1、BS 434-2:2006Bitumen road emulsions Part 2: Code of practice for the use of cationic bitumen emulsions on roads and other paved areasICS 75.140; 93.080.20NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBRITISH STANDARDPublishing and copyright informationThe BSI copyright notice
2、 displayed in this document indicates when the document was last issued. BSI 2006ISBN 0 580 49879 4The following BSI references relate to the work on this standard:Committee reference B/510Draft for comment 06/30147758 DCPublication historyFirst published as BS 2542 December 1954Second edition as BS
3、 2542 December 1960First published as BS 434-2 October 1973Second edition, February 1984Third (present) edition, December 2006Amendments issued since publicationAmd. no. Date Text affectedBS 434-2:2006 BSI 2006 iBS 434-2:2006ContentsForeword iii1 Scope 12 Normative references 13 Terms and definition
4、s 24 Emulsion types 35 Handling, storage and safety 76 Suitability of treatments and processes 87 Surface dressing of carriageways 98 Tack coat and bond coat emulsions 109 Slurry surfacing 1210 Retread 1711 Deep recycling 1812 Footway and cycleway construction and maintenance 2313 Patching and veloc
5、ity patching 2614 Permanent cold lay surfacing materials (PCSMs) 2715 Sealing and curing of cementitious materials 2916 Stress absorbing membrane interlayer (SAMIs) 3117 Miscellaneous uses 31Bibliography 33List of tablesTable 1 Temperature susceptibility of bitumen 5Table 2 Overview of processes 8Ta
6、ble 3 Particle size distribution of mixture for cold recycling 21Table 4 Suggested mix design test property criteria 21Table 5 Target rates of spread of binder for sealing and curing 30Summary of pagesThis document comprises a front cover, an inside front cover, pages i to iv, pages 1 to 34, an insi
7、de back cover and a back cover.BS 434-2:2006ii BSI 2006 This page deliberately left blank BSI 2006 iiiBS 434-2:2006ForewordPublishing informationThis part of BS 434 was published by BSI and came into effect on 29 December 2006. It was prepared by Technical Committee B/510, Road materials. A list of
8、organizations represented on this committee can be obtained on request to its secretary.SupersessionThis part of BS 434 supersedes BS 434-2:1984, which is withdrawn.Information about this documentThis new edition represents a full revision of the standard, and introduces the following principal chan
9、ges: refers to BS EN 13808; covers the use of polymer modified bitumen emulsions; includes guidance on the use of bitumen emulsions in the construction and maintenance of footways and cycleways; includes guidance on the use of bitumen emulsions as bond or tack coats; includes reference to permanent
10、cold lay surfacing materials; includes a bibliography containing sources of further information on the various techniques included in this British Standard.As a code of practice, this part of BS 434 takes the form of guidance and recommendations. It should not be quoted as if it were a specification
11、 and particular care should be taken to ensure that claims of compliance are not misleading.It has been assumed in the preparation of this British Standard that the execution of its provisions will be entrusted to appropriately qualified and experienced people, for whose use it has been produced.Any
12、 user claiming compliance with this part of BS 434 is expected to be able to justify any course of action that deviates from its recommendations.Assessed capability. Users of this British Standard are advised to consider the desirability of quality system assessment and registration against the appr
13、opriate standard in the BS EN ISO 9000 series by an accredited third-party certification body.Presentational conventionsThe provisions in this standard are presented in roman (i.e. upright) type. Its recommendations are expressed in sentences in which the principal auxiliary verb is “should”.Comment
14、ary, explanation and general informative material is presented in smaller italic type, and does not constitute a normative element.BS 434-2:2006iv BSI 2006Contractual and legal considerationsThis publication does not purport to include all the necessary provisions of a contract. Users are responsibl
15、e for its correct application.Compliance with a British Standard cannot confer immunity from legal obligations. BSI 2006 1BS 434-2:20061 ScopeThis part of BS 434 provides recommendations and guidance on the general usage of cationic bituminous emulsions on roads and other paved areas. The emulsions
16、covered conform to BS 434-1, or BS EN 13808 (modified and non-modified), or are proprietary emulsions.This British Standard provides guidance on where the various processes using bituminous emulsions are suitable for use and indicates where suitable design procedures may be found. Advice is also giv
17、en on those situations in which the processes are unsuitable or marginally suitable.Where there is an option, performance or outcome specifications have been used rather than input or recipe specifications. This follows the general approach adopted for European Standards and the general move towards
18、 performance specifications by many specifiers.Anionic emulsions are covered only for exceptional circumstances. Cationic emulsions have been specified for most purposes, although in some cases an anionic alternative may be used. 2 Normative referencesThe following referenced documents are indispens
19、able for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.BS 434-1:1984, Bitumen road emulsions (anionic and cationic) Part 1: Specification for bitumen roa
20、d emulsionsBS 594-2:2003, Hot rolled asphalt for roads and other paved areas Part 2: Specification for transport, laying and compaction of hot rolled asphaltBS 598-108, Sampling and examination of bituminous mixtures for roads and other hard paved areas Part 108: Methods for determination of the con
21、dition of the binder on coated chippings and for measurement of the rate of spread of coated chippingsBS 1377-3:1990, Methods of test for soils for civil engineering purposes Part 3: Chemical and electro-chemical testsBS 3136-2, Specification for cold emulsion spraying machines for roads Part 2: Met
22、ric unitsBS 3892 (all parts), Pulverized-fuel ashBS 4987-2:2003, Coated macadam (asphalt concrete) for roads and other paved areas Part 2: Specification for transport, laying and compactionBS 6463 (all parts), Quicklime, hydrated lime and natural calcium carbonateBS EN 197-1, Cement Part 1: Composit
23、ion, specifications and conformity criteria for common cementsBS EN 12271 (all parts), Surface dressing SpecificationsBS EN 12272-1:2002, Surface dressing Test methods Part 1: Rate of spread and accuracy of spread of binder and chippingsBS 434-2:20062 BSI 2006prEN 12273, Slurry surfacing Specificati
24、ons1)BS EN 12274 (all parts), Slurry surfacing Test methodsBS EN 12697-26, Bituminous mixtures Test methods for hot mix asphalt Part 26: StiffnessBS EN 12697-32, Bituminous mixtures Test methods for hot mix asphalt Part 32: Laboratory compaction of bituminous mixtures by vibratory compactorBS EN 138
25、08, Bitumen and bituminous binders Framework for specifying Cationic bitumen emulsionsNOTE See the Bibliography for sources of further information on the various techniques included in this British Standard.3 Terms and definitions For the purposes of this part of BS 434, the following terms and defi
26、nitions apply.3.1 bitumenvirtually involatile, adhesive and waterproofing material derived from crude petroleum, or present in natural asphalt, which is completely or nearly completely soluble in toluene, and very viscous or nearly solid at ambient temperatures3.2 bituminous binder adhesive material
27、 containing bitumen3.3 polymer modified bitumenbitumen whose rheological properties have been modified during manufacture by the addition of one or more polymers3.4 bitumen emulsion dispersion of bitumen in water, which usually contains an emulsifier to assist in maintaining the stability of the emu
28、lsion NOTE This term embraces emulsions in which the bitumen contains a small amount of flux derived from petroleum which has been added to facilitate emulsification and/or to enhance in-service characteristics.3.5 anionic bitumen emulsion emulsion in which the emulsifier imparts negative charges to
29、 the dispersed emulsion particles3.6 cationic bitumen emulsion emulsion in which the emulsifier imparts positive charges to the dispersed bitumen particles3.7 polymer-modified bitumen emulsion emulsion in which the dispersed phase is a polymer-modified bitumen or a bitumen emulsion modified with lat
30、ex1)prEN 12273 is currently still a draft European Standard. To be published by CEN as EN 12273 and adopted in the UK as BS EN 12273. BSI 2006 3BS 434-2:20064 Emulsion types4.1 GeneralThe UK specification for bitumen emulsion (BS 434-1) was last published in 1984 and has remained substantially uncha
31、nged since then apart from two minor amendments. It has recently been replaced by BS EN 13808 which is a significantly different document. This clause attempts to explain the differences within the context of the changes that have occurred since 1984.4.2 BS 434-1 classificationIn BS 434-1:1984 emuls
32、ions are classified on the basis of:a) polarity anionic or cationic (A or K);b) emulsion stability (on a scale of 1-rapid, 2-medium, 3-slow breaking);c) binder content.Thus a K1:70 emulsion is a rapid breaking cationic emulsion with a nominal binder content of 70%. An A2:50 emulsion is a medium brea
33、king anionic emulsion with a nominal binder content of 50%.The stability of emulsions can be changed by altering the type or quantity of emulsifier used in their manufacture. In recent years the development of tests to measure the break of the emulsion has resulted in numerical values, of breaking v
34、alue or breaking index, being attributed to emulsion. This more accurately reflects their stability than the traditional allocation of 1, 2 or 3 in BS 434-1:1984 (see above) as an indication of stability, and has allowed the stability of emulsion to be defined numerically (breaking index) in BS EN 1
35、3808.4.3 BS EN 13808 classification BS EN 13808 classifies emulsions in a more detailed way than BS 434-1 utilizing up to seven characters, on the following basis:polarity, e.g. C; nominal binder content, e.g. 67; indicate type of binder: B paving grade bitumen (BS EN 12591); P addition of polymer;
36、F addition of more than 2% flux; class of breaking value (from 0 to 7) (see 4.5).Thus for example a C70 B2 emulsion is a cationic bitumen emulsion with a 70% nominal binder content, produced from paving grade bitumen (conforming to BS EN 12591) with a class 2 breaking value.Similarly a C60 BPF6 emul
37、sion is a cationic bitumen emulsion with a nominal binder content of 60% containing polymer and flux and having a class 6 breaking value.BS 434-2:20064 BSI 20064.4 Polymer modified bitumen products4.4.1 BackgroundAt the time of publication of BS 434-1:1984 almost all bitumen emulsions were produced
38、using paving (penetration) grades of bitumen. A significant change since the initial publication of that British Standard has been the introduction and development of polymer modified bitumen products, the growing use of which has presented problems of specification. Initially these products were so
39、ld as proprietary products to specifications produced by manufacturers, a situation which leads to confusion with no standard specifications for them. This problem was recognized by the introduction of an assessment and certification scheme for such products under the HAPAS (Highway Authorities Prod
40、uct Approval Scheme) administered by the British Board of Agrment (BBA) which produced a list of tests, including ageing and rheology, against which emulsions can be assessed. If the performance of the emulsion satisfies the requirements of the scheme it is eligible to receive a BBA Roads and Bridge
41、s Certificate.The testing under this scheme goes beyond the requirements of BS 434-1 in that for surface dressing, for example, it not only requires testing of the emulsion and of the recovered binder from the emulsion (as in BS EN 13808) but also evidence of two years satisfactory performance on th
42、e road at a minimum of three appropriate sites. Many of the binder testing requirements of the HAPAS binder specifications for polymer modified bituminous emulsions are also stipulated in the Specification for Highway Works (SHW) 1, Clauses 919 and 922 for surface dressing, Clause 920 for bond coats
43、 and Clause 918 for slurry surfacing and the Notes for Guidance and Appendices relating to them.NOTE The British Board of Agrment/Highway Authorities Product Approval Scheme (BBA/HAPAS) is a scheme in which proprietary products may be validated and their performance measured and published. This ensu
44、res that a product, once placed on the market, has attached to it performance criteria which can be monitored by the purchaser and ultimately by BBA/HAPAS, as an independent UK certifying body. BBA is the UK representative of the European Technical Approval (ETA) system which is set up to validate p
45、roducts for which it has not been possible or is not yet possible to produce a British or European Standard. Further information on BBA/HAPAS and the certification status of products can be found on the BBA website at www.bbacerts.co.uk.4.4.2 Polymer modified bituminous emulsionsThe most significant
46、 advance in bituminous emulsions in the last two decades has been the introduction of polymer modified bituminous emulsions. The effect of polymer modification is to enhance the performance on the road, which can be observed in practice. Precisely how this improved performance is achieved, however,
47、is more difficult to define. BSI 2006 5BS 434-2:2006Bitumen is a thermoplastic material, which softens when heated and becomes hard and brittle when cooled. Thus at higher temperatures it can become too soft to hold the chippings in a surface dressing system and at cooler temperatures it can become
48、so hard and brittle that it fractures under traffic stresses and loses chippings. One effect of polymer modification is to widen the temperature range over which bitumen exhibits good binder properties. Table 1 compares the softening point (high temperature) and Fraass brittle point (low temperature
49、) properties of three paving grade bitumens and a polymer modified bitumen (the difference in temperature % T).From Table 1 it is clear that the polymer modified material exhibits a good level of performance over a wider temperature range than the paving grade binders. In addition to increasing the useful temperature range, polymer modification also enhances the performance over this range. Enhancement of a number of physical properties has been recognized and measured
