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        <title>Frontiers in Materials | Structural Materials section | New and Recent Articles</title>
        <link>https://www.frontiersin.org/journals/materials/sections/structural-materials</link>
        <description>RSS Feed for Structural Materials section in the Frontiers in Materials journal | New and Recent Articles</description>
        <language>en-us</language>
        <generator>Frontiers Feed Generator,version:1</generator>
        <pubDate>2026-06-03T18:54:39.659+00:00</pubDate>
        <ttl>60</ttl>
        <item>
        <guid isPermaLink="true">https://www.frontiersin.org/articles/10.3389/fmats.2026.1853214</guid>
        <link>https://www.frontiersin.org/articles/10.3389/fmats.2026.1853214</link>
        <title><![CDATA[Experimental study on the degradation behavior of FRP-confined RC columns under coupled Wind–Sand erosion and freeze–thaw cycles]]></title>
        <pubdate>2026-05-26T00:00:00Z</pubdate>
        <category>Original Research</category>
        <author>Wenhao Ren</author>
        <description><![CDATA[Reinforced concrete (RC) structures in cold and arid regions are simultaneously subjected to wind–sand erosion and freeze–thaw cycles, resulting in complex deterioration of their mechanical performance. To investigate this coupled effect, a series of laboratory tests were conducted on FRP-confined RC columns under controlled environmental conditions, including wind–sand erosion at a velocity of 26 m/s and freeze–thaw cycles ranging from −20 °C to +20 °C up to 200 cycles. The experimental results indicate that plain concrete specimens exhibit significant degradation, with reductions of 32.4% in compressive strength and 36.7% in flexural strength after 200 cycles. In contrast, specimens confined with CFRP, GFRP, and BFRP retain 87.2%, 84.6%, and 82.1% of their initial mechanical properties, respectively, demonstrating the effectiveness of FRP confinement in mitigating environmental damage. Based on the observed behavior, the damage evolution mechanisms under coupled wind–sand erosion and freeze–thaw actions are systematically analyzed. Wind–sand erosion increases surface permeability and facilitates moisture ingress, while freeze–thaw cycles induce internal microcracking and reduce material cohesion. The interaction between these processes forms a positive feedback mechanism that accelerates structural deterioration. Although FRP confinement restrains lateral expansion, it cannot prevent the accumulation of internal damage, leading to interfacial debonding, local bulging, and eventual rupture. Furthermore, a unified multi-parameter empirical model is proposed to quantitatively predict the degradation behavior of FRP-confined RC columns by incorporating the effects of freeze–thaw cycles, erosion intensity, and confinement characteristics. The proposed model shows good agreement with the experimental results, with the coefficient of determination (R2) ranging from 0.9126 to 0.9413 for all specimens, indicating high predictive accuracy and robustness. Finally, this paper presents engineering design recommendations for FRP-reinforced concrete columns under various environmental conditions.]]></description>
      </item><item>
        <guid isPermaLink="true">https://www.frontiersin.org/articles/10.3389/fmats.2026.1842532</guid>
        <link>https://www.frontiersin.org/articles/10.3389/fmats.2026.1842532</link>
        <title><![CDATA[Study on the durability and micro-mechanism of granite manufactured sand concrete under coupled alkali-silica reaction and sulfate attack]]></title>
        <pubdate>2026-05-21T00:00:00Z</pubdate>
        <category>Original Research</category>
        <author>Junhui He</author><author>Yuhan Luo</author><author>Xiaoyu Liu</author><author>Liuyuan Lan</author><author>Junlin Liang</author><author>Xiaolong Yang</author>
        <description><![CDATA[Granite manufactured sand is increasingly used as a substitute for river sand, but its potential alkali-silica reactivity may aggravate durability deterioration in sulfate-rich environments. This study investigated the coupled effect of alkali-silica reaction (ASR) and sulfate attack on granite manufactured sand concrete, and evaluated the mitigating performance of fly ash, silica fume, slag, alumina, and aluminum hydroxide by sulfate wet-dry cycling, chloride ion penetration testing, and SEM/EDS/XRD analyses. ASR accelerated sulfate-induced strength deterioration; after 100 wet-dry cycles, the concrete containing 30% fly ash maintained a corrosion resistance coefficient of about 0.79, whereas the coefficients of the other single-admixture mixtures were below 0.75. Among the blended systems, slag + alumina, slag + aluminum hydroxide, and fly ash + silica fume + slag all retained corrosion resistance coefficients above 0.75 after 100 cycles. EDS results further showed that the Ca/Si ratio decreased from 0.93 in the reference group to 0.64, 0.51, and 0.51 in the fly ash, silica fume, and slag groups, respectively, but increased to 1.43 in the alumina group, indicating clear differences in gel chemistry and sulfate-response pathways. Overall, mineral admixtures improved matrix compactness and chloride resistance, whereas aluminum-based additives alone provided weaker sulfate resistance; the combined use of mineral admixtures and aluminum-based compounds showed a synergistic benefit under coupled deterioration.]]></description>
      </item><item>
        <guid isPermaLink="true">https://www.frontiersin.org/articles/10.3389/fmats.2026.1824942</guid>
        <link>https://www.frontiersin.org/articles/10.3389/fmats.2026.1824942</link>
        <title><![CDATA[Mechanical properties and comprehensive evaluation of fly ash-metakaolin geopolymer mortar: combined effect of FA/MK ratio, NaOH concentration and curing condition]]></title>
        <pubdate>2026-05-21T00:00:00Z</pubdate>
        <category>Original Research</category>
        <author>Shaolong Wu</author><author>Zheng Zhang</author><author>Zhiqiang Huo</author><author>Zhengxun Yang</author><author>Jinwei Jia</author>
        <description><![CDATA[Geopolymers are widely regarded as the best low-carbon alternatives to ordinary Portland cement (OPC). However, most previous studies on precursor composition, alkali concentration, and curing conditions have been limited to single factors or partial combinations, failing to reflect the combined effects of all variables simultaneously. As a result, the optimal mixtures derived from isolated variables can easily fall into local optima and mask the true comprehensive potential of the material, significantly reducing their reference values. Therefore, this work designed a systematic experimental program covering 72 mix combinations, and a dynamic multi-objective evaluation model integrating the AHP-entropy weight method and grey clustering analysis was established to simultaneously assess mechanical performance, workability, and environmental impact (GWP). Comparative studies have shown that with the optimization of these factors, the comprehensive performance of Fly ash-metakaolin (FA-MK) geopolymer mortar has been significantly enhanced. The model identified an optimal mixture (FA/MK = 6:4, 12 mol/L NaOH, ambient curing) achieving a compressive strength of 65 MPa and a GWP of only 193.65 kg/t. Compared to higher-MK or heat-cured systems, this mixture avoids microstructural damage, reduces GWP by up to 66.36 kg/t, and improves workability, with a strength reduction of no more than 6.4 MPa. Compared to the pure FA system, compressive strength more than doubled at an acceptable environmental cost. More importantly, by integrating subjective AHP and objective entropy weighting, the model dynamically adjusts indicator weights to reflect specific engineering priorities, overcoming the limitations of traditional single-objective optimization. Beyond FA-MK geopolymers, it can be extended to other multi-source solid waste cementitious systems, serving as a flexible and practical tool for customized mixture design in sustainable construction.]]></description>
      </item><item>
        <guid isPermaLink="true">https://www.frontiersin.org/articles/10.3389/fmats.2026.1799973</guid>
        <link>https://www.frontiersin.org/articles/10.3389/fmats.2026.1799973</link>
        <title><![CDATA[Deformation and failure modes of bedded and jointed rock mass material]]></title>
        <pubdate>2026-05-20T00:00:00Z</pubdate>
        <category>Original Research</category>
        <author>Zixu Wang</author><author>Kepeng Hou</author><author>Huafen Sun</author><author>Yalei Zhe</author><author>Junwei Ma</author><author>Yubang Li</author>
        <description><![CDATA[The stability of bedded and jointed rock masses is threatened by progressive failure at the roof-wall junction, where a triangular relaxation zone (TRZ) forms due to excavation unloading. This study investigates the TRZ failure mechanism and its controlling factors. A mechanical model was developed to derive a stability coefficient considering bedding spacing, stacked overhanging segment length, and longitudinal joint length. FLAC3D simulations compared stope orientations along dip and strike directions. Sc decreases with increasing S and L but increases with B. Intact rock layers thicker than 10 cm show short-term self-stability. Dip-oriented stopes produced greater roof displacement and stress concentration than strike-oriented ones, triggering progressive bedding-plane failure. The TRZ evolves through delamination, cantilever bending, and chain failure along weak interfaces. Dip-oriented layouts intersect more bedding planes, worsening stability. These findings provide quantifiable criteria for support design and stope layout optimization to enhance mining safety.]]></description>
      </item><item>
        <guid isPermaLink="true">https://www.frontiersin.org/articles/10.3389/fmats.2026.1799597</guid>
        <link>https://www.frontiersin.org/articles/10.3389/fmats.2026.1799597</link>
        <title><![CDATA[Effect of RAP surface modification on mechanical properties of stable crushed gravel with mineral admixture]]></title>
        <pubdate>2026-05-20T00:00:00Z</pubdate>
        <category>Original Research</category>
        <author>Dengqin Yu</author><author>Zhibao Zhang</author><author>Hongtao Qin</author><author>Xu Wu</author><author>Jin Chen</author>
        <description><![CDATA[To address the key bottleneck of weakened bonding at the interface between inorganic binder and aggregate caused by the surface asphalt film on reclaimed asphalt pavement (RAP) coarse aggregate, a method using mineral admixture slurry for RAP interface modification is proposed. Through compaction, unconfined compressive strength, splitting strength, and drying shrinkage tests, the effects of different RAP contents (12%, 28%, 44%, 59%) on the mechanical properties of recycled mixtures before and after modification were systematically studied, and a comprehensive evaluation was conducted in combination with function fitting (R2 ≥ 0.94) and life cycle carbon emission accounting. The results show that interface modification reduces the optimum moisture content of the P component (modified RAP) by 1.10%∼7.20% compared with the unmodified NP component (unmodified RAP), significantly improving compaction properties; the compressive strength of the P component changes in a quadratic parabolic pattern with the increase of RAP content (R2 ≥ 0.94), reaching a 28-day compressive strength of 6.5 MPa at 28% content, which is 25.0% higher than that of fully crushed stone mixture, while the NP component shows a quadratic decreasing function (R2 ≥ 0.98); the 28-day splitting tensile strength of the P component increases by 94.1% compared with the 7-day strength, and the 60-day drying shrinkage microstrain is reduced by 67.1% compared with cement- stabilized crushed stone; carbon emission accounting shows that when the RAP content is 28%, the carbon emissions per unit volume of mixture are reduced by 54.3% compared with cement-stabilized crushed stone. Interface modification technology effectively achieves the synergistic optimization of “strength improvement-crack resistance enhancement-carbon reduction” for RAP recycled mixtures, providing a theoretical basis for the high-value utilization of RAP in semi-rigid bases.]]></description>
      </item><item>
        <guid isPermaLink="true">https://www.frontiersin.org/articles/10.3389/fmats.2026.1788487</guid>
        <link>https://www.frontiersin.org/articles/10.3389/fmats.2026.1788487</link>
        <title><![CDATA[Experimental study on mechanical properties and microscopic mechanism of solidified slit soil with nanocomposite fibers]]></title>
        <pubdate>2026-05-20T00:00:00Z</pubdate>
        <category>Original Research</category>
        <author>Qixiang Yin</author><author>Qiangqiang Cheng</author><author>Mingjiao Hou</author>
        <description><![CDATA[Solid waste management and utilization are pivotal to the operation of a circular economy. Within the present study, nano-silica and nano-graphene composite fibers were incorporated as modifiers into solidified silt soil specimens, with the aim of examining how these fibrous additives affect the specimens’ mechanical performance and microstructural evolution. The findings indicate that at the 28-day curing stage, the compressive strength of glass fiber-reinforced soil specimens is 75.6% greater than that of the unmodified control group; furthermore, the addition of 1.0% silica particles results in a further 118.3% enhancement in compressive strength. Additionally, the correlation between graphene content and material toughness exhibits a nonlinear trend: as the graphene dosage increases, the toughness of specimens modified with nano-graphene composite fibers rises initially before declining thereafter. In the early hardening phase, the introduction of nano-graphene composite fibers exerts a notable promotional effect on the tensile strength development of the soil specimens. Microstructural analysis results demonstrate that elevated silica particle concentrations enhance the interfacial adhesion between flocculent reaction products, crystalline phases, and the fiber-reinforced matrix. More specifically, acicular crystalline structures fill the interfacial gaps between glass fibers and matrix constituents, forming a strong mechanical interlocking mechanism between the fibers and their adjacent matrix. Collectively, this research lays a theoretical and experimental foundation for the stability control of solidified silt soil.]]></description>
      </item><item>
        <guid isPermaLink="true">https://www.frontiersin.org/articles/10.3389/fmats.2026.1839636</guid>
        <link>https://www.frontiersin.org/articles/10.3389/fmats.2026.1839636</link>
        <title><![CDATA[Performance evaluation and engineering application of high-modulus asphalt mixtures with various modifications]]></title>
        <pubdate>2026-05-18T00:00:00Z</pubdate>
        <category>Original Research</category>
        <author>Ao Dong</author><author>Zheng Zhang</author><author>Ruiyun Zhu</author><author>Guoshu Wang</author><author>Ziyao Ping</author><author>Tingting Xie</author><author>Dongzhao Li</author><author>Erhu Yan</author><author>Linbing Wang</author>
        <description><![CDATA[High-modulus asphalt mixtures are critical for long-life pavements due to their excellent deformation resistance. This study systematically compares three modification approaches—unmodified low-penetration-grade asphalt, natural asphalt modified asphalt, and polymer modified asphalt combined with two gradation systems (HFM-20 and HFM-16). Performance was evaluated through dynamic modulus, wheel tracking, and four-point bending fatigue tests. Results show that the natural asphalt modified mixture exhibits the best overall performance, combining high modulus, high rutting resistance, and excellent fatigue life, making it the preferred solution for long-life pavements. The polymer modified mixture demonstrates outstanding high-temperature performance, while the unmodified hard-grade asphalt shows high stiffness. HFM-20 gradation better leverages the advantages of hard-grade asphalt, whereas HFM-16 provides a compensatory effect for softer binders. Microstructural characterization (FTIR, SARA, XRF) reveals that natural asphalt’s organic components are fully compatible with petroleum asphalt. Higher asphaltene and resin contents enhance adhesion and high-temperature deformation resistance. The gel-type structure of natural asphalt, classified by the Gaestel colloidal instability index (Ic), provides superior rutting resistance compared to sol-type materials. The inorganic fraction, primarily calcium carbonate, forms a natural mastic structure that balances stiffness and flexibility. These synergistic microstructural features underpin the exceptional performance of natural asphalt modified mixtures. The findings have been successfully applied to the Wuyue Expressway expansion project, providing a technical basis for material selection and structural design of high-modulus asphalt mixtures.]]></description>
      </item><item>
        <guid isPermaLink="true">https://www.frontiersin.org/articles/10.3389/fmats.2026.1846633</guid>
        <link>https://www.frontiersin.org/articles/10.3389/fmats.2026.1846633</link>
        <title><![CDATA[Correction: Investigation of rutting deformation mechanisms and high-temperature deformation resistance of asphalt mixtures]]></title>
        <pubdate>2026-05-14T00:00:00Z</pubdate>
        <category>Correction</category>
        <author>Qilu Luo</author><author>Zhengmao Wei</author><author>Hongliu Rong</author><author>Richeng Huang</author><author>Jiabao Wang</author>
        <description></description>
      </item><item>
        <guid isPermaLink="true">https://www.frontiersin.org/articles/10.3389/fmats.2026.1808706</guid>
        <link>https://www.frontiersin.org/articles/10.3389/fmats.2026.1808706</link>
        <title><![CDATA[The impact of granite powder on the performance and hydration of concrete]]></title>
        <pubdate>2026-05-13T00:00:00Z</pubdate>
        <category>Original Research</category>
        <author>Liangfa Jiang</author><author>Wenqi Tang</author><author>Junlin Liang</author><author>Wenfeng Jiang</author><author>Shengyi Huang</author><author>Chenli Zhao</author>
        <description><![CDATA[Granite manufactured sand typically contains a certain amount of stone powder in engineering applications, and the variation in its content significantly affects the workability, mechanical properties, and cement hydration process of concrete. To systematically reveal the impact of granite stone powder on concrete performance, concrete mixtures were prepared with stone powder contents of 3%, 5%, 7%, 10%, 15%, and 20%. The effects of stone powder content on the workability and mechanical properties of concrete were studied. In addition, cement paste samples with 10% and 20% stone powder content were prepared, and X-ray diffraction (XRD), thermogravimetric analysis (TG-DTG), and scanning electron microscopy (SEM) were used to explore the mechanism of granite stone powder’s influence on cement hydration behavior. The results indicate that granite stone powder content has a significant impact on the workability of concrete: when the stone powder content is too low, the water retention of concrete is insufficient; when the content is too high, the slump is notably reduced. There is an optimal range for granite stone powder content in C30 and C40 manufactured sand concrete, and a moderate amount of stone powder can improve both compressive and flexural tensile strengths. Compared with limestone stone powder, granite stone powder has a larger particle size and an uneven gradation, resulting in a relatively weaker micro-aggregate filling effect and a less pronounced promoting effect on cement hydration. Additionally, granite stone powder reduces the early reaction rate of cement hydration to some extent. The findings provide a theoretical basis for the rational use of granite stone powder in concrete and offer reference value for promoting the application of granite manufactured sand in engineering projects.]]></description>
      </item><item>
        <guid isPermaLink="true">https://www.frontiersin.org/articles/10.3389/fmats.2026.1826062</guid>
        <link>https://www.frontiersin.org/articles/10.3389/fmats.2026.1826062</link>
        <title><![CDATA[Experimental study on the mechanical properties and dry–wet–freeze–thaw coupled durability performance of hydraulic basalt fiber mortar]]></title>
        <pubdate>2026-05-13T00:00:00Z</pubdate>
        <category>Original Research</category>
        <author>Jianpeng Zhang</author><author>Qingsong Li</author><author>Han Xu</author><author>Xiaodi Dong</author>
        <description><![CDATA[Studying the effects of short-cut basalt fiber on the properties of hydraulic mortar and its damage mechanism under dry–wet–freeze–thaw coupling is essential for optimizing the mix proportion of hydraulic mortar applied to high-salt and high-altitude regions in Xinjiang. This study conducted a single-factor experiment to examine the effects of fiber length and dosage on the mechanical properties of mortar and carried out dry–wet–freeze–thaw coupled cycle tests in a brine environment. The results showed that the incorporation of short-cut basalt fibers significantly enhanced the mechanical properties of the mortar, among which the 12 mm fibers (with a dosage of 1.0 kg/m3) exhibited the most pronounced reinforcing effect. Damage mechanism analysis revealed that the coupled damage in the brine environment mainly resulted from the combined effects of expansion and contraction during dry–wet cycles and pore expansion during freeze–thaw cycles, exhibiting a significant synergistic acceleration effect. The degree of damage was much greater than that observed in clear water. Further comparison revealed that 6 mm short-cut basalt fibers exhibited better dispersion properties and could effectively bridge microcracks, resulting in a more pronounced improvement in the durability of hydraulic mortar and making them more suitable for water structures in cold, arid, saline–alkali areas.]]></description>
      </item><item>
        <guid isPermaLink="true">https://www.frontiersin.org/articles/10.3389/fmats.2026.1833638</guid>
        <link>https://www.frontiersin.org/articles/10.3389/fmats.2026.1833638</link>
        <title><![CDATA[Investigation of evaluation indicators of agglomeration degree of recycled asphalt pavement materials]]></title>
        <pubdate>2026-05-13T00:00:00Z</pubdate>
        <category>Original Research</category>
        <author>Zhixin Lu</author><author>Fucheng Guo</author><author>Peilin Liu</author>
        <description><![CDATA[High-content reclaimed asphalt pavement (RAP) utilization is becoming a promising direction to achieve sustainable pavement maintenance. However, the agglomerate degree of RAP materials is hard to be accurately quantified. In this study, sieving tests, extraction tests, Micro-Deval abrasion test, and three-dimensional laser scanning technology were used to systematically analyze the agglomerate degree of RAP materials with different particle sizes, and evaluation indicators for overall agglomeration degree of RAP material and refinement evaluation indicators for agglomeration degree of various particle sizes were proposed. Results show that the coefficient of variation of sieve passing rate for RAP particles below the 9.5 mm sieve is higher than 10%, and the average overall agglomerate rate for RAP materials is 6.74. The agglomeration of RAP materials with the nominal maximum particle size ranging from 13.2 to 19 mm is mainly composed of aggregates retained on the 4.75 mm sieve, while the agglomeration of RAP materials with the nominal maximum particle size ranging from 1.18 to 9.5 mm was mainly composed of aggregates of the lower particle size. The agglomerate degree of RAP materials increases with the increase of the nominal maximum particle size, where RAP materials with the nominal maximum particle size of above 9.5 mm have a higher agglomerate degree. Compared to the extraction test, the crushing mass loss rate index based on the Micro-Deval abrasion test could more effectively evaluate the agglomerate degree of RAP materials, with a correlation coefficient of 0.96 with the extraction mass loss rate.]]></description>
      </item><item>
        <guid isPermaLink="true">https://www.frontiersin.org/articles/10.3389/fmats.2026.1778301</guid>
        <link>https://www.frontiersin.org/articles/10.3389/fmats.2026.1778301</link>
        <title><![CDATA[Using calcined fine coal gasification slag as a novel supplementary cementitious material for Portland cement]]></title>
        <pubdate>2026-05-13T00:00:00Z</pubdate>
        <category>Original Research</category>
        <author>Shulian Lv</author><author>Bo Fu</author>
        <description><![CDATA[Cement production accounts for approximately 8% of global anthropogenic CO2 emissions, underscoring the urgent need for low‑carbon supplementary cementitious materials (SCMs). Fine coal gasification slag (FCGS) is an abundant industrial by‑product, but its high residual carbon content results in low reactivity, limiting its application in cementitious systems. This study investigates the feasibility of using calcined fine coal gasification slag (CFCGS) as a reactive SCM in Portland cement (PC) composites. FCGS was thermally treated at 1,200 °C for 4 h to remove residual carbon and enhance its reactivity. The effects of CFCGS replacement (0–30 wt.%) on setting time, hydration kinetics, compressive strength, and microstructure were systematically evaluated. Incorporation of CFCGS prolonged both initial and final setting times, with the initial setting time increasing from 127 min to 268 min. Early‑age strength decreased at high replacement levels, but 28‑day compressive strength improved from 59 MPa (plain PC) to 66 MPa (30% CFCGS), reflecting enhanced long‑term reactivity. XRD, TG‑DTG, and 27Al NMR analyses revealed that CFCGS modified the hydration assemblage, decreasing portlandite and ettringite (AFt) contents while promoting the formation of C‑A‑S‑H and the conversion of AFt to AFm, owing to its high alumina content. These results demonstrate that calcination effectively upgrades low‑reactivity FCGS into a viable SCM, offering a promising strategy to reduce clinker use and CO2 emissions in cement production.]]></description>
      </item><item>
        <guid isPermaLink="true">https://www.frontiersin.org/articles/10.3389/fmats.2026.1842346</guid>
        <link>https://www.frontiersin.org/articles/10.3389/fmats.2026.1842346</link>
        <title><![CDATA[Tensile and shear performance of new-to-old concrete interface in reinforced double-layer linings of subsea shield tunnels]]></title>
        <pubdate>2026-05-08T00:00:00Z</pubdate>
        <category>Original Research</category>
        <author>Hanyuan Li</author><author>Fei Sun</author><author>Jin Feng</author><author>Yang Liu</author><author>Zhihui Xiong</author><author>Denghan Zhu</author><author>Kaifei Zhao</author>
        <description><![CDATA[The interfacial mechanical behavior of double-layer lining concrete in shield tunnels is a critical factor that ensures the synergistic load-bearing performance of the overall structure. In this research, laboratory tests, including shear and axial tensile tests, were conducted on new-to-old concrete interfaces under diverse working conditions. Taking into account the effects of interface treatment approaches, anchor bar parameters, and normal compressive stress, the variation rules for interfacial shear strength, tensile strength, and bond stiffness were quantified, and the core control factors affecting interfacial mechanical performance were identified. Afterwards, a refined numerical model targeting new-to-old concrete was built in ABAQUS to explore the damage evolution law and mechanical response features at the contact interface. Eventually, relying on the engineering background of Jintang Highway Subsea Shield Tunnel, the bearing performance of the double-layer superimposed lining under eccentric compression was analyzed, with emphasis on the impacts of interfacial mechanical parameters on the collaborative working efficiency of the lining structure. The findings demonstrate that the mechanical characteristics of new-to-old concrete interfaces are mainly controlled by interface treatment schemes, anchor bar parameters, and normal pressure. The simulated shear strength falls within the range of 2.804–5.197 MPa, and the tensile strength ranges from 1.543 MPa to 1.918 MPa, both of which are lower than the corresponding strength indexes of C40 concrete. The flexural bearing capacity of the double-layer superimposed lining is remarkably superior to that of the single-layer segment structure, and presents a positive correlation with the interface deterioration coefficient (λ). Under high axial compression, reinforcing the interfacial mechanical properties can prominently elevate the ultimate structural capacity of the tunnel lining; conversely, the lifting effect of interface performance optimization is relatively limited under low axial compression. Accordingly, the layout of anchor bars can be rationally optimized while ensuring interface roughness and the construction quality of the secondary lining.]]></description>
      </item><item>
        <guid isPermaLink="true">https://www.frontiersin.org/articles/10.3389/fmats.2026.1810487</guid>
        <link>https://www.frontiersin.org/articles/10.3389/fmats.2026.1810487</link>
        <title><![CDATA[Analysis of performance and carbon emission benefits for Micro-CaCO3 and fly ash composite admixture concrete]]></title>
        <pubdate>2026-05-08T00:00:00Z</pubdate>
        <category>Original Research</category>
        <author>Tao Han</author><author>Chaoliang Gou</author><author>Xianqing Zhong</author><author>Yu Liu</author><author>Jing Chen</author><author>Qingyu Wu</author>
        <description><![CDATA[In order to reduce the high dependence on cement in the concrete preparation process, based on the Guangxi Lianhe Expressway Project, Micro-CaCO3 and fly ash were selected for use as the composite admixtures to study the effects of their application on the concrete chemical properties, appearance quality and carbon emission in the life stage, and the SEM test was utilized to observe the microstructure of the corresponding mortar and to reveal its intrinsic mechanism. The research results show that Micro-CaCO3 composite fly ash admixture can improve the flowability and early strength of concrete. For low-strength concrete, it can reach standard strength in about 7 days. Meanwhile, concrete with an appropriate amount of composite admixture can enhance its resistance to elastic deformation. SEM images indicate that the incorporation of Micro-CaCO3 has a better filling and compacting effect on the internal pores of concrete. However, the dosage of Micro-CaCO3 to replace the equivalent amount of cement should be controlled between 10% and 20%, while excessive dosage will easily affect the hydration and consolidation effect between cement and fly ash, which can reduce the carbon emission ratio of concrete in the stages of materialization, transportation, and construction by about 9%–18%.]]></description>
      </item><item>
        <guid isPermaLink="true">https://www.frontiersin.org/articles/10.3389/fmats.2026.1787313</guid>
        <link>https://www.frontiersin.org/articles/10.3389/fmats.2026.1787313</link>
        <title><![CDATA[Study on the macro-micro influence of gradation area on the maximum shear stiffness of coarse-grained soils]]></title>
        <pubdate>2026-05-08T00:00:00Z</pubdate>
        <category>Original Research</category>
        <author>Chenchen Li</author><author>Chaodong Liang</author><author>Jun Du</author><author>Yubo Liu</author><author>Zhiming Xiong</author><author>Xinggang Shen</author><author>Zhiyu You</author><author>Ping Wang</author><author>Mingjie Jiang</author>
        <description><![CDATA[The accurate determination of the maximum shear stiffness of coarse-grained soils is critical for engineering safety design yet remains challenging due to its complex dependence on gradation. This study investigates the macro- and micro-scale effects of the gradation area, a comprehensive parameter characterizing the entire gradation curve, on this stiffness. Cyclic shear tests were conducted on coarse-grained soils with varying gradation areas. Concurrently, a discrete element method numerical model was developed to elucidate the underlying micromechanisms. Experimental results demonstrate that, under constant normal stress, the maximum shear stiffness decreases with an increasing gradation area, following an inverse relationship. A predictive formula incorporating the gradation area was thus proposed and validated against independent data. The micromechanical analysis reveals that a reduction in the gradation area corresponds to a higher proportion of coarse grains, which leads to a wider shear zone, more irregular particle motion, and the formation of a robust, high-strength force-chain network. The synergistic interaction of these mechanisms explains the observed increase in maximum shear stiffness for soils with smaller gradation areas. This study provides a macro-micro integrated understanding of how gradation regulates shear stiffness, offering theoretical support for the optimized design of granular materials in engineering applications.]]></description>
      </item><item>
        <guid isPermaLink="true">https://www.frontiersin.org/articles/10.3389/fmats.2026.1814311</guid>
        <link>https://www.frontiersin.org/articles/10.3389/fmats.2026.1814311</link>
        <title><![CDATA[Study on mechanical behavior of steel fiber reinforced high strength concrete five-pile caps]]></title>
        <pubdate>2026-05-07T00:00:00Z</pubdate>
        <category>Original Research</category>
        <author>Jie Lei</author><author>Shuo Li</author><author>Guodong Zhang</author><author>Jinyong Yang</author><author>Shuaiqi Song</author><author>Weifeng Bai</author>
        <description><![CDATA[Nine steel fiber reinforced high strength concrete (SFRHSC) five-pile caps with the plane dimensions of 800 mm × 800 mm and the overall thickness of 200mm∼400 mm were subjected to static load test and were analyzed combined with finite element analysis. The crack development and failure mode, the load-displacement curve, the concrete strain and steel strain of specimens were obtained, and the influences of the effective thickness of pile caps, steel fiber volume fraction and concrete strength grade on the mechanical behavior of pile caps were analyzed, and the mechanical mechanism of SFRHSC five-pile caps was clarified. The results show that the failure mode of SFRHSC five-pile caps is punching shear failure, and the load-transferring mechanism of SFRHSC five-pile caps conforms to strut-and-tie model. The stress on each pile is uneven, and the load borne by the middle pile is significantly higher than that of the corner pile. With the increase of the effective thickness of pile caps and the steel fiber volume fraction, the bearing capacity of pile caps is significantly improved. Finally, the calculation formula for the punching shear capacity of SFRHSC five-pile caps was established.]]></description>
      </item><item>
        <guid isPermaLink="true">https://www.frontiersin.org/articles/10.3389/fmats.2026.1822806</guid>
        <link>https://www.frontiersin.org/articles/10.3389/fmats.2026.1822806</link>
        <title><![CDATA[Effects of nano-TiC and nano-CaCO3 on steel fiber-reinforced cementitious mortar: a study on mechanical properties and freeze-thaw performance]]></title>
        <pubdate>2026-05-04T00:00:00Z</pubdate>
        <category>Original Research</category>
        <author>Tian Bai</author><author>Xin Yang</author><author>Zhengjun Wang</author><author>Kai Chen</author>
        <description><![CDATA[Steel fiber (SF) cement mortar, renowned for its dual advantages of strength and toughness, is widely used in construction, transportation, and other engineering fields. However, in actual service, it often faces challenges, such as weak bonding at the SF-cement matrix interface and insufficient freeze resistance in severe cold environments, which compromise the long-term durability of engineering structures. To optimize the performance of SF cement mortar, a composite cement mortar (TS) was developed. This study investigates the effects of single-blending nano-TiC(NT), nano-CaCO3 (NC), and their combined blending on the mechanical properties (flexural and compressive strength) and freeze-thaw resistance (mass and strength loss rates under freeze-thaw cycles) of the mortar. Analysis of variance was employed to examine the interactions among materials. Scanning Electron Microscope (SEM) and Energy Dispersive Spectroscopy (EDS) were also used to examine the microstructure of the mortar. Results indicate that the TS3 group with sole NT addition demonstrated stable mechanical property enhancement, achieving 28-day flexural and compressive strengths of 11.79 MPa and 38.21 MPa, respectively—representing 10.7% and 20.0% increases over the control group. The sole NC addition group exhibited significant performance fluctuations, while the TS6 group showed approximately 10% strength improvement at 28 days. Some groups experienced strength degradation due to NC agglomeration. Among the mixed-blended groups, the TS12 group exhibited the optimal “hydration-filling” synergistic effect, achieving a 28-day compressive strength of 38.89 MPa. Agglomeration occurred in most groups due to mismatched nanomaterial dosage or dispersion, resulting in strength reductions exceeding 14%. Under freeze-thaw cycles, the TS12 group demonstrated the best freeze resistance, with a compressive strength loss rate of 9.2% after 100 cycles. The TS3 group (single NT addition) and the TS6 group (single NC addition) also outperformed the control group, both suppressing freeze-thaw damage through optimized pore structure. The two-way ANOVA revealed that NT, NC, and their interaction exerted a highly significant influence on both the flexural strength and compressive strength of steel fiber cement mortar at 7-day and 28-day ages. SEM analysis revealed compact microstructures across all groups. EDS characterization results indicate that the elemental features in cement mortars with different additive combinations exhibit significant differences.]]></description>
      </item><item>
        <guid isPermaLink="true">https://www.frontiersin.org/articles/10.3389/fmats.2026.1794762</guid>
        <link>https://www.frontiersin.org/articles/10.3389/fmats.2026.1794762</link>
        <title><![CDATA[Optimizing design and performance analysis of prestress-impact synergistic plastic forming equipment based on Gaussian process regression surrogate modeling]]></title>
        <pubdate>2026-04-29T00:00:00Z</pubdate>
        <category>Original Research</category>
        <author>Shiyun Hu</author><author>Yang Yang</author><author>Qipeng Zhang</author>
        <description><![CDATA[IntroductionThis study proposes a novel prestress-impact synergistic plastic forming equipment for difficult-to-deform high-specific-strength materials, with a focus on TC4 titanium alloy.MethodsA dynamic optimization framework integrating finite element analysis (FEA) and Gaussian Process Regression (GPR) surrogate modeling is developed to enhance the structural dynamic performance.ResultsPrestressed modal analysis identifies the sixth mode as the weak mode, and multi-objective optimization using GPR-assisted NSGA-II achieves a 6.1% reduction in structural mass, a 3.6% increase in the sixth natural frequency, and an 8.7% decrease in maximum von Mises stress compared to the initial design, outperforming traditional response surface methodology. Experimental validation on a constructed prototype demonstrates that the synergistic process, combining controllable prestress with low-frequency impact excitation, significantly improves formability: height reduction increases 48.6% (versus 35.2% in static pressing), forming force and energy consumption decrease by 32.5% and 30%, respectively, while average grain size is refined from 28.4 µm to 12.7 µm with equiaxed α-phase fraction rising to 78% Vickers hardness improves from 312 HV to 358 HV due to enhanced dynamic recrystallization and bimodal microstructure evolution.DiscussionsThe integration of machine learning-based surrogate modeling provides an efficient and scalable approach for vibration-assisted forming systems, offering substantial energy savings and superior mechanical properties aligned with sustainable high-end manufacturing requirements.]]></description>
      </item><item>
        <guid isPermaLink="true">https://www.frontiersin.org/articles/10.3389/fmats.2026.1842970</guid>
        <link>https://www.frontiersin.org/articles/10.3389/fmats.2026.1842970</link>
        <title><![CDATA[Correction: Integrated experimental testing and optimisation of numerical data-driven modelling for eco-efficient GI-fibre mortars with recycled crushed waste clay bricks in ferrocement strengthening of RC beams]]></title>
        <pubdate>2026-04-28T00:00:00Z</pubdate>
        <category>Correction</category>
        <author>Md Jihad Miah</author><author>Mohammad Shamim Miah</author><author>Noor Md. Sadiqul Hasan</author><author>Humera Mughal</author>
        <description></description>
      </item><item>
        <guid isPermaLink="true">https://www.frontiersin.org/articles/10.3389/fmats.2026.1846510</guid>
        <link>https://www.frontiersin.org/articles/10.3389/fmats.2026.1846510</link>
        <title><![CDATA[Editorial: Sustainable and green materials in geotechnical engineering]]></title>
        <pubdate>2026-04-23T00:00:00Z</pubdate>
        <category>Editorial</category>
        <author>Bing Bai</author><author>Riyadh Al-Raoush</author><author>Reza Taherdangkoo</author><author>Wenbing Wu</author>
        <description></description>
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