Relatam-se e discutem-se resultados obtidos em ações de uma tentativa para mostrar que o formato da seção transversal de rodovias pode ser usado para explicar uma parcela do comportamento de pavimentos e qualidade de viagens em estradas vicinais. Incluiu-se o uso de medidas sobre variáveis para explicação de estado de equipamentos para drenar água das vias. O tipo de variável usada para explicar o comportamento de pavimentos e qualidade de viagens foi a distribuição de notas atribuídas a viagens por segmentos de rodovias por um grupo de avaliadores treinados. A técnica estatística usada para análise dos dados foi a regressão linear múltipla passo a passo. Relata-se resultados de aplicação a um estudo de caso sobre um conjunto de rodovias vicinais próximo à Araraquara, estado de São Paulo. / lt is related and discussed the results from actions in an attempt to show that the format of the cross section of highways can be used to explain the behavior of the pavements and quality of trips in local highways. Measures on variables to explain the state of drainage equipments was taking into account. The variable used to explain the behavior of pavements and quality of trips was the distribution of scores attributed to the highway segments trips by a group of trained appraisers. The statistical technique used to analyze the data was the multiple linear step-by-step regressions. lt is told the application results to a case study on a set of local highway segments near the city of Araraquara, State of Sao Paulo.

This thesis deals with the design of a pneumatic facing machine used to dress pavement surfaces aesthetically and anti-slip-wise. The introduction describes the general overview and examples of pavement. The second part deals with the analysis of the machine and its technical specifications. Further parts contain proposals for the pneumatic circuit, paint system and functional calculations. The drawing documentation has been prepared to the extent of manufacturing drawings and sets.

Unbound granular material is used in the pavement structure and usually comprises the bulk of the structural and foundation layers of a typical South African pavement. The term ‘unbound granular material’ refers to the classification of natural material, which has not been modified in any way. Various mechanistic-empirical models for the resilient response of unbound granular material have been developed over the years. However, few have incorporated important influencing parameters such as moisture or density on the basic stress-strain relationship or linked variables of the models to basic engineering properties of unbound granular material. This study builds on previous work by Theyse (2008a) and the cord modulus model developed by Theyse (2012). The Theyse (2012) model was selected to be further investigated, since it modelled the trends observed in the data realistically. The model depicts the stress dependent behaviour of unbound granular material, where an increase initial modulus is observed for increasing confinement pressure, as well as initial stress-softening with increasing stress ratio followed by stress stiffening. The model was calibrated for all bulk material samples under consideration in this thesis. The calibration process included linking variables of the model to mathematical functions that approximate the trends observed when variables were considered against level of saturation. A parametric analysis indicated that the saturation and stress-dependent cord modulus model realistically predict material behaviour. The saturation and stress-dependent cord modulus model was refined further and calibrated for crushed and natural unbound granular material. This refinement did not negatively influence the accuracy or ability to realistically predict the material behaviour. Basic material properties could be linked to predictive statistical distributions that could estimate the range of modulus values that can be expected for the material under consideration. However, the variables of the saturation and stress-dependent cord modulus model could not be linked to basic material properties due to the limit set of results available. / Thesis (PhD)--University of Pretoria, 2013. / gm2013 / Civil Engineering / unrestricted

Master of Science / Department of Civil Engineering / Mustaque Hossain / The AASHTO Guide for Design of Pavement Structures is the primary document used by the state highway agencies to design new and rehabilitated highway pavements. Currently the Kansas Department of Transportation (KDOT) uses the 1993 edition of the AASHTO pavement design guide, based on empirical performance equations, for the design of Jointed Plain Concrete Pavements (JPCP). However, the newly released Mechanistic-Empirical Pavement Design Guide (MEPDG) provides methodologies for mechanistic-empirical pavement design while accounting for local materials, environmental conditions, and actual highway traffic load distribution by means of axle load spectra. The major objective of this study was to predict pavement distresses from the MEPDG design analysis for selected in-service JPCP projects in Kansas. Five roadway sections designed by KDOT and three long term pavement performance (LTPP) sections in Kansas were analyzed. Project-specific construction, materials, climatic, and traffic data were also generated in the study. Typical examples of axle load spectra calculations from the existing Weigh-in-Motion (WIM) data were provided. Vehicle class and hourly truck traffic distributions were also derived from Automatic Vehicle Classification (AVC) data provided by KDOT. The predicted output variables, IRI, percent slabs cracked, and faulting values, were compared with those obtained during annual pavement management system (PMS) condition survey done by KDOT. A sensitivity analysis was also performed to determine the sensitivity of the output variables due to variations in the key input parameters used in the design process. Finally, the interaction of selected significant factors through statistical analysis was identified to find the effect on current KDOT specifications for rigid pavement construction. The results showed that IRI was the most sensitive output. For most projects in this study, the predicted IRI was similar to the measured values. MEPDG analysis showed minimal or no faulting and was confirmed by visual observation. Only a few projects showed some cracking. It was also observed that the MEPDG outputs were very sensitive to some specific traffic, material, and construction input parameters such as, average daily truck traffic, truck percentages, dowel diameter, tied concrete shoulder, widened lane, slab thickness, coefficient of thermal expansion, compressive strength, base type, etc. Statistical analysis results showed that the current KDOT Percent Within Limits (PWL) specifications for concrete pavement construction are more sensitive to the concrete strength than to the slab thickness. Concrete slab thickness, strength, and truck traffic significantly influence the distresses predicted by MEPDG in most cases. The interactions among these factors are also almost always evident.

Master of Science / Department of Civil Engineering / Sunanda Dissanayake / Motorists generally follow the guidance provided by the pavement markings while traveling on roads. Under certain circumstances, construction joints may be necessary in concrete pavements, which are generally designed to be coincident with the pavement markings. At some locations, however, the construction joints may not exactly match the pavement markings. These situations may create confusion in the minds of drivers, which may lead them to follow joints instead of the markings. In the absence of detailed studies on this topic, an effort was made in the present study to evaluate the effects of unmatched longitudinal construction joints and pavement markings on the lateral position of vehicles. Sites having the characteristics of unmatched longitudinal construction joints and pavement markings were identified, and detailed data were collected at one of the sites. Video camera technique was used for capturing the movements of vehicles along the test site for longer durations. The video tapes were later reduced in the laboratory to extract necessary information. The distance to the right side of the vehicles from right curb of the road, the type of vehicle, presence of vehicles in the adjacent lane, weather and light conditions, and the movement of the vehicles immediately after traversing the section of the road having unmatched longitudinal construction joints and pavement markings were the main parameters observed while reducing the data. Two surveys were also conducted for gathering the opinions of some practitioners and engineers on the issue. Statistical analyses were carried out using t-tests to evaluate if there were differences. Several comparisons were made for different types of vehicles based on various conditions. The analysis results indicated that there was a statistically significant difference between the actual and expected distances to the center-line of vehicles, implying that the lateral position of vehicles may have been affected by the joints. A model was also developed to determine the lateral position of the vehicles by considering the parameters used in the analysis. Based on the survey results and analysis of field data, it was found that the lateral position of vehicles may have been affected by the unmatched joints and pavement markings.

Please read the abstract (Thesis Summary) in the section, 00front of this document / Thesis (PhD (Transportation Engineering))--University of Pretoria, 2007. / Civil Engineering / PhD / unrestricted

Vehicle fuel consumption and emission are two important effectiveness measurements of sustainable transportation development. Pavement plays an essential role in goals of fuel economy improvement and greenhouse gas (GHG) emission reduction. The main objective of this dissertation study is to experimentally investigate the effect of pavement-vehicle interaction (PVI) on vehicle fuel consumption under highway driving conditions. The goal is to provide a better understanding on the role of pavement in the green transportation initiates. Four study phases are carried out. The first phase involves a preliminary field investigation to detect the fuel consumption differences between paired flexible-rigid pavement sections with repeat measurements. The second phase continues the field investigation by a more detailed and comprehensive experimental design and independently investigates the effect of pavement type on vehicle fuel consumption. The third study phase calibrates the HDM-IV fuel consumption model with data collected in the second field phase. The purpose is to understand how pavement deflection affects vehicle fuel consumption from a mechanistic approach. The last phase applies the calibrated HDM-IV model to Florida’s interstate network and estimates the total annual fuel consumption and CO2 emissions on different scenarios. The potential annual fuel savings and emission reductions are derived based on the estimation results. Statistical results from the two field studies both show fuel savings on rigid pavement compared to flexible pavement with the test conditions specified. The savings derived from the first phase are 2.50% for the passenger car at 112km/h, and 4.04% for 18-wheel tractor-trailer at 93km/h. The savings resulted from the second phase are 2.25% and 2.22% for passenger car at 93km/h and 112km/h, and 3.57% and 3.15% for the 6-wheel medium-duty truck at 89km/h and 105km/h. All savings are statistically significant at 95% Confidence Level (C.L.). From the calibrated HDM-IV model, one unit of pavement deflection (1mm) on flexible pavement can cause an excess fuel consumption by 0.234-0.311 L/100km for the passenger car and by 1.123-1.277 L/100km for the truck. The effect is more evident at lower highway speed than at higher highway speed. From the network level estimation, approximately 40 million gallons of fuel (combined gasoline and diesel) and 0.39 million tons of CO2 emission can be saved/reduced annually if all Florida’s interstate flexible pavement are converted to rigid pavement with the same roughness levels. Moreover, each 1-mile of flexible-rigid conversion can result in a reduction of 29 thousand gallons of fuel and 258 tons of CO2 emission yearly.

abstract: This research is a comprehensive study of the sustainable modifiers for asphalt binder. It is a common practice to use modifiers to impart certain properties to asphalt binder; however, in order to facilitate the synthesis and design of highly effective sustainable modifiers, it is critical to thoroughly understand their underlying molecular level mechanisms in combination with micro and macro-level behavior. Therefore, this study incorporates a multi-scale approach using computational modeling and laboratory experiments to provide an in-depth understanding of the mechanisms of interaction between selected modifiers and the constituents of asphalt binder, at aged and unaged conditions. This study investigated the effect of paraffinic wax as a modifier for virgin binder in warm-mix asphalt that can reduce the environmental burden of asphalt pavements. The addition of wax was shown to reduce the viscosity of bitumen by reducing the self-interaction of asphaltene molecules and penetrating the existing nano agglomerates of asphaltenes. This study further examined how the interplay of various modifiers affects the modified binder’s thermomechanical properties. It was found that the presence of wax-based modifiers has a disrupting effect on the role of polyphosphoric acid that is another modifier of bitumen and its interactions with resin-type molecules. This study was further extended to using nanozeolite as a mineral carrier for wax to better disperse wax in bitumen and reduce the wax's adverse effects such as physical hardening at low service temperatures and rutting at high service temperatures. This novel technique showed that using a different method of adding a modifier can help reduce the modifier's unwanted effects. It further showed that nanozeolite could carry wax-based modifiers and release them in bitumen, then acting as a scavenger for acidic compounds in the binder. This, in turn, could promote the resistance of asphalt binder to moisture damage by reducing the quantity of acidic compounds at the interface between the binder and the stone aggregates. Furthermore, this study shows that iso-paraffin wax can reduce oxidized asphaltene molecules self-interaction and therefore, reduce the viscosity of aged bitumen while cause brittleness at low temperatures. Additionally, a cradle to gate life-cycle assessment was performed for a new bio-modifier obtained from swine manure. This study showed that by partially replacing the bitumen with bio-binder from swine manure, the carbon footprint of the binder can be reduced by 10% in conjunction with reducing the cost and environmental impact of storing the manure in lagoons. / Dissertation/Thesis / Doctoral Dissertation Civil, Environmental and Sustainable Engineering 2020

El texto completo de este trabajo no está disponible en el Repositorio Académico UPC por restricciones de la casa editorial donde ha sido publicado. / A pavement management system (PMS) is a tool that supports decision-making specialists to maintain the pavement at an optimal service level. The absence of a PMS could lead to inadequate decision-making, a disorganized road inventory, poor selection in road maintenance techniques and inefficient technical support to justify the execution of maintenance activities. For these reasons, this research proposes the application of a PMS, with the objective of improving and standardizing the processes for evaluating the condition of roads that are under the jurisdiction of low-budget government organizations, guaranteeing the selection of the most appropriate type of maintenance. As a case of study, a 1.1 km local road located in one of the districts of Lima was evaluated, which was divided into 11 sections. With this evaluation, it was obtained that 2,605.43 m2 of the total road is in poor condition, due to the presence of functional failures. For the identification of failures, the pavement condition index (PCI), the international roughness index (IRI) and the present serviceability index (PSI) were used to determine the condition, roughness and serviceability of the pavement. In conclusion, it was identified that the proposed PMS is adequately adapted to the way of working and available budget of a local administration, since if it is applied it would only spend 20.55% of the fund that would be destined to a total reconstruction of road.

Pavement surface characteristics are important to both the safety of the pavement surface and the comfort of the drivers. As of yet, texture and friction measurements have not been incorporated into the design of pavement surfaces. Seven different wearing surface mixtures, placed at the Virginia Smart Road pavement facility, were studied over a one year time period for both friction and texture properties. A locked wheel skid trailer and a laser profilometer were used to assess the pavement surface characteristics. Laboratory testing of the pavement wearing surface mixtures was performed to determine volumetric and mixture specific characteristics. Testing included gyratory compaction, specific gravity, maximum theoretical specific gravity, ignition testing, and gradation analysis. These material properties were used to study the impact of material properties on pavement surface characteristics. The pavement surface characteristics were analyzed using regression analysis with some measured and calculated parameters relevant to the pavement wearing surface properties. Analysis variables included the skid number at 64 kilometers per hour measured using the ASTM E501 (smooth) and ASTM E524 (ribbed) tires, the mean profile depth, the slope of a linear SN-speed model, the skid number at zero speed from the Pennsylvania State University (1) model, and the International Friction Index parameters. Analysis determined that testing particulars such as the grade of the test did not significantly affect the measured skid number. However, there is a significant difference between the skid numbers measured using the two tires. Additionally, the relationship between speed and skid resistance is assessed differently between the two test tires. Regression analysis concluded that there is a relationship between surface characteristics and HMA design properties such as the VMA, VTM, Percent Passing #200 sieve, and Binder Type. The influence of these variables on each of the analysis parameters varied. / Master of Science