<rss version="2.0" xmlns:atom="https://www.w3.org/2005/Atom">
  <channel>
    <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" />
    <description></description>
    <language>en-us</language>
    <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>Transport Research International Documentation (TRID)</title>
      <url>https://trid.trb.org/Images/PageHeader-wTitle.jpg</url>
      <link>https://trid.trb.org/</link>
    </image>
    <item>
      <title>Effect of crumb tire rubber, microcrystalline synthetic wax, and nano silica on asphalt rheology</title>
      <link>https://trid.trb.org/View/1693630</link>
      <description><![CDATA[This study aims at exploring the influence of different modifiers on the physical and rheological properties of asphalt cements. Crumb Tire Rubber (CTR), Microcrystalline Synthetic Wax (MSW), and Nano Silica (NS) modifiers were used to modify asphalt cement of 60/70 penetration grade. Several percentages of CTR (9, 12, and 16%), MSW (2, 3.5, and 5%), and NS (3, 5, and 7%) by weight of the asphalt cement were tested. The penetration, softening point, flash and fire points, viscosity, dynamic shear rheometer (DSR), and bending beam rheometer (BBR) were carried out in this study. Experimental results showed an improvement in the high-temperature performance of asphalt cement by adding CTR and NS modifiers while adversely affecting properties at low temperatures. Also, the results did not show any enhancement in the high or low-temperature performance by adding MSW to the asphalt cement. The optimum contents of CTR and NS modifiers were found to be 12% and 5% by weight of the asphalt cement, respectively.]]></description>
      <pubDate>Wed, 29 Apr 2020 17:40:41 GMT</pubDate>
      <guid>https://trid.trb.org/View/1693630</guid>
    </item>
    <item>
      <title>Fatigue life and rutting performance modelling of nanosilica/polymer composite modified asphalt mixtures using Weibull distribution</title>
      <link>https://trid.trb.org/View/1691186</link>
      <description><![CDATA[This study has investigated the fatigue and rutting performance of composite polyethylene (PE) and polypropylene (PP) asphalt mixtures with the addition of nanosilica particles (NS). In this study, a composite modified asphalt binder was prepared using PE and PP with NS in a concentration of 1–4% by weight of bitumen. A flexural beam fatigue test using four-point flexural beam fatigue test was conducted. A Wessex wheel tracking test was also conducted to estimate the rutting deformation of the mixtures. Weibull distribution was applied to evaluate the fatigue life of the two composite mixtures at different strain levels. A parametric survival analysis was utilised to compare the reliability of the composites. Also, a Weibull failure rate function was used to fit the experimental Wessex wheel tracking rut depth results. The results showed that the fatigue life of the composite mixtures at all strain levels complied with a two-parameter Weibull distribution with a statistical coefficient of determination greater than 0.9. The survival analysis showed that the PP composites had higher reliability at all strain levels. Furthermore, a good correlation was observed between the fitted Weibull failure rate function and the experimental rut depth obtained from the Wessex wheel tracking test.]]></description>
      <pubDate>Mon, 30 Mar 2020 15:16:05 GMT</pubDate>
      <guid>https://trid.trb.org/View/1691186</guid>
    </item>
    <item>
      <title>Optimum content of nano-silica to ensure proper performance of an asphalt binder</title>
      <link>https://trid.trb.org/View/1575832</link>
      <description><![CDATA[There is a growing need to improve the performance properties of asphalt binders in order to minimise the occurrence of failure mechanisms such as permanent deformation, fatigue, adhesiveness and moisture damage. Nano-structured materials have taken a scientific-industrial boom as asphalt modifiers due to their mechanical, thermal and electrical properties, among others. The chemistry of the nano-material, and thus their inherent physical properties, ends up with each one having specific effects on the asphalt and variable blending forms depending on their nature. This paper evaluates the effect of the incorporation of nano-silica (nano-SiO₂) into a PG64-22 binder at various contents from 0.5% to 6.0%. Nano-SiO₂ is widely used in the painting industry to improve adhesion of the paint to walls and provides an impermeable coat. Morphological, rheological and thermal analysis techniques were used to quantify the effect of asphalt binder modification. Such techniques were differential scanning calorimetry, thermogravimetric analysis, as well as Fourier transform infrared spectroscopy and atomic force microscopy. Selection of the optimum modifier content was mainly based on dynamic shear rheometry asphalt fatigue and rutting tests and work of adhesion analysis.]]></description>
      <pubDate>Fri, 25 Jan 2019 10:34:14 GMT</pubDate>
      <guid>https://trid.trb.org/View/1575832</guid>
    </item>
    <item>
      <title>Application of nano-silica and styrene-butadiene-styrene to improve asphalt mixture self healing</title>
      <link>https://trid.trb.org/View/1563310</link>
      <description><![CDATA[Nanoparticles, due to their physical and chemical characteristics, present an inherent potential to improve the performance of bituminous materials. Presently, the technology of producing nanosized particles is evolving, and their application in various aspects of pavement engineering is becoming more cost-effective. Nanosilica, due to its spherical shape, high specific area, very tiny size and higher density compared to bitumen, presents an inherent potential to accelerate molecular randomisation movements, promote bitumen binder flow into microcracks and evolve healing index (HI) of hot mix asphalt (HMA). Moreover, it has been proved that Styrene–Butadiene–Styrene polymer (SBS) promotes fatigue life of HMA and decreases its temperature sensitivity. It would be interesting to know if the addition of nanosilica to modified binder with SBS will promote the total HI and lead to an enhanced HMA life cycle. In this study, the effects of four parameters, most importantly, the effect of the combination of nanosilica particles and SBS polymer to improve the self-healing of asphalt mixture was investigated using the Taguchi design of experiment (DOE) method. Experiments performed with the Superpave indirect tensile test included repeated loadings (fracture) and healing phases. These experiments showed that the combination of nanosilica and SBS promoted the self-healing of HMA, significantly. Moreover, the optimum condition to attain maximum HI and effect factor of each parameter, based on Taguchi DOE method, was obtained. Furthermore, scanning electron microscope images of fatigued, under healing and healed HMA samples were captured to investigate HMA self-healing mechanism.]]></description>
      <pubDate>Sat, 03 Nov 2018 15:17:21 GMT</pubDate>
      <guid>https://trid.trb.org/View/1563310</guid>
    </item>
    <item>
      <title>Rate of Carbonation in Cement Modified Base Course Material</title>
      <link>https://trid.trb.org/View/1541683</link>
      <description><![CDATA[In the absence of a carbonation model for soil cement, this research aims to assess the compatibility and applicability of an analytical model initially developed for concrete. Carbonation can be observed in any pavement layer which includes cement or lime. For instance, carbonation damages the cement-modified crushed rocks as a typical material for base course layer due to poor curing of material or cracking of asphalt. Experimental laboratory tests are utilised here in accelerated carbonation conditions to evaluate the analytical model. Cylindrical specimens are subjected to one-dimensional carbonation condition. Weight and ratio of constituents of mixes, as well as environmental factors, such as CO2 concentration and relative humidity are recorded for analytical estimation of failure progresses. Nanosilica is also introduced in mixes to explore its effects during carbonation reactions. Results show linear correlations between experimental records and analytical model calculations. Thus, it can be concluded that carbonation rate can be predicted in soil cement also. In addition, the inclusion of nanosilica has a positive influences by slowing of the carbonation progress.]]></description>
      <pubDate>Wed, 17 Oct 2018 12:09:05 GMT</pubDate>
      <guid>https://trid.trb.org/View/1541683</guid>
    </item>
    <item>
      <title>Three-dimensional surface texture of Portland cement concrete pavements containing nanosilica</title>
      <link>https://trid.trb.org/View/1540668</link>
      <description><![CDATA[Pavement surface texture is critical to tire/pavement interaction. Texture characteristics of concrete containing nanosilica pavement surface has not yet been directly investigated, although researchers have found that nanosilica improved pavement friction values and durability. Specimens with various nanosilica content are tested for three-dimensional (3D) texture height maps which are decomposed using discrete wavelet transform for the calculation of 3D texture indices for macrotexture and microtexture. It is found that 3D texture indices increase correspondingly with the increment of nanosilica content. Significant relationship with R² values between 0.80 and 0.99 is found between various texture indices and nanosilica content. The increased texture amplitude indicates enhanced pavement friction and then safety. The increment of core material volume implies more texture in the core region, which indicates better longevity of texture. The findings of this research agree with the results of other studies that nanosilica increased the abrasion resistance and frictional property of concrete surface.]]></description>
      <pubDate>Mon, 01 Oct 2018 14:39:58 GMT</pubDate>
      <guid>https://trid.trb.org/View/1540668</guid>
    </item>
    <item>
      <title>Effects of Nano-Silica and Rock Asphalt on Rheological Properties of Modified Bitumen</title>
      <link>https://trid.trb.org/View/1501554</link>
      <description><![CDATA[In this research study, rheological properties of sixteen asphalts with different contents of nano-silica and Qingchuan rock asphalt were analyzed by univariate analysis and variance analysis. The experimental tests performed were rotational viscosity (RV) test, dynamic shear rheometer (DSR) test, bending beam rheometer (BBR) test and scanning electron microscope (SEM) test. RV test results showed that the two materials had significantly influence on rotary viscosity. The compound modified asphalt had a better ability to resist deformation at high temperature. The results of DSR test revealed that Qingchuan (QC) rock asphalt had a remarkable impact on the complex shear modulus G* and phase angle d, while the effects of nano-silica were relatively small, which mainly improved G* and barely had any influence on d. From the results of BBR test, the low temperature performance of the modified asphalt subjected to degradation as the additives contents increasing. Meanwhile, the effects of nano-silica were relatively small. To achieve similar high temperature characteristics, the compound modified asphalt had smaller declination in low temperature performance compared with QC rock asphalt modified bitumen. And it was not cost effective for only using nano-silica to improving the anti-rutting performance of asphalt. From the results of DSR and BBR test, the performance grades of different combinations were obtained. Moreover, based on rheological properties of different combinations and the dispersion status of nano-materials, the optimal content, which consisted of 6% QC rock asphalt and 1% nano-silica, was determined.]]></description>
      <pubDate>Thu, 29 Mar 2018 09:34:01 GMT</pubDate>
      <guid>https://trid.trb.org/View/1501554</guid>
    </item>
    <item>
      <title>Resistance of concrete to different exposures with chloride-based salts</title>
      <link>https://trid.trb.org/View/1483157</link>
      <description><![CDATA[Formation of complex salts (oxychlorides) has been suspected for causing chemical degradation of concrete in cold regions. In this study, conditioned mode (controlled temperature and relative humidity) environmental scanning electron microscopy was specifically used to minimize changes in the crystal structures of oxychlorides phases and thus reliably capture their unaltered morphology and existence/effects on concrete exposed to different de-icing salts under two different environmental conditions (constant low temperature and wetting/drying (W/D) cycles). Formation of acicular flattened blades of 3- and 5-form magnesium oxychloride (MOX) and tiny fibrous crystals as well as subhedral pseudo-hexagonal calcium oxychloride plates (COX) were found in deteriorated concrete specimens, depending on the type of solution. The reversible formation of hydrous and anhydrous COX during W/D cycles had a significant effect on aggravating the kinetics of damage of concrete in this exposure. The combined salt (MgCl₂ + CaCl₂), which simulates using a synergistic maintenance and protective strategy for concrete pavements in winter, was the most aggressive solution; thus, this practice should be cautiously reconsidered. The incorporation of 30% fly ash had a pronounced effect on improving the concrete resistance to damage as reflected by sound mechanical properties and longevity. Also, the performance of concrete was much enhanced when an innovative supplementary cementitious material, nanosilica, was incorporated in the cementitious system.]]></description>
      <pubDate>Sun, 24 Sep 2017 16:17:36 GMT</pubDate>
      <guid>https://trid.trb.org/View/1483157</guid>
    </item>
    <item>
      <title>Influence of Fine Particles on Strength and Autogenous Shrinkage of Alkali-Activated Slag Pastes</title>
      <link>https://trid.trb.org/View/1439029</link>
      <description><![CDATA[Concrete industry has explored various options to reduce the usage of ordinary portland cement (OPC) in concrete by finding suitable replacement materials. Alkali activation of alumino-silicate materials as cement free binders for concrete is a promising alternative to the use of portland cement. The objective of the present study was to determine the role of different types of fine particles on the compressive strength, workability, setting time, reaction kinetics and autogenous shrinkage of the alkali activated slag cement. Sodium silicate and sodium hydroxide were used as the alkaline solutions for activating the slag cement. Nano silica, kaolinite clay and slightly modified kaolinite clay, referred to as coated clay, were used as the fine particles. The amount of fine particle used was 1% and 2% of the binder mass. Reaction kinetic of the pastes was evaluated using an in-situ isothermal conduction calorimetry. The fine particle addition significantly increased the compressive strength of the sodium silicate activated slag cement. Whereas, the workability, setting time and autogenous shrinkages were significantly reduced due to fine particle addition in the sodium silicate activated slag system. An entirely different behavior was obtained when the fine particles were added to a sodium hydroxide activated slag system. The compressive strength and autogenous shrinkage were not significantly affected by the fine particle addition in the sodium hydroxide activated slag. Nano silica was the most reactive fine particle irrespective of the type of activator used.]]></description>
      <pubDate>Mon, 13 Mar 2017 16:05:41 GMT</pubDate>
      <guid>https://trid.trb.org/View/1439029</guid>
    </item>
    <item>
      <title>Microstructure of lime and lime-pozzolana pastes with nanosilica</title>
      <link>https://trid.trb.org/View/1403710</link>
      <description><![CDATA[Nanosilica particles (nS) were added to lime (L) and lime-pozzolana (LP) pastes to study the effect of nS as a pozzolanic admixture in L and to synergistically improve the pozzolanic reactivity of LP. Relationships between microstructure and mechanical properties of the pastes were examined. The macroporosity of both pastes decreased, and the compressive strength increased. Scanning electron microscope (SEM) and X-ray microtomography (µ-CT) analysis accounted for explaining the inconsistent results between the porosity obtained by mercury intrusion porosimeter (MIP) and density by He-pycnometry. The strong pozzolanic reaction in LPnS explained the high consumption of mixing water, increment of density, and pores assigned to calcium silicate hydrate (CSH). The SEM analysis also showed that Brunauer-Emmett-Teller (BET) and Barrett-Joyner-Halender (BJH) can give erroneous results regarding the adsorption/desorption isotherms, thus affecting the values of the specific surface area and nanoporosity.]]></description>
      <pubDate>Sat, 30 Apr 2016 15:03:25 GMT</pubDate>
      <guid>https://trid.trb.org/View/1403710</guid>
    </item>
    <item>
      <title>Study on the effectiveness of PNS and LS superplasticizers in air lime-based mortars</title>
      <link>https://trid.trb.org/View/1400961</link>
      <description><![CDATA[Polynaphtalenesulfonate (PNS) and lignosulfonate (LS) were tested as superplasticizers in pastes and mortars of pure air lime and air lime with a pozzolanic additive, nanosilica (NS). LS showed a better plasticizing effect than PNS: the flowability of the samples with LS as well as the slump retention over time was larger. LS strongly hindered carbonation due to its ability to form Ca²+ complexes. In mortars with NS, PNS was seen to interfere with the calcium-silicate-hydrate (C-S-H) formation, resulting in lower mechanical strengths. Adsorption isotherms and zeta potential showed that PNS was more adsorbed than LS onto lime and C-S-H particles. PNS acted mainly through electrostatic repulsion owing to its high anionic charge density and flat adsorption. However, LS was more efficient as superplasticizer in air lime media, steric hindrance being the main mechanism responsible for avoiding flocculation. Furthermore, LS yielded high compressive strengths in mortars with NS.]]></description>
      <pubDate>Mon, 18 Apr 2016 12:31:29 GMT</pubDate>
      <guid>https://trid.trb.org/View/1400961</guid>
    </item>
    <item>
      <title>Influence of Nanosilica and Clay on the Strength, Workability, and Porosity of Alkali-Activated Slag Mortars</title>
      <link>https://trid.trb.org/View/1394209</link>
      <description><![CDATA[Nanoparticles, including nanosilica and nano-clay, have been used to modify setting times, rheology, and mechanical strength of portland cement-based binder systems. Alkali activated binders have recently emerged as potentially sustainable materials which can be used to replace ordinary portland cement (OPC) in concrete. The present study evaluates the role of nanosilica and kaolinite clay on the compressive strength, workability, and porosity of alkali-activated slag mortars. Ground granulated blast-furnace slag (slag/AA-S) mortar with 1-2% dosages of nanosilica (NS) and 2-6% of kaolinite clay (KC) were evaluated here. Significant improvement in compressive strength of AA-S mortar was observed when modified by either nanosilica or kaolinite at different dosages. Workability and setting time of nanoparticle-modified AA-S mortar suffered. The porosity of said mortars was generally reduced.]]></description>
      <pubDate>Tue, 29 Mar 2016 09:35:41 GMT</pubDate>
      <guid>https://trid.trb.org/View/1394209</guid>
    </item>
    <item>
      <title>Adhesion Performance of Nanosilica-Modified Binder</title>
      <link>https://trid.trb.org/View/1392895</link>
      <description><![CDATA[The interaction between the binder and the aggregate is fundamental in ensuring the adequate performance of asphalt mixtures, mainly under the presence of water. The work of adhesion that is generated by both materials directly affects the resistance of the asphalt mixture to moisture damage since it clearly quantifies the ease with which water can displace the binder from the aggregate surface. However, the effect of moisture and the physical-chemical interaction between binder and aggregate depends on the specific properties of each material and the conditions at which the asphalt mixture is produced and expected to perform. The study looks to characterize the bond strength between nano-silica modified asphalt and several aggregate sources that are typically used in Costa Rica. Each binder was characterized by means of the Superpave performance grade, Thermogravimetric Analysis (TGA) and Differential Scanning Calorimetry Analysis (DSC).To measure the strength of adhesion, the Binder Bond Strength (BBS) test was used. All testing was performed on the neat and modified binders, as well as on each binder - aggregate combination after rolling thin film oven (RTFO) and RTFO + pressure aging vessel (PAV) aging. The BBS results identify significant differences in the bond strength due to moisture conditioning and aging. The differences are highly dependent on the aggregate source. Furthermore, depending on the type of aggregate, different failure types where observed: cohesive vs. adhesive. The type of binder is also highly significant in determining strength of adhesion. The results also indicate an increase in the strength of addition associated to the aging process, where the main increase in resistance is observed after RTFO aging.]]></description>
      <pubDate>Tue, 22 Mar 2016 22:15:31 GMT</pubDate>
      <guid>https://trid.trb.org/View/1392895</guid>
    </item>
    <item>
      <title>Effect of Nano Seeds in C-S-H Gel Formation: Simulation Study from the Colloidal Point of View</title>
      <link>https://trid.trb.org/View/1369147</link>
      <description><![CDATA[The addition of external nanoparticles, mainly nano silica during the hydration of cement is a field of investigation in high performance cements. The added particles act as seeds and initiate early nucleation and subsequent growth of C-S-H gel. Nucleation is triggered very early, before enough clinker grains are dissolved or in other words, before the super saturation condition is attained. Hence, depending on the amount of added seed, the morphology and the mechanical properties of the product differ. Experimental studies in this area are less favored due to economic reasons and simulation studies are rare in the literature. An earlier work by some of the authors introduced a Monte Carlo model which dealt with the kinetics of the hydration process at early ages. The colloidal model incorporated random nucleation in the bulk, followed by an Avramian style layer by layer growth of 5nm sized C-S-H particles. The model was based on a Random Sequential Addition scheme and enabled a satisfactory rationalization of the early growth of C-S-H gel. In the present study, the authors extend this model for the addition of extra seeds and for different water to cement ratios.]]></description>
      <pubDate>Mon, 28 Sep 2015 08:57:33 GMT</pubDate>
      <guid>https://trid.trb.org/View/1369147</guid>
    </item>
    <item>
      <title>Nano-modification to improve the ductility of cementitious composites</title>
      <link>https://trid.trb.org/View/1363473</link>
      <description><![CDATA[Effect of nano-sized mineral additions on ductility of engineered cementitious composites (ECC) containing high volumes of fly ash was investigated at different hydration degrees. Various properties of ECC mixtures with different mineral additions were compared in terms of microstructural properties of matrix, fiber-matrix interface, and fiber surface to assess improvements in ductility. Microstructural characterization was made by measuring pore size distributions through mercury intrusion porosimetry (MIP). Hydration characteristics were assessed using thermogravimetric analysis/differential thermal analysis (TGA/DTA), and fiber-matrix interface and fiber surface characteristics were assessed using scanning electron microscopy (SEM) through a period of 90 days. Moreover, compressive and flexural strength developments were monitored for the same period. Test results confirmed that mineral additions could significantly improve both flexural strength and ductility of ECC, especially at early ages. Cheaper Nano-CaCO₃ was more effective compared to nano-silica. However, the crystal structure of CaCO₃ played a very important role in the range of expected improvements.]]></description>
      <pubDate>Tue, 25 Aug 2015 21:44:20 GMT</pubDate>
      <guid>https://trid.trb.org/View/1363473</guid>
    </item>
  </channel>
</rss>