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    <title>Research in Progress (RIP)</title>
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    <atom:link href="https://rip.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>
    <image>
      <title>Research in Progress (RIP)</title>
      <url>https://rip.trb.org/Images/PageHeader-wTitle-RIP.jpg</url>
      <link>https://rip.trb.org/</link>
    </image>
    <item>
      <title>Constructability of Concrete Materials Infused With Silica-Rich Biochar For Bridge Applications</title>
      <link>https://rip.trb.org/View/2633322</link>
      <description><![CDATA[Biochar additions to concrete binder have shown great promise for enhancing the early-age performance of material for bridge applications, including its hardening rate and strength development. Biochar is a waste product of the pyrolysis of organic material (wood, rice husks, corn husks, manure, or other agricultural waste products). Depending on the source, biochar is highly porous, with specific surface areas of ~300 m2/g, porosities up to 50 %, and pore sizes down to several nanometers. With high ash content biochar is pozzolanically active. It also may promote self-healing of the material via secondary mineralization involving dissolved alkali earths such as calcium. In cement, milled fast-pyrolysis char has been used at up to 32 % replacement by mass with improved compressive strengths due to its role as an internal curing source and nucleating agent for calcium silicate hydrate gel (C-S-H). The objective is to advance the TRL of biochar-infused concrete materials for implementation in bridge construction and repair. The approach to achieve that objective will be to determine the robustness of the material by investigating a wider range of w/c ratios, biochar dosages, and curing conditions for their effects on several important concrete properties, including the initial and final setting times, compressive strengths at 7 d, 28 d, and 90 d, and the secondary mineral formation extent at 7 d, 28 d, and 90 d.]]></description>
      <pubDate>Tue, 02 Dec 2025 16:36:45 GMT</pubDate>
      <guid>https://rip.trb.org/View/2633322</guid>
    </item>
    <item>
      <title>Development of Novel and Affordable Chip Seals for Maintenance and Pavement Preservation using Sustainable Materials</title>
      <link>https://rip.trb.org/View/2480349</link>
      <description><![CDATA[Pavement infrastructure is vital for quality of life, the economy, and societal prosperity. With rising demands and limited resources, maintaining and preserving this infrastructure is increasingly crucial. Severe weather events heighten these needs. Chip seals, commonly used in Region 6 and nationwide, are essential for preserving pavements. They seal against water intrusion and improve safety by enhancing friction through better macro- and micro-texture. For effective chip sealing, high-quality cover aggregate and binder are essential. For projects involving High Friction Surface Courses, ODOT and other state DOTs in Region 6 currently use Bauxite as the cover aggregate. Although effective, use of this imported material increases cost and reduces affordability. Recent developments in pavement surfaces with high reflectivity, make engineered chip sealing a suitable tool for addressing the heat island effects, particularly in urban areas. 
To this end, the research team will develop an innovative chip sealing technology and test it in the field using local and sustainable materials. The team seeks to use Tar Creek mine chat from Oklahoma and silica sand from Texas as cover aggregates and a specialized asphalt binder with high reflectivity to develop this innovative and affordable chip sealing technology. This specialized binder is transparent in nature and can dissipate heat faster than conventional black asphalt binder. Moreover, chat materials are very hard and angular, making them (i.e., washed chat with desired gradation) a suitable cover aggregate. Similarly, silica sands, being mined in several quarries in Texas, possess cover aggregate qualities. In the proposed study, both of these cover aggregates will be used as a replacement of Bauxite. 
Conventional pavements absorb and retain heat, contributing to Urban Heat Islands (UHIs), particularly in urban environments where temperatures are significantly higher than in rural areas. Chip sealing with high reflectivity will not only enhance pavement life and functionality (i.e., adequate friction) but also reduce UHIs and help combat the effects of extreme weather. The specific objectives of this proposed project are: (1) develop chip sealing with Tar Creek mine chat and silica sand and the specialized asphalt binder and evaluate laboratory performance; (2) use the developed chip sealings in one of the maintenance projects and evaluate field performance; (3) investigate the economic and environmental impacts related to extreme heat on socio-demographic populations and develop correlations between pavement albedo, heat index, and network centrality measures.
The following tasks will be pursued in this study. Task 1: Collection of necessary materials; Task 2: Evaluation of binder properties; Task 3: Determination of cover aggregates properties; Task 4: Evaluation of compatibility between binder and aggregates; Task 5: Development of chip seal mixes; Task 6: Evaluation of laboratory performance; Task 7: Evaluation of field performance; Task 8: Assessment of socio-economic impact, and Task 9: Submission of quarterly progress reports and a final report.
]]></description>
      <pubDate>Wed, 01 Jan 2025 15:56:19 GMT</pubDate>
      <guid>https://rip.trb.org/View/2480349</guid>
    </item>
    <item>
      <title>A framework to boost reactivity and consistency of agricultural residual ashes as a supplementary cementitious material</title>
      <link>https://rip.trb.org/View/2442008</link>
      <description><![CDATA[Project Description: Decarbonizing transportation infrastructure is one of the primary goals of the US DOT. This project aims at decarbonizing transportation infrastructure by reducing the cement usage during its construction and maintenance. For this purpose, agricultural residues (corn stover and wheat straw) with reactive silica are considered as an excellent replacement due to their wide availability in the US and reduced environmental footprint. This is because the combustion temperature for agricultural residues is significantly lower compared to the temperature required for cement clinker production. However, agricultural residues need to be pre-treated properly to be used as an effective source of replacement for cement. Although previous studies have showed that pre-treatment improves the reactivity, a framework for obtaining consistent quality of residual ashes is still missing. In this project the primary goal is to achieve such a framework that can be used to boost the reactivity and consistency of residual ashes. 

US DOT Priorities: This project supports one of the primary strategic goals of USDOT (i.e. climate and sustainability). The primary thrust area lies in preserving the environment by producing environmentally responsible construction material.  Construction and maintenance of transportation infrastructure is one of the major contributors to the release of global warming gases (especially CO2) due to the production of cement. Therefore, replacement of cement with agricultural residual ashes which has reduced environmental footprint will lower the production of cement. This project will provide a framework to boost the production of reactive and consistent quality of sustainable construction materials from agricultural residues thereby, preserving the environment.

Outputs: Major challenge of using agricultural residues as an alternative SCM is the lack of consistent quality due to change in source. This project is devised to address the above challenge. Following will be the output of the project: (1) Scientific understanding towards pre-treatment methods and the mechanism behind removal of impurities from the agricultural residues. (2) A pre-treatment framework based on empirical model that can be used to obtain consistent quality of the agriculture residual ashes. (3) Scientific understanding towards the reactivity and hydration mechanism on the usage of pre-treated and calcined agricultural ashes. (4) A life cycle analysis model that can be used to assess the cost and impact on choosing a particular pre-treatment method.

Outcomes/Impacts: This project will have the following outcomes: (1) This project will enable and enhance sustainable use of agricultural residues as an alternative SCM. By doing so, the impact of transportation infrastructure on the climate can be reduced. (2) 	Life cycle framework that can be used to choose between different pre-treatment methods based on the cost and environmental impact.

The research finding will be given through publications, conference proceedings, seminar, and workshop presentations, etc. With the help from local government and DOT, a pioneer project will be found for the field application of this new material, which can be used as a testing bed for long-term monitoring and data collection for its life cycle analysis.
]]></description>
      <pubDate>Thu, 17 Oct 2024 11:11:54 GMT</pubDate>
      <guid>https://rip.trb.org/View/2442008</guid>
    </item>
    <item>
      <title>Advancing Sustainable Transportation with Innovative Near-Zero Carbon Emission Cement Derived from 100% Industrial Byproducts</title>
      <link>https://rip.trb.org/View/2441837</link>
      <description><![CDATA[Project Description: 
The proposed project aims to develop a near-zero carbon emission cement made entirely from 100% industrial by-products. This initiative supports the Department of Transportation's goals by promoting sustainable construction practices that significantly reduce carbon emissions associated with infrastructure projects. By addressing the environmental impact of traditional Portland cement, which is a major contributor to greenhouse gas emissions, this project aligns with the Environmental Mitigation thrust area of the Environmentally Responsible Transportation Center for Communities of Concern (ERTC3). The primary objective is to create low-carbon cement formulations that reduce the carbon footprint of cement production, thereby supporting the sustainable development of transportation infrastructure.

US DOT Priorities:
The project aligns with USDOT priorities, notably in “Preserving the Environment” and “Climate and Sustainability.” By reducing carbon emissions from cement production, which is a major contributor to the transportation sector's overall carbon footprint, the project directly contributes to climate change mitigation efforts. Furthermore, by emphasizing sustainable materials derived from industrial by-products, it promotes environmentally responsible practices within the construction industry, supporting a greener economy and infrastructure.

Outputs:
The project is expected to produce a comprehensive database of industrial by-products suitable for cement production, optimized low-carbon cement formulations, and preliminary performance data from laboratory testing. Additionally, reports will be generated detailing the mechanical and environmental properties of the new materials, along with findings from the life cycle assessment to quantify the sustainability benefits.

Outcomes/Impacts:
The anticipated outcomes include a significant transformation in the transportation infrastructure landscape by promoting the use of low-carbon cement. This shift is expected to lead to reduced greenhouse gas emissions, enhanced sustainability of infrastructure, and potentially lower long-term costs due to their durability and lower maintenance needs. The project contributes to the regulatory frameworks focused on environmental and public health by providing a sustainable alternative to conventional materials. The successful adoption of these low-carbon cements can inform policy decisions and standards, leading to broader industry acceptance and practice changes aimed at a more sustainable transportation system. Ultimately, the project also emphasizes diversity and equity by involving graduate students from underrepresented backgrounds in the research process, thereby fostering inclusive practices in STEM fields.
]]></description>
      <pubDate>Thu, 17 Oct 2024 10:09:05 GMT</pubDate>
      <guid>https://rip.trb.org/View/2441837</guid>
    </item>
    <item>
      <title>Development Of Concrete Materials Infused With Biochar For Bridge Applications </title>
      <link>https://rip.trb.org/View/2404268</link>
      <description><![CDATA[Concrete’s high carbon footprint is an ongoing concern for infrastructure sustainability and environmental stewardship. A primary strategy in the quest for low-carbon concrete is to replace a portion of the portland cement with pozzolanic wastes generated by other industrial or societal activities. Biochar is a product of biowaste combustion. Some sources are pozzolanically active and can therefore enhance concrete’s later-age mechanical and durability properties of concrete. In addition, biochar efficiently absorbs atmospheric CO2, a first step in CO2 sequestration in concrete by carbonate mineralization. But despite this potential multifunctional nature of biochar, its assured use in concrete for bridge elements will not be realized until its influences on freshstate workability and early strength development are better understood and controlled. New materials enabled by this research will significantly decrease anthropogenic greenhouse gases (GHGs), increase the resilience and sustainability of civilian infrastructure, and provide a sink for biowaste materials that otherwise would be deposited in landfills. ]]></description>
      <pubDate>Sun, 21 Jul 2024 15:01:45 GMT</pubDate>
      <guid>https://rip.trb.org/View/2404268</guid>
    </item>
    <item>
      <title>Evaluation of Performance of Coal Ash in Florida Structural Concrete.</title>
      <link>https://rip.trb.org/View/2384733</link>
      <description><![CDATA[This research will review the existing literature on the procedures needed to produce concrete-quality pozzolanic materials from coal ash, based on whether the precursor materials were from landfilled, ponded, or as-collected coal ash sources. This will include the types of coal ash present and their chemical and mineralogical compositions. Any components of coal ash that could negatively affect the reactivity or long-term durability of concrete shall be identified along with procedures to remove them or mitigate their effects. Any components of coal ash that are leachable from concrete incorporating that ash, and that are known to be hazardous to health or the environment, shall be identified along with identified procedures or methods to remove or mitigate their effects.]]></description>
      <pubDate>Mon, 03 Jun 2024 14:19:48 GMT</pubDate>
      <guid>https://rip.trb.org/View/2384733</guid>
    </item>
    <item>
      <title>Permeability of Granular Materials, and Blended Salvaged Granular Materials</title>
      <link>https://rip.trb.org/View/2379666</link>
      <description><![CDATA[The Department does not currently have a clear understanding of how drainable a granular base material needs to be in a roadway section to optimize long-term pavement performance.  Furthermore, the Department does not fully understand how permeable the virgin granular materials used on projects are with our dense-graded material granular base sections.  There is also a lack of understanding of how permeability is affected by adding salvaged granular material once it has been blended into the virgin base course, gravel cushion, or salvaged granular material. Based on the previous research project SD97-03 completed by the Department, our current practice is to blend Recycled Asphalt Pavement (RAP) into virgin granular material with a blend ratio of no more than 50% RAP. Recycled Concrete Aggregate (RCA) can be used in lieu of virgin aggregates if it meets the specified gradation for the aggregate for which it replaces. The expectation with this practice is that both materials (virgin and blended) will have similar drainage characteristics.  With a better understanding of the drainage characteristics of RAP produced by various methods (process-in-place, cold-milling, micro-milling, and crushing) and RCA, the Department could better optimize the use of reclaimed materials in roadway sections and be assured that proper drainage has been achieved in the design in the most cost-effective manner possible.  Currently, that clear understanding is missing from our granular base material designs and this research opportunity could provide that clarity and assure that the best use of tax-payer funds is being utilized.]]></description>
      <pubDate>Tue, 14 May 2024 14:44:48 GMT</pubDate>
      <guid>https://rip.trb.org/View/2379666</guid>
    </item>
    <item>
      <title>Replacing Fossil Fuel-Based Asphalt Binder with Sustainable Lignin Binder 
from Wastes
</title>
      <link>https://rip.trb.org/View/2291282</link>
      <description><![CDATA[With an increased focus on renewable energy nationally, the availability of fossil fuel-based asphalt binders will become an issue. Consequently, asphalt materials costs are expected to rise significantly in the future. Also, fossil fuel-based binders are detrimental to the environment. In this study, the multi-institutional research team will use an agricultural waste-based binder to partially replace fossil fuel-based binders. The PIs have recently found that a 6% replacement of fossil fuel-derived binder with a sustainably sourced binder can improve the high-temperature performance grade, long-term aging index, and resistance to rutting and cracking performance. In that study, lignin samples from local Louisiana sources, specifically lignin from a paper mill, sugar cane bagasse, and rice husks (hulls), were tested in asphalt binders up to a 6% replacement. However, that study did not include UV oxidation, low-temperature flexibility, and moisture sensitivity that are important to pavement performance. The goal of this study is to evaluate the effectiveness of using more than 6% lignin from different sources in asphalt binders as a sustainable and renewable paving material to partially replace (up to 30%) fossil fuel-based binders. Also, the performance of asphalt mixes with lignin-based binder and Reclaimed Asphalt Pavement (RAP) will be investigated using a balanced mix design (BMD) approach. 
The proposed research will consist of six tasks split between the partner institutions. Task 1 (LTU lead) will examine the production of lignin from local waste sources for replacement of traditional asphalt binder. Task 2 (LTU lead) will involve incorporation of the derived lignin into binder blends at levels ranging from 8% to 35%. Task 3 (LTU lead) includes the evaluation of the rheological and chemical properties of binder blends. Task 4 (OU and LSU co-lead) will consist of the collection of aggregates and preparation of control mixes. The OU team will focus on developing BMD using the lignin binder blend and RAP. The LSU team will focus on the advanced characterization of mix fatigue and moisture-induced damage performance. Task 5 (OU lead) will include the evaluation of the performance of asphalt mixes with lignin binder blend and RAP relative to rutting, cracking, and moisture-induced damage. Task 6 (LSU lead) will include advanced laboratory characterization of asphalt mixes with the lignin binder blend to measure cracking behavior and moisture susceptibility.
]]></description>
      <pubDate>Wed, 15 Nov 2023 17:17:02 GMT</pubDate>
      <guid>https://rip.trb.org/View/2291282</guid>
    </item>
    <item>
      <title>Evaluation of Bio-Inspired Water Treatment Plant Sludge Materials Through Mycelium</title>
      <link>https://rip.trb.org/View/2266623</link>
      <description><![CDATA[Researchers are focusing on developing innovative, sustainable materials characterized by low energy consumption and versatility. Mycelium-based materials, an emerging topic in sustainable construction, offer promise due to mycelium's renewable properties and its ability to break down organic matter, potentially serving as a building block for eco-friendly construction materials. The objective of this research is to use water treatment plant (WTP) sludge as a substrate for mycelium to develop a bio-inspired sustainable construction material for transportation infrastructure.

Mycelium is a root-like structure of a fungus consisting of a mass of branching, thread-like hyphae. Mycelium fibrous network structure can bind material together by growing into its substrate and provide tensile strength. A WTP produces large quantities of sludge as a result of treatment processes of raw water such as flocculation, filtration, and coagulation. Instead of shipping this non-hazardous waste sludge to commercial landfills, it can be used as a substrate for mycelium to grow sustainable, renewable construction materials.

Various substrate mix designs using WTP and mycelium will be prepared to test and optimize mechanical properties of the designs, including compressive and tensile strength, and others. Microstructure of the mix designs and development of mechanical properties will also be evaluated over time. Leachate tests will be performed to assess the environmental impacts, if any, of the developed materials. Water erosion and landslide resistance of the developed materials will also be evaluated to determine their suitability for use as a construction material in the transportation infrastructure.

To achieve its goals, the research project will employ graduate and undergraduate students in experiments and plans to disseminate findings through journal papers and reports. This collaborative approach and knowledge sharing are essential components of the research's technology transfer plan, contributing to the broader understanding and adoption of eco-friendly construction materials.
]]></description>
      <pubDate>Sat, 14 Oct 2023 07:18:59 GMT</pubDate>
      <guid>https://rip.trb.org/View/2266623</guid>
    </item>
    <item>
      <title>Developing Sustainable Waste Plastics Asphalt Roadway Construction</title>
      <link>https://rip.trb.org/View/2263563</link>
      <description><![CDATA[This proposed topic is in line with the Environmentally Responsible Transportation Center for Communities of Concern (ERTC3) thrust area of “Environmental Justice – assessment and mitigation of harmful environmental effects on vulnerable communities”. The results will lead to effective utilization of waste plastics in hot/warm mix asphalt.  A design method would facilitate the use of waste plastics and safeguard the performance of roadway.]]></description>
      <pubDate>Fri, 06 Oct 2023 18:56:13 GMT</pubDate>
      <guid>https://rip.trb.org/View/2263563</guid>
    </item>
    <item>
      <title>Bio-waste Materials as Supplementary Cementitious Materials for Coastal Concrete Applications</title>
      <link>https://rip.trb.org/View/2259932</link>
      <description><![CDATA[In the U.S., coal fly ash is by far the most used supplementary cementitious material (SCM). Despite being used every day, the supply of coal fly ash in the U.S. has become a matter of concern because we are blending different coals that produce less amount of Class F fly ash – a type of fly ash that is preferred by the concrete industry. Therefore, it is critical to identify and evaluate alternative SCMs that can offer concrete equivalent or better strength and durability characteristics to Class F fly ash. This is especially critical in coastal areas where concrete durability remains a challenge. One area that is being overlooked by the concrete industry for alternative SCMs is bio-waste materials, which include agricultural waste, eggshells, burnt oyster shell, etc. In this project, the feasibility of using two bio-waste materials, sugarcane bagasse ashes and ground waste eggshells, as alternative SCMs in portland cement concrete for coastal applications is investigated. ]]></description>
      <pubDate>Tue, 03 Oct 2023 15:07:40 GMT</pubDate>
      <guid>https://rip.trb.org/View/2259932</guid>
    </item>
    <item>
      <title>Synthesis of Information Related to Highway Practices. Topic 55-05. Use and Availability of Supplementary Cementitious Materials for Concrete</title>
      <link>https://rip.trb.org/View/2209729</link>
      <description><![CDATA[It is common practice to use supplementary cementitious materials (SCMs) in the production of concrete.  The use of SCMs as a partial replacement for cement results in more durable, higher performing concrete, lower energy consumption, and reduced green gas emissions.  The most common SCMs are industrial byproducts such as fly ash, ground granulated blast-furnace slag (slag cement), and silica fume. There are also some natural pozzolans being used in the concrete industry such as calcined shale, calcined clay, and metakaolin. There are many beneficial effects of using SCMs for both fresh and hardened concretes, including enhanced workability, reduction in bleeding, reduction in the heat of hydration, strength gain with time, and reduced permeability and improved resistance to chemical distress.  The level of improvement achieved differs among the SCMs. Although fly ash is the most commonly used SCM, others are also being used due to a shortage of fly ash.  

The objective of this synthesis is to document state department of transportation (DOT) practices for using SCMs in concrete. ]]></description>
      <pubDate>Mon, 10 Jul 2023 21:12:39 GMT</pubDate>
      <guid>https://rip.trb.org/View/2209729</guid>
    </item>
    <item>
      <title>Nanomodified Cementitious Composites Incorporating Waste Polymer Microfibers for Durable and Environmentally Friendly Infrastructure </title>
      <link>https://rip.trb.org/View/2023816</link>
      <description><![CDATA[Used face masks resulting from the COVID-19 pandemic are forming a new waste stream that poses a considerable environmental risk to the ecosystem if not properly disposed of. Typically, single-use medical masks are made of polypropylene (PP) or polyester fabric, and they are extremely difficult to be naturally degraded. Another similar waste stream is induced by the vast quantity of waste textiles (e.g., waste clothes), which also mainly contain polypropylene or polyester products. Based on the published research of PP fiber-reinforced cementitious composites, the research team proposes to convert the waste medical masks/textiles into cost-effective PP microfibers that can replace the more expensive commercial PP microfibers used by the concrete industry. To this end, this proposed project will build on the team’s previous research experience, which relates to fiber-reinforced cementitious composites and nanotechnology for concrete, and then develop nanomodified microfiber-reinforced cementitious composites (nm-FRCCs) featuring comparable engineering performance with cementitious composites reinforced by commercial polymer microfibers. At the first stage of this work, the laboratory study aims to do the following: (1) Convert waste masks/textiles to microfibers that feature comparable diameter with commercial concrete industry-adoptive PP fibers, and (2) Fabricate nmFRCCs that feature promising mechanical properties and durability performance. Specifically, nanomaterials (graphene oxide and nanoclay) will be introduced to modify the waste mask/textile fibers (WM/TFs) and thus enhance the interfacial transition zone (ITZ) between the fibers and the cementitious matrix. To further investigate the influence of nanomaterials on the engineering performance of nmFRCCs, the scanning electron microscopy (SEM), Energy-dispersive X-ray spectroscopy (EDX), Thermogravimetry analysis (TGA), Differential Scanning Calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), Electron probe microanalysis (EPMA), and X-ray diffraction analysis (XRD) will be employed to illustrate the hydration mechanisms (especially the interfacial hydration process) of nmFRCCs and to shed light on how the constituent materials affect the mechanical strengths and durability performance of the nmFRCCs.]]></description>
      <pubDate>Fri, 16 Sep 2022 11:11:51 GMT</pubDate>
      <guid>https://rip.trb.org/View/2023816</guid>
    </item>
    <item>
      <title>Management of Mud and DGS during Highway Construction and Maintenance</title>
      <link>https://rip.trb.org/View/2003585</link>
      <description><![CDATA[One of the most common issues with highway construction is mud sticking to vehicle tires and being tracked onto public roads (herein referred to as “trackout”). This can result in dangerous, slippery conditions on roads travelled by the public, and in addition drivers are not happy about the prospect of mud being flung onto their vehicles. By many accounts, trackout accounts for the majority of complaints and violations for construction companies. To prevent trackout, the conventional approach is to install a rock driveway at the site exit. This is intended to provide sufficient roughness to dislodge attached mud prior to the vehicle exiting onto a public road. There are a number of manufacturers of devices which work on the same principle – to vibrate the tire sufficiently to dislodge the mud. However, there has been virtually no testing of any system for preventing mud trackout, nor any information on where trackout is most likely. This project is intended to determine the force necessary to dislodge mud from tires, with an evaluation of the effects of soil particle size distribution and moisture conditions. In addition, testing of the rock driveway and at least two additional commercial systems will be conducted at full scale. The results should provide guidance on the best mud removal approaches and systems and conditions where these are most likely needed.

Diamond grinding slurry (DGS) is a byproduct created by concrete pavement maintenance operations. Disposal of DGS is currently regulated based on minimal information. Currently, the North Carolina Department of Transportation (NCDOT) can land apply the material as a soil amendment, dispose of the material at a commercial facility, or use a mechanical press plate system to separate the water from the solids in order to reuse the water. Land application is possible, but the land required to safely apply the material is not always available. The other two methods are expensive as several million gallons for DGS are produced each year in North Carolina. Sediment basins used in sediment and erosion control have been effective at removing sediment from runoff. The proposed project is designed to determine if the same settling technology can be applied to DGS material to separate concrete residues from water in a cost effective basin. The water can then be reused in diamond grinding operations. Flocculating agents, such as polyacrylamide (PAM), will also be tested to see if they enhance separation of concrete particles. The results should provide improved guidance on DGS processing as well as the feasibility of a sediment basin compared to current disposal methods.]]></description>
      <pubDate>Fri, 05 Aug 2022 08:19:35 GMT</pubDate>
      <guid>https://rip.trb.org/View/2003585</guid>
    </item>
    <item>
      <title>Environmental Friendly Applications of Ground Tire Rubber (GTR) In Producing Concrete</title>
      <link>https://rip.trb.org/View/1948638</link>
      <description><![CDATA[Over 280 million waste tires are generated in the United States on an annual basis. A majority of 3.3 million waste tires generated in Arkansas are either dumped in the landfill or burnt for generating energy; neither of them is a sustainable approach. Handling and disposal of these waste tires is a huge challenge for solid waste management departments of agencies such as the Arkansas Department of Environmental Quality (ADEQ). However, these waste tires can be recycled and utilized as new construction materials to produce durable concrete as the rubber possess favorable engineering properties. The main objective of this study is to assess the feasibility of the use of GTR in preparing durable paving concrete. Specifically, the current study has the following objectives: (a) collect appropriate GTR samples for paving concrete, (b) evaluate fresh and engineering properties of GTR-modified concrete, (c) evaluate the long-term durability properties of GTR-modified concrete, (d) determine the optimum dosage of GTR based on fresh, mechanical, and durability properties tests results, and (e) develop guidelines in implementing GTR-modified concrete.
The aforementioned goals of this project will be accomplished through a comprehensive review of available literature and extensive laboratory testing of selected GTR-modified concrete samples. The following two different sizes of GTR will be studied: (i) Mesh #40 as a replacement of sand; and (ii) Mesh #200 as a replacement of the supplemental cementitious material (SCM). Another variation will be a combination of replacements of both sand and SCM with their optimum dosages. To this end, properties (e.g., workability, air content, and Super Air Member No.) of fresh concrete and strength properties (compressive, tensile, flexural, and elastic modulus) of hardened concrete will be evaluated in accordance with the American Society for Testing and Materials (ASTM) Standards. Durability properties such as alkali-silica reactivity, drying shrinkage, sulfate resistance, and scaling resistance of hardened concrete will also be evaluated per the ASTM methods. Laboratory findings will be implemented in the field through the construction of a small test section (walking trail or sidewalk), and the in-place quality of in-place concrete will be evaluated. Industry partners will provide necessary technical assistance throughout the project. In particular, their assistance in the field demonstration project will be highly beneficial. The test section will also serve as a good learning experience for student researchers as they will work alongside the professional crews during concrete pouring and finishing work.
The technical merit of this project is that this study will assess the feasibility of GTR as a replacement of sand, fly ash, and/or a combination of replacements of sand and fly ash for paving concrete. Such knowledge and techniques do not exist in the public domain today. The current study aims to reduce this knowledge gap. Findings of the proposed study will be disseminated to professionals and communities through technical papers, presentations, and/or radio podcasts at journals, conferences, symposia, etc.
Experimental data gathered from this study are expected to help agencies, contractors, and suppliers in the region to produce durable concrete with GTR. The guidelines developed from the proposed study are expected to be implemented by the state, industry partners, and ready-mix concrete producers in the region. The proposed study will facilitate in meeting multiple objectives of Tran-SET, and they are: (i) promote sustainability and resiliency of the transportation infrastructure renewal and upgrade; (ii) introduce and implement cost-effective solutions to the transportation infrastructure backlog of projects; (iii) develop cost-effective solutions for the construction and maintenance of the transportation infrastructure in metropolitan and rural areas; and (iv) promote workforce development through learning and continuous education.]]></description>
      <pubDate>Fri, 06 May 2022 12:26:44 GMT</pubDate>
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