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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
521

La influencia del RAP en la resistencia estructural de un pavimento reciclado en frío para el proyecto de conservación vial de la carretera Binacional Mazocruz – Puente Internacional / The influence of RAP on the structural resistance of a cold recycled pavement for the road conservation Project of the Mazocruz Binational Road – International Bridge

Flores Falcón, Carla Sofía, Saldaña Núñez, Antuanet Yahaira 21 July 2020 (has links)
El Proyecto de “Mejoramiento de la carretera Dv. Humajalso-Desaguadero y Tacna-Tarata-Capazo-Mazocruz por niveles de servicio” se encuentra en los departamentos de Tacna, Puno y Moquegua, Perú. Este proyecto es ejecutado por el Consorcio Vial Santa Rosa. La presente tesis, ubicado en el proyecto en mención, desarrolla el estudio de la influencia el RAP en el paquete de pavimento que será reciclado en frío, consistiendo en el pavimento reciclado; en este caso, al pavimento de asfalto existente más la base granular existente. Por lo que, se plantea el análisis escenarios desde base cero para tener una línea guía de referencia con espesores típicos de reciclados de 15 cm, 20 cm y 25 cm; en donde, se analiza la variación de la influencia del RAP con una proporción de cemento que se le agrega de 1% y 2% para estudiar el comportamiento con ayuda del CBR y del número estructural perteneciente a la fórmula de AASHTO. Se planteará el diseño del pavimento con cemento por medio de AASHTO. Por último, se verá en los resultados la influencia negativa que tiene el RAP en la resistencia estructural y la proporción aproximada de decremento de esta y las recomendaciones del caso. / The Project of “Mejoramiento de la carretera Dv. Humajalso-Desaguadero y Tacna-Tarata-Capazo-Mazocruz por niveles de servicio” is located in the departments of Tacna, Puno and Moquegua, Perú. This project is executed by Consorcio Vial Santa Rosa. This thesis, located in the project in question, develops the study of the influence of the RAP on the pavement package that will be cold recycled, consisting of the recycled pavement; in this case, to the existing asphalt pavement plus the existing granular base. Therefore, it is proposed to analyze scenarios from scratch to have a reference guideline with typical recycled thicknesses of 15 cm, 20 cm and 25 cm; where, the variation of the influence of the RAP is analyzed with a proportion of cement added of 1% and 2% to analyze the behavior with the help of the CBR and the structural number belonging to the AASHTO formula. The design of the pavement with cement through AASHTO will be considered. Finally, the negative influence of the RAP on the structural strength and the approximate proportion of its decrease will be seen in the results and the recommendations of the case. / Tesis
522

AN AGENT-BASED FRAMEWORK FOR INFRASTRUCTURE MAINTENANCE DECISION MAKING

Jephunneh Bonsafo-Bawuah (9229868) 13 August 2020 (has links)
<div>A transportation system plays a significant role in the economic development of a region by facilitating the movement of goods and services. No matter how well the infrastructure is designed or constructed, it is beneficial to know maintenance needs in the life cycle of the infrastructure so that the service life of the pavement is prolonged by minimizing its life-cycle cost requirements. The pavement life-cycle performance helps maintenance investment decision-makers to efficiently utilize the available infrastructure funds. This research focuses on developing</div><div>a framework for identifying a more effective and efficient way of decision making on the management and maintenance of infrastructure. The developed framework uses an agent-based modeling approach to capture the interaction that exists between different components of the transportation system and their characteristics such as traffic volume and pavement condition, user cost, agency cost, etc. The developed agent-based is useful to investigate the effects of time-varying vehicular density on pavement deterioration and the road users’ driving behavior. The developed framework was demonstrated as a two-lane highway as a case study. Using the developed agent-based simulation framework, it was possible to identify when the road</div><div>infrastructure maintenance should be done to increase the desired PCR value. Also, it was possible to show a decrease in PCR can affect the cost of road users. The framework can track the time to determine when maintenance should be done based on the PCR values that determine whether the</div><div>pavement is in good, moderate, or bad condition. Regardless of the degree of road users’ patience to stay in their travel lanes (patience), the vehicle distribution on the road is balanced in the long run because road users tend to change their travel lanes to minimize their overall travel times. When the patient level is low, road users tend to change lanes more, causing a high number of vehicles on the left lane as it is considered the lane changing lane in two-lane highways. It was also observed that as the patience of the road users increases, the number of vehicles that use the right lane is almost the same as the number of vehicles that use the left lane.</div>
523

Recyklace asfaltových směsí se standardním množstvím R-materiálu / Recycling of asphalt mixtures with standard amount of RAP

Staňková, Michaela January 2022 (has links)
The diploma thesis deals with the design of an asphalt mixture for an abrasive layer with a standard R-material content (20 %) without the use of other softening additives, while the properties of the aged asphalt binder in the mixture were compensated by dosing "softer binder 70/100". Asphalt mixtures type ACO 11+ are designed to meet the requirements ČSN 73 6121: 2019. The aim of the work is to verify the expected properties of the asphalt mixture performed functional and empirical tests according to the standards for asphalt mixtures of the ČSN EN 12697 series.
524

SIMPLE EVALUATION METHODS FOR ROAD PAVEMENT MANAGEMENT IN DEVELOPING COUNTRY / 発展途上国向け道路舗装の簡易な評価手法に関する研究

Heng Salpisoth 24 March 2014 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第18249号 / 工博第3841号 / 新制||工||1589(附属図書館) / 31107 / 京都大学大学院工学研究科都市社会工学専攻 / (主査)教授 河野 広隆, 教授 宮川 豊章, 准教授 服部 篤史 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM
525

Assessment of Tree Canopy Effects Overtop Low Volume Roadways

Horn, Andrea L. 20 September 2019 (has links)
No description available.
526

Fatigue Failure Model for Local Roads in Ohio that Use Road User Maintenance Agreements Due to the Increase in Truck Traffic

Gopallawa, Praveen January 2019 (has links)
No description available.
527

Effects of Mix, Aging, and Production Types on the I-FIT and IDEAL-CT Cracking Indices

Mansour, Mustafa 25 August 2020 (has links)
No description available.
528

LCA: A Tool to Study Feasibility and Environmental Impacts of Substituting Asphalt Binders

Adesokan, Qudus, 0000-0003-2503-3688 January 2021 (has links)
Finding innovative technologies for building our roads has always been of paramount importance. From moving to warm mix asphalt to decrease our indulgence in high energy consumption to substituting fly ash for asphalt binders to reduce dependence on pure asphalt binders from petroleum, engineers have painstakingly tried to develop new ways to improve the ways that flexible pavements are made. The major problem facing the next generation of civil engineers is sustainable practices on the field. Over the years, significant progress has been made in this regard on the impacts of building pavements on the environment. Characterizing these improvements tends to be difficult, and that is where Life Cycle Assessment (LCA) comes in. LCA is a technique used to analyze and quantify the environmental impacts of a product, system, or process. LCA shows where the significant impacts occur and how improvements can be made while recommending better practices. Even with its many advantages, its use is very constrained, especially in the United States, as it is still a very novel approach in design coupled with limited datasets and protocol for its operation. With modern technologies of substitute materials for binders like bio-oil from food waste, reclaimed asphalt pavement (RAP), and fly ash, there is a need to understand their environmental impacts. Furthermore, in this regard is where LCA can help using three significant areas: selection of materials, normalization, and characterization. Characterization refers to the identification and quantification of the relationships between the life cycle results and the environmental impacts. This research explores the environmental impacts of substituting other materials for asphalt binders using LCA. With variations in modifying levels of substitutes, results show promising levels in emissions of harmful gasses to both the air and water. This study explores ways used in normalizing this process as well as setting up a pathway for other asphalt binder substitutes. / Civil Engineering
529

Conventional Pavements and Perpetual Pavements: A Rational and Empirical Approach

Wang, Wenqi 14 December 2013 (has links)
A study has been conducted to compare conventional pavements and perpetual pavements with a particular emphasis on perpetual pavements. One of the main drawbacks of conventional pavements and motivations for this work is the maintenance required for hot mix asphalt (HMA) pavements with sub-drainage systems. Perpetual pavements, as the name suggests, are designed with a long life. However, this is a relatively new concept and there are still many unknowns concerning their performance. This dissertation was written to answer some of the questions. The study examines structural response and performance of perpetual pavements. Also, deterioration and performance of perpetual pavements will be contrasted to conventional pavements. Empirical data from the National Center of Asphalt Technology (NCAT) Test Track study was obtained, analyzed and used as a basis for evaluating theoretical models. Computational models for both conventional and perpetual pavements were constructed and analyzed using the general purpose finite element analysis software ABAQUS. Geometry, materials and loading are modeled with sufficient accuracy. This research examined several types of responses of perpetual pavements. It extends the traditional criteria of pavement distress by suggesting that longitudinal strain at the surface of a pavement HMA layer as an important criterion. Shear strain was studied and it provides a reasonable explanation of some distresses in pavements. By studying the FEA results from conventional and perpetual pavements and a thorough investigation of the thickness effects, it provides some rationale on why strain at the top of thick pavements is critical. The effects of dynamic wheel loadings are presented. Finally, the effect of environment, specifically temperature and moisture, on perpetual pavements are studied.
530

Towards the application of UAS forroad maintenance at the Norvik Port

RODRIGUEZ MILLIAN, JULIAN DARIO January 2019 (has links)
One of the vital processes for the maintenance of infrastructure is the collection of information about the inventory and current state of the infrastructure. Such activities are mostly done manually by the inspector in the field. However, Unmanned Aerial Vehicles (UAV) offer the possibilities to improving the accuracy, precision, and efficiency of those tasks. The present dissertation focusses on the evaluation of the requirements and possibilities for the incorporation of UAV in the assessment of port infrastructure, with an emphasis on pavement infrastructure. The first step to reach the goal of the research was the elaboration of an extensive literature review where the leading practices and trends for the use of Unmanned Aerial Systems (UAS) were identified. Based on the literature review, it was possible to propose a roadmap for the implementation of the UAS in the assessment of port infrastructure. The roadmap was implemented in a case study for the Norvik port in Stockholm while the restrictions and information allowed. This research produced several key findings. First, it was possible to recognize the lack of precise definitions in the pavement assessment, the faults in the current manual collection of pavement distresses and the voids in an investigation regarding the recognition of pavement defects different than cracking as some of the critical problems in the area. Additionally, the current applications like bridge and structural inspection, and available technologies like LiDAR or visual sensors were identified along with its improvement opportunities and restrictions. The key steps for the implementation of a UAS for assessing infrastructure were formulated as the identification of the needs and critical parameters, the selection of the UAS components, mainly the UAV and sensor, and the postprocessing of the data. The main conclusion drawn from the research is that it is possible to use UAS to assess the state of the infrastructure. However, not all UAS are suitable for all situations or necessities. The selection of the UA, according to the needs and limitations of the project, plays a vital role regarding the viability of implementation of a UAS for monitoring port infrastructure. The sufficiency of a UAS is closely related on its capability to acquire the information of the selected structures, with the required quality, and overcome the limitations, challenges, and restrictions of the site of application. As a way forward, the most important element to address is the implementation of Machine Learning (ML) techniques and Artificial Intelligence (AI) to extract the relevant features of the data automatically.

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