirements of class A1-40or class K1-40of BS434or cut-back bitumen complying with the requirements of BS3690, should be applied to the surface before the se
49、ctions are laid. Where emulsion is used, it is essential that it be allowed to break before the kerb is laid. 7.3.4 Supply of material. The asphalt mix should be transported to the site in suitably insulated vehicles so as to prevent an excessive drop in temperature and as a protection against adverse weather conditions. The temperature at which the asphalt should be delivered to the hopper of the extrusion machine is dependent upon the mix composition but will normally be within the range135C to 180C. 7.3.5 Laying. It is essential that all machine parts in contac
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