Acceptability of Alternative Materials in Road Construction SETRRA [PDF]

Zitiervorschau

Sétra Service d'études sur les transports, les routes et leurs aménagements

March 2011 Translate february 2012

Acceptability of Alternative Materials in Road Construction Environmental Assessment

Technical departement for transport, roads and bridges

MINISTRY OF ECOLOGY. SUSTAINABLE DEVELOPMENT. TRANSPORT AND HOUSING

Page laissée blanche intentionnellement

Methodological guide

Acceptability of Alternative Materials in Road Construction Environmental Assessment

Éditions Sétra

This methodological guide dedicated to the acceptability of alternative materials in road construction has been drafted by a working group composed of:

• Laurent Chateau, ADEME • Patrick Vaillant, MEDDTL • Frédéric Leray, MEDDTL • Amandine Orsini, Sétra • Sabine Cavellec, Sétra • Jérôme Crosnier, CETE de Lyon • Dominique Guyonnet, BRGM • Gaël Bellenfant, BRGM • Patrice Piantone, BRGM • Benoît Hazebrouck, INERIS • Jérémie Domas, INERIS • Jacques Méhu, INSAVALOR • Agnès Jullien, IFSTTAR

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Acceptability of Alternative Materials in Road Construction

Table of Contents Foreword

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Section 1: Purpose, Definitions and Scope

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1 - Purpose

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1.1 - Purpose of Methodological Guide

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1.2 - Purpose of Application Guides

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2 - Definitions

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3 - Scope

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3.1 - Type of Alternative Materials

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3.2 - Type of usage

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Section 2: Environmental Assessment Approach

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1 - Introduction

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2 - Description of Assessment Approach

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2.1 - Stage 1. Description of Waste and its Source

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2.2 - Stage 2. Description of Alternative Material, Road Material and Projected Road Usage

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2.3 - Stage 3. Environmental Characterisation of Alternative and Road Materials

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3 - Application Guide Content

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Appendices

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1 - Acronyms

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2 - Organisational Rules for Composing Samples

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2.1 - Introduction

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2.2 - General Rules

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2.3 - Initial Positioning of a Material Source produced Discontinuously

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2.4 - Compliance testing for a Discontinuously Produced Source

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3 - Limit Values associated with Level 1 Environmental Characterisation

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4 - Limit Values associated with Level 2 Environmental Characterisation

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5 - Modelling Principles Applied

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Bibliography



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Table of Contents

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Foreword Representing no less than 40% of France’s total waste production, building and civil engineering, along with industry, generate around 350 million tonnes of mineral waste each year. Underpinned by sustainable development logic, waste recycling under controlled environmental conditions has become unavoidable in terms of curtailing global impacts relating to use of natural resources. In this connection, road construction represents a suitable channel for recycling most mineral waste materials of natural or artificial origin. However, since resorting to alternative materials in road construction cannot be limited to simply verifying their mechanical and geotechnical characteristics, the French ministry responsible for sustainable development, supported by the public bodies within its scientific and technical network or under its supervision, has developed a methodology for assessing the environmental characteristics of these materials. The present methodological guide is therefore designed to offer an approach to assessing the environmental acceptability of alternative materials produced from waste and intended for road construction usage. It applies to alternative materials, whose usefulness for road construction applications has been previously justified to ensure that the road does not become a substitute for disposal to landfill. This methodological guide is mainly intended for civil engineering professionals and industrial organisations wishing to study the possibilities of recycling the waste materials they possess or produce through road construction applications. In relation to alternative material sources from which experience feedback is convincing, this methodological guide has been broken down into more operational application guides, mainly intended for Engineers, whose aim is to provide a solid reference frame on which technical personnel can base project design or analysis of alternatives proposed within a tender call. Reference to the assessment approach provided in this methodological guide is therefore of no use for alternative materials covered by an application guide. In such cases, the instructions given in relevant application guide should be directly followed(1). This methodological guide and its associated application guides are wholly embraced by an approach that promotes alternative material usage in road construction under controlled environmental conditions.

General Manager for Infrastructure, transport and the Sea,

General Manager for Risk Prevention,

Daniel Bursaux

Laurent Michel

(1) This statement is also transitionally valid for alternative materials produced from iron and steel industry slag or road demolition materials, for which application guides prepared by the relevant professional federations are expected between now and the end of 2011.

Foreword

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Section 1 Purpose, Definitions and Scope 1 - Purpose 1.1 - Purpose of Methodological Guide The purpose of this methodological guide is to provide an approach to assessing the environmental acceptability of alternative materials produced from waste and intended for road construction usage. It is mainly intended for civil engineering professionals and industrialists and has been designed for use: • either by a professional federation wishing to study road construction recycling options for a given waste material source. The conclusions of this study would then lead to preparation of a more directly operational application guide (cf. Subsection 1.2 below), which can be referred to not only by Clients and Engineers when designing their projects or appraising alternatives proposed within a call for tender , but also by public authorities when defining operating conditions for the relevant facilities classified for environmental protection; • or by a classified facility operator, when wishing to study directly road construction recycling options for waste materials that he possesses or produces, in particular when no application guide covers his waste. The operator must then conduct this study and it can be referred to by public authorities for establishing operating conditions of facilities classified for environmental protection.

1.2 - Purpose of Application Guides The main purpose of an application guide is to record the conclusions reached, when applying the assessment approach provided by the present methodological guide (initial characterisation), for the main sources of alternative materials manufactured from wast(2) and to define the framework surrounding the quality assurance plan applicable to producing these materials (compliance testing).

(2) Preparation of an application guide potentially concerns the following waste streams: road demolition waste, excavated geological materials, municipal solid waste incinerator bottom ash, iron and steel industry slag, sediments, coal combustion fly ash, etc.

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Acceptability of Alternative Materials in Road Construction

Unlike this methodological guide, application guides are drafted with a view to providing Clients and Engineers responsible for civil engineering operations with a sound reference, on which they can directly base their projects or appraisal of alternatives proposed within a call for tender. Reference to the assessment approach provided in this methodological guide is therefore of no help for alternative materials covered by an application guide. In such cases, the instructions given in relevant application guide shall be directly followed. In relation to alternative materials already used in road construction, the experience feedback(3) results can be used as extensively as required during preparation of the corresponding application guide, especially when they contribute to meeting the requirements of the assessment approach described in Section 2. Moreover, depending on the level of environmental characterisation which the material complies with and the level of non-conservative parameters (e.g. pH, oxidationreduction potential) measured during environmental characterisation (cf. Section 2, Subsection 2.3), • Use of alternative materials in very rugged terrain or highly fractured underground areas; • Use of alternative materials below the highest known water mark , near watercourses, in areas listed as specifically sensitive in relation to aquatic environments and their usages (e.g. close protection perimeter around a drinking water supply abstraction area, bathing area) or in environments subject to specific exposure conditions (e.g. continuous or periodic water saturation, presence of complexing compounds such as humic acids); • Temporary storage of materials within a road work site boundary and their usages conditions.

(3) Experience feedback for some of the alternative materials commonly used is partly described on website http://ofrir.ifsttar.fr of the Observatoire Français des Ressources dans les Infrastructures [French observatory of resources in infrastructures]. The purpose of this observatory is to make available classified and summarized information, validated to a certain extent, to national road stakeholders for promoting approaches to recycling and using local alternative materials and to indicate the different hindrances to them, in particular those of geotechnical or environmental order.

Finally, each application guide must detail the duties of the different road project stakeholders to ensure memorisation of road construction projects, which have resorted to alternative materials. Application guides are prepared at the initiative of the main professional federations concerned and validated by the Ministry with responsibility for sustainable development with the possible support of public bodies within its scientific and technical network or under its supervision, in cooperation with representatives of the Client organisation and environmental protection associations. They are revised under the same conditions.

2.3 – Road Usage The purpose, for which road materials are used to ensure the construction, rehabilitation or maintenance of road structures, i.e. structures supporting road traffic (traffic lane or parking area) or structures located within the road coverage, whose construction has been made necessary due to the existence of infrastructure (phonic or visual protection, etc.).

2 - Definitions The following terminology is used in this guide.

2.1 – Alternative Material Any material manufactured from waste and intended for use, alone or mixed with other alternative or conventional materials, within a road material. An alternative material is therefore a constituent, possibly single, of a road material.

2.2 – Road Material Any alternative material or mixture of an alternative material and other alternative or conventional materials suitable for road usage. A road material is therefore a material, which is fit to leave a manufacturing facility for implementation in its current condition in road construction.



Section 1: Purpose, Definitions and Scope

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3 - Scope 3.1 - Type of Alternative Materials The environmental assessment approach developed through the course of this methodological guide is applicable to any typology of alternative materials manufactured from waste and used in the form of aggregates, graded aggregates, soils, fillers or binders, except for those manufactured from hazardous waste or containing a radioactive substance (cf. Section 2, Subsection 2.1.2). However, implementation of the methodology described in Section 2 below must be limited to only alternative materials, whose usefulness in road construction has been previously justified; for example, because their structural properties comply with current construction specification standards. This requirement is of prime importance in preventing the road becoming a substitute for disposal to landfill.

3.2 - Type of usage

For information purposes, the methodology described within the scope of this guide was mainly developed based on results of calculations modelling the impact of structures integrating alternative materials on groundwater (cf.. Appendix 5). On the other hand, no specific assessment has been made of the impact associated with particles from these materials being put into suspension in air. This is why the road construction usages quoted above refer to scenarios involving implementation within paved or capped road structures. Nevertheless, we may consider that road materials, which satisfy the conditions concerning level 1 environmental characterisation (cf. Section 2, Subsection 2.3.5), can be implemented for the following unpaved or uncapped road construction usages: • usage for wearing courses; • usage for uncapped pavement or shoulder sublayers; • usage for engineering embankments associated with road infrastructure or for uncovered shoulders; • usage for preloading fills required road infrastructure construction; • usage for drainage systems (e.g. trench or counterfort drain, reservoir pavement).

The following road construction usages are foreseen within the scope of this guide: • usage for underlaying courses of capped pavement or shoulder sublayers (4): subgrade fill, capping layer, sub-base course, base course, sub-grade, binder course; • usage for covered engineering embankments associated with road infrastructure (e.g. phonic protection) or for capped shoulders (5).

Figure 1 - Position of different layers forming a road pavement structure

(4) Surfaced with a surfacing layer considered impervious (asphalt, bituminous mixes, wearing surface dressings, cement concrete, binderjointed paving blocks) at a 1% minimum gradient. (5) Covered by at least 30 cm of natural materials (including topsoil) with a 5% minimum gradient on the top of this cover to limit water infiltration.

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Acceptability of Alternative Materials in Road Construction

Section 2: Environmental Assessment Approach 1 - Introduction The purpose of the environmental assessment approach described hereafter is to know whether an alternative material manufactured from waste can be integrated into a road material for one or more usages falling within the scope defined in Section 1.

2 - Description of Assessment Approach 2.1 - Stage 1. Description of Waste and its Source

Prior to applying this approach, it should be ensured that the alternative material proposed for usage in road construction fulfils a useful function, i.e. its structural, geotechnical and/or hydraulic characteristics are suitable for its intended usage and comply with current construction specification standards.

2.1.1 - Aims

The environmental assessment approach is based on Standard NF EN 12920+A1 (6) , which defines the methodology for determining the release of material constituents to water under specified usage or storage conditions. It also benefits from the methodological lessons of the Carex(7) programme initiated by Ademe and conducted by LCPC and INSA, Lyon.

• Verify whether the waste falls within the scope of this guide (cf. Subsection 2.1.2 below).

The assessment and acceptability of an alternative material in road construction depends on accurate knowledge of: • the waste from which the alternative material is manufactured (cf. Subsection 2.1 below); • the method of manufacturing the alternative material and the associated road material, and the projected road usage (cf. Subsection 2.2 below); • the environmental characterisation of the alternative and road materials (cf. Subsection 2.3 below).

The purpose of this first stage is to: • Provide essential information concerning the waste and its source, from which the alternative material is manufactured.

• Acquire knowledge of the process that produced the waste to gain a better grasp of the potential consequences for its characteristics and for those of the alternative and road materials manufactured from it. Most of the information to be provided at this stage is already required by “waste” regulations and therefore does not call for a major investigation. In cases in which the road material requires in fine a formulation, which contains several alternative materials (aggregates, fillers, binders, etc.), each waste source used for manufacturing these alternative constituent materials must be subjected to this first stage. Description of alternative and road material manufacturing forms the object of Stage 2.

2.1.2 - Type of Waste Accepted (6) AFNOR. NF EN 12920+A1. Caractérisation des déchets – Méthodologie pour la détermination du comportement à la lixiviation d’un déchet dans des conditions spécifiées. Novembre 2008 [EN 12920:2006+A1:2008 Characterization of waste. Methodology for the determination of the leaching behaviour of waste under specified conditions]. (7) François D., Jullien A., Kerzreho JP., Vernus E. Retour d’expérience sur le comportement mécanique et environnemental d’ouvrages et de plots routiers instrumentés: CAREX study. Final report. November 2005. (ADEME agreement 0372C0006). Available at http://ofrir.ifsttar.fr [Feedback concerning the mechanic and environmental behaviour of experimental and real field test sections (so-called CAREX study) (in French)]



Alternative materials manufactured from waste and used in road construction must be capable of being implemented under the conditions and with the same equipment as the natural materials they replace, most frequently in various environments. Furthermore, construction sites are not facilities classified for environmental protection and construction operations are rarely covered by the law on water, so alternative and road material usage is not specifically controlled by the State.

Section 2: Environmental Assessment Approach

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This is why alternative materials likely to be used in road construction must not have been manufactured from waste that is hazardous(8) or contains a radioactive substance(9). Assessment of the hazardous nature of the waste is therefore required just before the alternative material manufacturing phase as part of applying the assessment approach. Thus, any non-hazardous fraction resulting from a hazardous waste treatment operation(10) - except for any stabilisation operation (11) - is considered a non-hazardous waste material within the scope of this methodological guide. In general, an operation involving stabilisation, dilution or mixing of waste is prohibited for the sole purpose of satisfying the acceptability criteria defined in this methodological guide.

2.1.3 - Content When performing Stage 1, information concerning the following should be acquired and summarised: 1. Geographical sources and origins of the waste and estimate of its size (tonnage). 2. Appearance of the waste: smell, colour, physical form (granular, powdery, pasty, monolithic). 3. The 6-digit code and classification of the waste based on the list of waste materials in Appendix II of Clause R.541-8 of the French environmental code. The code must correspond to non-hazardous waste (cf. Subsection 2.1.2 above).

N.B. If the code corresponds to a “mirror entry” (12) or when it ends with 99 (13), qualification can be simply solved by examining the current elimination channels for the relevant waste. If not, the producer of the waste material must provide a document justifying its classification with respect to the hazard properties quoted in Appendix I of Clause R.541-8 of the French Environmental Code.

4. The final destination of the waste: current treatment channels (recycling and disposal). 5. The type of process producing the waste and its operation. 6. For industrial waste not covered by a specific datasheet on the OFRIR observatory website, the chemical and mineralogical composition of the waste. The aim is to acquire and summarise information concerning content of major, minor and trace elements, particular those listed in the tables in Appendices 3 and 4, and the mineral compounds composing it. This information must clearly show the parameters specific to the studied waste, which must be considered when assessing the acceptability of alternative and road materials for road construction to be manufactured from it. Information concerning the mineralogical composition must include the possible presence of minerals liable to cause variations in pH, oxidationreduction potential or formation of unwanted compounds (reactivity), in particular: free lime, magnesium, metal aluminium, sulphides, sulphates.

2.2 - Stage 2. Description of Alternative Material, Road Material and Projected Road Usage 2.2.1 - Aims The purpose of this second stage is to: • Provide essential information concerning the alternative material, the associated road material and the projected road construction usage. • Acquire knowledge of the alternative and road material preparation process to gain a better grasp of the potential consequences for their behaviour within the structure.

(8) Any waste material presenting at least one of the hazardous properties defined in Appendix I of Clause R.541-8 of the French Environmental Code is considered hazardous. An asterisk indicates hazardous waste in the list of waste materials included in Appendix II of the same clause. (9) Within the meaning of Directive 96/26/Euratom of the council of 13/05/96, a radioactive substance is any substance that contains one or more radionuclides, whose activity or concentration cannot be neglected from a radiation protection standpoint. (10) Example: removal of a pollutant-loaded fraction by particle attrition and/or separation. (11) In this guide, any operation designed to use different reactants and binders, particularly hydraulic or organic, for the purpose of limiting pollutant solubility and thus emission into the environment is considered a stabilisation operation.

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Acceptability of Alternative Materials in Road Construction

(12) A waste material is given a so-called “mirror” entry when it is likely to fall under two different codes: one that classifies it as hazardous and one that classifies it as non-hazardous, depending on whether it contains hazardous substances or not. In general, these “mirror” entries involve two successive headings in the list of waste materials given in Appendix II of Clause R.541-8 of the French Environmental Code and the waste material concerned will fall under the heading that classifies it as hazardous, if it contains at least one of the hazardous properties defined in Appendix I of the same clause. (13) These codes group together all waste materials not specified elsewhere in the list of waste materials given in Appendix II of Clause R.541-8 of the French Environmental Code.

In cases in which the road material is prepared from a mixture containing several alternative materials, points 1 to 3 of Subsection 2.2.3 above must be applied to each of the alternative materials included in its composition.

2.2.2 - Type of Manufacturing Phases Accepted Alternative material manufacturing can be more or less complex and be based on a succession or combination of physical treatments embraced by the term “preparation” and/or simple physico-chemical treatments embraced by the term “maturation”. O n ce m a n u fa c t u re d , t h e a l te r n at i ve m ate r i a l i s implemented alone and in its current condition or in a mix with other materials (aggregates, fillers, binders, etc.) after a so-called “formulation” stage, in one of the road usages covered by this guide. At this stage, the manufactured material is called a road material. The main purpose of these manufacturing stages must remain achievement of the necessary structural, geotechnical and hydraulic performance characteristics to comply with standardised usage specifications and/ or requirements relating to chemical compatibility with materials and components in contact with the alternative material (e.g. pipes). In general, an operation involving stabilisation, dilution or mixing of waste materials is prohibited for the sole purpose of satisfying the acceptability criteria defined in this methodological guide.

2.2.3 - Content When performing Stage 2, the information concerning the following should be acquired and summarised: 1. The places of production, storage and manufacturing of the alternative material as well as its possible trade name and uses other than for road construction. 2. Manufacturing of the alternative material from the waste source: a - Co n ce r n i n g i t s p re p a rat i o n , t h e t y p e a n d characteristics of the implemented physical treatments should be detailed: crushing, screening, sorting/ particle size reduction, phase separation (ferrous metals, non-ferrous metals, possible unburnt residues, residual mineral phase), etc. b - Co n ce r n i n g i t s m at u rat i o n , t h e t y p e a n d c h a ra c t e r i s t i c s o f t h e i m p l e m e n t e d p h y s i c a l chemical reactions (oxidation, carbonation, leaching, dewatering), the operating procedure duration and method – depending on whether it is passive (simple aging without action on heap) or active (reworking of heap, e.g. by turning it over to homogenize reactions throughout its volume) should be detailed. 3. If the alternative material is manufactured from an industrial waste source not covered by a specific



datasheet on the OFRIR observatory website, the chemical and mineralogical composition of the alternative material. The aim is to acquire and summarise information concerning content of major, minor and trace elements, particular those listed in the tables in Appendices 3 and 4, and the mineral compounds composing it. This information should enable the list of specific parameters to be considered, when assessing alternative and road material acceptability for road construction, to be drawn up. Information concerning the mineralogical composition must include the possible presence of minerals liable to cause variations in pH, oxidation-reduction potential or formation of unwanted compounds (reactivity), in particular: free lime, magnesium, metal aluminium, sulphides, sulphates. 4. The type of road material envisaged (14) and a reminder of both the useful function of the alternative material in this road material with respect to the projected road construction usage and the corresponding reference frame (standard or regional engineering guide). 5. The places of production, storage and manufacturing of the road material as well as its possible trade name. 6. M anufacturing of the road material from the alternative material and other constituents: a - Concerning the other constituents entering into the road material formulation, their type (aggregates, fillers, binders, etc.) and origin (natural or artificial) should be detailed, their main physical and environmental characteristics should be quoted and their useful function in this alternative material should be recalled. b - Concerning the road material formulation, the relative proportion of each constituent in the mix should be given and the formulation process should be described. 7. The road material usage within the structure (base course, sub-base course, capping layer, subgrade fill, engineering embankment, etc.) and the projected depths and heights. 8. Examples of previous national usages and reference projects, if they exist, at least detailing for each structure: - its identification and location; - work commencement and completion dates; - t he project Prime Contractor’s name and contact details; - the project Client’s name and contact details; - the project Contractors’ names and contact details;

(14) Examples: soil equivalent, unbound mixture, bound mixture with hydraulic binders, bound mixture with bituminous binders, untreated granular mix, granular mix bound with cementitious or bituminous binders, self-compacting concrete.

Section 2: Environmental Assessment Approach

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-m  ate rial u s a ge w ith in th e str u ctu re a nd i ts corresponding depth or height; -w  hen used as pavement base course, the traffic volume sustained by the structure; -w  hen used as capped engineering embankment, the main useful function of the structure.

2.3 - Stage 3. Environmental Characterisation of Alternative and Road Materials 2.3.1 - Aims The overall aim of this stage is to demonstrate that the alternative and road material emissions are compatible with projected water quality compliance (cf. Appendix 5). At this stage, three levels of investigation are envisaged for ultimately graduating the demonstration effort based on the risk created by the relevant materials in relation to the environment:

is necessary to assessing its acceptability for road construction. Associated limit values should be proposed for each of the complementary specific parameters, selected on the basis of accurate exhaustive material characterisation, particularly in relation to metallic trace elements, to complete the tables included in Appendices 3 and 4. Selected parameters and values must be validated by the Ministry responsible for sustainable development, particularly within an application guide preparation framework. In general, sampling must ensure that each component present in the material is present in the sample based on the same probability (cf. Appendix 2). Analysis methods in compliance with current analysis standards must be selected such that detection and associated quantification limits allow the results to be unambiguously positioned with respect to the limit values for the monitored parameters.

• Level 1 based on conducting leaching tests and total content analyses (cf. Subsection 2.3.5).

Hydrogen potential (pH), conductivity and oxidationreduction potential (so-called “redox potential”) are subject measurements in compliance with procedures applicable to leaching (NF EN 12457-2 or NF EN 12457-4) or percolation (NF CEN/TS 14405) tests.

• Level 2 is based on conducting percolation tests (cf. Subsection 2.3.6).

2.3.4 - Presentation of Results

• Level 3 is based on performing a specific study (cf. Subsection 2.3.7). Level 1 performance and environmental characterisation is compulsory.

In general, all characterisation results must at least display the following information: • Sampling method used to obtain laboratory samples. • Date of tests and references of analysed samples.

2.3.2 - Type of Materials to be Characterised

• Current standards applied or testing procedures used, if no applicable standards.

Environmental characterisation applies to both alternative and road materials.

• Names and addresses of laboratories performing sampling, tests and analyses.

In cases in which a road material is manufactured from a mix containing several alternative materials, each alternative material entering into its composition must be subjected to Stage 3.

With regard to leaching tests (NF EN 12457-2 or NF EN 12457-4), results must be presented in tabular form for each monitored parameter in terms of quantity released in mg/kg. When the result is less than the quantification limit, this quantification limit value must be recorded in the table preceded by the symbol “