Progress & Result



Nereide logo

EC life

LIFE15 ENV/IT/000268

 

Activities update at March 2018

THE FIRST LOW-NOISE EMISSION ROAD SURFACES FOR THE PROJECT NEREIDE HAVE BEEN COMPLETED 

FROM ELT RECYCLED RUBBER POWDER TO ASPHALT MILLINGS, THE NEW PAVEMENTS PRODUCED AND LAID WITH “WARM” TECHNOLOGY REDUCE THE EMISSIONS OF POLYCYCLIC AROMATIC HYDROCARBONS (PAHs) BY 30%.

Coordinated by the Department of Civil and Industrial Engineering of the University of Pisa in collaboration with ARPA Tuscany, BRRC-Belgian Road Research Centre, Ecopneus, IDASC-CNR the Institute of Acoustics and Sensoristics “Orso Mario Corbino” and Region Tuscany, the Project LIFE Nereide (Noise Efficiently REduced by RecycleD pavEments) was born with the main objective to contribute to the resolution of the environmental issues linked to the disturbance phenomena created by vehicle noise. This problem is particularly felt in urban areas and it is strictly dependent on the characteristics of the flooring surface. To this aim, the project wants to define some guidelines for the planning, construction and monitoring of two experimental sites, created using 12 bitumen conglomerate mixes for wear layers at low sound emissions. Such mixes will be produced at lower temperatures than the ones of the traditional hot conglomerates, using the so-called “warm” technologies. They will be composed of not only new aggregate and bitumen, but also of asphalt millings coming from the demolition of existing road flooring and from rubber powder derived from End-of-Life Tyres (ELTs).

The key eco-objectives the project Nereide wants to achieve are, thus:

• noise pollution mitigation;

• reduction of CO2 emissions into the atmosphere, thanks to the lowering of the processing temperatures and the reuse of waste materials, that would otherwise be destined to the landfill. 

For the drafting of the guidelines that will contain useful information for the identification of technologies, materials and typologies of intervention to adopt, without prejudice to the mechanical performance and the levels of surface grip of the new floorings, the project provides for the realisation of 12 road stretches. It will be one stretch of road per mix. Each stretch will be adjacent to the following one and approximately 400 m long. These mixes will be laid on two distinct experimental sites on the urban roads of Tuscany. The roads have been appropriately chosen among those identified as in need of acoustic improvement within the scope of the regional plans of noise reduction.

The laying of the new surfaces is planned in two moments, with a one-year gap in between, respectively: in autumn 2017 and 2018. 

In addition to the experimental stretches in bitumen conglomerate, the experimentation of a porous-elastic flooring, PERS (PoroElastic Road Surface), is planned first in Belgium and then in Italy in summer 2018. With this type of surface, it will be possible to reuse greater percentages of rubber from ELTs. After a year from the beginning of the project and planning to start road resurfacing with the mixes containing rubber powder by the end of autumn 2017, the following activities have been carried out.

The individuation of the experimental sites 

The urban road stretches subject of intervention have been chosen based on a priority index linked to the contemporary presence of several schools and of over 800 people exposed to daily noise levels higher than 65 dB(A). The first experimental site of about 2,400 metres has been identified on the “S.R.T. 439 Sarzanese-Valdera” in the town of Massarosa (LU). 

The project of the experimental mixes and the Life Cycle Assessment

The design of the mixes represents, without any doubt, the most important task of the project. An in-depth knowledge of the materials, of the volumetric composition and of the mechanical characteristics of the thickened mix is fundamental to be able to predict its behaviour once installed.

A revision of the existing technologies has been carried out. Its aim was the definition of the maximum quantities of recycled materials (rubber powder and asphalt millings) that may be used in the mixes. It was also necessary for the identification of additives or specific technologies used for the reduction of the temperature for the laying of the modified asphalts. After such revision activities, the design of the mixes planned for the first period of installation was developed in the laboratory. 

In detail, the mixes are:

Two “traditional” hot control mixes;

A draining mix 0-12;

a Splittmastix Asphalt (SMA) 0-12 mix;

four innovative “warm” mixes, containing rubber powder with uneven aggregate gradation, of which: two with open graded aggregate assortment and two “gap graded” types. For each aggregate size, the two methodologies for the introduction of rubber powder within the bitumen conglomerate will be used (“dry” and “wet” processes).

In order to identify and be able to quantify the material and energy consumption as well as the emissions released into the environment associated to the life cycle of the proposed experimental surfaces, a careful Life Cycle Assessment (LCA) was also carried out. It compared all possible combinations of wear courses containing asphalt millings, rubber powder and produced with warm technology with a traditional hot asphalt mixture, taken as point of reference. 

The results obtained from the comparative LCA have shown that the combined effect of the mixes with warm technology and the use of recycled materials reduce noticeably the environmental costs associated to the processes of road surfacing and maintenance of the wear courses. It, thus, represents a valid alternative to traditional technologies. It also fully meets the “eco-environmental” requisites expected from this new technology. In particular, the use of these recycled materials allows, above all with reference to asphalt millings, noticeable savings of raw materials such as bitumen and aggregates. Moreover, the technology of Warm Mix Asphalts (WMA) allows the reduction of production and laying temperatures, thus reducing the environmental emissions during such operations.

The ante-operam monitoring campaign  

Alongside laboratory testing, some ante-operam monitoring campaigns have been carried out with reference to noise, structural and functional indicators on the stretch or road of the S.R.T. 439 “Sarzanese-Valdera” in the town of (LU), where the laying of the first six mixes is planned.

The aim is to be able to quantify the benefits obtained following a “before-after” approach.

Structural surveys and surface characteristics

The survey of the structural characteristics was carried out with a Falling Weight Deflectometer (FWD) equipped with a Ground Penetrating Radar (GPR) for the constant detection of the existing surface thickness. Due to the construction inhomogeneity of the inspected surface, the usual procedures for the structural surface analyses are, in general, not very reliable.   Indeed, S.R.T. 439 “Sarzanese-Valdera” falls within those roads of ordinary viability based on ancient historical roads. These are characterised by the presence of an intermediate layer, placed on the subbase made with natural stones of variable thickness, and by thin bitumen conglomerate layers. The usual analysis procedures (using deflectometric surveys made with FWD) estimate the values of the elastic modules of the layers by the means of back analysis methods. Consequently, they estimate the critical parameters for the determination of the useful residual life of the surfaces by using the values of the modules calculated in this way. For this reason, it was decided to carry out an estimate of critical deformations using more stable methods, which are also less sensitive to thickness variations by the means of the analysis of the road structure parameters.

The evaluation of the surface characteristics was made with reference to macrotexture and grip. The texture was detected by the means of a mobile laser profilometer. Based on the obtained results, the macrotexture was calculated with reference to ETD. The grip measurements, carried out with a Skiddometer BV11, were expressed in terms of BPN, CAT and F60 (according to IFI’s model). Such indicators fall within the Life Performance Indicators (LPI). These represent the monitoring indexes of the impacts of the project. 

Noise survey and measurement protocols

The acoustic performances have been evaluated by ARPAT (the Environmental Protection Body of Region Tuscany) and by CNR-IDASC (Institute of Acoustics and Sensoristics “Orso Mario Corbino”)

with reference to tyre-road noise, with Close Proximity Index (CPX) and Standard Pass-By (SPB) methods. The sound absorption was measured with the Adrienne Method.

The noise levels of the psychoacoustic indicators, obtained thanks to the Close Proximity Index (CPX) method, have been calculated for every single stretch of road where the experimental mixes will be laid, bearing in mind the specific stretch of road (different traffic fluxes and speed), the orography and other specific elements, such as the presence of noisy activities. Alongside the standard phonometric surveys, a survey was carried out among the population in order to have a clear picture of the perceived level of noise. The phonometric results confirm a situation of real disturbance, with Lden levels higher than 65 dB(A) and Lnight levels higher than a 60 dB(A) for all road stretches. On the other hand, the values given by the CPX method, which measures the acoustic quality of the road surface, confirm the possibility of a clear improvement with the aid of appropriate sound-absorbing or low-emission floorings.

Alongside the monitoring, ARPAT and IDASC are developing measurement protocols in addition to the standard ones provided for by the Legislation that would allow a better estimate of the influence of each type of flooring on sound emissions.

In particular, ARPAT has prepared a protocol that can derive the SBP indicators as defined by the Rules and Regulations by the means of normal fixed control units of noise control and a simple traffic counter, but without the need of manned measurements. Such protocol provides for the use of SEL devices instead of the LAmax. This is in line with the Harmonoise Project, which, once validated, will make it possible to estimate the disturbance of every single vehicular category, thus facilitating mobility policies. IDASC is developing a system whose objective is the improvement of the measurement methods of noise absorption in situ, using pressure-speed waves mounted on board of a vehicle, instead of a microphone, for the measurement of the reflected wave - as provided for by the Adrienne Method. The new measurement protocol will be confronted with the regulated method (Adrienne) and will be validated on the new surfaces of the project.

Future activities

The post-operam noise and functional monitoring campaigns will then follow the realisation of the first six experimental stretches of road. During these monitoring activities new acoustic measurement protocols will be experimented.

At the same time, the ante-operam monitoring activities will be carried out on the stretches of the second location where the laying of the six remaining experimental mixes containing asphalt millings and rubber powder (as well as PERS-type wear) is planned.

Progress at may 2017

Summary of UNIVERSITA’ DI PISA – DICI activities

In this first phase of the project, the activities of the Department of Civil and Industrial Engineering at the University of Pisa consisted of a preliminary analysis and review of the state of the art of existing techniques for the detection of the highest amounts of recycled materials (recycled asphalt pavements and crumb rubber from End-of-Life tyres) and specific additives and technologies used to reduce the temperatures of set-up and realization. On the basis of this and on the results obtained from a preliminary study of the constituent materials, the design mix was conducted in laboratory to develop technical specifications for the new types of low noise emission mixtures containing recycled rubber (CRM) and produced with the "warm" technology, forecast in the first stretch campaign.

In order to assess the degree of environmental sustainability of the proposed experimental pavements, a thorough Life Cycle Assessment (LCA) study was conducted on all possible combinations of wear layers containing recycled asphalt and recycled rubber, produced with warm technology; this LCA was compared with a gap layer wrapped at hot temperature, as a reference; this procedure of analysis made possible to evaluate the environmental burdens associated with each type of mixture in terms of material, energy consumption and emissions, providing results that fully satisfy the "green” objectives expected.

At the same time, on the stretched sections of the SRT 439 Sarzanese-Valdera in Massarosa (LU), where the first experimental realization was planned in the fall of 2017, were performed measurement of lift with a Falling Weight Deflectometer (FWD) equipment and carried out a continuous evaluation of pavement thickness with Ground Penetrating Radar (GPR) equipment. 

The processing of the acquired data made possible to determine the criterions of the constituent layers of the package and therefore to assess the remaining useful life of the existing pavement and the increase in expected life as a result of the realizations of the new layers.

 

Summary of ARPAT activities

ARPAT activities focuses on monitoring implementation sites. Actually the ante-operam monitoring at first implementation site (Comune di Massarosa (LU)) is completed and analysis are ongoing. To permorm these actions, ARPAT contributed to the selection of candidates sites with Regione Toscana in order to identify suitable places for laying the new pavements. Sites of regional action plans have been filtered and visited according technical parameters and final decision has been taken by Regione Toscana.

Then a selection of acoustical methods and indicators have been carried out to define methodologies for ante and post operam monitoring campaigns. ARPAT has also contributed in methods for psychoacoustical measurements such that noise and psychoacoustical parameters have been acquired in agreed locations. 

CPX, method has been applied along the whole stretch of road that will be layed with the new pavements. Noise from continuous noise monitoring stations was acquired in 6 locations rapresentative of each stretch of new surfaces. 

In combination with standard by law noise levels (Italian and European) several additional noise indicators will be elaborated from continuous monitoring. 

ARPAT is also developping a new methodology in order to acquire SPB-like data in urban areas without manned measurements. Urban pass by methodology has been tested in two location to select indicators and to define measurement protocol. Data analysis is actually ongoing. Data has been also acquired according a preliminary protocol in 4 of 6 ante operam locations in order to test indicators. 

In the next 3 months, analysis of urban pass by will be finalized and method is going to be validated before the end of 2017. Ante-operam acoustic indicators will be reported in september

ARPAT has also acquired together with CNR population data from municipality in order to evaluate people living along the road stretches that will benefit from mitigation. Finally ARPAT has been involved in several dissemination activities. Two scientific papers have been published (ICSV and AIA conferences). Two events at fairs and two workshops have been attended to disseminate projects. Arpat newsletters reported news on nereide in November and March issues. 

 

Summary of ECOPNEUS activities

Ecopneus coordinate the design and implementation of communication materials to support project activities. The LIFE Nereide website will serve throughout the duration of the project as a constant point of reference for partners and potential stakeholders, as well as an up-to-date source of information about project objectives, initiatives and progress. The site contains all the key information about the project, planned actions, expected goals, partners and their roles.

Have been realized also a Papers Notice Board, which contain the main informations, both in english and in Italian, about the Nereide project: summary of objectives and results attended, Nereide Logo and Logos of the partners. The paper notice boards have been printed and sent to all the partners and placed in public places. Also, a roll-up has been created with a summary of the poster’s information: it will be used during conference, workshop and other public events, according to the foreseen dissemination activities.

Other communication tools are been planned and realized, to maximize the dissemination of informations to specific public: a tri-fold leaflet, a small folder for public events and 1-to-1 meeting, a PowerPoint standard presentation and a press release format. 

Thanks to dedicated press activities carried out by Ecopneus on a selection of journalist interested to the topic and to other dissemination activities carried out by the other partners, over 100 articles has been published, also on the major national newspaper.

During the Asphaltica Fair, the most important national event on asphalts and roads that was held the 22-25 February in the city of Verona, a demonstration workshop was organized by Ecopneus on the modified asphalt. According to the NEREIDE Project partners, one of the focus during the workshop was the NEREIDE project. Massimo Losa, Professor of the Department of Civil and Industrial Engineering (DICI) at the University of Pisa (that is the Project coordinator) and Gaetano Licitra, member of ARPAT, the regional environmental protection agency of Tuscany region, have outlined the objectives and the expected results of the project to the participants at the workshop.

Over 70 people (including representatives of the Public Administration, decision makers, academics and companies of the sector) attended at the event. About 1,500 persons have been invited via e-mail and a selection of about 600 have been called by phone to point out the event. A NEREIDE panel was also strategically placed in an area of the Ecopneus’ stand at Asphaltica, that allows visitors to sit and read about the project objectives and activities forecasted.

A further opportunity for networking was held in July during a conference dedicated to the LIFE ReFibre project (which aims to obtain extremely durable pavements thanks to the use of recycled materials), during which a session was dedicated to the Nereide project.

Other actions will be implemented to support the advancements of project activities.