Dimensionamento de pavimentos flexíveis para aeroportos

This work discusses the design of flexible pavements for airports, with the aid techniques and tools necessary for the calculation and design critical aircraft as the Boeing 777-300ER. Also discussed the layers that make up the pavement, the materials used and the method used for design pavement (FAA method)

Estudo sobre o potencial de alguns latossolos da região do Vale do Paraíba, estado de São Paulo, para uso em camadas estruturais de pavimentos de baixo volume de tráfego

The main purpose of this research is to raise, through lab rehearsals, the geometric properties of some oxisols from the region of Vale do Paraíba as well as comparing them to demands prescribed by Technical Specifications ESP08/05 of the Road Department of the State of Paraná, for sub-base or fine grained lateritic soil base (SAFL) and in the Technical Specification ET-DEP00/006 of the Road Department of the State of São Paulo (DER/SP) for subbase or crushed stone base. According to the results that were obtained it will be feasible to appraise the usage of these sorts of soils in structure layers of low-weight traffic pavements

Qualidade da construção civil de estrutura de concreto armado, alvenaria de vedação e revestimento externo de obras verticais

The main purpose of this research is to raise, through lab rehearsals, the geometric properties of some oxisols from the region of Vale do Paraíba as well as comparing them to demands prescribed by Technical Specifications ESP08/05 of the Road Department of the State of Paraná, for sub-base or fine grained lateritic soil base (SAFL) and in the Technical Specification ET-DEP00/006 of the Road Department of the State of São Paulo (DER/SP) for subbase or crushed stone base. According to the results that were obtained it will be feasible to appraise the usage of these sorts of soils in structure layers of low-weight traffic pavements

Algumas metodologias de avaliação para pavimentos de baixo volume de trafego

This work has as objective, show and compares some of several evaluation methods of pavements, based in the rules and researches realized by another authors, with focus on low traffic volume pavements, which are generally more economic flexible pavements subjected to low loads. Were addressed structure evaluation methods and superficial evaluation methods applied to that kind of pavement, exposing of clearly the procedures to be performed, the advantages and disadvantages, as well the results obtained in the execution of each one of these. This theme was chosen by the widespread use of this type of pavement in the road network of the country and the fact that there is no still a culture of the practical of evaluation nor technical knowledge on the part of municipal governments that are usually responsible for these roads. This study also aims to guide the process of maintenance preventive or recuperative, as they are often made improvements that do not actually solve the real problem of the roads

Estudo da influência da adição de resíduos de óleo em concretos para aplicação em pavimentos

Pós-graduação em Engenharia Civil - FEIS

Classificação híbrida: pixel a pixel e baseada em objetos para o monitoramento da condição da superfície dos pavimentos rodoviários

Monitorar a condição de uso de toda a extensão das rodovias brasileiras é tarefa dispendiosa e demorada. Este trabalho trata de novas técnicas que permitem o levantamento da condição da superfície dos pavimentos rodoviários de forma ágil utilizando imagens hiperespectrais de sensor digital aeroembarcado. Nos últimos anos, um número crescente de imagens de alta resolução espacial tem surgido no mercado mundial com o aparecimento dos novos satélites e sensores aeroembarcados de sensoriamento remoto. Propõe-se uma metodologia para identificação dos pavimentos asfálticos e classificação das principais ocorrências dos defeitos na superfície do pavimento. A primeira etapa da metodologia é a identificação da superfície asfáltica na imagem, utilizando uma classificação híbrida baseada inicialmente em pixel e depois refinada por objetos. A segunda etapa da metodologia é a identificação e classificação das ocorrências dos principais defeitos nos pavimentos flexíveis que são observáveis nas imagens de alta resolução espacial. Esta última etapa faz uso intensivo das novas técnicas de classificação de imagens baseadas em objetos. O resultado final é a geração de índices da condição da superfície do pavimento a partir das imagens que possam ser comparados com os indicadores vigentes da condição da superfície do pavimento já normatizados pelos órgãos competentes no país.

Study of materials and technology of ancient floor mosaics' substrate

Ancient pavements are composed of a variety of preparatory or foundation layers constituting the substrate, and of a layer of tesserae, pebbles or marble slabs forming the surface of the floor. In other cases, the surface consists of a mortar layer beaten and polished. The term mosaic is associated with the presence of tesserae or pebbles, while the more general term pavement is used in all the cases. As past and modern excavations of ancient pavements demonstrated, all pavements do not necessarily display the stratigraphy of the substrate described in the ancient literary sources. In fact, the number and thickness of the preparatory layers, as well as the nature and the properties of their constituent materials, are often varying in pavements which are placed either in different sites or in different buildings within a same site or even in a same building. For such a reason, an investigation that takes account of the whole structure of the pavement is important when studying the archaeological context of the site where it is placed, when designing materials to be used for its maintenance and restoration, when documenting it and when presenting it to public. Five case studies represented by archaeological sites containing floor mosaics and other kind of pavements, dated to the Hellenistic and the Roman period, have been investigated by means of in situ and laboratory analyses. The results indicated that the characteristics of the studied pavements, namely the number and the thickness of the preparatory layers, and the properties of the mortars constituting them, vary according to the ancient use of the room where the pavements are placed and to the type of surface upon which they were built. The study contributed to the understanding of the function and the technology of the pavements��€™ substrate and to the characterization of its constituent materials. Furthermore, the research underlined the importance of the investigation of the whole structure of the pavement, included the foundation surface, in the interpretation of the archaeological context where it is located. A series of practical applications of the results of the research, in the designing of repair mortars for pavements, in the documentation of ancient pavements in the conservation practice, and in the presentation to public in situ and in museums of ancient pavements, have been suggested.

Performance evaluation of low environmental impact asphalt concretes using the mechanistic empirical design method based on laboratory fatigue and permanent deformation models

The "sustainability" concept relates to the prolonging of human economic systems with as little detrimental impact on ecological systems as possible. Construction that exhibits good environmental stewardship and practices that conserve resources in a manner that allow growth and development to be sustained for the long-term without degrading the environment are indispensable in a developed society. Past, current and future advancements in asphalt as an environmentally sustainable paving material are especially important because the quantities of asphalt used annually in Europe as well as in the U.S. are large. The asphalt industry is still developing technological improvements that will reduce the environmental impact without affecting the final mechanical performance. Warm mix asphalt (WMA) is a type of asphalt mix requiring lower production temperatures compared to hot mix asphalt (HMA), while aiming to maintain the desired post construction properties of traditional HMA. Lowering the production temperature reduce the fuel usage and the production of emissions therefore and that improve conditions for workers and supports the sustainable development. Even the crumb-rubber modifier (CRM), with shredded automobile tires and used in the United States since the mid 1980s, has proven to be an environmentally friendly alternative to conventional asphalt pavement. Furthermore, the use of waste tires is not only relevant in an environmental aspect but also for the engineering properties of asphalt [Pennisi E., 1992]. This research project is aimed to demonstrate the dual value of these Asphalt Mixes in regards to the environmental and mechanical performance and to suggest a low environmental impact design procedure. In fact, the use of eco-friendly materials is the first phase towards an eco-compatible design but it cannot be the only step. The eco-compatible approach should be extended also to the design method and material characterization because only with these phases is it possible to exploit the maximum potential properties of the used materials. Appropriate asphalt concrete characterization is essential and vital for realistic performance prediction of asphalt concrete pavements. Volumetric (Mix design) and mechanical (Permanent deformation and Fatigue performance) properties are important factors to consider. Moreover, an advanced and efficient design method is necessary in order to correctly use the material. A design method such as a Mechanistic-Empirical approach, consisting of a structural model capable of predicting the state of stresses and strains within the pavement structure under the different traffic and environmental conditions, was the application of choice. In particular this study focus on the CalME and its Incremental-Recursive (I-R) procedure, based on damage models for fatigue and permanent shear strain related to the surface cracking and to the rutting respectively. It works in increments of time and, using the output from one increment, recursively, as input to the next increment, predicts the pavement conditions in terms of layer moduli, fatigue cracking, rutting and roughness. This software procedure was adopted in order to verify the mechanical properties of the study mixes and the reciprocal relationship between surface layer and pavement structure in terms of fatigue and permanent deformation with defined traffic and environmental conditions. The asphalt mixes studied were used in a pavement structure as surface layer of 60 mm thickness. The performance of the pavement was compared to the performance of the same pavement structure where different kinds of asphalt concrete were used as surface layer. In comparison to a conventional asphalt concrete, three eco-friendly materials, two warm mix asphalt and a rubberized asphalt concrete, were analyzed. The First Two Chapters summarize the necessary steps aimed to satisfy the sustainable pavement design procedure. In Chapter I the problem of asphalt pavement eco-compatible design was introduced. The low environmental impact materials such as the Warm Mix Asphalt and the Rubberized Asphalt Concrete were described in detail. In addition the value of a rational asphalt pavement design method was discussed. Chapter II underlines the importance of a deep laboratory characterization based on appropriate materials selection and performance evaluation. In Chapter III, CalME is introduced trough a specific explanation of the different equipped design approaches and specifically explaining the I-R procedure. In Chapter IV, the experimental program is presented with a explanation of test laboratory devices adopted. The Fatigue and Rutting performances of the study mixes are shown respectively in Chapter V and VI. Through these laboratory test data the CalME I-R models parameters for Master Curve, fatigue damage and permanent shear strain were evaluated. Lastly, in Chapter VII, the results of the asphalt pavement structures simulations with different surface layers were reported. For each pavement structure, the total surface cracking, the total rutting, the fatigue damage and the rutting depth in each bound layer were analyzed.

Laboratory study of grouted macadams impregnated with mine waste geopolymeric binder

A new type of pavement has been gaining popularity over the last few years in Europe. It comprises a surface course with a semi-flexible material that provides significant advantages in comparison to both concrete and conventional asphalt, having both rut resistance and a degree of flexibility. It also provides good protection against the ingress of water to the foundation, since it has an impermeable surface. The semi-flexible material, generally known as grouted macadam, comprises an open-graded asphalt skeleton with 25% to 35% voids into which a cementitious slurry is grouted. This hybrid mixture provides good rut resistance and a surface highly resistant to fuel and oil spillage. Such properties allow it to be used in industrial areas, airports and harbours, where those situations are frequently associated with heavy and slow traffic. Grouted Macadams constitute a poorly understood branch of pavement technology and have generally been relegated to a role in certain specialist pavements whose performance is predicted on purely empirical evidence. Therefore, the main objectives of this project were related to better understanding the properties of this type of material, in order to predict its performance more realistically and to design pavements incorporating grouted macadam more accurately. Based on a standard mix design, several variables were studied during this project in order to characterise the behaviour of Grouted Macadams in general, and the influence of those variables on the fundamental properties of the final mixture. In this research project, one approach was used to the design of pavements incorporating Grouted Macadams: a traditional design method, based on laboratory determined of the stiffness modulus and the compressive strength.

Prove accelerate per la verifica strutturale di trattrici agricole

The needs of customers to improve machinery in recent years have driven tractor manufacturers to reduce product life and development costs. The most significant efforts have concentrated on the attempt to decrease the costs of the experimental testing sector. The validation of the tractor prototypes are presently performed with a replication of a particularly unfavourable condition a defined number of times. These laboratory tests do not always faithfully reproduce the real use of the tractor. Therefore, field tests are also carried out to evaluate the prototype during real use, but it is difficult to perform such tests for a period of time long enough to reproduce tractor life usage. In this context, accelerated tests have been introduced in the automotive sector, producing a certain damage to the structure in a reduced amount of time. The goal of this paper is to define a methodology for the realization of accelerated structural tests on a tractor, through the reproduction of real customer tractor usage. A market analysis was performed on a 80 kW power tractor and a series of measures were then taken to simulate the real use of the tractor. Subsequently, the rainflow matrixes of the signals were extrapolated and used to estimate the tractor loadings for 10 years of tractor life. Finally these loadings were reproduced on testing grounds with special road pavements. The results obtained highlight the possibility of reproducing field loadings during road driving on proving grounds (PGs), but the use of two field operations is also necessary. The global acceleration factor obtained in this first step of the methodology is equal to three.

Studio numerico e sperimentale delle miscele di aggregati per i conglomerati bituminosi

I crescenti volumi di traffico che interessano le pavimentazioni stradali causano sollecitazioni tensionali di notevole entità che provocano danni permanenti alla sovrastruttura. Tali danni ne riducono la vita utile e comportano elevati costi di manutenzione. Il conglomerato bituminoso è un materiale multifase composto da inerti, bitume e vuoti d'aria. Le proprietà fisiche e le prestazioni della miscela dipendono dalle caratteristiche dell'aggregato, del legante e dalla loro interazione. L’approccio tradizionalmente utilizzato per la modellazione numerica del conglomerato bituminoso si basa su uno studio macroscopico della sua risposta meccanica attraverso modelli costitutivi al continuo che, per loro natura, non considerano la mutua interazione tra le fasi eterogenee che lo compongono ed utilizzano schematizzazioni omogenee equivalenti. Nell’ottica di un’evoluzione di tali metodologie è necessario superare questa semplificazione, considerando il carattere discreto del sistema ed adottando un approccio di tipo microscopico, che consenta di rappresentare i reali processi fisico-meccanici dai quali dipende la risposta macroscopica d’insieme. Nel presente lavoro, dopo una rassegna generale dei principali metodi numerici tradizionalmente impiegati per lo studio del conglomerato bituminoso, viene approfondita la teoria degli Elementi Discreti Particellari (DEM-P), che schematizza il materiale granulare come un insieme di particelle indipendenti che interagiscono tra loro nei punti di reciproco contatto secondo appropriate leggi costitutive. Viene valutata l’influenza della forma e delle dimensioni dell’aggregato sulle caratteristiche macroscopiche (tensione deviatorica massima) e microscopiche (forze di contatto normali e tangenziali, numero di contatti, indice dei vuoti, porosità, addensamento, angolo di attrito interno) della miscela. Ciò è reso possibile dal confronto tra risultati numerici e sperimentali di test triassiali condotti su provini costituiti da tre diverse miscele formate da sfere ed elementi di forma generica.

Caratterizzazione avanzata in laboratorio di materie prime secondarie rigenerate o stabilizzate con emulsione di bitume e leganti cementizi

Il recupero dei materiali di scarto è un aspetto di grande attualità in campo stradale, così come negli altri ambiti dell’ingegneria civile. L’attenzione della ricerca e degli esperti del settore è rivolta all’affinamento di tecniche di riciclaggio che riducano l’impatto ambientale senza compromettere le prestazioni meccaniche finali. Tali indagini cercano di far corrispondere le necessità di smaltimento dei rifiuti con quelle dell’industria infrastrutturale, legate al reperimento di materiali da costruzione tecnicamente idonei ed economicamente vantaggiosi. Attualmente sono già diversi i tipi di prodotti rigenerati e riutilizzati nella realizzazione delle pavimentazioni stradali e numerosi sono anche quelli di nuova introduzione in fase di sperimentazione. In particolare, accanto ai materiali derivanti dalle operazioni di recupero della rete viaria, è opportuno considerare anche quelli provenienti dall’esercizio delle attività di trasporto, il quale comporta ogni anno il raggiungimento della fine della vita utile per centinaia di migliaia di tonnellate di pneumatici di gomma. L’obiettivo della presente analisi sperimentale è quello di fornire indicazioni e informazioni in merito alla tecnica di riciclaggio a freddo con emulsione bituminosa e cemento, valutando la possibilità di applicazione di tale metodologia in combinazione con il polverino di gomma, ottenuto dal recupero degli pneumatici fuori uso (PFU). La ricerca si distingue per una duplice valenza: la prima è quella di promuovere ulteriormente la tecnica di riciclaggio a freddo, che si sta imponendo per i suoi numerosi vantaggi economici ed ambientali, legati soprattutto alla temperatura d’esercizio; la seconda è quella di sperimentare l’utilizzo del polverino di gomma, nelle due forme di granulazione tradizionale e criogenica, additivato a miscele costituite interamente da materiale proveniente da scarifica di pavimentazioni esistenti e stabilizzate con diverse percentuali di emulsione di bitume e di legante cementizio.

Context-sensitive design in transportation infrastructure: relating tire/pavement noise with wearing course characteristics

A design can be defined as context-sensitive when it achieves effective technical and functional transportation solutions, while preserving and enhancing natural environments and minimizing impacts on local communities. Traffic noise is one of the most critical environmental impacts of transportation infrastructure and it affects both humans and ecosystems. Tire/pavement noise is caused by a set of interactions at the contact patch and it is the predominant source of road noise at the regular traffic speeds. Wearing course characteristics affect tire/pavement noise through various mechanisms. Furthermore, acoustic performance of road pavements varies over time and it is influenced by both aging and temperature. Three experimentations have been carried out to evaluate wearing course characteristics effects on tire/pavement noise. The first study involves the evaluation of skid resistance, surface texture and tire/pavement noise of an innovative application of multipurpose cold-laid microsurfacing. The second one involves the evaluation of the surface and acoustic characteristics of the different pavement sections of the test track of the Centre for Pavement and Transportation Technology (CPATT) at the University of Waterloo. In the third study, a set of highway sections have been selected in Southern Ontario with various types of pavements. Noise measurements were carried out by means of the Statistical Pass-by (SPB) method in the first case study, whereas in the second and in the third one, Close-proximity (CPX) and the On-Board Sound Intensity (OBSI) methods have been performed in parallel. Test results have contributed to understand the effects of pavement materials, temperature and aging on tire/pavement noise. Negligible correlation was found between surface texture and roughness with noise. As a general trend, aged and stiffer materials have shown to provide higher noise levels than newer and less stiff ones. Noise levels were also observed to be higher with temperature increase.

The role of paved surfaces in the Urban Heat Island phenomenon: Assessment of fundamental thermal parameters and finite element analysis for UHI mitigation

Nowadays the environmental issues and the climatic change play fundamental roles in the design of urban spaces. Our cities are growing in size, many times only following immediate needs without a long-term vision. Consequently, the sustainable development has become not only an ethical but also a strategic need: we can no longer afford an uncontrolled urban expansion. One serious effect of the territory industrialisation process is the increase of urban air and surfaces temperatures compared to the outlying rural surroundings. This difference in temperature is what constitutes an urban heat island (UHI). The purpose of this study is to provide a clarification on the role of urban surfacing materials in the thermal dynamics of an urban space, resulting in useful indications and advices in mitigating UHI. With this aim, 4 coloured concrete bricks were tested, measuring their emissivity and building up their heat release curves using infrared thermography. Two emissivity evaluation procedures were carried out and subsequently put in comparison. Samples performances were assessed, and the influence of the colour on the thermal behaviour was investigated. In addition, some external pavements were analysed. Albedo and emissivity parameters were evaluated in order to understand their thermal behaviour in different conditions. Surfaces temperatures were recorded in a one-day measurements campaign. ENVI-met software was used to simulate how the tested materials would behave in two typical urban scenarios: a urban canyon and a urban heat basin. Improvements they can carry to the urban microclimate were investigated. Emissivities obtained for the bricks ranged between 0.92 and 0.97, suggesting a limited influence of the colour on this parameter. Nonetheless, white concrete brick showed the best thermal performance, whilst the black one the worst; red and yellow ones performed pretty identical intermediate trends. De facto, colours affected the overall thermal behaviour. Emissivity parameter was measured in the outdoor work, getting (as expected) high values for the asphalts. Albedo measurements, conducted with a sunshine pyranometer, proved the improving effect given by the yellow paint in terms of solar reflection, and the bad influence of haze on the measurement accuracy. ENVI-met simulations gave a demonstration on the effectiveness in thermal improving of some tested materials. In particular, results showed good performances for white bricks and granite in the heat basin scenario, and painted concrete and macadam in the urban canyon scenario. These materials can be considered valuable solutions in UHI mitigation.

Progettazione di pavimentazioni portuali

L’oggetto di studio della tesi è centrato sulla progettazione di pavimentazioni ad alta resistenza nell’ambito dei porti commerciali. Nel capitolo 1, viene effettuata una descrizione delle caratteristiche principali dei porti, proseguendo con l’esposizione dei principi organizzativi dei porti commerciali. In particolar modo, vengono illustrate le operazioni che si registrano in un terminal container e le proprietà dei diversi mezzi speciali che vi operano. Nel capitolo successivo, si procede con la definizione dei materiali più comunemente utilizzati nella realizzazione delle pavimentazioni di un porto e quindi con la descrizione delle principali tipologie di soluzioni adottate nella progettazione. Successivamente, nel capitolo 3, vengono enunciati i principali metodi di calcolo per la progettazione di una pavimentazione portuale e si prosegue con l’approfondimento del metodo descritto dal manuale pubblicato dalla British Ports Association (BPA):”The structural design of heavy duty pavements for ports and other industries”. Infine, nell’ultimo capitolo, viene illustrato il processo di progettazione in base al metodo BPA, mediante lo svolgimento di un esempio di calcolo della pavimentazione.