Browsing by Author "Sivaneswaran, Nadarajah"

Now showing 1 - 7 of 7
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    Applying Pavement Life Cycle Assessment Results to Enhance Sustainable Pavement Management Decision Making
    Bryce, James Matthew (Virginia Tech, 2014-06-27)
    Sustainable pavement management implies maintaining acceptable condition of pavements while also considering the tradeoff between cost, environmental impacts and social impacts of pavement investments. Typical pavement management practices only consider economic considerations, and environmental mitigation techniques are employed after the selection of the maintenance action is complete. This dissertation presents a series of papers that demonstrate the impact of decision making on the environmental impact of the pavements both at the project and network levels of pavement management. An analysis was conducted of two models that relate pavement properties to vehicle rolling resistance and fuel consumption. These models were used, along with other tools to evaluate the impact of including the use phase of a pavement into pavement lifecycle assessments. A detailed project level lifecycle assessment was conducted, and it was found that the vehicles on the pavement during the use phase contribute the most to environmental pollutants by a significant margin over other phases of the lifecycle. Thus, relatively small improvements in the factors which contribute to rolling resistance may significantly influence the environmental impacts of the pavement. Building on this, a network level lifecycle assessment method was proposed to probabilistically quantify energy consumption for a given set of expected maintenance actions. It was shown that, although maintenance actions require a certain amount of energy consumption, this energy can be offset by improved road conditions leading to reduced rolling resistance. However, this tradeoff of reduced energy consumption also includes increased costs for a given network condition. In other words, the lowest energy consumption values did not tend to fall along the line defined by minimizing the cost divided by the pavement condition. In order to demonstrate how this tradeoff should be addressed, a novel decision analysis framework was developed, and implemented on a specific pavement network. Finally, a survey of transportation professionals was evaluated to determine their optimal points within the solution space defined by minimizing costs and energy consumption while maximizing pavement condition. It was found that the solution space could be greatly reduced by implementing their responses using the proposed decision analysis framework.
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    Incorporating Traffic Speed Deflection Data in Pavement Management Decision Making for Flexible Pavements
    Thyagarajan, Senthilmurugan; Sivaneswaran, Nadarajah; Petros, Katherine (2015-06-04)
    Systematic pavement condition evaluation and development of an optimized set of pavement treatment strategies are two key tasks in the pavement management process that assists in making informed decisions on future construction actions. Current State Highway Agency's pavement management systems are primarily based on surface condition data, and surface cracking is mainly used as an indicator of the pavement structural condition. However, with effective pavement preservation activities that intervene early to preserve and extend the life of pavements and increasingly thicker long-life pavements, the surface cracks can no longer be a reliable indicator of structural condition of the pavement structure. This study envisions the use of data from Traffic Speed Deflection Devices (TSDD) in network level structural assessment and optimizing the pavement treatment strategies for flexible pavements within a modern pavement management framework. The methodology used the tensile strain at the bottom of the asphalt layer predicted from TSDD measurements to evaluate structural deterioration well before the occurrence of surface cracks, enabling more optimum treatment intervention. Mechanistic analyses were used to predict treatment benefits as a function of time and pavement condition at the time of application. The methodology allows the pavement engineer to identify an optimized series of treatment types and their timing over an analysis horizon that minimizes the life cycle cost while maintaining an above acceptable level of service. Finally the study illustrates the effectiveness of Remaining Service Interval (RSI) concept for consistent reporting of future construction needs based on optimum time remaining until a defined treatment type.
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    Investigation of Applicability and Use of a Pavement Response Model with High Speed Deflection Devices (HSDDs)
    Siddharthan, Rajaratnam V.; Nasimifar, Mahdi; Rada, Gonzalo R.; Nazarian, Soheil; Sivaneswaran, Nadarajah; Thyagarajan, Senthilmurugan (2014-09)
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    Network Level Decision-Making Using Pavement Structural Condition Information From The Traffic Speed Deflectometer
    Shrestha, Shivesh (Virginia Tech, 2022-02-01)
    Pavement structural condition plays a critical role in the rate of pavement deterioration, yet most state highway agencies' network-level decision-making processes are primarily based on surface distresses. Despite the limitations of the traditional structural condition measuring devices, some states have experimented with stationary deflection devices for network-level applications. Over the past decade, continuous deflection devices have become capable of measuring the network-level pavement structural condition information. However, since the traffic speed deflection devices use newer technology, there is a need for guidelines on how the state agencies could make use of this information for pavement management decision-making. This dissertation developed processes and enhanced tools to incorporate the pavement structural condition from the TSD into Virginia's network-level pavement management process This first part of the study developed pavement deterioration models for a subset of road networks in Virginia, to show that the pavement structural condition as measured by the TSD has an impact on the rate of deterioration of the surface condition. A structural condition matrix was then developed to augment the treatment selection process currently used by VDOT. Application of the augmented matrix on the tested Interstate network resulted in reducing the percentage of the network requiring CM and increasing the percentage requiring PM and RM. The second part of the study investigated the possibility of using pavement deflection measurements obtained from the TSD for network-level structural evaluation of pavements in Virginia. The study reported that the structural condition obtained with the TSD can replace the structural condition obtained from the FWD that is currently used in the VDOT PMS. The effective structural number (SNeff) calculated from the TSD and FWD had similar distribution, and the calculated consistency between the TSD SNeff and FWD SNeff was higher than the consistency between the SNeff from two repeated sets of FWD measurements. The third part of the study simulated the network level decision-making approaches based on both the structural condition parameter and the surface condition parameter, considering cases with and without the pavement treatment interval. The study reported that network-level decisions based on the pavement surface condition alone can result in significantly different treatment selection, compared to decisions based on the pavement structural condition. The study reported savings of 9% and 11% for cases with and without considering the pavement treatment intervals, using decision-making based on the structural condition.
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    Network Level Pavement Structural Evaluations - A Way Forward
    Sivaneswaran, Nadarajah (2014-09-17)
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    Pavement Remaining Service Interval: A Logical Replacement to Remaining Service Life Concept
    Sivaneswaran, Nadarajah; Visintine, Beth A.; Rada, Gonzalo R.; Elkins, Gary E.; Thyagarajan, Senthilmurugan (2015-06-04)
    The process of providing and managing a pavement network requires a plethora of decisions to be made. At the heart of those decisions is the prediction of future construction events, but many issues exist with the current remaining service life (RSL) terminology that confuse, confound, and complicate proper interpretation, interagency data exchange, and use. The major source of ambiguity with RSL is the use of the term "life" to represent different points in the construction time-line. There could be up to four different types of future construction events on which a RSL definition could be based, depending on the condition of the pavement, and it is impossible for a single number called RSL to properly describe all of these future construction events. The recommended path to consistency involves adopting terminology of time remaining until a defined construction treatment is required. RSL is replaced by "Remaining Service Interval" or "RSI" This terminology has the ability to unify the outcome of different approaches for determining needs by focusing on when and what treatments are needed, and the service interruption created. This paper explains the RSI concept and outlines the validation efforts using State Highway Agencies and the Pavement Health Track analysis tool at the national level. It also details how RSI can contribute to the requirements of the Moving Ahead for Progress in the 21st Century (MAP-21) legislation.
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    Use of High-Speed Deflection Devices in Network-Level PMS Applications: Are We Ready?
    Rada, Gonzalo R.; Nazarian, Soheil; Visintine, Beth A.; Siddharthan, Rajaratnam V.; Sivaneswaran, Nadarajah (2015-06-04)
    As highway agencies begin to consider structural adequacy as part of their routine pavement management activities by incorporating deflection testing, it is important to advance from falling weight deflectometers (FWDs) to a more viable alternative for network-level applications. The development of devices that measure pavement deflections at traffic speeds represents this viable alternative. The modern versions of the devices include the Greenwood Traffic Speed Deflectometer (TSD) and the Applied Research Associates, Inc. (ARA) Rolling Wheel Deflectometer (RWD), but are these devices ready for implementation? To answer this question, the Federal Highway Administration (FHWA) undertook a study whose objective was to establish a reliable measure of the structural condition of pavements as it deteriorates over time under traffic and environmental loading, based on deflection measurements taken at traffic speeds. As part of the study, a literature review was conducted and questionnaires were developed for and provided to device manufacturers, owners and users, which were then followed-up by interviews. Both devices were found to be viable, so a work plan was developed and implemented to evaluate them. The work plan included field-testing and analysis activities, but it purposely did not contemplate comparisons with Falling Weight deflectometers (FWDs). This paper presents the major findings, conclusions and recommendations from the project effort to date. The only remaining activity is the development of processes for incorporating pavement structural information within pavement management system (PMS) applications.