Electric vehicles diffusion: changing pavement acoustic design?

Abstract Electric vehicles (EVs) are progressively entering into the current noisy urban ecosystem. Even though EVs are apparently quieter than traditional Internal Combustion Engine Vehicles (ICEVs), they have an impact on noise maps and road pavement designers should take this into consideration when designing future low-noise road pavements. Consequently, the main objective of this study is to define what are the most important aspects that road pavement designers should take into account. For this reason, in this paper, the noise emitted by EVs was analysed, considering parameters (e.g., speed and frequency) and comparisons, in order to identify crucial characteristics. Results show that EV noise could call for the improvement of pavement acoustic design due to the Acoustic Vehicle Alerting System (AVAS), high-frequency peaks, and noise vibration harshness

Smart Materials and Technologies for Early Warning, Monitoring, and Increased Expected Life of Transportation Infrastructure

Different approaches can be used to make cities and transportation infrastructures smarter, more sustainable, and durable. These changes will positively affect the work of many stakeholders, such as authorities, road agencies, citizens, users, and driverless vehicles. Unfortunately, despite the fact that smart materials are becoming more and more common, the integration level between smart materials and early warning technologies is still in need of a holistic approach.In light of this, the main objective of the work presented in this paper is to provide an overview of the materials and technological solutions that can be used in the field of transportation infrastructures to satisfy some of the Sustainable Development Goals of the United Nation (resolution A/RES/70/1/2015).The solutions above include an innovative monitoring method, set up by the authors of this paper, which is based on the concept of vibro-acoustic signature. The method mentioned above is a Non-Destructive Test and sensor-based solutions in order to detect damage to road pavements. The proposed method was validated using Finite Element Modelling simulations, and experimental investigations followed by data analysis carried out using Machine Learning- and Wavelet-based algorithms.Results show that smart materials and technologies can be used to target A/RES/70/1/2015 goals and to improve the sustainability of the current and future transportation infrastructures. Materiali e tecnologie intelligenti per allerta, monitoraggio, e per aumentare la vita utile delle infrastrutture di trasportoDifferenti approcci possono essere utilizzati per rendere le città e le infrastrutture di trasporto più intelligenti, sostenibili e durature. Queste tendenze influenzeranno positivamente il lavoro di molti portatori di interesse come ad esempio le autorità competenti, le società che si occupano di strade, i cittadini, gli utenti, ed i veicoli senza guidatore. Sfortunatamente, malgrado il fatto che i materiali intelligenti sono sempre più utilizzati, il livello di integrazione tra materiali intelligenti e tecnologie per l’allerta precoce ha ancora bisogno di un approccio olistico.Alla luce di questo, l’obiettivo principale del lavoro presentato in questo documento è quello di fornire una panoramica su soluzioni basate su materiali e tecnologie che potrebbero essere utilizzate nel campo delle infrastrutture di trasporto per soddisfare alcuni degli obiettivi della risoluzione per lo sviluppo sostenibile (Sustainable Development Goals) delle Nazioni Unite (A/RES/70/1/2015).Le soluzioni su citate includono un metodo innovativo, messo a punto dagli autori della memoria, il quale è basato sul concetto di firma vibro-acustica. Il metodo su citato è una soluzione basata su test non distruttivi (NDT) e sensori per l’identificazione di danni nelle pavimentazioni stradali. Il metodo proposto è stato validato attraverso simulazioni fatte con un modello agli elementi finiti (FEM), e indagini sperimentali seguite da un’analisi dati svolta usando un modello basato sull’apprendimento automatico (machine learning).I risultati mostrano che materiali e tecnologie intelligenti possono essere utilizzate per raggiungere gli obiettivi della risoluzione A/RES/70/1/2015 e migliorare la sostenibilità delle attuali e future pavimentazioni stradali.Different approaches can be used to make cities and transportation infrastructures smarter, more sustainable, and durable. These changes will positively affect the work of many stakeholders, such as authorities, road agencies, citizens, users, and driverless vehicles. Unfortunately, despite the fact that smart materials are becoming more and more common, the integration level between smart materials and early warning technologies is still in need of a holistic approach.In light of this, the main objective of the work presented in this paper is to provide an overview of the materials and technological solutions that can be used in the field of transportation infrastructures to satisfy some of the Sustainable Development Goals of the United Nation (resolution A/RES/70/1/2015).The solutions above include an innovative monitoring method, set up by the authors of this paper, which is based on the concept of vibro-acoustic signature. The method mentioned above is a Non-Destructive Test and sensor-based solutions in order to detect damage to road pavements. The proposed method was validated using Finite Element Modelling simulations, and experimental investigations followed by data analysis carried out using Machine Learning- and Wavelet-based algorithms.Results show that smart materials and technologies can be used to target A/RES/70/1/2015 goals and to improve the sustainability of the current and future transportation infrastructures. Materiali e tecnologie intelligenti per allerta, monitoraggio, e per aumentare la vita utile delle infrastrutture di trasportoDifferenti approcci possono essere utilizzati per rendere le città e le infrastrutture di trasporto più intelligenti, sostenibili e durature. Queste tendenze influenzeranno positivamente il lavoro di molti portatori di interesse come ad esempio le autorità competenti, le società che si occupano di strade, i cittadini, gli utenti, ed i veicoli senza guidatore. Sfortunatamente, malgrado il fatto che i materiali intelligenti sono sempre più utilizzati, il livello di integrazione tra materiali intelligenti e tecnologie per l’allerta precoce ha ancora bisogno di un approccio olistico.Alla luce di questo, l’obiettivo principale del lavoro presentato in questo documento è quello di fornire una panoramica su soluzioni basate su materiali e tecnologie che potrebbero essere utilizzate nel campo delle infrastrutture di trasporto per soddisfare alcuni degli obiettivi della risoluzione per lo sviluppo sostenibile (Sustainable Development Goals) delle Nazioni Unite (A/RES/70/1/2015).Le soluzioni su citate includono un metodo innovativo, messo a punto dagli autori della memoria, il quale è basato sul concetto di firma vibro-acustica. Il metodo su citato è una soluzione basata su test non distruttivi (NDT) e sensori per l’identificazione di danni nelle pavimentazioni stradali. Il metodo proposto è stato validato attraverso simulazioni fatte con un modello agli elementi finiti (FEM), e indagini sperimentali seguite da un’analisi dati svolta usando un modello basato sull’apprendimento automatico (machine learning).I risultati mostrano che materiali e tecnologie intelligenti possono essere utilizzate per raggiungere gli obiettivi della risoluzione A/RES/70/1/2015 e migliorare la sostenibilità delle attuali e future pavimentazioni stradali

Variability of HMA characteristics and its influence on pay adjustment

The goal of this paper is to formalize and validate a model in order to determine a pay adjustment on the basis of mechanical and functional performance of transportation infrastructures. A model to determine the pay adjustment based on life expectancy of a pavement and the variability of its main properties was formulated. Five different paths and points of view are used in order to obtain information on model suitability and robustness. An algorithm has been proposed to estimate a pay adjustment (PA, negative or positive), based on life cycle cost analysis, when both structural and non-structural deficiencies/surplus in characteristics are detected. The five different methodologies, used for deriving PA, demonstrate the validity of the model in which the PA depends on both position and dispersion measures. It has been demonstrated that the model can help in analysing a project and construction management under a common framework. Analyses and validation demonstrate that the proposed model can efficiently overcome typical problems in PA determination and in contract administration, where decisions based upon objective and sound criteria are needed. Both practitioners and researchers are expected to benefit from the outcomes of this study

Particulate Matter from Non-exhaust Sources

Air pollution is an important issue worldwide. Solid components in air (particulate matter, PM) originate from a variety of natural or anthropogenic sources and have different morphological, physical, and chemical properties. Their presence in the air also depends on meteorological conditions, such as humidity, rainfall, and wind speed. PM pollution has adverse effects on environment and human health. Therefore, it is very important to address sources and processes involved in PM generation. Among the existing sources, a special attention must be paid to PM emissions from road traffic, i.e., exhaust sources (e.g., fuel combustion) and non-exhaust sources (e.g., road, tyre, brakes). These traffic-related sources contribute to PM concentrations in cities, and this calls for research into new possible systems and/or mitigation measures. In light of the facts above, the objectives of this study are 1) To evaluate the contribution to PM emission from traffic-related sources. 2) To evaluate existing mitigation measures and to identify new ones to reduce PM production. First results show that: 1) Non-exhaust sources have a different role in PM generation and they differently affect PM10, PM2.5, and PM0.1. 2) Even if emissions-related regulations have led to reductions in exhaust emissions from road traffic, other mitigation measures could reduce the non-exhaust part of emissions (e.g., brakes wear, road wear, and tyre wear). 3) New technologies could be developed to reduce PM from non-exhaust sources

Sensor-based pavement diagnostic using acoustic signature for moduli estimation

AbstractThe diffusion of smart infrastructures for smart cities provides new opportunities for the improvement of both road infrastructure monitoring and maintenance management.Often pavement management is based on the periodic assessment of the elastic modulus of the bound layers (i.e., asphalt concrete layers) by means of traditional systems, such as Ground Penetrating Radar (GPR) and Falling Weight Deflectometer (FWD). Even if these methods are reliable, well-known, and widespread, they are quite complex, expensive, and are not able to provide updated information about the evolving structural health condition of the road pavement. Hence, more advanced, effective, and economical monitoring systems can be used to solve the problems mentioned above.Consequently, the main objective of the study presented in this paper is to present and apply an innovative solution that can be used to make smarter the road pavement monitoring. In more detail, an innovative Non-Destructive Test (NDT)-based sensing unit was used to gather the vibro-acoustic signatures of road pavements with different deterioration levels (e.g. with and without fatigue cracks) of an urban road. Meaningful features were extracted from the aforementioned acoustic signature and the correlation with the elastic modulus defined using GPR and FWD data was investigated.Results show that some of the features have a good correlation with the elastic moduli of the road section under investigation. Consequently, the innovative solution could be used to evaluate the variability of elastic modulus of the asphalt concrete layers, and to monitor with continuity the deterioration of road pavements under the traffic loads

Innovative Technologies and Materials for more Sustainable Transportation Infrastructures

nnovative technologies and materials can develop the goals stated in the UN resolution A/RES/70/1. To be more precise, low-noise road pavements (for example Porous asphalt concretes, asphalt rubberised mixture, and texture-optimised pavements) have volumetric, surface (such as drainability, texture, friction and acoustic performance), and mechanistic properties that decay over time. This depends on the particular technology used and on the many variables, processes, and phenomena with consequences in terms of safety, quietness, and budget.    In light of these issues, the objectives of this study are confined into discussing several prospective developments related to the improvement of the road pavements currently used in the urban context. A new methodology aimed at improving the design of the main properties of a road pavement is presented.The abovementioned methodology was set up based on laboratory and on-site tests, which were carried out over recent decades in order to monitor the variation of surface and volumetric properties over time. Road surfaces with premium properties (such as low-noise emissions) can increase pavement and acoustic durability, and the proposed methodology can greatly improve the overall sustainability of current transportation infrastructures, fulfilling some of the goals stated in the UN Resolution A/RES/70/1. Tecnologie e materiali innovativi per infrastrutture di trasporto più sostenibiliLe tecnologie e i materiali innovativi possono favorire gli obiettivi contenuti nella risoluzione A/RES/70/1 delle Nazioni Unite. Le pavimentazioni stradali a bassa rumorosità (ad esempio le pavimentazioni porose, le miscele bituminose con gomma e le pavimentazioni con tessitura ottimizzata) hanno proprietà volumetriche, superficiali (quali drenabilità, tessitura, aderenza e prestazioni acustiche) e proprietà meccaniche che decadono nel tempo. Ciò dipende dalla particolare tecnologia utilizzata e da molteplici variabili. Molti processi e fenomeni sono coinvolti, con conseguenze in termini di sicurezza, rumorosità e budget. Alla luce di questi problemi, gli obiettivi di questo studio riguardano la messa a punto di una metodologia volta a migliorare la progettazione delle principali proprietà di una pavimentazione stradale e in particolare di quelle relative alla superficie. Le proprietà superficiali e volumetriche sono state monitorate, analizzate, in laboratorio e in situ. I risultati mostrano che l'uso di superfici stradali “speciali” (aventi, ad esempio, bassa emissione di rumore) può aumentare la durata complessiva della pavimentazione e che il metodo messo a punto può migliorare notevolmente la sostenibilità complessiva delle infrastrutture di trasporto, raggiungendo alcuni degli obiettivi indicati nella risoluzione A/RES/70/1.Innovative technologies and materials can develop the goals stated in the UN resolution A/RES/70/1. To be more precise, low-noise road pavements (for example Porous asphalt concretes, asphalt rubberised mixture, and texture-optimised pavements) have volumetric, surface (such as drainability, texture, friction and acoustic performance), and mechanistic properties that decay over time. This depends on the particular technology used and on the many variables, processes, and phenomena with consequences in terms of safety, quietness, and budget.    In light of these issues, the objectives of this study are confined into discussing several prospective developments related to the improvement of the road pavements currently used in the urban context. A new methodology aimed at improving the design of the main properties of a road pavement is presented.The abovementioned methodology was set up based on laboratory and on-site tests, which were carried out over recent decades in order to monitor the variation of surface and volumetric properties over time. Road surfaces with premium properties (such as low-noise emissions) can increase pavement and acoustic durability, and the proposed methodology can greatly improve the overall sustainability of current transportation infrastructures, fulfilling some of the goals stated in the UN Resolution A/RES/70/1. Tecnologie e materiali innovativi per infrastrutture di trasporto più sostenibiliLe tecnologie e i materiali innovativi possono favorire gli obiettivi contenuti nella risoluzione A/RES/70/1 delle Nazioni Unite. Le pavimentazioni stradali a bassa rumorosità (ad esempio le pavimentazioni porose, le miscele bituminose con gomma e le pavimentazioni con tessitura ottimizzata) hanno proprietà volumetriche, superficiali (quali drenabilità, tessitura, aderenza e prestazioni acustiche) e proprietà meccaniche che decadono nel tempo. Ciò dipende dalla particolare tecnologia utilizzata e da molteplici variabili. Molti processi e fenomeni sono coinvolti, con conseguenze in termini di sicurezza, rumorosità e budget. Alla luce di questi problemi, gli obiettivi di questo studio riguardano la messa a punto di una metodologia volta a migliorare la progettazione delle principali proprietà di una pavimentazione stradale e in particolare di quelle relative alla superficie. Le proprietà superficiali e volumetriche sono state monitorate, analizzate, in laboratorio e in situ. I risultati mostrano che l'uso di superfici stradali “speciali” (aventi, ad esempio, bassa emissione di rumore) può aumentare la durata complessiva della pavimentazione e che il metodo messo a punto può migliorare notevolmente la sostenibilità complessiva delle infrastrutture di trasporto, raggiungendo alcuni degli obiettivi indicati nella risoluzione A/RES/70/1

On the Dependence of Acoustic Pore Shape Factors on Porous Asphalt Volumetrics

The sound absorption of a road pavement depends not only on geometric and volumetric factors but also on pore shape factors. In turn, pore shape factors mainly refer to thermal and viscous factors (i.e., thermal and viscous effects that usually occur inside porous materials). Despite the presence of a number of studies and researches, there is a lack of information about how to predict or estimate pore shape factors. This greatly affects mixture design, where a physical-based or correlation-based link between volumetrics and acoustics is vital and plays an important role also during quality assurance and quality control (QA/QC) procedures. Based on the above, the objective of this study is to link mixture volumetrics and pore shape factors. In particular, 10 samples of a porous asphalt concrete were tested in order to estimate their thickness, air voids content (vacuum-sealing method, ASTM D6857/D6857M), sound absorption coefficient (Kundt’s tube, ISO 10354-2), airflow resistivity (ISO 9053-2), and permeability (ASTM PS 129). Subsequently, two models (herein called STIN and JCAL) were used to derive both volumetrics and pore shape factors from the estimated parameters listed above, and statistical analysis was carried out to define correlations among the parameters and models performance. Results confirm the complexity of the tasks and point out that estimates of the pore shape factors can be derived based on mixture volumetrics. Results can benefit researchers (in acoustic and pavement mixtures) and practitioners involved in mix design and pavement acceptance processes

“Noisy” issues in road acoustics: A white paper

Despite almost a century of studies dealing with traffic noise, researchers and practitioners still face old and new issues when designing a low-noise pavement. Given that, this manuscript aims at focusing on a number of unsolved questions, namely theoretical or technological. 1) Is it viable to balance diverse road-related needs (i.e., noise, expected life, texture levels, and friction)? 2) How much does the pavement material affect its acoustic performance (the remaining factors being constant)? 3) How much reliable is the relationship between road texture and mixture aggregate gradation? Based on the analysis of these issues, it emerges that: 1) optimal pavement design involves complex mix optimization and there are theoretical and practical bases to set up a balanced approach to address the complexity of pavement design; 2) high percentages of crumb rubber could optimise road acoustic response but this latter has a relationship with the tyre/road noise (expressed, for example, in terms of close proximity index) that calls for further investigation; 3) aggregate gradation appears to be a reliable basis to predict surface texture and therefore, under given boundary conditions, tyre/road noise; and 4) further studies and investigations are needed in terms of local calibration of deterioration curves and setting up of a sound method to assess the frequency response of asphalt concretes and to govern on-site noise indicators based on mixture properties

Quantifying the Effect of Present, Past and Oncoming Alignment on the Operating Speeds of a Two-Lane Rural Road

In the last decades several studies were conducted in order to develop operating speed prediction models for two-lane rural roads. Many factors were found to affect the operating speed, such as radius of horizontal curve or curvature changes rate, grade, length of horizontal curve, deflection angle, sight distance, superelevation rate, side friction factor, and pavement conditions. Though this, many issues arise when there is an appreciable and continuous variance of geometric features along the road and, for example, short and long tangents coexist in the same road. In such conditions, assessing homogeneous sections, calibrating robust algorithms aimed at V85 prediction is a severe task and safety goals are not easily achieved. In the light of the abovementioned facts, objective and scopes of this work were confined into the quantifications of the effect of past, present, and future geometric elements on operating speeds. In particular, attention was focused on the consistency of the assumption of an environmental speed as a reference value for both short (dependent) and long (independent) tangents. Authors proposed a new operating speed model in which the geometric features of the previous and oncoming alignment were explicitly considered. The proposed speed prediction algorithm was validated on the basis of a wide experimental survey carried out in a rural road of the Province of Reggio Calabria – southern Italy. Problem modelling, experimental plan and results discussion are reported. Results proved the validity of the proposed model even if further experiments are needed to make the model able to predict the operating speed in different type of roads

Factors Affecting Variance and Bias of Non-Nuclear Density Gauges for Porous European Mixes and Dense-Graded Friction Courses

It is well known that the implementation of contractor quality control/agency quality assurance (QC/QA) can support quality improvements in hot mix asphalt (HMA) pavements, both for porous European mixes (PEMs) and dense-graded friction courses (DGFCs). On the other hand, many reasons and reports highlight the importance of proper in situ air voids content, due to major influence on service properties (rate of rutting, fatigue life, structural strength, permeability, ravelling, etc.). Another relevant standpoint is that in-lab determinations of density, though often reliable and accurate, are low-speed tests. All these facts outline the potential role of field measurement of density through non-nuclear density gauges. In the light of the above facts, the main object of the paper was confined as the study of factors affecting variance and bias of non-nuclear density gauges both for PEMs and DGFCs. Bias, variance and parameters’ dependence resulted to be appreciably affected by mix typology and characteristics. In particular, when related to mix type, monovariate regressions with low-speed methods resulted able to provide a useful tool in QC/QA procedures and road asset management. Further practical applications have been outlined