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    <title>Transport Research International Documentation (TRID)</title>
    <link>https://trid.trb.org/</link>
    <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>
    <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>
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      <title>Transport Research International Documentation (TRID)</title>
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      <link>https://trid.trb.org/</link>
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    <item>
      <title>Assessing the Potential of Hydrogenated Styrene Poly(β-Farnesene) Copolymer as a Bio-Based Alternative to Petroleum-Derived Polymers in Asphalt Binder Modification</title>
      <link>https://trid.trb.org/View/2545595</link>
      <description><![CDATA[This study investigated the performance of hydrogenated styrene poly(β-farnesene) (HSF), a bio-based and renewable copolymer, as an asphalt binder modifier, evaluating whether it can achieve properties comparable to a commercial polymer-modified binder. Modified binders were produced by incorporating HSF into 30/45 and 50/70 base binders, then compared to a reference polymer-modified binder (60/85-E). The methodology focused on optimizing HSF incorporation time using rheological parameters and fluorescence microscopy. Following optimization, varying HSF concentrations (6%, 8%, 10%, and 12%) were evaluated through high-temperature (viscosity, high-temperature PG, and MSCR) and intermediate-temperature (frequency sweep, LAS) rheological tests. Results showed that high-temperature PG increased by 2 grades for both 50/70 and 30/45 base binders at 10% HSF. MSCR results at 70 °C revealed that non-recoverable creep compliance (Jnr3.2) was reduced by 98.01% for the 50/70 binder and by 98.75% for the 30/45 binder, both at 12% HSF. Percent recovery (%R3.2) at 70 °C reached 81.73% for the 50/70 binder and 89.28% for the 30/45 binder at 12% HSF. LAS results at 20 °C showed that binders with 12% HSF outperformed 60/85-E in Fatigue Factor by 3.78% (50/70) and 3.61% (30/45) at strain amplitudes of 1.25%–2.5%. To match 60/85-E in all evaluated rheological criteria, the recommended HSF contents were 12% for the 50/70 binder and 10.5% for the 30/45 binder. The HSF copolymer demonstrated technical feasibility as a modifier for asphalt binders, potentially delivering performance comparable to that of SBS copolymers.]]></description>
      <pubDate>Fri, 23 May 2025 15:34:59 GMT</pubDate>
      <guid>https://trid.trb.org/View/2545595</guid>
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    <item>
      <title>Preparation, microstructures and properties of shape memory hydrogenated epoxy resin-modified emulsified asphalt</title>
      <link>https://trid.trb.org/View/2487530</link>
      <description><![CDATA[To improve the mechanical, anti-ageing and shape memory properties of emulsified asphalt, a new shape memory hydrogenated epoxy resin (SMHE) modified emulsified asphalt (SHEA) was developed and its modification mechanism was revealed. Effects of SMHE on microstructures and chemical compositions of evaporated residues (ER) were studied, as well as rheological and shape memory properties of ER were evaluated. The results show that SHEA is successfully prepared by first emulsification and then modification method and the basic pavement properties of SHEA meet current technical specification requirements. Also, SMHE is well dispersed in ER and an interpenetrated structure is formed. When the SMHE dosage is 6%, the thermal stability and microthermal toughness of SHEA are well improved, and the shape recovery ability of molecular chain segments in SMHE is also increased so that deformation resistance and anti-crack of SHEA are improved. Finally, the chemical reactions occur in the curing process of SMHE system in SHEA, and then the SMHE system is physically cross-linked with ER. The strength, toughness and shape memory properties of ER are enhanced by a suitable SMHE dosage of 6%. This study improves various properties of emulsified asphalt, and understands strengthening and toughening mechanisms of SMHE on emulsified asphalt.]]></description>
      <pubDate>Wed, 29 Jan 2025 16:57:25 GMT</pubDate>
      <guid>https://trid.trb.org/View/2487530</guid>
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    <item>
      <title>Hydrogen Embrittlement of Advanced High-Strength Steel S960mc Used in Transport and Vehicle Industry and the Influence of Potassium Thiocyanate During Hydrogenation</title>
      <link>https://trid.trb.org/View/2475777</link>
      <description><![CDATA[Advanced high-strength steels (AHSS) are currently facing a serious challenge from hydrogen embrittlement, which significantly affects their mechanical properties. Problems arise when hydrogen diffuses into the material and accumulates at grain boundaries, inclusions, or microcracks, degrading the material's characteristics. The main objective of the study is to investigate the effects of adding potassium thiocyanate (KSCN) to the sulfuric acid base solution during electrolytic hydrogenation using microalloyed martensitic AHSS grade S960MC. An increase in hydrogen diffusion into the examined material across its full surface is produced by adding thiocyanate ions to the electrolyte. This is the rationale behind the decision to add KSCN to the sulfuric acid base solution. The addition of KSCN to the base environment induced a considerable reduction in fracture strain, and the degradation was attributed to hydrogen buildup at grain boundaries, impurities and microcracks. These steels have an extensive list of applications in the automotive industry and are frequently used in the form of sheets for welding. Therefore, it is important to understand how their mechanical characteristics and behaviour vary in various circumstances, including hydrogen-rich environments.]]></description>
      <pubDate>Thu, 09 Jan 2025 09:51:40 GMT</pubDate>
      <guid>https://trid.trb.org/View/2475777</guid>
    </item>
    <item>
      <title>Emission Performance of Lignin-Derived Cyclic Oxygenates in a Heavy-Duty Diesel Engine</title>
      <link>https://trid.trb.org/View/1825986</link>
      <description><![CDATA[In earlier research, a new class of bio-fuels, so-called cyclic oxygenates, was reported to have a favorable impact on the soot-NOx trade-off experience in diesel engines.  In this paper, the soot-NOx trade-off is compared for two types of cyclic oxygenates.  2-phenyl ethanol has an aromatic and cyclohexane ethanol a saturated or aliphatic ring structure.  Accordingly, the research is focused on the effect of aromaticity on the aforementioned emissions trade-off.  This research is relevant because, starting from lignin, a biomass component with a complex poly-aromatic structure, the production of 2-phenyl ethanol requires less hydrogen and can therefore be produced at lower cost than is the case for cyclohexane ethanol.  The goal of this paper, realized by means of experiments on a modified DAF heavy-duty diesel engine, is to investigate whether or not the (potentially prohibitively) expensive hydrogenation step from 2-phenyl ethanol to cyclohexane ethanol has an added value from an emissions perspective.  The results suggest that this is not the case and hydrogenation therefore does not seem like an interesting additional step in the production process.]]></description>
      <pubDate>Fri, 17 Jun 2022 09:04:22 GMT</pubDate>
      <guid>https://trid.trb.org/View/1825986</guid>
    </item>
    <item>
      <title>Method of treating OT4-1 titanium alloy used in severe climatic conditions before applying chemical coatings</title>
      <link>https://trid.trb.org/View/1885747</link>
      <description><![CDATA[The paper addresses the electrochemical and physical-chemical processes occurring on the surface of OT4-1 titanium alloy at different options of its treatment. The authors identified patterns of changes in the structure and composition of the films formed on the surface of titanium alloy. In addition, the influence of titanium alloy treatment on hydrogenation was investigated.]]></description>
      <pubDate>Thu, 28 Oct 2021 09:19:48 GMT</pubDate>
      <guid>https://trid.trb.org/View/1885747</guid>
    </item>
    <item>
      <title>Effect of Intake Air Hydrogenation Coupled with Intake Air Humidification on Combustion and Emissions of Marine Diesel Engine</title>
      <link>https://trid.trb.org/View/1847567</link>
      <description><![CDATA[The purpose of this study is to investigate the effect of intake air hydrogenation coupled with intake air humidification (IAH) on the combustion and emission of marine diesel engines. A 3D numerical model of four-stroke turbocharged intercooled marine diesel engine was established by using commercial software AVL-Fire. The effects of hydrogen and water injected into the intake port on engine in-cylinder combustion and emission characteristics at 1350 r/min and partial load were studied. The novelty of this study is to combine different hydrogen-fuel ratios and water-fuel ratios, so as to find the optimization method that can reduce NOᵪ and soot emissions and ensure the thermal efficiency of the engine doesn’t decrease. The results show that by injecting a small quantity of hydrogen (the ratio of hydrogen mass to diesel mass is 1.40%) into the intake port of diesel engine as the activator of in-cylinder combustion, the indicated specific fuel consumption (ISFC) of diesel is reduced by 2% and NOᵪ emissions are reduced by 6.7%. However, the intake air hydrogenation will make in-cylinder combustion temperature higher, resulting in the limited effect of NOᵪ emissions reduction, so it is difficult to meet the requirements of emission regulations only by adopting intake air hydrogenation technology. Using the technology of intake air humidification, the low temperature combustion of diesel engine can be realized. When the water-fuel ratio is 1.0, NOᵪ emissions are reduced by 62.2%. Therefore, by coupling technology of intake air hydrogenation and intake air humidification, the method of improving fuel economy and reducing NOᵪ and soot emissions can be explored, so as to optimize engine performance and meet stricter emission regulations.]]></description>
      <pubDate>Mon, 27 Sep 2021 09:59:04 GMT</pubDate>
      <guid>https://trid.trb.org/View/1847567</guid>
    </item>
    <item>
      <title>Bio-based palm oil as an additive for asphalt binder: Chemical characterization and rheological properties</title>
      <link>https://trid.trb.org/View/1840800</link>
      <description><![CDATA[The asphalt industry has been increasingly concerned with solutions to develop new binder materials from sustainable resources that meet environmental and technical criteria. In this context, binder flow modifiers emerged as an alternative to reduce mixing and compaction temperatures, influencing binder performance. This study evaluated the effect of hydrogenated palm oil fat (HPF) and hydrogenated palm fat amide (FAA) - synthesized from palm oil - on the empirical, chemical, and rheological properties of asphalt binder (AB). The HPF and FAA were characterized by Fourier Transform Infrared Spectroscopy (FTIR), ⁱH and ⁱ³C Nuclear Magnetic Resonance NMR, Thermogravimetric Analysis (TGA and DSC). The additives presented good thermal resistance for paving applications and behave as low-viscosity modifiers, improving the workability of the asphalt binders reducing mixing and compaction temperatures. The additives have little effect on the rutting resistance at higher temperatures; however, HPF promoted greater resistance at lower temperatures. After short-term aging it was observed that both HPF and FAA present a rejuvenating effect. The peculiarities of crystalline phases of HPF and FAA, which results in different melting temperatures, was recognized to be responsible for the rheological effects linked with viscoelasticity. The results highlight the potential of using derivatives of palm oil as a binder flow modifier, with technical, economic, and environmental benefits.]]></description>
      <pubDate>Wed, 21 Apr 2021 16:17:49 GMT</pubDate>
      <guid>https://trid.trb.org/View/1840800</guid>
    </item>
    <item>
      <title>Investigation of Combustion and Emission Performance of Hydrogenated Vegetable Oil (HVO) Diesel</title>
      <link>https://trid.trb.org/View/1749071</link>
      <description><![CDATA[Hydrogenated Vegetable Oil (HVO) diesel fuels have the potential to provide a reduced carbon footprint for diesel engines and reduce exhaust emissions. Therefore, it is a strong candidate for transport and diesel powered machines including electricity generators and other off-road machines. In this research, a waste cooking oil derived HVO diesel was investigated for its combustion and emission performance including ignition delays, size segregated particulate number emissions and gaseous emissions. The results were compared to the standard petroleum diesel. A EURO5 emission compliant three litre, direct injection, intercooled IVECO diesel engine equipped with EGR was used which has a maximum power output of 96kW. The engine was equipped with an integrated DOC and DPF aftertreatment system. Both the upstream and downstream of the aftertreatment emissions were measured. The tests were conducted at different RPM and loads at steady state conditions. A DMS500 particle size measurement instrument was used for measuring particles between 5 nm and 1000nm. The engine was instrumented with a number of thermocouples so that the engine conditions were closely monitored. Gaseous emissions were measured using a HORIBA 7100 series gas analyzer. The results showed that HVO reduced particulate numbers significantly at the upstream of the aftertreatment system. The particle number emissions were not much different between HVO and standard diesel at the downstream of the aftertreatment system due to the low particle number concentrations.]]></description>
      <pubDate>Thu, 17 Dec 2020 09:55:29 GMT</pubDate>
      <guid>https://trid.trb.org/View/1749071</guid>
    </item>
    <item>
      <title>Improving Engine Efficiency and Emission Reduction Potential of HVO by Fuel-Specific Engine Calibration in Modern Passenger Car Diesel Applications</title>
      <link>https://trid.trb.org/View/1749058</link>
      <description><![CDATA[The optimization study presented herein is aimed to minimize the fuel consumption and engine-out emissions using commercially available EN15940 compatible HVO (Hydrogenated Vegetable Oil) fuel. The investigations were carried out on FEV’s 3rd generation HECS (High Efficiency Combustion System) multi-cylinder engine (1.6L, 4 Cylinder, Euro 6). Using a global DOE approach, the effects of calibration parameters on efficiency and emissions were obtained and analyzed. This was followed by a global optimization procedure to obtain a dedicated calibration for HVO. The study was aiming for efficiency improvement and it was found that at lower loads, higher fractions of low pressure EGR in combination with lower fuel injection pressures were favorable. At higher loads, a combustion center advancement, increase of injection pressure and reduced pilot injection quantities were possible without exceeding the noise and NOx levels of the baseline Diesel.In a second stage, WLTP cycle simulations were used to quantify the emissions and fuel consumption benefits with HVO, both for a drop-in scenario as well as for a scenario where HVO was operated with a dedicated calibration. Simulation results revealed that HVO as drop-in fuel shows overall an improved thermodynamic efficiency. An increased volumetric fuel consumption of ~ 2 % was found due to the lower density of paraffinic HVO fuel. NOx emissions were comparable to baseline Diesel, whereas, a significant reduction in emissions of CO, HC and PM was observed owing to superior ignition behavior, the absence of aromatics or Sulphur and improved evaporation behavior. For the optimized scenario, maintaining NOx and noise targets similar to baseline Diesel, the engine efficiency with HVO improved by 6.3%, corresponding to a tank-to-wheel CO2 reduction of 9%. This efficiency improvement was high enough to compensate the low density of HVO, resulting in an overall improvement in volumetric fuel consumption by 1.6% w.r.t. Diesel. Furthermore, the emissions of HC, CO and PM were reduced by more than 50%. The lower PM emissions with HVO contributes to an extended DPF regeneration interval, thereby reducing DPF related drawbacks.]]></description>
      <pubDate>Thu, 17 Dec 2020 09:55:29 GMT</pubDate>
      <guid>https://trid.trb.org/View/1749058</guid>
    </item>
    <item>
      <title>Alternative component containing diesel fuel from different waste sources</title>
      <link>https://trid.trb.org/View/1697236</link>
      <description><![CDATA[Mixtures with high fatty acid content are produced during vegetable oil and animal fat purification and paper production. These waste fractions can be converted into alternative fuels through several steps. The co-hydrogenation of waste polypropylene thermal cracked fraction or waste fatty acid mixture with unrefined gas oils is a potential solution for their conversion into hydrocarbons. The co-processing of these three different fractions was not yet investigated in these ratios. So the aim of the research work was to produce high quality diesel fuels and to study the occurring reactions and the interaction among these different compounds. The catalytic conversion of the mixture of unrefined gas oil, waste polypropylene cracked fraction (20 wt %) and waste fatty acid mixture (10, 20 and 30 wt %) was carried out on a commercial sulphided nickel-molybdenum-alumina catalyst. The effect of the feedstock compositions and the process parameters on the quantity and quality of the products was studied. The favourable process conditions to produce high quality diesel fuel blending components were selected (e.g., 10 wt % fatty acid waste, 360 °C temperature, 1.0 h−1 liquid hourly space velocity). The performance properties of this fuel were better than the conventional diesels’, so their usage can be more environmentally friendly and lead to lower pollutant emission.]]></description>
      <pubDate>Thu, 20 Aug 2020 14:03:43 GMT</pubDate>
      <guid>https://trid.trb.org/View/1697236</guid>
    </item>
    <item>
      <title>Dynamic Simulation Software for Prediction of Hydrogen Temperature and Pressure during Fueling Process</title>
      <link>https://trid.trb.org/View/1561595</link>
      <description><![CDATA[In this study, in order to relax the pre-cooling regulations at hydrogen fueling stations, we develop a software algorithm to simulate an actual hydrogen fueling process to Fuel Cell Vehicle (FCV) tanks. The simulation model in the software consists of the same filling equipment found at an actual hydrogen fueling station. Additionally, the same supply conditions (pre-cooling temperature, pressure and mass flow rate) as at a hydrogen fueling station were set to the simulation model. Based on the supply conditions, the software simulates the temperature and pressure of hydrogen in each part of filling equipment. In order to verify the accuracy of the software, we compare the temperature and pressure simulated at each stage of the filling process with experimental data. We show that by using the software it is possible to accurately calculate the hydrogen temperature and pressure at each point during the fueling process. Subsequently, we carry out a sensitive analysis of the filling equipment with large heat capacity, the initial temperature in the FCV tank and the pre-cooling temperature, and then propose an effective step to relax the regulation regarding the pre-cooling temperature.         KeywordsFilling equipment, Hydrogen fueling station, Hydrogen temperature, Hydrogen pressure, Pre-cooling temperature       ]]></description>
      <pubDate>Thu, 30 Jan 2020 11:10:14 GMT</pubDate>
      <guid>https://trid.trb.org/View/1561595</guid>
    </item>
    <item>
      <title>Catalytic Process for the Conversion of Coal-derived Syngas to Ethanol</title>
      <link>https://trid.trb.org/View/1265497</link>
      <description><![CDATA[The catalytic conversion of coal-derived syngas to C2+ alcohols and oxygenates has attracted great attention due to their potential as chemical intermediates and fuel components. This is particularly true of ethanol, which can serve as a transportation fuel blending agent, as well as a hydrogen carrier. A thermodynamic analysis of carbon monoxide (CO) hydrogenation to ethanol that does not allow for byproducts such as methane or methanol shows that the reaction: 2 CO + 4 H2 (yields) C2H5OH + H2O is thermodynamically favorable at conditions of practical interest (for example, 30 bar, (approx)< 250 C). However, when methane is included in the equilibrium analysis, no ethanol is formed at any conditions even approximating those that would be industrially practical. This means that undesired products (primarily methane and/or carbon dioxide (CO2)) must be kinetically limited. This is the job of a catalyst. The mechanism of CO hydrogenation leading to ethanol is complex. The key step is the formation of the initial C-C bond. Catalysts that are selective for EtOH can be divided into four classes: (1) rhodium (Rh)-based catalysts, (2) promoted copper (Cu) catalysts, (3) modified Fischer-Tropsch catalysts, or (4) Mo-sulfides and phosphides. This project focuses on Rh- and Cu-based catalysts. The logic was that Rh-based catalysts are clearly the most selective for EtOH (but these catalysts can be costly), and Cu-based catalysts appear to be the most selective of the non-Rh catalysts (and are less costly).]]></description>
      <pubDate>Mon, 28 Oct 2013 09:47:02 GMT</pubDate>
      <guid>https://trid.trb.org/View/1265497</guid>
    </item>
    <item>
      <title>Production of Renewable Diesel Fuel</title>
      <link>https://trid.trb.org/View/1214446</link>
      <description><![CDATA[Vegetable oils have been investigated as a way to provide a renewable source for diesel fuel. A successful approach to using vegetable oils in diesel engines has been transesterification of the oils with simple alcohols to produce mono-alkyl esters, or biodiesel. A recent development in the area of alternative diesel fuels is a fuel produced from vegetable oils and animal fats using specially modified hydrogenation processes in a conventional petroleum processing facility. This fuel is usually called renewable diesel. This project has focused on developing an understanding of the processes involved with renewable diesel production from a variety of bio-based feedstocks. The project has determined that Raney nickel is an effective catalyst for hydrogenation and deoxygenation of fatty acids, which is a key step in the production of renewable diesel. The authors have also determined that deoxygenation can take place in a hydrogen-lean environment so that fatty acids can be deoxygenated without having to be completely hydrogenated. This is an important observation because hydrogenation affects the fuel’s cold flow properties by increasing its melting point.  Decarboxylation without full hydrogenation continues to be explored as a way to provide renewable diesel with superior low temperature properties.]]></description>
      <pubDate>Fri, 21 Sep 2012 15:10:29 GMT</pubDate>
      <guid>https://trid.trb.org/View/1214446</guid>
    </item>
    <item>
      <title>USE OF ASPHALT MEMBRANES TO REDUCE EXPANSION IN CERTAIN TYPES OF EXPANSIVE SOILS</title>
      <link>https://trid.trb.org/View/121892</link>
      <description><![CDATA[NINETEEN EXPERIMENTAL TEST SECTIONS WERE BUILT IN AN INTERSTATE HIGHWAY SECTION TO DETERMINE THE SUCCESS OF A MEMBRANE CONSTRUCTED FROM 50-60 PENETRATION CATALYTICALLY BLOWN ASPHALT CEMENT PLACED ON MANCOS SHALE SOIL TO PREVENT INTRUSION OF MOISTURE INTO THE SUBGRADE AND KEEP THE EXPANSIVE CLAYS IN EQUILIBRIUM. THE MEMBRANE MERELY NEEDS TO ACT AS A LID OR ROOF TO PREVENT MOSITURE FROM ENTERING OR ESCAPING AT THE SURFACE. THE MANCOS SHALE IN SITU IS A HIGHLY CONSOLIDATED MATERIAL WITH A DRY DENSITY OF 130-150 LBS/CU FT. THIS EXPERIMENT IS INTENDED TO BE A FIVE YEAR STUDY. THIS REPORT IS MADE AFTER TWO AND ONE-HALF YEARS OF INSTALLATION. CONCLUSIONS REACHED ARE: (1) SOME MECHANISM CAUSES FREE WATER TO BE ACCUMULATED OR GENERATED IN THE GRANULAR MATERIALS UNDER ASPHALT PAVEMENTS, EVEN IN DESERT AREAS WHERE THERE IS NO WATER TABLE, (2) AS USED, HYDRATED LIME DOES NOT EFFECTIVELY PREVENT SWELLING OF MANCOS SHALE, (3) AIR PERMEABLE GRANULAR SUBBASE AND BASES ARE APPARENTLY RESPONSIBLE FOR HYDROGENESIS, SUGGESTING THAT DENSE GRADED BITUMINOUS BASES MAY ACT AS VAPOR BARRIERS WHEN PLACED DIRECTLY ON THE SUBGRADE, (4) ASPHALT MEMBRANES CONSTRUCTED FROM CATALYTICALLY BLOWN ASPHALTS CAN BE EFFECTIVE IN PREVENTING MOISTURE FROM INTRUDING INTO SUBGRADE SOILS, AND (5) WITH PROPER ENGINEERING CONTROL, IT SEEMS THAT PAVEMENT STRUCTURAL SECTIONS MAY BE THINNED DOWN IF THE SUBGRADE MOISTURE CAN BE KEPT STATIC.]]></description>
      <pubDate>Sun, 15 Aug 2004 02:41:14 GMT</pubDate>
      <guid>https://trid.trb.org/View/121892</guid>
    </item>
    <item>
      <title>ASPHALT MEMBRANES AND EXPANSIVE SOILS</title>
      <link>https://trid.trb.org/View/118354</link>
      <description><![CDATA[EXPANSIVE SOIL PROBLEMS IN HIGHWAY CONSTRUCTION IN COLORADO ARE DESCRIBED. COLORADO HAS LARGE AREAS WHERE EXPANSIVE SOILS PREDOMINATE INCLUDING: (1) SECTIONS WHERE MANCOS SHALE AND PIERRE SHALE ARE PREVALENT, (2) A LARGE BAND OF CLAYS NAMED THE LARAMIE FORMATION, (3) A DENVER FORMATION, AND (4) CREEK VALLEYS CONTAINING COMPARATIVELY RECENT DEPOSITS OF PLASTIC, FINE-GRAIN MATERIALS. DISTRESS FROM SWELLING SOILS IS EVIDENT IN MANY COSTLY WAYS AND IS PARTICULARLY OBVIOUS IN PORTLAND CEMENT CONCRETE PAVING. RESEARCH FOR THE INTERSTATE 70 CONSTRUCTION PROJECT INDICATED THAT ASPHALT MEMBRANE IS ONE OF THE BETTER SOLUTIONS TO EXPANSION PROBLEMS IN MANCOS SHALE CUTS. INVESTIGATION HAS SHOWN THAT 2 1/2 YEARS AFTER PLACEMENT THE ASPHALT MEMBRANE ON THE PROJECT IS IN EXCELLENT CONDITION. IT IS STILL PLIABLE, UNIFORM IN CHARACTER, AND SHOWS NO SIGNS OF MOVEMENT OR CRACKING. TENTATIVE CONCLUSIONS INDICATE THAT SOME MECHANISM IS AT WORK WHICH CAUSES FREE WATER TO BE ACCUMULATED OR GENERATED IN THE GRANULAR MATERIALS UNDER ASPHALT PAVEMENTS, EVEN IN DESERT AREAS WHERE THERE IS NO WATER TABLE. AIR PERMEABLE GRANULAR SUBBASE AND BASES ARE APPARENTLY RESPONSIBLE FOR HYDROGENESIS. THIS SUGGESTS THAT DENSE-GRADED ASPHALT BASES MAY ACT AS VAPOR BARRIERS WHEN PLACED DIRECTLY ON THE SUBGRADE. IT HAS BEEN FOUND THAT WATER WAS NOT ACCUMULATED UNDER ASPHALT PAVEMENTS WHERE ASPHALT STABILIZED BASE WAS PLACED DIRECTLY ON THE SUBGRADE. SPECIFICATIONS FOR CATALYTICALLY-BLOWN ASPHALT ARE PRESENTED. THE PURPOSE OF THE MEMBRANE IS TO PREVENT INTRUSION OF MOISTURE INTO THE SUBGRADE AND TO KEEP THE EXPANSIVE CLAYS IN EQUILIBRIUM.]]></description>
      <pubDate>Sun, 15 Aug 2004 01:53:22 GMT</pubDate>
      <guid>https://trid.trb.org/View/118354</guid>
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