Ce travail de thèse s'articule autour de plusieurs variations sur le thème du rebond d'une goutte d'eau sur une surface non-mouillante. Nous engendrons des rebonds spéciaux que nous caractérisons expérimentalement. Notre analyse de ces rebonds se concentre sur la mise en évidence des paramètres et des phénomènes physiques contrôlant leur extension spatiale et temporelle, deux quantités qu'il est important de comprendre tant d'un point de vue fondamental qu'appliqué. Nous étudions, dans un premier temps, les effets de la géométrie du substrat sur le rebond d'une goutte d'eau. Nous montrons qu'une modification locale, l'ajout d'une macrotexture ponctuelle, crée un mécanisme de rebond nouveau que nous associons à une réduction du temps de contact d'un facteur 2. Nous réalisons également des impacts sur des substrats coniques et sphériques en mettant en avant les différences et les similitudes avec les impacts sur une surface plane. Dans un second temps, nous nous intéressons aux effets créés par un substrat mobile. Nous étudions l'impact de gouttes sur des surfaces déformables et comprenons comment l'échelle de temps du rebond est influencée par une interaction entre celle de la goutte et celle du substrat. Nous discutons aussi l'influence de la déformation du substrat sur le splash. Notre étude de l'influence du mouvement s'est poursuivie en utilisant des surfaces rigides auxquelles nous pouvons imposer un déplacement vertical. En soumettant des gouttes initialement au repos à un mouvement impulsionnel, nous engendrons de surprenantes cavités coniques dont nous modélisons la dynamique. Cette expérience permet de faire un constat étonnant, la faible adhésion des surfaces superhydrophobes est nécessaire à l'obtention des cavités. Nous réalisons des impacts sur une surface dont le déplacement peut-être déclenché au moment du contact entre le liquide et le solide à l’aide du signal provenant d’un capteur de force de type MEMS. Nous atteignons des temps de contact extrêmement réduits, de l’ordre de 20% de celui observé sur le même substrat sans mouvement. Enfin, nous modifions le liquide et non le substrat. Nous montrons que des gouttes jusqu'à 200 fois plus visqueuses que l'eau peuvent rebondir sur des matériaux superhydrophobes. / This thesis revolves around the ability of liquid drops to bounce off superhydrophobic materials. We generate special rebounds and characterize them experimentally.We focus on finding the relevant physical phenomena to describe the temporal and spatial extension of such events, both quantities being of importance from the fundamental and applied point of vue. First, we study the influence of the susbtrate geometry. We modify the surface locally, by introducing a singular macrotexture, and show that it leads to a new bouncing mechanism that shortens the contact time by a factor typically 2. We also modify the substrate at the size of the drop. We perform impacts on non wetting cones and spheres and compare them to what is observed on a flat surface. Then, we study the effect of substrate motion. We make impacts on soft materials that can be deformed by the drop. We show that this situation can lead to fast bouncing and interpret the contact time as the result of an interplay between the timescale of the drop and that of the substrate. We also discuss the influence of substrate deformation on splashing. We go deeper into the effect of substrate motion by using rigid materials which movement we can trigger. We evidence new liquid shapes, conical cavities, by submitting a drop, initially at rest, to a vertical impulse.Surprisingly, the low, but present, adhesion of superhydrophobic materials is the key ingredient needed to observe such shapes. We also work on the effect of motion at the onset of impact, by trigerring the substrate movement using the signal from a MEMS force sensor intregrated in the surface. This setup allow us to reach contact times that represent 20% of the contact time on an immobile substrate. Finally, we change perspective and modify the liquid instead of the solid. We show that viscous drops can bounce as long as their viscosity does not exceed 200 times that of water.

This research sought to integrate measurement and prediction of surface macrotexture for use in pavement management systems. This was achieved through two experiments, the first modeled the behavior of a binder-rich stone matrix asphalt when subjected to traffic loading using a heavy vehicle simulator to report the effect on pavement macrotexture. The second experiment compared high-speed macrotexture measurement devices on a variety of surfaces and under various operating conditions. The change in macrotexture due to traffic loading showed that as the cumulative load increased, the macrotexture decreased due to bleeding on the pavement's surface. A regression model determined that, on average, the macrotexture's root mean square (RMS) decreased 0.14 mm per million equivalent single axle load applied. A comparison of RMS and mean profile depth (MPD) outputs indicated that RMS was more sensitive to changes in macrotexture due to bleeding. In comparing devices, pairwise device agreement was evaluated using a Limits of Agreement. The results demonstrate good repeatability for each of the devices tested. The agreement analysis showed that not all high-speed devices can be used interchangeably for all pavement surfaces. Data acquisition speed was found to be a factor in macrotexture parameter calculation for two of the devices. The effect of speed was found to be worse on randomly textured surfaces than on transversely textured surfaces. / Master of Science / This thesis sought to integrate the collection and prediction of a pavement surface property known as macrotexture for use in the management of pavement networks. This was achieved through two experiments, the first of which modeled the behavior of asphalt concrete with a higher than typical asphalt content when subjected to simulated traffic to determine the effect on pavement macrotexture. The second experiment compared five high-speed macrotexture measurement devices on a variety of pavement surface types and under various operating conditions. The change in macrotexture due to traffic loading showed that as the cumulative traffic increased, the macrotexture decreased due to the asphalt coming out on the surface, referred to as bleeding. For the comparison of measurement devices data were processed using current industry standards. The results demonstrate good repeatability for each of the devices tested. The analysis also showed that not all high-speed devices can be used interchangeably for all pavement surface types. Vehicle speed was found to be a factor for two of the devices. The effect of speed was found to vary by surface type. Finally, vehicle acceleration was shown to influence the parameters produced by one of the devices, demonstrating that care should be taken to gather high-quality datasets for the critical pavement characteristic of macrotexture.

The purpose of this thesis was to assess the repeatability and reproducibility of two high-speed macrotexture measuring systems. The first portion of the study collected macrotexture measurements using the two high-speed systems on the Virginia Smart Road facility and validated the reproducibility of the mean profile depth (MPD) measurements with reference CT Meter measurements. The various data sets were then compared with each other. The objective was to determine whether the two systems are collecting repeatable and reproducible data. The analysis showed that the two high-speed systems investigated have good repeatability (0.105 mm for the Ames and 0.113 mm for the SCRIM) when measuring the average MPD of the sections investigated. The two systems produce measurements that are highly-correlated (Ames R2 = 0.9591 and SCRIM R2 = 0.9157) with the reference ones obtained with the CT Meter. While the Ames systems, with the data processed using the Virginia Tech filter, measures MPD values that are very close to those of the CT Meter, with a virtually zero systematic bias. The SCRIM obtains slightly lower readings. The differences are thought to be due to the filtering of the raw pavement elevation measurements used by the SCRIM processing software to eliminate dropout and spikes in the laser measurements. / Master of Science

Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / Uma dificuldade que acomete as empresas de construÃÃo pesada em relaÃÃo à seguranÃa viÃria à atingir valores mÃnimos de aderÃncia exigidos em campo para o revestimento de pavimentos. Valores mÃnimos de microtextura, ensaiados atravÃs do pÃndulo britÃnico, e faixas de macrotextura, ensaiadas pelo ensaio de mancha de areia, sÃo encontrados no Manual de RestauraÃÃo de Pavimentos AsfÃlticos do DNIT de 2006. Nas situaÃÃes onde esses parÃmetros ligados à aderÃncia sÃo controlados, o revestimento precisa ser reexecutado quando a micro e a macrotextura nÃo se aproximam do exigido pelas normas. Trata-se de um problema apenas observado durante a fase de construÃÃo, uma vez que nÃo se determina a aderÃncia em laboratÃrio, na fase de projeto. Pesquisas apontam que as mudanÃas nas propriedades dos agregados e na granulometria podem afetar a micro e a macrotextura da camada de rolamento. A fim de contribuir na questÃo da aderÃncia, buscando a previsÃo desse parÃmetro ainda indiretamente em laboratÃrio, objetivou-se desenvolver uma metodologia capaz de testar granulometrias para verificar o efeito das fraÃÃes dos materiais das peneiras nesta aderÃncia da superfÃcie do pavimento. A metodologia proposta consistiu em comparar a textura da massa asfÃltica compactada em campo e em laboratÃrio utilizando os ensaios de mancha de areia e de pÃndulo britÃnico. Objetivou-se, ainda, desenvolver um modelo capaz de predizer o valor de macrotextura da camada de rolamento atravÃs de granulometrias das misturas asfÃlticas estudadas. O modelo foi composto por dados de fraÃÃes retidas entre as peneiras nÂ40 e 3/8â. Os principais resultados obtidos levaram à conclusÃo de que a metodologia desenvolvida em laboratÃrio foi consistente no aspecto de microtextura entre campo e laboratÃrio. Em relaÃÃo ao modelo, houve uma correlaÃÃo considerada satisfatÃria, portanto, indicando o potencial da previsÃo da macrotextura ainda na fase de projeto a partir da granulometria a adotar. / A difficulty that affects pavement contractors regarding road safety is to achieve minimum values of surface friction required to the pavement in the field. Minimum values of microtexture tested through the British pendulum and ranges of macrotexture tested by the sand patch test are found in the DNIT Manual of Asphalt Pavements Restoration (2006). In situations where the friction parameters are controlled, oftentimes the pavement needs to be reexecuted when the micro and macrotexture do not meet the required values. This is a problem only observed during the construction phase as friction is not determined indirectly in the laboratory during the design phase. Research indicates that changes in the properties of the aggregates and the particle size can affect the microtexture and macrotexture of the surface course. In order to contribute to the topic of friction, seeking the prediction of this parameter in the laboratory, this work aimed to develop a methodology capable of evaluating gradations and the effect of the sieve fractions of materials in the of pavement surface friction. The proposed methodology consisted in comparing the texture of the asphalt mixture compacted in laboratory, and field tests using sand patch and British pendulum. It also aimed to develop a model to predict the value of macrotexture of the surface course through the gradation of the asphalt mixtures studied. The model was composed by data of retained fractions in sieve #40 to 3/8". The main results obtained led to the conclusion that the methodology developed in the laboratory was consistent in the aspect of microtexture between field and laboratory. Regarding the model, there was a satisfactory correlation, indicating the potential of predicting macrotexture in the design phase from the mixture gradation.

<p>Pavement macrotexture contributes greatly to road surface friction, which in turn plays a significant role in reducing road incidents. Conventional methods for macrotexture measurement techniques (e.g., the sand patch method, the outflow method, and laser measuring) are either expensive, time-consuming, or of poor repeatability. This thesis aims to develop and evaluate affordable and convenient alternative approaches to determine pavement macrotexture. The proposed solution is based on multi-view smartphone images collected in situ over the pavement. Computer vision techniques are then applied to create high resolution three-dimensional (3D) models of the pavement. The thesis develops the analytics to determine two primary macrotexture metrics: mean profile depth and aggregation loss. Experiments with 790 images over 25 spots of three State Roads and 6 spots of the INDOT test site demonstrated that the image-based method can yield reliable results comparable to conventional laser texture scanner results. Moreover, based on experiments with 280 images over 7 sample plates with different aggregate loss percentage, the newly developed analytics were proven to enable estimation of the aggregation loss, which is largely compromised in the laser scanning technique and conventional MPD calculation approach. The root mean square height based on the captured images was verified in this thesis as a more comprehensive metric for macrotexture evaluation. It is expected that the developed approach and analytics can be adopted for practical use at a large scale. </p>

This thesis compared macrotexture measurements obtained using the volumetric method (Sand Patch) and three laser-based devices: MGPS system, ICC laser profiler, and Circular Texture Meter (CTMeter). The study used data from three sources: two controlled experiments conducted at the Virginia Smart Road, field data collected on eight newly constructed hot-mix-asphalt (HMA) roadway surfaces, and data collected on airport surfaces at the Wallops flight facility, Virginia. The data collected at the Virginia Smart Road, a controlled-access two-lane road that includes various HMA and concrete surfaces, was used for the main analysis. The other two sets of data were used for verification and validation of the model developed. The analysis of the data collected at the Virginia Smart Road showed that the CTMeter mean profile depth (MPD) has the highest correlation with the volumetric (Sand Patch) mean texture depth (MTD). Furthermore, texture convexity had a significant effect on the correlation between the measurements obtained with different devices. Two sets of models for converting the laser-based texture measurements to an estimated MTD (ETD) were developed. One set of equations considered all the data collected at the Virginia Smart Road, and the other excluded the measurements on the Open-Graded Friction Course (OGFC). The developed models were tested using measurements collected at eight roadway sections throughout Virginia and the Wallops flight facility. The model, excluding the OGFC section, was successfully applied to other sites. / Master of Science

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Ce travail de recherche a pour objectif général de proposer un modèle de mise en relation du design émotionnel avec la macrotexture et les matériaux pour aider les concepteurs à la sélection de finitions pour les produits industriels. Cette modélisation vise à valoriser le produit à travers l’exploration des mécanismes sensoriels, sémantiques et émotionnels, qui interviennent lors de la perception du produit par le consommateur. Le processus perceptif est ainsi pris en compte à travers différents modalités sensorielles de manière à enrichir le processus de conception. Le secteur d’application de notre recherche a été le secteur automobile, avec le produit « volant ». Ce produit a été analysé dans la catégorie Grand Public. Dans cette catégorie, les matériaux ont été analysés sur un ensemble de 7 différents modèles de volants avec une population française et brésilienne. Par ailleurs, différents paramètres techniques tels que, la dureté, la rugosité et la dissipation thermique, ont été pris en compte dans la mise en relation pour renforcer la communication entre les domaines du Design et l’Ingénierie. / This research has the overall goal to propose a model linking emotional design with macrotexture and materials to help designers in the selection of finishes for industrial products. This model aims to promote the product through the exploration of sensory, semantic and emotional mechanisms, involved in the perception of the product by the consumer. The perceptive process is thus considered through different sensory modalities to enrich the design process. The application sector of our research was the automotive sector, with the product "steering wheel". This product was analyzed in the General Public category. In this category, the materials were analyzed within a set of 7 different steering wheels models by a population of French and Brazilian users. Moreover, different technical parameters such as, hardness, roughness and heat dissipation have been taken into account in the linking to strengthen communication between the fields of Design and Engineering.

This dissertation is compiled of the findings of several phases of a detailed research study that was aimed at investigating the Skid Resistance phenomenon. In the first phase of the dissertation research a study was performed to evaluate the different factors that influence frictional measurements obtained using the Dynamic Friction Tester (DFT). A temperature calibration factor that would account for temperature effects on DFT readings and IFI computations was developed. In addition, other variables that also affect the friction measurements obtained using the DFT are identified. In the next phase of the dissertation research the effect of pavement roughness on the Skid Resistance was investigated. The variation of the normal load and its nonlinear relation to SN was used to explain lower SN values measured on relatively rougher surfaces. The feasibility of using the International Roughness Index (IRI) and the Dynamic Load Coefficient (DLC) as predictors of the reduction in SN due to pavement roughness was also investigated. In the final phase of the dissertation research an in-depth investigation was carried out to better understand the principles underlying the concept of the International Friction Index (IFI), and specifically the role played by the Speed Constant ( Sp) parameter in the IFI computations. The parameter Sp dictates the speed variation of the wet friction measurements taken on a given pavement surface. The results of the current investigation suggest the revision of the procedure for computation of the Sp parameter to incorporate device specific properties. Furthermore, the incorporation of vehicle characteristics in the Sp parameter computations would help address a well known deficiency of the IFI, which is the inconsistent FR60 (predicted friction at 60 km/h) obtained from the friction values measured at two different slip speeds on the same surface. This study also showed that the modification of the Sp parameter reduces significantly the slip speed dependency of the device calibration parameters A and B. Finally, a modified IFI procedure that incorporates device specific slip conditions is presented. The modified IFI procedure showed consistently better predictive capability than the conventional ASTM procedure on all the different devices considered in this study.