Bsi bs en 12272 2 2003

covers12272p2 fm BRITISH STANDARD BS EN 12272 2 2003 Surface dressing — Test methods — Part 2 Visual assessment of defects The European Standard EN 12272 2 2003 has the status of a British Standard IC[.]

Surface dressing —

Test methods —

Part 2: Visual assessment of defects

The European Standard EN 12272-2:2003 has the status of a

British Standard

ICS 93.080.20

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This British Standard, was

published under the authority

of the Standards Policy and

Strategy Committee on

6 February 2004

© BSI 6 February 2004

National foreword

This British Standard is the official English language version of

EN 12272-2:2003

The UK participation in its preparation was entrusted by Technical Committee B/510, Road materials, to Subcommittee B/510/2, Surface dressings, sprays and slurry, which has the responsibility to:

A list of organizations represented on this subcommittee 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 Correspondence Index”, or

by using the “Search” facility of the BSI Electronic Catalogue or of British

Standards Online

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 does not of itself confer immunity from legal obligations.

— 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 interests 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 EN title page, pages 2 to 15 and a back cover

The BSI copyright notice displayed in this document indicates when the document was last issued

Amendments issued since publication

NORME EUROPÉENNE

EUROPÄISCHE NORM June 2003

ICS 93.080.20

English version

Surface dressing - Test methods - Part 2: Visual assessment of

defects

Enduits superficiels d'usure - Méthodes d'essai - Partie 2:

Evaluation visuelle des défauts Oberflächenbehandlung - Prüfverfahren - Teil 2: VisuelleBeurteilung von Inhomogenitäten

This European Standard was approved by CEN on 21 February 2003.

CEN members are bound to 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 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 Management Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands, Norway, Portugal, Slovakia, Spain, Sweden, Switzerland and United Kingdom.

EUROPEAN COMMITTEE FOR STANDARDIZATION

C O M I T É E U R O P É E N D E N O R M A L I S A T I O N

E U R O P Ä IS C H E S K O M IT E E FÜ R N O R M U N G

Management Centre: rue de Stassart, 36 B-1050 Brussels

© 2003 CEN All rights of exploitation in any form and by any means reserved

worldwide for CEN national Members. Ref No EN 12272-2:2003 E

Contents

Page

Foreword 3

1 Scope 4

2 Normative references 4

3 Terms and definitions 4

4 Visual assessment of defects 8

4.1 General 8

4.2 Qualitative assessment 8

4.2.1 Procedure 8

4.3 Quantitative assessment 9

4.3.1 Fatting up, tracking, bleeding, scabbing, and tearing 9

4.3.2 Fretting 10

4.3.3 Streaking 11

5 Expression of results 11

5.1 General 11

5.2 Qualitative assessment 11

5.3 Quantitative assessment 11

5.3.1 Fatting up, tracking and bleeding 11

5.3.2 Scabbing and tearing 12

5.3.3 Fretting 12

5.3.4 Streaking 12

6 Test report 12

Annex A (normative) Qualitative assessment 13

Annex B (normative) Quantitative assessment 14

Bibliography 15

3

Foreword

This document (EN 12272-2:2003) has been prepared by Technical Committee CEN/TC 227 "Road materials", the secretariat of which is held by DIN

This European Standard shall be given the status of a national standard, either by publication of an identical text or

by endorsement, at the latest by December 2003, and conflicting national standards shall be withdrawn at the latest

by December 2005

This European Standard is one of a series of standards as listed below:

EN 12272-1, Surface dressing — Test methods — Part 1: Rate of spread and accuracy of spread of binder and

chippings

EN 12272-2, Surface dressing — Test methods — Part 2: Visual assessment of defects

EN 12272-3, Surface dressing — Test method — Part 3: Determination of binder aggregate adhesivity by the Vialit

plate shock test method

Annexes A and B are normative

According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands, Norway, Portugal, Slovakia, Spain, Sweden, Switzerland and the United Kingdom

1 Scope

This European Standard is applicable to all surface dressings (roads, airfields and other trafficked areas) and specifies qualitative and quantitative methods of the visual assessment of defects of surface dressing

The results of the qualitative evaluation carried out by visual assessment when specified shall be reported in annex

A This is a rapid practical test and may be specified as the primary test so that if the results are obvious or are without any doubt the more time consuming quantitative test method may be avoided The quantitative test method shall be carried out when specified and the table of results in annex B reported

The visual assessment reports for both methods have identical records and thus both may be used to check the specification for visual assessment of defects (prEN 12271-4) The rapid qualitative test methods is dependent on the skill and experience of the operator and therefore the repeatability and the reproducibility values will not be as precise, but the convenience of the method and lack of disruption to traffic will ensure its use

The national application document may state whether either or both or sequentially the qualitative and quantitative tests are to be used and may relate this to types of site (for example lightly trafficked roads may not be required to

be quantitatively assessed)

The test may be used to evaluate the durability or performance of a surface dressing For example fretting may indicate poor adhesion of the binder to chippings

Not applicable

3 Terms and definitions

For the purposes of this European Standard, the following terms and definitions apply

3.1

mosaic

arrangement of chippings such that they are in shoulder to shoulder contact and are thus supported laterally

NOTE The initial stability of a surface dressing is dependent upon the formation of a close mosaic and the cohesion and adhesion of the binder Subsequent durability is gained by re-orientation of the chippings by traffic to form a tight mosaic, and sufficient binder to secure the chippings to the existing road surface before the onset of embedment

3.2

embedment

process whereby chippings are forced into an existing road surface by the action of traffic (see Figure 1) resulting

in a reduction of macrotexture with time, which is rapid in the first summer and thereafter stabilises for well designed surface dressings

NOTE Factors affecting embedment are

 increased traffic, especially heavy goods vehicles, increases the rate of embedment;

 road hardness: cement concrete, for example, does not allow embedment;

 summer months, when the average road temperature is higher, results in softer roads with less resistance to embedment;

 size of chippings: large chippings reduce the rate of embedment;

5

 traffic speed: slow traffic experienced on hills and at junctions increases embedment by extending the loading time Conversely, fast traffic, such as that in the overtaking lane of a dual carriageway, results in less embedment;

 shaded areas: a reduction in average road temperature reduces embedment;



Figure 1a — No embedment (very hard substrate and/or low traffic volume)

Figure 1b — Typical embedment

Figure 1c —Fatting up (nearly total embedment soft substrate chipping size too small – poor design) Key

1 Road surface level before treatment

2 Blackened surface (especially in wheel tracks) and loss of texture

3 Chippings embedded by traffic

Figure 1 - Embedment

Key

1 Road surface level before treatment

2 Typical bituminous globules at the surface

3 Binder flow

Figure 2 — Bleeding 3.3

defect

state of a surface dressing where the mosaic is covered by binder as in the case of fatting up, tracking and bleeding or is disrupted as in the case of scabbing, tearing, fretting or streaking (see 3.4 to 3.10)

NOTE Defects also occur due to poor methods of construction such as inadequate traffic control Surface dressings are vulnerable to traffic stress in their early life before the binder has sufficient cohesion or emulsion binders have had a chance to break Turning of the chippings by warm rubber tyres on exposed binder leads to disruption of the mosaic, scabbing and tearing often with an appearance similar to tracking Missed areas and ridges caused by overlaps and other installation faults such as poor traffic management should in any case be picked up by the contractor’s factory production control document

7

3.4

fatting up

result of almost total embedment (see Figure 1a, b, c)

NOTE The result of fatting up is an undesirable smooth surface (loss of macrotexture) often with excess binder at the surface leading to a very low skid resistance Fatting up in the wheel tracks is known as tracking and is caused by channelised traffic

3.5

tracking

fatting up in the wheel tracks caused by channelised traffic, sometimes initiated by bleeding or poor construction techniques

3.6

bleeding

exudation of bituminous binder from a road surface (see Figure 2)

NOTE 1 The binder rises to the surface through the mosaic of chippings This is especially noticeable with low viscosity fluxed bituminous binders

NOTE 2 Bleeding is more likely to occur with binder rich substrates

NOTE 3 High road temperatures, low viscosity binder, excess binder, and water pressure causing stripping of the binder from underlying materials are the common causes of bleeding

NOTE 4 The result of bleeding is an undesirable smooth surface (loss of macrotexture) often with excess binder at the surface leading to a very low skid resistance The effect is similar to fatting up although not restricted to the wheel tracks and the causes are different

3.7

scabbing

detachment of both binder and chippings after application from the existing road surface

NOTE 1 Scabbing often occurs when the surface of the existing road is contaminated with mud, oil, dust, animal droppings, etc

NOTE 2 Scabbing also occurs when the existing road surface is too wet for successful adhesion of the binder

NOTE 3 Scabbing may occur when adhesion of the dressing to the existing road is less than the cohesion of the binder in the mosaic This is noticeable on roads where bleeding has taken place and traffic has torn away areas of binder and chippings

at points of high traffic stress

3.8

tearing

concentrated (localised) loss of chippings from the mosaic of a completed surface dressing or excessive fretting over a continuous area of more than 0,01 m2

NOTE 1 Excessive fretting on badly constructed asphalt patch-repairs or areas under trees, is a common problem that may

be corrected by careful design

NOTE 2 Tearing may occur at points of high traffic stress

NOTE 3 Tearing may occur as a result of snow or ice removal

3.9

fretting

random loss of chippings from the mosaic of a completed surface dressing Concentrated loss of chippings over a continuous area of more than 0,01 m2 is not random loss and is considered as tearing

NOTE 1 Fretting occurs mainly where there is insufficient binder to hold the chippings It is particularly noticeable when the existing road surface varies in macrotexture, porosity or road hardness

NOTE 2 When surface dressing does not stabilise to form a mosaic of chippings, fretting will generally occur when the first frosts arrive The binder alone has insufficient cohesion to prevent the chippings from being dislodged by traffic forces This type

of brittle failure is exacerbated by short loading time due to high traffic speed and low ambient temperatures

NOTE 3 Fretting also occurs when adhesion of binder to chippings is lost When water displaces the binder from aggregate

or when fines or dust or damp or wet chippings have prevented adhesion from taking place initially Failure is sometimes localised and this then becomes tearing (see 3.8)

NOTE 4 Minor random loss of chippings, which does not affect the homogeneity of the mosaic, is not considered to be fretting This includes the initial loss of excess chippings used in construction that do not fit into the mosaic

3.10

streaking

loss of chippings from a completed surface dressing such that more than one line appears parallel to the direction

of application

NOTE 1 Lack of binder is the main cause of streaking and this may be caused by an irregular transverse distribution of binder across the spray bar

NOTE 2 Poor construction techniques such as insufficient overlap of binder spray at longitudinal joints may result in loss of chippings due to lack of binder The appearance is similar to streaking though only in one line, at a joint

3.11

width of lane

when there are no road markings, the lane width is the full road width; when there are road markings, the lane width is the distance between the centre marking and kerb or verge; and when there are more than two lanes, then the outside or centre lanes and hard shoulder (safety zone) are considered separately

4 Visual assessment of defects

4.1 General

A 100 m ± 1m section of surface dressing is chosen for visual assessment for each lane of the road (see 3.11 for definition of lane width)

The section reference shall be recorded in the relevant annex

Sections may be located anywhere along the road except that they shall not overlap

The remainder of the site that is not chosen for test or the area between sections is deemed to be without defects

at the time of carrying out the test

NOTE 1 The sections should be chosen in order to maximise the number of defects in each section

NOTE 2 If the defects are localised there may be only one section chosen in one lane for the entire length of road treated NOTE 3 Where the whole site has defects to be evaluated, it may be convenient to divide it up into 100 m ± 1 m sections that are contiguous (for example a 1 km road with no road markings would have ten sections, or twenty if there was a centre line marking)

4.2 Qualitative assessment

The qualitative assessment uses the visual assessment report in annex A

4.2.1 Procedure

Determine the lane section where the visual assessment is to be made (see 4.1)