<?xml version="1.0" encoding="utf-8"?><rss version="2.0" xmlns:atom="http://www.w3.org/2005/Atom"><channel><title>TRB Publications Index</title><link>http://pubsindex.trb.org/</link><atom:link href="http://pubsindex.trb.org/common/TRIS Suite/feeds/rss.aspx?tc=NN%3ARkmm" rel="self" type="application/rss+xml" /><description></description><language>en-us</language><copyright>Copyright © 2015. National Academy of Sciences. All rights reserved.</copyright><docs>http://blogs.law.harvard.edu/tech/rss</docs><managingEditor>tris-trb@nas.edu (Bill McLeod)</managingEditor><webMaster>tris-trb@nas.edu (Bill McLeod)</webMaster><image><title>TRB Publications Index</title><url>http://pubsindex.trb.org/Images/PageHeader-wTitle.png</url><link>http://pubsindex.trb.org/</link></image><item><title>Construction of Resilient Pavement Using Proper Interface Layers and Pavement Solar Collectors</title><link>http://pubsindex.trb.org/view/2384915</link><description><![CDATA[The resilience of pavements depends not only on asphalt mixture performance and structural design but also on the bonding between two adjacent pavement layers and interlayer performance as well as on traffic and environmental conditions. This paper thus aims to assess the impacts of several parameters on the interface shear resistance. Accordingly, the response surface method (RSM) was initially employed to design an experimental matrix based on the factors that exhibit the highest impacts on the shear resistance of the interface including the dosage of emulsions, temperature, and loading rate (as the independent variables) and responses obtained from the Leutner shear test. A pull-off test was also performed to evaluate the bonding between layers. Furthermore, the possibility of moderating the influence of ambient temperature on the interface using the pavement solar collector (PSC) system was investigated. The results showed that temperature is the most influential factor that can compromise the interface performance. The applied loading rate and dosage of emulsions also affected the bonding between pavement layers. The optimization analysis indicated that the utmost interface shear resistance could be attained at mid-range temperatures, coupled with the application of emulsions up to a specific limit. While the emulsion dosage can be controlled during pavement construction, it is beyond human capability to restrain the environmental temperature throughout the pavement’s lifespan. Nevertheless, the PSC system exhibited a superb ability to effectively reduce and increase the interface temperature during summer and winter, respectively, beneficially resulting in higher interface shear strength and consequently construction of more climate-resilient pavements.]]></description><pubDate>Thu, 30 May 2024 11:57:12 GMT</pubDate><guid>http://pubsindex.trb.org/view/2384915</guid></item><item><title>Resiliency Against Flooding in Pavement Geotechnics: Practice Review of State Transportation Agencies</title><link>http://pubsindex.trb.org/view/2381952</link><description><![CDATA[Extreme weather events driven by climate change pose significant threats to our transportation infrastructure, particularly road pavements, in the United States. This paper proposes a guiding framework for designing resilient pavements. The framework was established after comprehensive reviews of the state of practice from pavement design manuals and construction-, implementation-, and practice documents publicly available on websites of state departments of transportation (DOTs) across the country. The objective of this study was to evaluate the infrastructure flood readiness and awareness of transportation agencies based on the state DOT website surveys. Qualitative analyses of transportation agency engineering and construction manuals revealed a varying degree of consideration among the different states for resiliency in transportation infrastructure design policies. Web scraping of state DOT websites highlighted the awareness levels of resiliency and sustainability issues concerning pavements. The importance of constructing permeable pavement base layers to alleviate flood-induced damage was investigated for assessing moisture infiltration effects on pavement performance and how to incorporate these improvements into mechanistic-empirical pavement design concepts. The findings underscored the need to incorporate climate change stressors and predictive climate data modeling in pavement design to enhance infrastructure resilience. Through study findings and considering implementation of the guidelines proposed in this paper, transportation engineers and state agencies are anticipated to be able to better prepare for future extreme weather challenges and safeguard the nation’s transportation assets.]]></description><pubDate>Thu, 23 May 2024 11:20:28 GMT</pubDate><guid>http://pubsindex.trb.org/view/2381952</guid></item><item><title>Flexible Pavement Resiliency and Mitigation Strategies Following Adverse Environmental Events</title><link>http://pubsindex.trb.org/view/2166535</link><description><![CDATA[Water accelerates flexible pavement damage in various ways, including subgrade and granular pavement materials strength reduction, frost heave, swelling of expansive subgrade soils, and asphalt binder stripping of aggregate in asphalt concrete (AC) mixes. This paper presents case studies of AC pavement sections in the U.S. that withstood high moisture events with limited effect on pavement performance and no immediate need for major maintenance or rehabilitation actions. The case studies comprise pavement sections in Florida and Louisiana that were subjected to catastrophic flooding events, a pavement section in Delaware that is constantly exposed to tidal water level variations, and pavement sections in Montana and Minnesota that experience seasonal freeze-thaw. These cases illustrated that flexible pavements could withstand climatic changes when appropriately designed and constructed. Mechanically or chemically stabilized subgrade, proper drainage, and/or minimizing plastic fines in unbound layers are all techniques that could effectively control moisture damage.]]></description><pubDate>Fri, 05 May 2023 10:01:13 GMT</pubDate><guid>http://pubsindex.trb.org/view/2166535</guid></item><item><title>Enhanced Pavement Design and Analysis Framework to Improve the Resiliency of Flexible Airfield Pavements</title><link>http://pubsindex.trb.org/view/2137476</link><description><![CDATA[Changes in climatic conditions can directly affect pavement performance. However, accounting for environmental factors in airport pavement design remains a challenge since design methods such as FAA rigid and flexible iterative elastic layered design (FAARFIELD) do not consider moisture and temperature variation as input. Therefore, to address this research gap and improve the resilience of airport pavements, this research proposes a new methodology for the structural design of flexible airport pavements. The proposed methodology in this research was applied to a case study of an international airport in Canada, using actual field data. Five scenarios were evaluated including the current climate, temperature increase, lower matric suction, and two flooding events. The results of the proposed design method showed that the traditional FAARFIELD analysis can possibly overestimate fatigue damage, and underestimate rutting damage. The outcomes showed that climate change can increase pavement damage and shorten the service life from 7 to 14?years in the scenarios evaluated. It was also concluded that the lowering of the matric suction can result in the highest damage levels. Considering the implications of climate change on transportation infrastructure, the proposed methodology can contribute to designing more resilient airport pavements in the future, since it accounts for climate variations, temperature, and moisture changes, as well as extreme events such as flooding over the design life of flexible airport pavements.]]></description><pubDate>Mon, 13 Mar 2023 16:59:10 GMT</pubDate><guid>http://pubsindex.trb.org/view/2137476</guid></item><item><title>Full-Scale Experimental Evaluation of the Flood Resiliency of Thin Concrete Overlay on Asphalt Pavements</title><link>http://pubsindex.trb.org/view/1897027</link><description><![CDATA[The capacity to resist flooding is one of the critical challenges of pavement resiliency in locations subject to inundation. Flooding increases moisture contents, which weakens most pavement materials. Although the effect of moisture on the mechanical properties of most pavement materials is reversible, the structural damage caused by trafficking applied on the weakened pavement structure is not. The critical time for structural damage is typically after the flood and before “life-line” pavements have dried back when trucks are bringing in relief supplies and hauling out demolition. This fact, together with the increased occurrence of extreme weather events and sea level rise resulting from climate change, emphasizes the need to better understand the impacts of flooding on identified life-line pavements. This paper evaluates the flooding resiliency of thin concrete overlay on asphalt (COA) pavements by studying the effects that water saturation produces on the pavement structure. The research is based on the structural response and distresses measured in five thin COA sections that were instrumented with sensors and tested with a heavy vehicle simulator (HVS) under flooded conditions. The research shows that the flooding did not produce a noticeable change in the structural capacity of the COA, based on the structural response measured under the loading of the HVS wheel and the falling weight deflectometer, but did result in some structural damage to the asphalt base in some of the sections.]]></description><pubDate>Tue, 14 Dec 2021 19:51:33 GMT</pubDate><guid>http://pubsindex.trb.org/view/1897027</guid></item><item><title>Evaluation and Comparison on the Moisture Susceptibility and Healing Property of Asphalt and Mastic</title><link>http://pubsindex.trb.org/view/1759228</link><description><![CDATA[The bond between asphalt and aggregate plays a fundamental role in the mixture’s resistance to moisture damage and cracking. Healing is another inherent property of asphalt which is related to the mixture’s durability. Many studies have investigated the two properties at the meso level, including the binder bond strength (BBS) test. However, it has not been decided whether the test on the unfilled asphalt or mastic could accurately evaluate and predict the mixture performance. In this study, the BBS test was employed to evaluate the bond, moisture susceptibility, and healing property of four representative modified asphalt and the corresponding mastic, including SBS, crumb rubber (CR), high-density polyethylene (HDPE) and gilsonite modifications. The influence of limestone mineral filler on the asphalt was investigated through Fourier transform infrared (FTIR) spectrum experiment. The Hamburg wheel-track test and four-point beam fatigue-healing test were also performed for the correlation between the binder results in BBS test and the mixture performance. The results show that gilsonite enhances the asphalt bond strength, whereas the linear SBS, HDPE, and CR have a negative effect. The HDPE-modified asphalt presents superior healing performance. The limestone mineral filler improves the asphalt bond and moisture susceptibility, except for CR-modified asphalt, but harms the healing capability. The FTIR test results show that the interaction between asphalt and mineral filler is mainly physical rather than chemical. Correlation analyses between binder tests and mixture tests verify that the BBS test on the unfilled asphalt could predict the moisture susceptibility and healing property of mixtures effectively.]]></description><pubDate>Thu, 04 Feb 2021 10:57:24 GMT</pubDate><guid>http://pubsindex.trb.org/view/1759228</guid></item><item><title>MILDGLASS: GFRP Strand for Resilient Mild Pre-Stressed Concrete</title><link>http://pubsindex.trb.org/view/1709907</link><description><![CDATA[This project develops corrosion-resistant tendons for PC application that, in addition to durability and mechanical performance, exhibits favorable constructability and cost characteristics. These Glass Fiber Reinforced Polymer (GFRP) tendons address the need for cost-effective corrosion-resistant prestressing systems. These tendons are coilable, shippable and compatible with traditional techniques applied to steel-PC tensioning and construction.  The focus of this project is on GFRP that retains immunity to corrosion and maintains a material cost comparable to traditional carbon steel reinforcement ($1.15/ft.) while also showing higher strain at failure (2.0% ultimate elongation) and lower modulus of elasticity (approximately 45 GPa) with respect to other non-corrosive reinforcing solutions such as High Strength Stainless Steel (HSSS) and Carbon FRP (CFRP). The low modulus is an advantageous feature in PC construction during fabrication (larger and more controllable displacement at prestressing) and design (lower elastic shortening).]]></description><pubDate>Wed, 03 Jun 2020 13:07:17 GMT</pubDate><guid>http://pubsindex.trb.org/view/1709907</guid></item><item><title>A Framework for Assessment of Sustainability and Resilience in Subgrade Stabilization for a High-Volume Road</title><link>http://pubsindex.trb.org/view/1497402</link><description><![CDATA[Sustainability studies for civil infrastructure have primarily focused on methods and tools for quantifying resource consumption, environmental consequences, and socio-economic implications of a project. On the other hand, resilience analyses are based on the attributes of robustness and adaptiveness of the system. This study presents a multi-criteria analysis-based framework for a combined evaluation of sustainability and resilience of a civil infrastructure. The individual metrics (impact categories) are quantified, and a combined sustainability and resilience index ICSR is introduced to assess the sustainability and resilience of a high-volume road construction project in Texas. The pavement was constructed on sulfate-rich expansive clays, and the subgrade was stabilized with materials such as lime and fly ash. The framework offers flexibility to the user in attaching weights to an impact category based on its relative priority in the analysis. A pictographic representation of both sustainability and resilience elements could be effected through this framework.]]></description><pubDate>Fri, 30 Mar 2018 16:30:44 GMT</pubDate><guid>http://pubsindex.trb.org/view/1497402</guid></item><item><title>Adaptation Planning for Climate-Resilient Urban Infrastructure</title><link>http://pubsindex.trb.org/view/1439728</link><description><![CDATA[The emergence of climate-induced-weather-events has provoked a new class of modeling to provide the vulnerable infrastructures with climate-adaptive, resilient platforms. While adaptation planning is inevitable to neutralize the aftermath of climate-change-induced hazards, quantitative approaches have been less practiced in real-size case studies. Taking on this challenge, the authors investigate a planning response to enhance the resilience of transportation network in the face of random arrival of 100- and 500-year flooding episodes. Modeling the interdependency between fuel supply-chain and transportation infrastructures, the proposed approach investigates the transportation network’s maximum performance by enhancing the robustness of fuel supply-chain in time of disaster. The model features a multi-stage mathematical program. The first stage which is an asset allocation model, investigates the optimum investing portfolio by propositioning assets a priori of hazards. Within the second stage, variables are conditioned on the decisions made through the first stage, and seek the transportation system’s overall resilience: minimum unmet travel demand and maximum fuel accessibility in the aftermath of extreme events. The proposed model illustrates how to allocate resources proactively and how the transportation network’s post-disaster operability could be protected by a resilient motor fuel supply-chain infrastructure. Results also emphasize on the importance of an integrated planning approach where a higher degree of resilience aligned with less costly resilience-enhancing strategies is expected through smart allocation of resources across the infrastructure’s elements.]]></description><pubDate>Tue, 14 Mar 2017 10:31:30 GMT</pubDate><guid>http://pubsindex.trb.org/view/1439728</guid></item><item><title>Successful Approaches to Vulnerability Assessments and Adaptation Evaluation from 2013-2015 FHWA Climate Resilience Pilot Program</title><link>http://pubsindex.trb.org/view/1439319</link><description><![CDATA[Under FHWA’s 2013-2015 Climate Change Resilience Pilot Program, nineteen state Departments of Transportation, Metropolitan Planning Organizations, and Federal Land Management Agencies conducted projects to analyze climate change and extreme weather vulnerability of various transportation assets and systems, and evaluate climate adaptation options. The pilot projects have made significant advances in the state of the practice of adapting transportation systems to climate change. This paper provides a synthesis of best practices and approaches across the pilot projects to overcome several challenging areas: setting a manageable scope, coordinating with other agencies on related work, collecting and analyzing data, measuring vulnerability, evaluating adaptation options, calculating costs and benefits of adaptation options, and incorporating results into transportation decision-making and existing practices.]]></description><pubDate>Tue, 14 Mar 2017 10:31:29 GMT</pubDate><guid>http://pubsindex.trb.org/view/1439319</guid></item><item><title>Track Support Measurements for Improved Resiliency of Railway Infrastructure</title><link>http://pubsindex.trb.org/view/1438436</link><description><![CDATA[Track support is necessary for reliable, resilient railroad track infrastructure. Ability to recover quickly from adversity is a hallmark of the railway industry, and ability to rapidly restore track to service is a main element contributing to resilience of rail service. Poor track support conditions can increase dynamic and impact loading on track superstructure components that can accelerate deterioration of track components, potentially inhibiting the resilience of railroad track. As track components deteriorate or material properties continue to degrade in an area, affected ties become poorly supported and shed their load to better-supported ties. Various problems develop owing to increased tie load, rail stress, and ballast stress, leading to ballast degradation and track or tie vibrations. These problems can be avoided if proper track support is uniformly provided so that no area is overstressed. Several measurement techniques are discussed for evaluating track support: modulus and transient displacements, including track deflection techniques, video cameras, accelerometers, spectral analysis of surface waves for assessment of sublayer moduli, and falling weight deflectometer for deflection and basin analyses. These measurement techniques are compared and contrasted, are illustrated by using a track bearing capacity example, and are demonstrated as useful in assessing tie and track support problems with the goal of improving inspection and maintenance at problem locations. Data from these tests can be useful in designing track and maintenance plans to avoid track support failures, a necessary step to ensure track infrastructure resiliency.]]></description><pubDate>Tue, 24 Jan 2017 15:15:21 GMT</pubDate><guid>http://pubsindex.trb.org/view/1438436</guid></item><item><title>Transportation Asset Management: Summary of the 11th National Conference</title><link>http://pubsindex.trb.org/view/1439869</link><description><![CDATA[The 11th National Conference on Transportation Asset Management was held in Minneapolis, Minnesota, on July 10–12, 2016. Organized by the Transportation Research Board (TRB) of the National Academies of Sciences, Engineering, and Medicine, the conference was supported by the Federal Highway Administration (FHWA), the Federal Transit Administration, and the Transportation Asset Management Pooled Fund project. It was hosted by the Minnesota Department of Transportation (DOT).  The conference featured opening and closing sessions, 30 breakout sessions in five functional and two cross-cutting virtual tracks, a poster session, and four workshops. A peer exchange on implementing transportation asset management was also held in conjunction with the conference.  Speakers at the conference highlighted the advancements and improvements being made in transportation asset management programs at the state, regional, metropolitan, and local levels. Information on the innovative approaches being used by transit and other modes was interwoven throughout the conference. These approaches are addressing emerging issues, local needs, and federal requirements to ensure the best use of limited resources for transportation and transit investment decisions. Asset management programs are addressing climate change and extreme weather events, engaging diverse stakeholders in ongoing conversations, and using more robust and timely data. Programs are expanding to include risk assessments, vulnerability evaluations, and return on investment (ROI) analyses. Asset management is also being considered from a regional perspective in some areas. Although numerous advancements are occurring, speakers noted that many of the keys to successful asset management programs remain the same. These factors include top leadership support, establishing a strong basic foundation, involving personnel from throughout an agency, and transparency with policy makers and the public. Conference participants also discussed issues that would benefit from further research and technology transfer activities. This summary highlights the key elements from the conference. Comments from speakers in the opening session are presented first. The five track leaders’ comments on the discussion of the topics addressed in the breakout sessions are summarized in the closing session.]]></description><pubDate>Mon, 12 Dec 2016 08:54:25 GMT</pubDate><guid>http://pubsindex.trb.org/view/1439869</guid></item><item><title>Development and Implementation of the Asphalt Embrittlement Analyzer</title><link>http://pubsindex.trb.org/view/1405345</link><description><![CDATA[This project involved the development of an acoustic emission-based Asphalt Embrittlement Analyzer (AEA) device as an advanced diagnostic tool to assess the degree of aging, crack resistance, and resiliency of near-surface properties in asphalt pavements. A sophisticated computer code was developed to analyze acoustic emission (AE) signals, to identify microcrack presence and location, and to produce a diagnostic schematic illustrating embrittlement temperature versus location (depth from surface of pavement). The AEA test offers: simplicity and portability; the ability to characterize the continuous and rapid change in surface properties as a function of depth from the surface; suitability for characterization of both binders and mixtures; relative insensitivity to sample size and fracture size effect; relative insensitivity to sample geometry; and suitability for determining the optimum timing and method(s) for preventive maintenance and rehabilitation. In addition, as a design tool, the AEA can be used to assess the effectiveness and proper use of rejuvenators in achieving the goal of restoring the pavement surface to a crack-resistant state.]]></description><pubDate>Fri, 29 Apr 2016 14:14:54 GMT</pubDate><guid>http://pubsindex.trb.org/view/1405345</guid></item><item><title>A Sensitivity Analysis of a Dynamic Restricted Equilibrium Model to Evaluate the Traffic Network Resilience</title><link>http://pubsindex.trb.org/view/1393282</link><description><![CDATA[Extreme weather events have a devastating impact on traffic networks. Therefore, mathematical tools that are able to measure systematically the impacts of extreme weather events, i.e. to evaluate its resilience, should be developed. With the aim of improving the resilience of a traffic network when affected by a hazard, a profound knowledge of the model to evaluate resilience is necessary. Consequently, the model parameters should be analized, since these parameters represent the characteristics of the network and this analysis will permit to identify those characteristics that should be improved to reach a more resilient system. This paper develops a sensitivity analysis that reduces the number of studied point needed due to its statistical approach using a global technique (Latin Hypercube), without losing efficiency, as a local technique (One-At-a-Time) is applied too. This analysis confirms that the model to evaluate the resilience represents the real behavior of the traffic network. The results show that the intensity of the hazards is the most sensitive parameter. When hazard intensity is low, the impedance of the system becomes the most sensitive parameter]]></description><pubDate>Wed, 27 Jan 2016 17:12:22 GMT</pubDate><guid>http://pubsindex.trb.org/view/1393282</guid></item><item><title>Impacts of Climate Disasters on Tourist Adaptation Behavior in Bangladesh</title><link>http://pubsindex.trb.org/view/1393207</link><description><![CDATA[To assess the impacts of climate disasters on the behavior of tourists in Bangladesh, this study makes an initial attempt to investigate tourists’ adaptation behavior in response to climate disasters. The survey included both tourists’ previous adaptation behavior and their stated adaptation behavior in response to different climate disasters in future. The choice modeling analysis of tourists’ previous behavior revealed that a cyclone is more likely to result in the cancellation of a trip and a flood is more likely to result in a change in trip timing. As for the stated behavior analysis, it is confirmed that most variables related to disaster severity show significant influence on adaptation behavior. The results also indicate construction of disaster- resilient transportation networks is essential to avoid trip cancellations. In addition, enhancing tourism service quality in Bangladesh could play a significant role in reducing the probability of both trip cancellations and changes of destination.]]></description><pubDate>Wed, 27 Jan 2016 17:12:15 GMT</pubDate><guid>http://pubsindex.trb.org/view/1393207</guid></item></channel></rss>