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DISmantling and RECycling Techniques for road MATerials - Sharing knowledge and practices

Final Report Summary - DIRECT_MAT (DISmantling and RECycling Techniques for road MATerials - Sharing knowledge and practices)

Executive summary:

DIRECT_MAT refers to a three year Coordination and support action (CSA) of the Seventh Framework Programme (FP7) that ended in December 2011. This CSA pertains to the work programme for the sub theme 'Sustainable Surface Transport' and it mainly addresses the topic 'End-of-life strategies for vehicles/vessels and infrastructure'.

The project objectives were to share and disseminate, at the European scale, national knowledge and field practices regarding the demolition and recycling of road and road-related materials with the view of encouraging and improving recycling practices for road infrastructure construction and maintenance.

The attainment of these objectives was made possible thanks to the involvement of 20 participants from 15 European countries, who collected documents and field practices to provide the European road community with classified, assessed and illustrated demolition and recycling experience. Their contribution took the form of a free accessible web database (please see online) comprising:
- Four syntheses of national and international documented practices (also called Literature reviews (LRs)), dealing respectively with unbound, hydraulically bound, bituminous bound and 'other' (e.g. dangerous such as tar or simply unwanted materials such as steel from reinforced concrete) road or road-related materials. These syntheses aim to investigate and summarise common approaches as well as major differences between national guidelines dealing with road demolition and recycling.
- A set of nearly 130 jobsites, representative of national daily practice regarding road demolition and recycling, that have been investigated for the purpose of collecting Field and laboratory data (FLD) and benchmarking actual field practices to national documented guidelines. These jobsites are mostly geo-tagged, which allows to determine additional information such as traffic and climate conditions.
- Three Best practice guides (BPGs) elaborated from the benchmarking of jobsite data to literature reviews and gathering European consensual recommendations as well as common research issues on demolition and sustainable end-of-life for road infrastructure materials. These BPGs respectively deal with unbound, hydraulically bound and bituminous bound road materials, with a fourth BPG dealing with 'other' road or road-related materials to be input to the database shortly.

The DIRECT_MAT database not only offers information to stakeholders on facilitating the correct re-use of road and road-related waste products back into roads without generating health impacts, but also aims to become a daily-used tool for keeping records of jobsite data and information feedback at the European scale. Thereby, the DIRECT_MAT database should provide European Committee for Standardisation (CEN) technical committees with technical information and the European Commission with scientific information to allow better identification of outstanding research needs in this area.

Project context and objectives:

The European Union (EU) main road network represents roughly 5 million kilometres (even more with the additional networks of the new Member States (MS) Rumania and Bulgaria), and the road is by far the most widespread means of transportation, given that it serves around 80 % of passenger transport and 50 % of freight. Moreover, experiencing an average 2 % - 3 % use growth rate since 1995, the road network is and will remain essential to the European economy and society over the foreseeable future; furthermore, road transport contributes towards job and wealth creation, as stipulated in the white paper on European Transport Policy.

The price for this indisputable success takes the form of road maintenance, which is essential in restoring road quality after decades of bearing traffic loads. From an economic point of view, road maintenance represents roughly EUR 20 billion a year across the EU and 30 % of the total investment in road networks. One of the major road maintenance expenditures is road dismantling, along with the production, transport and implementation of fresh road materials. From an environmental point of view, road maintenance is responsible for detrimental impacts to the environment relative to waste production and natural resource consumption. Road wastes do indeed represent a significant share of the 510 million tons of annual construction wastes within the EU, and road maintenance uses account for the majority of the 2.7 billion tons of natural aggregate produced every year.

As mentioned by the ERTRAC project, road infrastructure quality is of primary importance, yet the associated costs must be considered as well since public authorities need to keep their spending under control. It is necessary therefore to simultaneously optimise the quality-to-cost ratio of road infrastructure and encourage environmentally friendly road maintenance practices.

Reducing the proportion of road materials originating from natural resource extraction and increasing the recycling of locally-available road wastes into new road materials represents a significant contribution to minimising both the economic and environmental impacts of road maintenance. This approach is in total agreement with the objectives assigned by Europe for natural waste management, which require unequivocally to ensure that the consumption of renewable and non-renewable resources does not exceed the carrying capacity of the environment, and to achieve a decoupling of resource use from economic growth, through significantly improved resource efficiency and the reduction of waste. With regard to waste, the specific target is to reduce the quantity going to final disposal by 20 % by 2010 and 50 % by 2050.

At present, many European countries have acquired experience in dismantling and recycling road materials back into roads, either on their own or by applying European research results. As a result, it should be pointed out that 50% of the 50 million tons of reclaimed asphalt pavement produced each year are now being recycled into hot and cold bituminous mixtures. However, depending on available wastes and local regulations, the level of national practices differs significantly from one European country to the next. Furthermore, several countries have started to recycle road-related materials, such as vehicle tyres used as binder additive or lightweight aggregates for roads.

A wide array of know-how and research & development results on road material recycling can thus be found, yet they are dispersed throughout the various MS and not widely implemented. Indeed, the lack of sharing of practical and only locally available experience unfortunately produces no added value. Consequently, it is believed that the time has come to share national experiences at the European level, as this will provide major benefit to the European economy and environment.

For this purpose, the main objectives of the DIRECT_MAT project consist of:
- summarising and comparing national documented recycling practices on road or road-related materials;
- collecting data from national recycling jobsites in order to investigate actual implementation of documented practices;
- elaborating consensual best practice guidelines and identify research needs at the European scale from the benchmarking of jobsite data to documented practices;
- implementing the preceding results into a free-access European web database dedicated to the sharing of national knowledge and field practices regarding the demolition and recycling of road and road-related materials.

The project addresses the re-use of unbound, hydraulically bound and asphalt road materials as well as other road or road-related materials not presently re-used to any great extent in road construction (such as vehicle tyres).

Project results:

In order to reach the project objectives, the work programme was organised into seven Work packages (WPs):
- WP1: dedicated to the overall management of the project;
- WP2: focusing on dismantling unbound road materials and the recycling of road and road-related materials back into unbound road layers;
- WP3, WP4 and WP5, similar to WP2 but respectively focusing on hydraulically bound, bituminous bound and other materials not commonly recycled into roads instead of unbound materials;
- WP6: dedicated to building and feeding the web database;
- WP7: in charge of dissemination actions, namely through a dedicated website.

The foregrounds consist of a database, which provides free on-line access to best practice guides, practical application case studies, harmonised literature reviews and national document references on demolition and recycling of road and road-related materials.

Potential impact:

Several benefits are expected from the project.

From a technical standpoint, this project will provide stakeholders and practitioners with online available and validated guidelines, to help them decide and proceed appropriately with the demolition and recycling of road or road-related materials back into new roads. The information provided will not only stem from research results throughout Europe, but also from actual practice in laboratories and construction sites. By increasing the confidence of stakeholders and practitioners in the reuse of road or road-related products, the project will actively contribute to reducing the waste associated with road maintenance.

From a regulatory point of view, a European regulation set regarding the re-use of road materials in new roads is under implementation on a step-by-step basis. Directive 2006/12/EC adopted by the European Parliament and the Council Directive of April 5, 2006 on waste prohibits the abandonment, dumping or uncontrolled disposal of waste and requires MS to promote waste prevention, recycling and processing for re-use.

From a scientific perspective, the web database provides scientists with an online access to: national document references, harmonised literature review, and practical application case studies based on jobsite data sets. These resources will prove helpful for developing research projects, as well as testing and improving models. In turn, scientists are given the opportunity to upload new laboratory or worksite data for the benefit of the entire European road research community. Furthermore, the statement of an integrated and shared view of road material research needs should improve the coordination of corresponding national research programmes at the European level and establish priorities for European research and technological development.