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    <title>Transport Research International Documentation (TRID)</title>
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    <atom:link href="https://trid.trb.org/Record/RSS?s=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" rel="self" type="application/rss+xml" />
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    <copyright>Copyright © 2026. National Academy of Sciences. All rights reserved.</copyright>
    <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>Pressure-dependent rheology of bentonite-conditioned sand and its application in EPB shield tunnelling</title>
      <link>https://trid.trb.org/View/2649817</link>
      <description><![CDATA[Earth Pressure Balance (EPB) shield tunneling in water-rich, cohesionless sandy ground faces significant challenges, including tunnel face instability and spewing from the screw conveyor. Conditioning the excavated material with bentonite slurry is a critical technique for ensuring construction safety. However, a comprehensive understanding of the rheological properties of conditioned soil under realistic confining pressures remains elusive, which limits the precise control of tunneling parameters. This study aims to systematically investigate the influence of soil gradation, slurry injection ratio (SIR), and confining pressure (P) on the rheology of bentonite-conditioned sand. A custom-developed mechanical pressurized vane rheometer was used to conduct tests on two typical sands—poorly graded sand (SP) and well-graded sand (SW)—under various SIR (25 %–40 %) and confining pressures (P = 200 kPa, 300 kPa). The results indicate that the conditioned soil behaves as a Bingham fluid, with its yield stress (τ0) and plastic viscosity (k) exhibiting a significant non-linear increase as confining pressure increases and SIR decreases. Based on these laboratory findings, a pressure-dependent rheological parameter dataset was established and integrated into a full-scale three-dimensional computational fluid dynamics (CFD) model. The CFD model, validated against field data from the Shenyang Metro project, accurately predicted the muck pressure distribution and operational parameters within the shield machine, with a maximum relative error of less than 7 %. The findings of this research provide a valuable reference for optimizing soil conditioning strategies and advancing numerical simulations of EPB shield tunneling in similar geological conditions.]]></description>
      <pubDate>Thu, 26 Mar 2026 17:03:06 GMT</pubDate>
      <guid>https://trid.trb.org/View/2649817</guid>
    </item>
    <item>
      <title>Ultraviolet Aging Resistance of Asphalt Modified with Ce-Doped Bentonite</title>
      <link>https://trid.trb.org/View/2632729</link>
      <description><![CDATA[Bentonite and cerous ions were introduced to investigate their effect on the antiultraviolet aging of asphalt. In this paper, Ce-doped bentonite is obtained by mixing cerous nitrate with calcined activated bentonite. The Ce-doped bentonite and asphalt are mixed in high speed-shears to modify asphalt. Through the basic performance test and rheological properties test to study the ultraviolet (UV) aging properties of asphalt modified with Ce-doped bentonite. The results show that bentonite and cerous ions can improve the antiultraviolet aging performance of asphalt. In a certain range, the higher the cerous content, the better the modification effect. gel permeation chromatography, thermogravimetry analysis, and Fourier transform infrared spectroscopy tests analyze the changes in the microstructure of asphalt before and after modification. In addition, layered experiments are designed to prove that asphalt aging is affected by internal depth. After adding bentonite and cerous ions, the asphalt showed excellent UV resistance either on the surface or the interior. The work provides a feasible method for improving the ultraviolet aging resistance of asphalt and promoting rare-earth doped materials modified asphalt, which has a good prospect.]]></description>
      <pubDate>Tue, 17 Mar 2026 16:15:50 GMT</pubDate>
      <guid>https://trid.trb.org/View/2632729</guid>
    </item>
    <item>
      <title>Stabilising highly expansive soil by using Nano-Clay additive</title>
      <link>https://trid.trb.org/View/2643516</link>
      <description><![CDATA[This study aims to investigate the efficacy of hydrophilic bentonite Nano-Clay in improving the geotechnical characteristics of expansive soil sourced from the Al-Mushaqar region in Jordan. In this study sonic wave-assisted and manual mixing techniques applied to expansive soil specimens. Subsequently, a comparative analysis was conducted to explain the disparities in outcomes between these two mixing methods. Various proportions of Nano-Clay were introduced into the soil, ranging from 0% to 2.5% by dry weight of the soil. The study focused on evaluating their influence on key parameters, including compaction, Unconfined Compressive Strength (UCS), and Free Swell Index (FSI). The introduction of Nano-Clay into the soil exhibited a noteworthy enhancement in its strength characteristics, accompanied with a reduction in its swelling tendencies. Notably, the application of 0.5% Nano-Clay during sonication led to a remarkable 53.4% augmentation in UCS and a simultaneous 41% reduction in FSI. In contrast, non-sonicated samples treated with 1% Nano-Clay exhibited a notable 35.21% increase in UCS and a substantial 52.4% reduction in FSI. These findings underscore the significant potential of Nano-Clay in fortifying expansive soils, thereby offering promising prospects for geotechnical engineering applications.]]></description>
      <pubDate>Sun, 15 Feb 2026 17:07:25 GMT</pubDate>
      <guid>https://trid.trb.org/View/2643516</guid>
    </item>
    <item>
      <title>Prediction of soil conditioner dosages for shield tunneling in sandy soil based on machine learning</title>
      <link>https://trid.trb.org/View/2649961</link>
      <description><![CDATA[Inadequate soil conditioning during Earth Pressure Balance shield (EPBS) tunneling in sandy strata frequently causes operational issues. This study developed a data-driven framework integrating 15 operational and geological parameters from Shenyang Metro Line 4. Using principal component analysis for dimensionality reduction and quantitative TPI/FPI criteria for dataset selection, and constructed SVR, XGBoost, and LightGBM models optimized via PSO, BO, and Optuna. The LightGBM-Optuna ensemble demonstrated superior performance, reducing prediction errors by 45–58 % compared to baseline configurations. Application to suboptimal datasets validated a 13.15 % reduction in specific energy consumption, demonstrating significant potential for intelligent tunneling control.]]></description>
      <pubDate>Thu, 15 Jan 2026 09:22:33 GMT</pubDate>
      <guid>https://trid.trb.org/View/2649961</guid>
    </item>
    <item>
      <title>Investigation of the effect of coal char on cement-treated bentonite-sand mixtures for pavement applications</title>
      <link>https://trid.trb.org/View/2608529</link>
      <description><![CDATA[Coal-derived char, a byproduct of coal pyrolysis, is a porous, carbon-rich material with potential to enhance cement-treated soils. This study examined its effect on problematic soils containing expansive clay (sodium bentonite), focusing on mixtures for subgrade (25% bentonite, 75% sand, 1% cement denoted as 25–75 mix) and sub-base/base (50% bentonite, 50% sand, 5% cement denoted as 50–50 mix) applications. Char was added at 0, 10, 20, and 40% by cement weight. Tests included Atterberg limits, optimum water content (OWC), unconfined compressive strength (UCS), triaxial compression, unsoaked California bearing ratio (CBR), consolidation, and freeze–thaw. UCS increased with curing time, cement, and char content. Consolidation and freeze–thaw parameters, like compression coefficient and weight loss, respectively, improved with cement and char addition. With cement treatment, CBR values rose by 2.5 times for the 25–75 mix, exceeding the “excellent subgrade” range, and 3.5 to 4 times for the 50–50 mix, surpassing “high-quality base” standards. However, char addition did not further increase CBR, likely due to its porous nature, making samples more penetrable. Nevertheless, all CBR values exceeded AASHTO recommendations. Overall, coal char shows promise for improving cement-treated soils in environmentally friendly pavement applications.]]></description>
      <pubDate>Tue, 02 Dec 2025 09:56:41 GMT</pubDate>
      <guid>https://trid.trb.org/View/2608529</guid>
    </item>
    <item>
      <title>Experimental study on bentonite-cement synergistic improvement of hydro-mechanical performance in loess tunnel foundation</title>
      <link>https://trid.trb.org/View/2603160</link>
      <description><![CDATA[The surrounding rock of loess tunnel foundation often deteriorates due to long-term upper load and water immersion softening, leading to structural issues such as pavement cracking and upheaval. Therefore, the feasibility of improving the hydro-mechanical performance of the surrounding rock of the tunnel foundation with bentonite and cement was explored by means of laboratory tests, model tests and microscopic tests. Permeability and unconfined compressive strength (UCS) tests were performed to determine the optimal mix ratio of the foundation improvement material. Model tests were designed to compare and analyze the effects of the improved layer on tunnel surrounding rock and structural behavior. Additionally, SEM and MIP tests were used to study the modification mechanisms of bentonite and cement on the microstructure of loess. The results indicate that a mix ratio of 6 % bentonite + 6 % cement is optimal, reducing the hydraulic conductivity to 10⁻⁸ m/s by pore-filling effects of bentonite while increasing the UCS of loess by approximately 10 times due to cement hydration products. Microscopic analysis reveals that bentonite fills pores via its layered structure, reducing macropore connectivity, while cement hydration generates C-S-H gels and ettringite, cementing particles into a denser structure. Model test results confirm the effectiveness of the bentonite-cement improved base layer. It reduces the surrounding rock moisture content growth rate by approximately 50 %. The treatment also decreases incremental surrounding rock pressure (ΔP) by about 60 %, achieving significant water infiltration control. Furthermore, the bending moments and axial forces in the tunnel structure decrease by 50∼70 % and distribute more uniformly after improvement. The synergistic effect of bentonite and cement effectively blocks water migration pathways while enhancing the structural stability of surrounding rock, providing a scientific basis and optimized solution for mitigating water-induced softening and uneven settlement in loess tunnel foundation.]]></description>
      <pubDate>Wed, 12 Nov 2025 09:35:16 GMT</pubDate>
      <guid>https://trid.trb.org/View/2603160</guid>
    </item>
    <item>
      <title>Different organic treatments of natural bentonite and their effects on the road and aging performance of SBS modified asphalt mixtures</title>
      <link>https://trid.trb.org/View/2608790</link>
      <description><![CDATA[In this study, three distinct types of organically modified bentonites (KH560-Bentonite, DC5700-Bentonite and Fluid-like-Bentonite) were successfully prepared through different organic treatments of cost-effective natural bentonite using γ-(2,3-epoxypropoxy)propytrimethoxysilane (KH560), 3-(trimethoxysilyl propyl) dimethyl octadecyl ammonium chloride (DC5700) and nonylphenol polyoxyethylene ether sodium sulfate (NPES) as modifiers. A systematic investigation and comparative analysis were conducted to evaluate the effects of various organically modified bentonites on the road performance and aging characteristics of SBS-modified asphalt mixtures (PmAM). The results demonstrate that organically modified bentonite improves the Marshall stability of PmAM by 1.24–2.93 kN compared to unmodified bentonite, while simultaneously enhancing its high-temperature deformation resistance. The organic treatments with different modification methods effectively improved the dispersion of bentonite in the matrix and reduced stress concentration. Notably, the flexible long-chain structure of Fluid-like-Bentonite significantly enhanced the low-temperature performance of the mixture. In terms of water stability, the organically modified bentonite improved the immersion residual stability to 86.1∼92.3 %, as its lamellar structure effectively inhibits moisture penetration within the asphalt mixture. Long term aging test shows that organically modified bentonites can significantly delay the deterioration of PmAM performance and improve the anti-aging ability of PmAM. Based on comprehensive analysis of PmAM performance before and after aging, the three types of organically modified bentonites exhibited varying degrees of improvement on both road performance and aging resistance of PmAM, with the enhancement effectiveness following the order: Fluid-like-Bentonite > DC5700-Bentonite > KH560-Bentonite. This study provides significant theoretical support and technical guidance for the development of high-performance asphalt pavement materials.]]></description>
      <pubDate>Mon, 27 Oct 2025 09:37:33 GMT</pubDate>
      <guid>https://trid.trb.org/View/2608790</guid>
    </item>
    <item>
      <title>Large-scale model tests on the moisture and strength evolution of BT-SAP improved subgrade under full environmental cycle conditions</title>
      <link>https://trid.trb.org/View/2573260</link>
      <description><![CDATA[Subgrade moisture redistribution and strength degradation under coupled thermo-hydraulic cycles pose serious challenges for the long-term performance of transportation infrastructure. To overcome the limitations of small-scale tests and enable realistic assessment, an advanced all-weather environmental simulation platform was developed, integrating rainfall, snowfall, fog generation, temperature control, full-spectrum solar radiation, and real-time monitoring. Using this facility, large-scale trapezoidal subgrade models were constructed with and without bentonite-based superabsorbent polymer (BT-SAP). Two composite improvement schemes: layered and wrapped structures were tested alongside an unimproved control over 6 full environmental cycles. Key performance indicators (internal moisture distribution, surface compaction degree, deformation modulus, and settlement) were recorded. Results show that BT-SAP markedly reduces upward moisture migration, maintains surface compaction degrees within 6.25 % loss of initial values, and the deformation modulus within a 22.6 % loss of its original value, and preserves deformation modulus above 50 MPa after 6 cycles. Layered and wrapped subgrade structures exhibit comparable stabilization performance, with the layered design offering simpler constructability. These findings demonstrate BT-SAP’s capability to mitigate moisture-induced strength degradation and provide a scalable, full-section improvement methodology for enhancing subgrade durability under realistic environmental loading.]]></description>
      <pubDate>Mon, 08 Sep 2025 14:54:04 GMT</pubDate>
      <guid>https://trid.trb.org/View/2573260</guid>
    </item>
    <item>
      <title>Optimization of Synthetic Fiber–Reinforced Calcined Bentonite–Based Recycled Aggregate Geopolymer Composites Based on Multicriteria Decision Support Method</title>
      <link>https://trid.trb.org/View/2526487</link>
      <description><![CDATA[The study evaluated the mechanical and durability properties of synthetic fiber–reinforced, metabentonite (MB)–based geopolymer composites (GCs) using 50×50×50-mm cubes for compressive strength and 40×40×160-mm prisms for flexural strength, according to standards for density and void analysis, direct tensile strength, and splitting tensile strength. Durability assessments included abrasion resistance and high-temperature effects, with the latter potentially adhering to standards for fire resistance tests of construction materials. First, a preliminary study was adopted on the calcination of bentonite, which was carried out at 900°C. GCs were prepared in various MB/ground granulated blast furnace slag (GBFS) ratios (25%, 50%, 75%, and 100%) with molar concentrations (8M, 10M, 12M, and 14M) and 2:1 Na₂SiO₃/NaOH. Synthetic fiber reinforcement such as polypropylene fiber (PPF) polyamide fiber (PAF), and basalt fiber (BF) with 0.5%, 1%, 1.5%, and 2% consumption ratios were employed for the mixtures of GCs. This comprehensive study followed a series of steps. The first step depended on determining the mechanical behavior. The second step included the durability behavior of the best GCs for each fiber type inclusion. The best solution chosen/mixture optimization of GCs step depended on a multicriteria decision-making method and a capable method (TOPSIS—Technique for Order of Preference by Similarity to Ideal Solution) to evaluate the results. Accordingly, the best GCs were obtained, and the durability index of the best GC was determined. The GCs were subjected to high temperatures of 200°C, 400°C, 600°C, and 800°C, and the results showed that optimal GCs based on TOPSIS–multicriteria decision support method have 1% PPF, 0.5% PAF, and 0.5% BF fiber content. The BF-containing series showed the best performance among the fiber types. The offered GCs were the possible net-zero/low-carbon materials for future cities.]]></description>
      <pubDate>Fri, 25 Apr 2025 16:07:21 GMT</pubDate>
      <guid>https://trid.trb.org/View/2526487</guid>
    </item>
    <item>
      <title>Enhancing rigid pavement performance: Experimental study and design optimization of bentonite clay-blended concrete with a focus on durability</title>
      <link>https://trid.trb.org/View/2537433</link>
      <description><![CDATA[This study evaluates bentonite clay (BNC) as a sustainable supplementary cementitious material for enhancing the structural performance of rigid pavement systems, with a dual focus on durability and eco-efficiency. Using Response Surface Methodology (RSM), the effects of varying BNC content on concrete properties were systematically analyzed. Results indicate that increasing BNC reduces workability, with slump values declining from 10.21 to 62.55 % due to its high-water absorption and decreases density (2355 kg/m³ for control vs. 2293 kg/m³ for 20 % BNC) owing to its lower specific gravity. While early-age strength diminishes at higher BNC levels, an optimal replacement of 12–16 % enhances long-term compressive strength via pozzolanic reactions, achieving 37.55 MPa at 91 days for the 16 % BNC mix. Flexural strength improvements are attributed to BNC’s crack and shrinkage mitigation. However, excessive BNC content (>16 %), compromises durability, evidenced by reduced ultrasonic pulse velocity (UPV) and increased porosity. BNC enhances sulfate resistance and thermal stability, demonstrating suitability for hot climates. Cement substitution with BNC reduces the carbon footprint by 31.91 %, aligning with sustainability goals. RSM-derived empirical models exhibit strong predictive accuracy (F-values: 67.07 for compressive strength, 36.92 for flexural strength; non-significant lack-of-fit, p > 0.04). The optimized mix (16 % BNC, 82-day curing) balances strength, durability, and environmental benefits. This work advances sustainable pavement design, addressing performance trade-offs and promoting low-carbon construction practices.]]></description>
      <pubDate>Thu, 24 Apr 2025 09:30:37 GMT</pubDate>
      <guid>https://trid.trb.org/View/2537433</guid>
    </item>
    <item>
      <title>Comparison of Whole Rock XRF and Portable XRF for Quantifying Calcium-Based Stabilizers in Chemically Treated Soil</title>
      <link>https://trid.trb.org/View/2437737</link>
      <description><![CDATA[Problematic subgrade soils are commonly stabilized with additives such as lime, cement kiln dust, and fly ash to improve their mechanical behavior. To reduce costly repairs post-construction, it is important to control the amount and uniformity of chemical stabilizer across the stabilized layer. Currently, there are no routine in field quality control techniques for assessing stabilizer content. This study was conducted to evaluate Whole Rock (WRA) and portable X-ray fluorescence (PXRF) spectrometry techniques for subgrade soil stabilization quality control. To accomplish this, two single-mineral based clays (kaolinite and bentonite) and a silty sand were mixed with four different calcium (CaO)-based additives: lime, cement kiln dust, fly ash (Class C), and Portland cement to achieve stabilizer contents (SCs) ranging from 0 to 64%. The deviations between stabilizer content determined using WRA and actual stabilizer content were found to be minimal and nearly normally distributed, indicating the high accuracy of the WRA measurements. The deviations between PXRF measurements and actual stabilizer content, while low, were higher than those found using WRA. Additionally, the influence of other factors, i.e., sample preparation method, particle size, scan technique, and scan duration, on the accuracy and precision of PXRF was investigated. The results revealed particle size to be the only significant variable affecting the accuracy of the PXRF measurement. Higher accuracy was obtained when soil was processed to pass a #40 sieve or finer. Results from this study identify an efficient method for determining SC in the field, leading to safer, more reliable roadways.]]></description>
      <pubDate>Wed, 09 Oct 2024 10:20:49 GMT</pubDate>
      <guid>https://trid.trb.org/View/2437737</guid>
    </item>
    <item>
      <title>Measurement and Modeling of Thermo-Hydro-Mechanical Behaviors of Frozen Clays: Frost Susceptibility and Compressibility</title>
      <link>https://trid.trb.org/View/2352382</link>
      <description><![CDATA[The risk of geohazards associated with frozen subgrades is well recognized, but a comprehensive framework to evaluate frost susceptibility from microstructural characteristics to macroscopic thermo-hydro-mechanical (THM) behaviors has not been established. This study aims to propose a simple framework for quantitatively assessing frost susceptibility and compressibility in frozen soils. A systematic THM model was devised to predict heat transfer, soil freezing characteristics, and stress states in frozen soils. Constant freezing experiments and oedometer compression tests were performed on bentonite clays under varying temperatures (-5°C, -10°C, and -20°C) and stress levels to validate the proposed model. Additionally, soil electrical conductivity measurements were employed to assess the temperature- and stress-dependent volumetric and mechanical properties of frozen soils. The model used Fourier’s law to compute the transient soil temperature profile and estimated the volume change and stress states based on the soil freezing characteristic curve. Experimental results showed that frost heave of bentonite reached between 9.0% and 26.6% of axial strain, which was largely predicted by the proposed model. It also demonstrated that the frost heave was mainly attributed to the fusion of the porewater. Additionally, the preconsolidation pressure of frozen soils exhibited a rapid increasing trend with decreasing temperature, which was explained by the temperature-dependent ice morphology in the soil interpore. Furthermore, the findings also demonstrated a remarkable sensitivity in the electrical conductivity in response to the soil temperature during the frost heave process and the stress state under the loading or unloading path.]]></description>
      <pubDate>Tue, 19 Mar 2024 15:18:33 GMT</pubDate>
      <guid>https://trid.trb.org/View/2352382</guid>
    </item>
    <item>
      <title>Performance-optimised design of sand fog seal for pavement cold repair using RSM I-optimal methodology</title>
      <link>https://trid.trb.org/View/2310691</link>
      <description><![CDATA[Sand fog seal is a preventive maintenance material to repair the early distresses in asphalt pavements. The objective of this study is to develop an optimal design guideline for sand fog seal to balance the demand for rapid traffic opening with the need to keep good road performance. Based on the response surface methodology (RSM) and I-optimal methodology, the effects of the components’ ratios (including water, filler, and sand) and their interactions on the curing process and surface function of sand fog seal were investigated. The test results showed that water can regulate the fluidity and dispersibility of the fresh sand fog seal mortar, but will prolong the curing process. The modified sodium bentonite, as the filler, can shorten the full curing time of sand fog seal due to its good moisture absorption and permeability. Moreover, the interaction of water and filler significantly affected the bonding strength, and the recommended water-filler ratio was 1.5. The sand content should be controlled to less than 25% to ensure good adhesion and abrasion resistance. Finally, a formulation design guideline for sand fog seal based on desirability optimization methodology (DOM) was proposed, with recommended formulation of 21.8% water, 30% filler, and 25% sand.]]></description>
      <pubDate>Fri, 02 Feb 2024 16:14:55 GMT</pubDate>
      <guid>https://trid.trb.org/View/2310691</guid>
    </item>
    <item>
      <title>Effect of synchronous surface grafting and intercalation bentonite on properties of SBS modified bitumen</title>
      <link>https://trid.trb.org/View/2317787</link>
      <description><![CDATA[To better enhance the improvement effect of natural bentonite on the comprehensive performance of styrene-butadiene-styrene thermoplastic elastomer modified bitumen (SMB), in this study, 3-(trimethoxysilopropyl) dimethyl octadecyl ammonium chloride (DC5700) was used for synchronous surface grafting and intercalation of bentonite (DC5700-Bentonite). Meanwhile, γ-(2,3-epoxypropoxy)propytrimethoxysilane (KH560) surface grafting bentonite (KH560-Bentonite) and octadecyldimethylbenzylammonium chloride (ODBA) intercalation bentonite (ODBA-Bentonite) were used as comparison samples. The structure and properties of the bentonite and organic bentonites (DC5700-Bentonite, KH560-Bentonite and ODBA-Bentonite) were tested by X-ray diffractometer (XRD), Fourier transform infrared spectrometer (FTIR), ultraviolet-visible spectrometer and contact angle measurement. The effects of bentonite and organic bentonites on physical, rheological and aging properties of SMB were investigated. FTIR and XRD results showed that KH560 was chemically grafted onto the surface of bentonite, ODBA was organically intercalated into the bentonite, while DC5700 achieved synchronous surface grafting and intercalation on the bentonite. Compared with KH560-Bentonite and ODBA-Bentonite, DC5700-Bentonite had the best lipophilicity and ultraviolet shielding ability. When the bentonite content was 4 wt%, KH560-Bentonite, ODBA-Bentonite and DC5700-Bentonite could increase the rutting factor of SMB by 2.9 ℃, 4.9 ℃ and 6.5 ℃, respectively, and reduce the ductility of SMB by 6.5 cm, 4.2 cm and 3.1 cm. Meanwhile, compared to SMBs containing KH560-Bentonite or ODBA-Bentonite, the SMB containing DC5700-Bentonite had the smallest creep stiffness at − 12 ℃, − 18 ℃, and − 24 ℃. The results indicated that DC5700-Bentonite was more conducive to increasing high-temperature performance of SMB than KH560-Bentonite and ODBA-Bentonite, and its adverse effects on low-temperature ductility and low-temperature cracking resistance of SMB were also significantly reduced. After thermal and ultraviolet aging, the deterioration extent of physical and rheological properties of SMB containing DC5700-Bentonite was significantly smaller than that of SMB containing KH560-Bentonite and ODBA-Bentonite. FTIR revealed that DC5700-Bentonite was more beneficial than KH560-Bentonite and ODBA-Bentonite in inhibiting the increase of carbonyl index and the decrease of butadiene index in SMB during aging. The comprehensive results revealed that compared to KH560 surface grafting bentonite and ODBA intercalation bentonite, DC5700 synchronous surface grafting and intercalation bentonite were more conducive to improving the physical and rheological properties, and aging resistance of SMB.]]></description>
      <pubDate>Wed, 24 Jan 2024 09:50:22 GMT</pubDate>
      <guid>https://trid.trb.org/View/2317787</guid>
    </item>
    <item>
      <title>A simple method to determine soil-water retention curves of compacted active clays</title>
      <link>https://trid.trb.org/View/2277417</link>
      <description><![CDATA[Determining the Soil Water Retention Curve (SWRC) of an active clay constitutes a challenge due to the significant, and sometimes irreversible, volume changes that occur during wetting and drying cycles. A novel yet simple method of experimentally determining the evolution of the SWRCs with moisture cycles is presented based on the results of a rigorous experimental study. Its purpose is to support the modelling of water flux in earthworks exposed to weather cycles that cause deterioration. Firstly, three SWRC branches (the primary drying, a scanning drying, and a scanning wetting branch) are measured and used to fit the proposed generic SWRC semi-empirical model in terms of water ratio, that, in the adsorptive region, is independent of the compaction conditions (void ratio and water content at compaction). Soil Shrink-Swell Curves (SSSCs) in terms of water ratio versus void ratio, that are easy to measure, can be determined for different compaction conditions over several drying and wetting cycles. Finally, the SSSCs are combined with the generic SWRC model to determine the evolution of the SWRCs with moisture cycles for the compaction conditions of interest. This method is demonstrated for two London clays of high and very high plasticity. Samples were compacted in five different conditions, varying in gravimetric water content and dry density, and were cycled six times between 1 and 80 MPa of total suction. The generic SWRC model was fitted to the experimental data. The model was able to estimate the SWRC in terms of degree of saturation over the six drying-wetting cycles without propagation of error. The significance of the research is that SWRC can now be determined over a range of wetting and drying cycles quickly and simply and enable modelling of deterioration of clays fills due to the action of weather to be accurate.]]></description>
      <pubDate>Mon, 20 Nov 2023 09:10:30 GMT</pubDate>
      <guid>https://trid.trb.org/View/2277417</guid>
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