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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>Research in Progress (RIP)</title>
      <url>https://rip.trb.org/Images/PageHeader-wTitle-RIP.jpg</url>
      <link>https://rip.trb.org/</link>
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    <item>
      <title>Quarry By-product Fines for Otta Seal Surfacing of Local Roads</title>
      <link>https://rip.trb.org/View/2417469</link>
      <description><![CDATA[An Otta seal is a cost-effective surface treatment that is formed by adding graded aggregate to a thick application of soft binder. It is worked into the aggregate as traffic rolls over it. This project will examine the use of quarry by-product fines, a leftover material from crushed rock extraction found in abundance in Illinois, as aggregates in Otta seals. Researchers will review design parameters as well as conduct lab testing to prepare mechanistic-based design and construction guidelines for Otta seals with quarry by-product aggregates. Effectively using Otta seals with quarry by-product aggregates will reduce operational costs and maintenance needs as well as minimize aggregate segregation and provide environmental benefits.]]></description>
      <pubDate>Fri, 16 Aug 2024 09:11:26 GMT</pubDate>
      <guid>https://rip.trb.org/View/2417469</guid>
    </item>
    <item>
      <title>Quantifying Soil Moisture Reduction by Wicking Geotextile to Minimize Pavement Distresses</title>
      <link>https://rip.trb.org/View/2341500</link>
      <description><![CDATA[Excessive moisture in pavement foundations including base courses and subgrade is one of the major causes for pavement distresses, which often pose safety risks to vehicles and drivers and increase the cost for maintenance and reconstruction. Moisture can weaken pavement foundations and become a source for freeze-thaw problems in cold regions, which accelerate the deterioration of pavements with time. Therefore, pavement drainage is critical to pavement performance. Typical drainage systems are effective for saturated soils but become less effective or ineffective for unsaturated soils. Wicking geotextile that contains deep-grooved fibers can generate suction when in contact with water and reduce moisture in unsaturated soils. However, the effectiveness of the wicking geotextile in reducing moisture depends on several factors including the percent of fines in soils. So far, no simple test method is available to evaluate the effectiveness of the geotextile in reducing moisture in soils including those with fines and no fine content limit has been established for the wicking geotextile to be effective.  The proposed research is to develop a simple soil box test to quantify the effectiveness of the wicking geotextile in reducing moisture in sands at different fine contents and distances from the geotextile as compared with the conventional geotextiles. The soil box tests will first determine field capacities of silty sands at different fine contents and then evaluate moisture reduction by geotextiles by measuring moisture contents at different distances from the geotextile location at different times. These tests will determine the amount of moisture reduction and the distance of influence, and the fine content limit for the geotextile to be effective. The objective of this research is to develop a simple test method to quantify soil moisture reduction by geotextile and provide guidance for its use in sands with fines.  ]]></description>
      <pubDate>Sat, 17 Feb 2024 16:20:34 GMT</pubDate>
      <guid>https://rip.trb.org/View/2341500</guid>
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      <title>Aggregate Specification to Reduce Dust and Improve Sustainability of Local Rock-Surfaced Roads</title>
      <link>https://rip.trb.org/View/2255777</link>
      <description><![CDATA[Kansas has large rural areas, which are connected by more than 100,000 miles of county roads. Over 53,000 miles of these county roads are surfaced with aggregates. KDOT Specification Section 1112 provides three types of aggregates for surfacing of county secondary roads: crushed stone, sand-gravel, and limestone gravel. The current specifications for crushed stone surfacing include no Plasticity Index (PI) requirement, but plasticity is an important parameter for binding aggregates together for a smooth surface and limiting the amount of fines lost (dust). The Gravel Roads Construction and Maintenance Guide developed by FHWA (2015) has provided good guidelines for construction and maintenance of gravel roads in the nation and requires a PI of 4-12 for crushed rock surfacing. However, this guide was developed based on the local experiences in South Dakota and may not be fully applicable to the practice of rock-surfaced road construction and maintenance in Kansas. In fact, a certain portion of rocksurfaced roads in Kansas have underperformed and even failed, thus requiring repair and frequent maintenance. Some crushed limestone from local quarries is very porous and absorbs water; therefore, it is not durable. To address these problems, there is an urgent need to develop a specification for crushed rock surfacing that will reduce the amount of fines lost (dust), bind the rock surfacing materials together more cohesively to form a crust and shed water, and reduce required maintenance. This proposed study will be partnered with members of the Kansas Association of Counties who have expressed interest in this study.]]></description>
      <pubDate>Tue, 26 Sep 2023 16:04:24 GMT</pubDate>
      <guid>https://rip.trb.org/View/2255777</guid>
    </item>
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      <title>Beneficiation of High Sulfur Fly Ashes and Quarry Fines for Sustainable Ternary Concrete Mixtures

</title>
      <link>https://rip.trb.org/View/1925911</link>
      <description><![CDATA[With an estimated 50% of all concrete produced containing some continuous flight auger (CFA) [6,7] and when CFA demand for use in concrete is increasing [1] while its supply is decreasing [9,10], it is evident that viable alternatives are necessary now and in the future for sustaining the production of durable and sustainable (low CO₂) concrete. This research will develop a ternary cement (e.g., ASTM C595 Type IT cement) that 3 combines the widely available high SO₃ CFA and quarry fines to reduce the Portland cement content of concrete by 50% or more. This new cement will be compliant with ASTM C595 and as such, will be immediately usable by concrete producers. Additionally, the availability of high SO₃ CFA and quarry fines would supplement the existing supply of conventional SCMs and allow the industry to proceed with its construction operations uninterrupted while meeting ambitious sustainability targets with respect to CO₂ emissions. In addition, there could be materials cost savings, even after beneficiation of these SCMs, given that they are currently discarded as waste materials. This research will explore the design and performance evaluation of a new ASTM C595 Type IT blended cement that includes high SO₃ CFA and quarry fines. 
The specific objectives are:
(1) Characterization of high SO₃ CFA and quarry fines in terms of their composition, mineralogy, physical properties, and pozzolanic reactivity.
(2) Designing and developing a new Type IT cement containing high SO₃ CFA and quarry fines to reach at least 95% of the compressive strength of a control Type IT cement at 28 days.
(3) Evaluating the impact of this new cement on fresh properties of concrete, including workability, setting time, and admixture performance.
(4) Studying the durability performance of concrete made with the new cement blend.
]]></description>
      <pubDate>Fri, 11 Mar 2022 09:19:39 GMT</pubDate>
      <guid>https://rip.trb.org/View/1925911</guid>
    </item>
    <item>
      <title>Evaluate the Importance of Fine Aggregates in Achieving Adequate Skid Resistance in TxDOT Hot Mix Asphalt Mixtures</title>
      <link>https://rip.trb.org/View/1879832</link>
      <description><![CDATA[The lack of skid resistance has been an important issue for Texas Department of Transportation (TxDOT) pavement as many of them cannot hold adequate skid resistance in the long run, and even some newly constructed roads are observed to have poor skid resistance. Skid resistance is a function of the quality of the aggregate as well as the micro-and macro-texture of the surface. Those textures can be modified by using the appropriate type and amount of fine aggregates and fines in asphalt concrete. The main focus of the research is understanding the effects of fine aggregates and fines on the skid resistance of asphalt concrete since their impacts on the skid resistance and performance. The research team will evaluate the current practices and research studies commissioned by TxDOT (in particular) and other states (in general) on the use of fine aggregates and fines in asphalt concrete to improve skid resistance. The major objective of this project shall be critical to evaluate the influence of fine aggregates and high-quality fines on the skid resistance of asphalt concrete.]]></description>
      <pubDate>Thu, 23 Sep 2021 10:06:19 GMT</pubDate>
      <guid>https://rip.trb.org/View/1879832</guid>
    </item>
    <item>
      <title>Internal Friction Angle of Sands with High Fines Content </title>
      <link>https://rip.trb.org/View/1745648</link>
      <description><![CDATA[There are three main objectives of this study. The first is to evaluate the effect of
fines content on the value of internal friction angle of sand soils mixed with fines
typically encountered in Louisiana. The second objective is to evaluate the effect
of fines content on the interface friction angle between sand soils mixed with fines
and both concrete and steel surfaces. Lastly, the study will determine the threshold
percent of fines content beyond which the sand soils mixed with fines will behave
as cohesive soils, rather than cohesion less soils, and the effect on design of driven
piles. ]]></description>
      <pubDate>Thu, 15 Oct 2020 15:47:37 GMT</pubDate>
      <guid>https://rip.trb.org/View/1745648</guid>
    </item>
    <item>
      <title>Use of Waste Quarry Fines as a Binding Material on Unpaved Roads</title>
      <link>https://rip.trb.org/View/1505639</link>
      <description><![CDATA[In this project, the research team proposes to conduct laboratory and field tests to examine the impact of inclusion of waste quarry fines in granular aggregate materials used in unpaved road designs, using materials collected from various quarries. Based on the laboratory test results, field test sections will be constructed using materials with different quarries. The field performance of sections built with different quarry fines will be compared. Then, a comprehensive cost-performance and life cycle cost analyses will be conducted to evaluate the cost effectiveness and sustainability of these unpaved roads to determine whether it is economically advantageous to add waste quarry fines into granular unpaved road materials. It should be noted that this study is proposed to be conducted under the partnership of the Iowa Highway Research Board (IHRB) and Recycled Materials Resource Center (RMRC).

The objectives of the proposed research are to: (1) Determine the stiffness and strength of unpaved road materials blended with different quarry fines; (2) Determine the long term performance of field test sections built with optimum quarry fines content; and (3) Analyze the life cycle cost and cost effectiveness of this approach.

The research team will consist of personnel from the Department of Civil, Construction, and Environmental Engineering at Iowa State University to effectively manage the project and complete the required tasks. For planning purposes, it is assumed that this project will have a 24 month duration. The proposed research will consist of seven tasks: Task 1: Meet with the Project's Technical Advisory Committee (TAC) to Review the Project Scope and Work Plan.
Task 2: Literature Review.
Task 3: Collection of Materials and Development of a Laboratory Test Matrix.
Task 4: Laboratory Testing.
Task 5: Construction of Field Test Sections and Development of Field Testing Plan.
Task 6: Analyses of the Cost Effectiveness of Materials Available in Iowa.
Task 7: Preparation of Draft/Final Report.]]></description>
      <pubDate>Wed, 21 Mar 2018 11:43:11 GMT</pubDate>
      <guid>https://rip.trb.org/View/1505639</guid>
    </item>
    <item>
      <title>Guidelines for the Waste Concrete Fines</title>
      <link>https://rip.trb.org/View/1334963</link>
      <description><![CDATA[This project will develop guidelines for using waste concrete fines (and the associated wastewater) in concrete by developing methods to rapidly characterize fines samples and evaluating the performance of concrete using these recycled materials. Work in Stage 1 begins with a literature review on issues related to the use of recycled concrete fines. Subsequently, sources of recycled fines will be identified and samples collected and dried. The fines will be characterized after mixing them with water to create solutions/suspensions with 1 to 15% solids and their indices of refraction, pH, and conductivity will be determined. Mortar samples will then be prepared and their setting times and strengths will be measured for a range of recycled fines contents for fines with varying particle sizes. Correlations will be investigated and established to help develop a performance-prediction model for different recycled fines materials. This model will be used to develop guidelines for the use of recycled concrete fines in new concrete mixtures. In Stage 2, a laboratory-scale water recirculation system will be constructed incorporating in-line (continuous reading) sensors for measuring index of refraction, conductivity, and pH. Waste materials will be added to the recirculation system and evaluated using the in-line sensors. Concrete mixtures will then be prepared using the optimal blends of water from the recirculation system (containing waste concrete fines) and freshwater, based on both the in-line measurements and the characteristics of the desired concrete mixtures. An implementation plan for ready-mix concrete producers when upgrading their plants with in-line sensors will be developed along with instructions on applying the guidelines for use of recycled fines.]]></description>
      <pubDate>Thu, 11 Dec 2014 01:00:48 GMT</pubDate>
      <guid>https://rip.trb.org/View/1334963</guid>
    </item>
    <item>
      <title>Potential Use and Applications for Reclaimed Millings</title>
      <link>https://rip.trb.org/View/1258342</link>
      <description><![CDATA[The purpose of this project is to document the usefulness of retaining and using milled asphalt material for a number of maintenance activities.]]></description>
      <pubDate>Wed, 07 Aug 2013 01:00:57 GMT</pubDate>
      <guid>https://rip.trb.org/View/1258342</guid>
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