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    <title>Transport Research International Documentation (TRID)</title>
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    <atom:link href="https://trid.trb.org/Record/RSS?s=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" rel="self" type="application/rss+xml" />
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    <copyright>Copyright © 2026. National Academy of Sciences. All rights reserved.</copyright>
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    <managingEditor>tris-trb@nas.edu (Bill McLeod)</managingEditor>
    <webMaster>tris-trb@nas.edu (Bill McLeod)</webMaster>
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    <item>
      <title>Tire Derived Aggregate Embankment Design and Construction for Saskatchewan Highway 39</title>
      <link>https://trid.trb.org/View/2665661</link>
      <description><![CDATA[Saskatchewan recycles all tires, including passenger car and light truck tires, agricultural tires, and semi tires. It is environmentally and socially acceptable to recycle tires, and agencies in North America have been doing so for years. Recycling tires is important because scrap tires take up landfill space, pose a risk of fire when stockpiled incorrectly, hold water when not shredded, and can help conserve natural aggregate resources, depending on the application. Tire Derived Aggregate (TDA) is an engineered material made from shredded tires. TDA has been used in civil engineering applications as lightweight fill to build embankments, roadway ramps, weigh scales, backfill for retaining walls, and to repair frost heaves for over 40 years.  In 2022, the Saskatchewan Ministry of Highways (ministry) constructed the ministry’s first highway embankment with TDA as lightweight fill. A greenfield project site on a new section of Highway 39 near Corinne required a large embankment fill for the southbound lanes and had in-situ soils that would benefit from the frost protection properties that TDA offers. TDA was utilized as lightweight fill in a location where the road embankment section was being built over an existing dugout. The TDA embankment section was 34.0 m by 147.6 m and 1.9 m thick and was constructed with a total of 6,332 cubic metres of TDA. Using a conversion of 100 tires per cubic metre of TDA, approximately 632,000 tires were recycled. A 2.95 m thick clay fill embankment with an additional soil surcharge layer of 0.75 m was placed on top of the TDA layer and allowed to settle prior to further construction. The surcharge load was removed to accommodate the pavement structure, and a flexible asphalt concrete pavement structure was constructed on top of the embankment, and the road was opened to traffic in 2024.  This paper presents the design and construction details for this project, the instrumentation used to monitor the TDA layer, and comments on lessons learned. The TDA embankment layer environmental and geotechnical monitoring is also summarized.]]></description>
      <pubDate>Thu, 12 Mar 2026 08:52:52 GMT</pubDate>
      <guid>https://trid.trb.org/View/2665661</guid>
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    <item>
      <title>Experimental Analysis of Electric Road Pavement Structures in Heavy Vehicle Simulator Tests</title>
      <link>https://trid.trb.org/View/2635354</link>
      <description><![CDATA[Electric Road Systems (ERS) constitute a powerful tool for promoting Electric Vehicle (EV) adoption and reducing greenhouse gas emissions in Canada's transportation sector. Electric Roads (eRoads) with wireless inductive charging enable dynamic on-the-road charging for EVs, enhancing travel ranges, reducing the need for frequent recharging, and allowing for smaller battery sizes. However, the impact of integrating inductive charging coils into pavement structures on their response to traffic and climate conditions remains underexplored, particularly in the Canadian context. This study investigates the mechanical behaviour of eRoad pavements with inductive coils compared to conventional structures under freeze-thaw conditions, representing early spring weather in Canada. Three pavement sections were constructed in a large-scale laboratory test pit at Laval University: two sections with inductive coils and varying surface course thicknesses, and one control section without coils. Sensors, including strain gauges, load cells, temperature sensors and humidity probes, monitored pavement performance under various traffic and environmental conditions, simulated using a heavy-vehicle simulator. Key findings indicate that eRoad pavements show mechanical performance comparable to conventional pavements under freeze-thaw conditions. Future research should focus on further data analysis and numerical modeling to fully understand the impact of inductive coils and inform the design of effective and durable eRoads.]]></description>
      <pubDate>Tue, 20 Jan 2026 11:16:31 GMT</pubDate>
      <guid>https://trid.trb.org/View/2635354</guid>
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    <item>
      <title>Grusslitlager och stödremsa med filler från asfalttillverkning</title>
      <link>https://trid.trb.org/View/2598664</link>
      <description><![CDATA[This report addresses challenges with gravel wearing courses, which are now primarily made from crushed rock instead of natural gravel. This shift has resulted in 70-80% of materials failing to meet the Swedish Transport Administration's specifications, mainly due to a lack of fine material and clay-key components for stability, density, and resistance to surface softening. At the same time, asphalt production generates a surplus of filler, which is often discarded. The project proposes using this surplus to improve gravel wearing courses by compensating for the lack of fine material. The aim is to study how different filler levels affect the performance and quality of gravel wearing courses and to develop a cost-effective, consistent production method. The study includes lab tests and field trials using materials from various rock quarries. Results show that materials without filler do not meet grain size requirements, but filler addition can correct this. Filler also reduces permeability, improving resistance to water infiltration. A new method for mixing moist filler into production proved effective, yielding a homogeneous material with the desired filler content. Field trials on road 2227 in Dalsland showed that sections with filler had slightly better surface quality and fewer potholes after one year, with no significant differences in loose gravel or unevenness.]]></description>
      <pubDate>Fri, 12 Sep 2025 10:19:49 GMT</pubDate>
      <guid>https://trid.trb.org/View/2598664</guid>
    </item>
    <item>
      <title>Noise-reducing properties of pavements using steel slag as aggregate in asphalt mixes</title>
      <link>https://trid.trb.org/View/2598653</link>
      <description><![CDATA[The original purpose of this project was to construct a test section of a double-layer porous asphalt pavement where steel slag was used as the aggregate in the wearing course. The contents of the project also included a summary of the performance of earlier tests with steel slag as the aggregate in dense pavements in Sweden. It was also found that including an international literature review would be very useful. The literature review was not comprehensive but included the latest and most relevant findings. Among many advantages for steel slag over natural aggregates, the literature mentions durability, less rutting and dark colour. Also polished stone values and abrasion resistance are generally high. The main disadvantage is the higher mass which makes transportation from steel works to paving sites more expensive. Some of the dense Swedish steel slag pavements presented in this report have served well for long times, under moderate or high traffic volumes. The overall assessment comes out quite positive. The main subject in this report, is a test of steel slag aggregate in the top layer of a double-layer porous asphalt pavement paved in 2017 on motorway E4 in Huskvarna, in this report followed until 2023. This project started, as planned, in 2016 with laboratory studies aiming at gaining experience of designing steel slag pavements with high air voids content for durable performance, especially with traffic noise reduction in focus. This trial section was paved simultaneously when the double-layer pavement through Huskvarna had to be repaved where then the main section could serve as a control or reference section. Both the test and the control sections had an identical bottom layer while the top layer of the test section had the stone aggregate replaced by steel slag. In this way it has been possible to compare the performance of the steel slag section with a longer section of double-layer porous asphalt which is using only natural coarse aggregates.]]></description>
      <pubDate>Fri, 12 Sep 2025 10:19:38 GMT</pubDate>
      <guid>https://trid.trb.org/View/2598653</guid>
    </item>
    <item>
      <title>Lösningar för snabbare utveckling av skogsbilvägar i Sverige</title>
      <link>https://trid.trb.org/View/2534317</link>
      <description><![CDATA[]]></description>
      <pubDate>Fri, 04 Apr 2025 15:16:38 GMT</pubDate>
      <guid>https://trid.trb.org/View/2534317</guid>
    </item>
    <item>
      <title>Uppföljning av provsträckor med ökad asfaltåtervinning : E20 Hova</title>
      <link>https://trid.trb.org/View/2534316</link>
      <description><![CDATA[The project aimed to evaluate the long-term performance of asphalt pavements containing increased amounts of reclaimed asphalt (RA). This was achieved by monitoring test sections on E20 Hova with higher RA content. Six test sections (1 to 6. were constructed, each with varying RA percentages and rejuvenation techniques. Sections 1 to 3, referred to as RA sections, used penetration graded bitumen. Sections 4 to 6, referred to as PMB sections, used polymer-modified bitumen. Sections 1 and 4 served as reference sections.  Sections 2 and 3 contained 30% RA in the binder layer and 50% RA in the bituminous base course layer, using rejuvenator and soft bitumen, respectively. PMB section 5 contained 20% RA in the binder layer and 30% RA in the bituminous base course layer. PMB section 6 contained 0% RA. The follow-up from 2018 to 2023 focused on functional and structural properties. Functional properties were assessed by measuring transvers profiles for rutting, while structural properties were evaluated using deflection measurements and asphalt strain gauges.  Results indicated that RA sections 2 and 3 showed slightly higher rut depths compared to the reference section, but the differences were not significant. Both sections demonstrated comparable performance, suggesting effective rejuvenation techniques. PMB sections 5 and 6 showed similar functional properties, with section 4 exhibiting about 30% more rutting. The proximity of sections 5 and 6 to an exit ramp contributed to reduced rutting due to higher lateral wander. Climate impact analysis revealed that using RA reduced the environmental footprint, with PMB mixtures containing 20% + 30% RA reducing CO2 emissions by approximately 2 kg/m² or 5-7 kg per ton of asphalt.  In conclusion, increasing RA content up to 50% in penetration graded bitumen and up to 30% in PMB did not result in significant negative effects. However, further monitoring and laboratory analyses are recommended to draw definitive conclusions.]]></description>
      <pubDate>Fri, 04 Apr 2025 15:16:37 GMT</pubDate>
      <guid>https://trid.trb.org/View/2534316</guid>
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    <item>
      <title>Förstudie för en nordisk provvägsanläggning</title>
      <link>https://trid.trb.org/View/2534262</link>
      <description><![CDATA[This study highlights technical and organizational conditions for a test road facility. The study will also highlight possible business models and operation and management of the facility, which includes initial financing at the beginning and over time. The purpose of a fixed test road facility is to offer opportunities for validation of more cost-effective or more environmentally friendly road structures. The facility will also provide the opportunity to study or validate new maintenance and technological solutions in a real traffic environment. The study started with external monitoring and mapping of existing demo and test track facilities. A more detailed analysis has been provided to show specific needs and expected upcoming challenges in the field. Analysis of the business model and organization for similar test facilities have presented the possible business models for organization, ownership, operation and maintenance. Investment costs and profitability analysis have been presented, for establishing and operation of a Nordic test track facility over two five-year periods, together with a market demand and profitability analysis.  Results from the study show great potential for a Nordic test road facility. There is also great interest from construction industries for a test road facility. MnROAD is the only test facility with the ability to manage traffic and test in a real traffic environment which is very extensive. Evaluation of the research activities at MnROAD has shown great profitability with a profit ratio of 9 (profits / costs) during the first phase. A test road facility, which is designed for Nordic challenges would contribute to increased productivity and increased innovation within this area in Sweden.]]></description>
      <pubDate>Fri, 04 Apr 2025 15:15:52 GMT</pubDate>
      <guid>https://trid.trb.org/View/2534262</guid>
    </item>
    <item>
      <title>Structural response analysis of concrete pavement</title>
      <link>https://trid.trb.org/View/2491236</link>
      <description><![CDATA[Cement concrete or concrete pavements are an integral part of the road network in many countries. In the United States, concrete pavements comprise approximately 45% of the road network. In comparison, the share in Sweden is almost negligible. In 2007, the Swedish Transport Administration (Trafikverket) initiated in close collaboration with the paving industry a field project with the aim of building knowledge and understanding on the structural response of concrete pavements. This report aims to characterize the structural response of a concrete pavement under varying traffic and environmental conditions. This is achieved by utilizing in-situ strains, stresses and deflections measured over an extended period of time from a concrete test slab. The structural responses and environmental conditions were measured using strain gauges, geophones, soil pressure cells and temperature measuring sensors. These instruments were installed at different locations of interest within the concrete slab. Loading was applied using dynamic falling weights and heavy trucks that travel at different speed levels. The strain measurements from the heavy truck were used to establish a relationship between applied axle load level and induced strain at various location of the slab.]]></description>
      <pubDate>Fri, 17 Jan 2025 15:16:58 GMT</pubDate>
      <guid>https://trid.trb.org/View/2491236</guid>
    </item>
    <item>
      <title>Ett forum för interaktiv omvärldsbevakning av vätgas för tunga fordon</title>
      <link>https://trid.trb.org/View/2440062</link>
      <description><![CDATA[The purpose of the project is to: (i) increase knowledge about hydrogen-powered heavy duty vehicles and construction machines regarding the entire value chain from raw materials and primary energy to end users, within policy, regulations, economics, technology and other important enablers for a possible future market introduction, and (ii) contribute to good conditions for effective pilot projects with hydrogen-powered Heavy duty vehicles in Sweden. Hydrogen is emphasized as an important ingredient in the energy system of the future. However, it is unclear to what extent the hydrogen will serve as a fuel. The approach to hydrogen is about strategic decisions for many actors. The market is greatly influenced by policy and the development of the energy system in general. The Alternative Fuels Infrastructure Regulation, AFIR, is an example of a potentially decisive factor for the supply of energy to electrified vehicles.]]></description>
      <pubDate>Thu, 10 Oct 2024 14:37:55 GMT</pubDate>
      <guid>https://trid.trb.org/View/2440062</guid>
    </item>
    <item>
      <title>Lignin i asfaltbeläggning: provväg med fossilreducerat bindemedel</title>
      <link>https://trid.trb.org/View/2440061</link>
      <description><![CDATA[The overall purpose of this project is to significantly reduce the use of fossil resources when building and maintaining roads. Fossil free transports is a common objective of contractors and the Swedish Transport Administration. Concerning asphalt production, the transition from fossil fuel has been rapid and next in turn is reducing fossil resources in the binder, and possibly, allowing for a temporary carbon sink. The main goal of the project is to scale-up binder production using kraft lignin (kraft lignin and bitumen) and by building a test road to study the characteristics of this innovative binder used in asphalt concrete. Kraft lignin is a commercial product from the forest industry.]]></description>
      <pubDate>Thu, 10 Oct 2024 14:37:55 GMT</pubDate>
      <guid>https://trid.trb.org/View/2440061</guid>
    </item>
    <item>
      <title>Monitoring the Post Construction Structural and Environmental Behaviours of an Instrumented Smart Pavement Section</title>
      <link>https://trid.trb.org/View/2301610</link>
      <description><![CDATA[Pavement infrastructure worldwide is pivotal to successful economic growth. However, like all infrastructure, it requires proper Maintenance and Rehabilitation (M&R) strategies and evidence-based Pavement Management Systems (PMS) to ensure that the pavement condition can meet the desired level of service under the impact of traffic loads and given climatic loading parameters. With the improvement of new paving materials, climate change and extreme weather events impacts solely relying on traditional M&R techniques, where monitoring periods are scheduled sporadically, may not be enough to understand pavement's performance and their mechanistic response to varying loading and climatic conditions. However, pavement design and management can benefit from the concept of Smart Pavements, considering the recent advances in Artificial Intelligence (AI) and instrumentation monitoring systems. This study presents a summary of the current progress for the “smart pavements” concept currently being implemented within a section of a major two-lane arterial roadway in Kitchener, Ontario. The goal is to enable pseudo-real-time monitoring of the section and understand the actual in-situ responses through advanced instrumentation and by running Machine Learning models to improve our understanding and prediction of long-term pavement performance. Thus far, the installation and construction of the instrumented section have been completed, and preliminary results have been obtained. This paper presents the preliminary pavement environmental and structural behaviours immediately after the construction of the section, as well as five months after construction. The instrumentation installed in each layer consists of horizontal and vertical asphalt concrete strain gauges, moisture probes, pressure cells, and temperature strings. The impact of asphalt temperature right after construction until service condition and loading frequencies on the structural behaviors of the pilot section were monitored through several rounds of known weight axial truck. The results are used to establish a baseline for better interpretation of the pavement structure during its in-service monitoring period.]]></description>
      <pubDate>Mon, 04 Dec 2023 16:47:31 GMT</pubDate>
      <guid>https://trid.trb.org/View/2301610</guid>
    </item>
    <item>
      <title>Alberta Transportation's Experience with Full Depth Reclamation</title>
      <link>https://trid.trb.org/View/2237080</link>
      <description><![CDATA[Alberta Transportation defines Full Depth Reclamation (FDR) as the in-situ process of pulverizing the entire Asphalt Concrete Pavement (ACP) layer and blending it with a portion of the underlying Granular Base Course (GBC). This pulverized blend is mixed with a bituminous stabilizing agent (foamed asphalt cement or emulsion) and a small amount of active filler such as Portland cement. Additional aggregate may be required to improve the gradation of the reclaimed material. The recycled mat is then overlaid with ACP or a double seal coat. In 2001, Alberta Transportation constructed its first stabilized FDR test section on Hwy 49:04 northwest of Grande Prairie. To the end of 2017, Alberta Transportation has completed 26 FDR projects representing 290 two-lane kilometres of pavement. Three highways were overlaid with a double seal coat, while the remaining were overlaid with ACP. Some projects treated the driving lanes only, while others treated the full width of the pavement. This paper discusses Alberta Transportation's project selection methodology, design criteria specifications, and construction methodology. Monitoring to-date has included site inspections, analysis of Laser Crack Measurement System data, pavement smoothness testing, and structural evaluation. Monitoring results are presented along with potential improvements to the design and construction methodologies.]]></description>
      <pubDate>Tue, 19 Sep 2023 14:27:43 GMT</pubDate>
      <guid>https://trid.trb.org/View/2237080</guid>
    </item>
    <item>
      <title>Pavement Structure Performance Monitoring System for the Regina Bypass Project</title>
      <link>https://trid.trb.org/View/2244536</link>
      <description><![CDATA[The "Regina Bypass" highway project currently underway involves the construction of some 45 km of double lanes in each direction, more than 18 km of rehabilitation of an existing section of Highway # 1, and 5 km of reinforcement works of an existing new section. The project is being realized under a Design-Build-Finance-Operate and Maintain (DBFOM) approach and will be operated by the concessioners group until late October 2049. High Modulus bituminous mixes were developed using customized mix design studies that optimized their rheological characteristics to the local climate. Pavement structures and High Modulus mixes are continuously monitored by control stations equipped with deep temperature sensors, and pressure and strain gauges. The goals of such a monitoring system are: 1) to compare the design hypotheses with the in-situ pavement thermal and structural behaviour, and, 2) to monitor the long-term mechanical behaviour of those materials exposed to an extreme climate like that observed in Regina. The first year of monitoring has already demonstrated the advantages of such a system and shows that the ground can freeze to a depth of 1.52 m and that the asphalt materials temperature on the base 'course can go down to -30°C. The strain analysis demonstrates the advantages of the mix designs that have been used.]]></description>
      <pubDate>Tue, 19 Sep 2023 14:27:42 GMT</pubDate>
      <guid>https://trid.trb.org/View/2244536</guid>
    </item>
    <item>
      <title>Validation of heavy vehicle loading responses and temperature predictions in flexible pavements using field data</title>
      <link>https://trid.trb.org/View/2145758</link>
      <description><![CDATA[It is well established that both traffic-related loading and environmental conditions influence the structural behaviour of pavements. Pavement design methods aim to consider the effect of traffic loading and environmental variables on pavement structure, foresee their changes during the lifetime of the pavement and predict the resulting distresses and pavement life. Newer models are required to further advance the development of pavement design methods. Validations using reliable and representative data are required prior to incorporating these models in pavement design methods. The impact of environmental factors such as temperature, moisture content and freeze-thaw cycles on pavement behaviour have been examined in this doctoral thesis. Furthermore, the impact of increased loading by new long heavy vehicles on low-volume roads subjected to large variations of the environmental conditions has been investigated. The findings presented in this thesis have been based on field data collected on roads that have been and currently are in day-to-day operation. The collected data on mechanical response, temperature, moisture and frost was used to validate models on mechanical behaviour and thermal behaviour, as well as the effect of their interaction in pavement structures.  The models developed and validated in this study are aimed to be integrated into a new mechanistic-empirical pavement design framework that is currently under development in Sweden. The work done for this thesis is presented hereby in the form of 5 papers and a short summary part. This thesis is a continuation of a licentiate thesis previously published at KTH Royal Institute of Technology. Part of the material published in the licentiate thesis has been included in this doctoral thesis. In paper 1, air temperature data recorded over a span of 10 years from 44 meteorological stations and temperature data from built-in sensors in 49 pavement structures located in different locations throughout Sweden were analysed. The data was used to statistically correlate the freezing index, calculated using the mean daily air temperature and the frost penetration depth in the cross-section of the pavement. Comparisons were made for the results obtained for various climatic zones in the country. The output of the paper is a country-specific empirical chart obtained through exponential interpolation and nonlinear prediction limits that indicates a range of expected frost penetration depth based on historical air temperature data.  Paper 2 presents a study in which the structural response of a test section was evaluated using built-in sensors. The instrumentation consisted of asphalt strain gauges (ASG) recording the tensile strain in the bottom of the asphalt layer, strain measuring units (εMU) recording the vertical strain in the granular layers, and soil pressure cells (SPC) recording the vertical stresses in the granular layers. Falling weight deflectometer (FWD) measurements were performed on the structure to backcalculate the stiffness of the layers from the measured surface deflections. The aim of the study was to evaluate the structural response of the structure under loading by three long heavy vehicles (LHV) weighing ~64 tonnes, ~68 tonnes, and ~74 tonnes and compare the resulting estimated accumulated damage from each vehicle. The main finding from the paper was that the damage caused to pavements by long heavy vehicles was slightly larger than the damage caused by shorter vehicles with fewer axles but higher axial loading and tyre pressure. Paper 3 focuses on the effect of environmental factors and their variation on the structural behaviour of a thin pavement structure. Loading by long heavy trucks was applied to a test section at four different measurement campaigns performed at different seasons over one year. The variation of temperature and moisture in the structure was monitored continuously for the entire duration for which the study was performed. Thermocouples embedded in the asphalt layer and a frost rod placed in the granular layers were used to monitor the temperature variation in the structure. The moisture variation was monitored using time-domain reflectometer (TDR) probes. The correlation of the changes in temperature and moisture to the changes in mechanical stiffness of the layers was investigated.  The instrumentation used to monitor the mechanical response, temperature variation, and moisture variation in the structure was found to be reliable for collecting data over the entire duration of the study. The main finding of the study is that it is possible to model the mechanical behaviour of thin pavement structures using multilayer elastic theory (MLET) calculations modelling, using linear-elastic material models if the stiffness of the asphalt layer is adjusted based on temperature and the stiffness of the granular layers is adjusted based on moisture levels. In Paper 4, the same response testing procedure as in Paper 3 was performed for a second pavement structure with a thicker asphalt layer. Data from response testing results for 2 pavement structures on 4 different dates, with a focus on the spring thaw period, were considered in the paper. Three different strategies for material modelling were used to investigate the mechanical response of the pavement structures. The layers were initially modelled using linear material parameters and the response results were compared both to calculations in which a viscoelastic model was used for the asphalt layer and to calculations in which a nonlinear K-Theta model was used for the granular layers.  Comparisons were made between the calculated response using each modelling strategy and the measured response values. It was found that the viscoelastic and nonlinear models provided only marginal improvements in the range of 1%-4% in predicting the mechanical response of the structures. Based on the results, it was concluded that the linear elastic model was sufficiently accurate in capturing the mechanical behaviour of both pavement structures, including at the critical locations. Paper 5 presents the development and validation of a one-dimensional finite control volume (FCV) model capable of predicting temperature in pavements. The model is intended to be implemented into a new mechanistic-empirical pavement design framework currently under development in Sweden. The model uses easily obtainable meteorological data for air temperature, solar radiation, and wind speed for the three main modes of heat transfer, namely conduction, convection and radiation.  To validate the model and estimate its accuracy, comparisons were made between the measured temperature and the calculated temperature values, using the FCV model. Comparisons were made for the pavement surface temperature, the temperature within the asphalt layer, and the temperature in the granular layers for 4 pavements located in different climatic zones in Sweden. In general, good agreement was found between the measured and calculated temperature values. Points for future improvements include better consideration of the surface properties, including the latent heat transfer in the calculations, and coupling the model to a moisture transfer model.]]></description>
      <pubDate>Mon, 03 Apr 2023 16:47:32 GMT</pubDate>
      <guid>https://trid.trb.org/View/2145758</guid>
    </item>
    <item>
      <title>Uppföljning av provväg E6 med polymermodifierade bundna lager : Uddevalla</title>
      <link>https://trid.trb.org/View/1948889</link>
      <description><![CDATA[The test road Geddeknippel–Kalsås was built in 2003–2006 as a part of the E6 motorway north of Uddevalla in both south and north directions. Test sections were constructed with polymer-modified bitumen (PMB) consisting of several variants of SBS (styrene-butadiene-styrene) and EVA (Ethylene-vinyl acetate). The test sections have been planned by the Swedish Transport Administration in collaboration with industry. The purpose is to clarify the benefit of using the PMB in asphalt mixtures in asphalt concrete layers of flexible pavements.  Long-term-pavement-performance was carried out through laboratory tests of samples and follow-up measurements. Evaluation of the pavement’s sections and prognoses of deterioration development at the test sections has been carried out with various models and test methods. The results showed that the asphalt concretes with and without PMB aged over time, however, to varying degrees. Hardening of asphalt concrete due to aging affects the development of pavement conditions and this must be considered for correct assessment of degradation of the sections. It was found that the PMBs used in this work can significantly affect the function of asphalt concretes. The choice of a PMB must be planned considering the desired functional characteristics and the asphalt concrete layer position in a road structure. Different PMB variants may be needed for different purposes. For example, different PMBs may be needed against rutting alternative fatigue cracking and sometimes the conventional asphalt concrete may be most optimal considering pavement life and from a socioeconomic aspect.  Rutting model PEDRO has been found to be a practical tool for clarifying the impact of the most important parameters on rut growth in bitumen-bound layers. It describes the proportion of rut depth from each asphalt layer and in respect of the layer’s functional properties and position in the road structure for an optimal choice of asphalt materials. The Swedish Transport Administration's investment in counting traffic volume through WIM (Weight-in-motion) measurements is superior to the current method based on estimation of the traffic volume from AADT (Average Annual daily traffic) in prediction of in-situ life. However, so far there are very limited WIM measurements.]]></description>
      <pubDate>Fri, 06 May 2022 17:07:53 GMT</pubDate>
      <guid>https://trid.trb.org/View/1948889</guid>
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