Materials and Structures最新文献

{"title":"Double-layered hybrid GFRP–steel reinforced concrete beams: flexural response, ductility, and failure modes","authors":"Nikhil Ghate,&nbsp;Rahul Bhartiya,&nbsp;Satadru Das Adhikary","doi":"10.1617/s11527-026-03320-0","DOIUrl":"10.1617/s11527-026-03320-0","url":null,"abstract":"<div><p>Glass fiber reinforced polymer (GFRP) bars have been increasingly considered as a corrosion-resistant alternative to steel reinforcement. However, their brittleness and low-elastic modulus limit structural ductility. To overcome these limitations, this study proposes and analytically investigates a novel double-layered hybrid GFRP–steel reinforced concrete (DLHGRC) beam configuration, in which the steel reinforcement is placed in the inner layer to minimize corrosion risk, while GFRP reinforcement is placed in the outer layer to potentially enhance the durability of the longitudinal reinforcement. The flexural behavior of DLHGRC beams is examined with emphasis on identifying the permissible vertical position range of the steel reinforcement layer that ensures a ductile, tension-controlled failure mode. A comprehensive analytical model is developed, and approximately 3000 beam configurations are analyzed to evaluate the effects of reinforcement ratios, material properties, reinforcement arrangement, and section aspect ratios. Five failure modes are identified, among which a tension-controlled failure mode without GFRP rupture is found to be the most structurally acceptable. Limiting neutral axis depths corresponding to steel yielding and GFRP rupture are analytically derived, along with a novel expression for the limiting tensile GFRP reinforcement ratio. Based on these results, a modified flexural design philosophy and a rational design procedure specifically for DLHGRC beams are formulated. The findings demonstrate that reinforcement arrangement strongly governs failure mode and ductility, at higher reinforcement ratios (particularly &gt;2%), and that the allowable range of steel reinforcement decreases as the steel reinforcement layer shifts towards the neutral axis. Overall, DLHGRC beams offer a composite solution that balances durability with ductility.</p></div>","PeriodicalId":691,"journal":{"name":"Materials and Structures","volume":"59 9","pages":""},"PeriodicalIF":3.9,"publicationDate":"2026-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149189894","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigation of effective prestress in unbonded post-tensioned concrete flexural members at elevated temperatures","authors":"Kwanwoo Yi,&nbsp;Thomas H.-K. Kang","doi":"10.1617/s11527-026-03309-9","DOIUrl":"10.1617/s11527-026-03309-9","url":null,"abstract":"<div><p>This study develops a mechanics-based formulation to evaluate the effective prestress in unbonded post-tensioned concrete flexural members subjected to elevated temperatures, enabling fire design using existing tendon stress at ultimate models without modification. The approach is derived from strain compatibility between concrete and prestressing steel, incorporating thermal expansion and temperature-dependent tendon behavior, and is applicable to both restrained and unrestrained conditions. The proposed formulation, when used in combination with suitable tendon stress at ultimate models, shows good agreement with experimental fire test data in predicting ultimate flexural capacities. The underlying reasons for their differing performance under elevated-temperature conditions were discussed. This research provides a practical approach for incorporating temperature-induced prestress degradation into fire design and improves the understanding of the fire response of unbonded post-tensioned concrete structures.</p></div>","PeriodicalId":691,"journal":{"name":"Materials and Structures","volume":"59 9","pages":""},"PeriodicalIF":3.9,"publicationDate":"2026-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149189820","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Research on the nano-micro interaction mechanism of nano-SiO2 particles in cement paste","authors":"Jie Zhang,&nbsp;Yongsheng Ji,&nbsp;Furong Gao,&nbsp;Yuejin Zhou,&nbsp;Xingyu Mou","doi":"10.1617/s11527-026-03292-1","DOIUrl":"10.1617/s11527-026-03292-1","url":null,"abstract":"<div><p>The poor dispersion and severe agglomeration of externally added nano-SiO₂ powder represent a persistent technical bottleneck restricting its performance enhancement efficiency in cement-based materials. This study develops an acidic nano-SiO₂ precursor solution using acetic acid as the stabilizing medium and industrial water glass as a low-cost silicon source. A combined investigation incorporating pH gradient stability tests, saturated Ca(OH)₂ simulated pore solution reactions, cement paste performance comparisons, transmission electron microscopy (TEM) / energy dispersive spectrometer (EDS) characterizations, and Materials Studio molecular dynamics simulations is conducted to systematically reveal the nanoparticle stabilization mechanism in the precursor, and its precipitation behavior and modification effect in cementitious environments. Results show that precursors with pH ≤ 6 exhibit excellent long-term storage stability, as acetic acid molecules adsorb onto SiO₂ surfaces through hydrogen bonding and electrostatic interactions to form a protective shell that inhibits agglomeration. The weakly acidic precursor (pH=6) achieves an optimal balance between stability and reactivity: when exposed to the alkaline cement matrix, acetic acid is neutralized, inducing in-situ precipitation of monodisperse SiO₂ nanoparticles that uniformly distribute within the pore structure and on cement particle surfaces. These in-situ generated nanoparticles exert nucleation seeding and micro-filling effects, promoting calcium silicate hydrate gel formation and refining pore structure, fundamentally eliminating the agglomeration issue associated with conventionally added nano-SiO₂ powder. This work provides a cost-effective technical pathway and theoretical basis for the efficient application of nano-SiO₂ in cement-based construction materials.</p></div>","PeriodicalId":691,"journal":{"name":"Materials and Structures","volume":"59 9","pages":""},"PeriodicalIF":3.9,"publicationDate":"2026-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149189751","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Separation of adhered mortar from fine-recycled concrete aggregates using air winnowing","authors":"Pranav Saraswat,&nbsp;Bhupendra Singh","doi":"10.1617/s11527-026-03321-z","DOIUrl":"10.1617/s11527-026-03321-z","url":null,"abstract":"<div><p>Adhered mortar on fine-RCA can restrict its effective utilization because of its influence on aggregate characteristics. Selective removal of adhered mortar from fine-RCA is challenging due to the heterogeneous size, density, and morphology of aggregate–mortar particles. Therefore, this study investigates air winnowing as a simplified physical fractionation technique for fine-RCA based on differential particle transport under airflow. Fine-RCA processed at 450, 900, and 1300 rev/min was collected and classified into near-fan and far-fan regions based on the distance travelled by the particles. Separation performance was evaluated using particle size distribution (PSD), mass recovery, X-ray fluorescence (XRF), X-ray diffraction (XRD), loss on ignition (LOI), and image analysis method (IAM). The 450 rev/min condition provided the most effective separation, achieving 93.69% overall recovery while maintaining the near-fan fraction within the specified IS 383 gradation limits. XRF showed minor differences in bulk elemental composition, while XRD indicated similar dominant mineralogical phases with differences mainly in their relative proportions. In contrast, LOI indicated greater mass loss in the far-fan fraction. IAM quantified 38.43 ± 2.86% adhered mortar in the far-fan fraction compared with 31.96 ± 4.76% in the near-fan fraction, with the difference being statistically significant and associated with a large effect size (Hedges’ g = 1.60). The results demonstrate that controlled air winnowing can achieve the fractionation into aggregate-rich and mortar-rich fractions without complex separation equipment. This provides a simplified, low-resource technique for the processing of fine-RCA, with separation quality depending on the combined effects of recovery, gradation retention, and mortar enrichment.</p><h3>Graphical abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":691,"journal":{"name":"Materials and Structures","volume":"59 9","pages":""},"PeriodicalIF":3.9,"publicationDate":"2026-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149189501","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Co-assembly of superplasticizer and viscosity modifying agent in designing printable concrete mixtures","authors":"Kee-Hong Ler,&nbsp;Chau-Khun Ma,&nbsp;Chee-Loong Chin,&nbsp;Izni Syahrizal Ibrahim,&nbsp;Khairul Hazman Padil,&nbsp;Li-Jing Chan,&nbsp;Shing-Mei Chiew,&nbsp;Mohd Aminul Izmeer Ab Ghafar,&nbsp;Yong-Zheng Goh","doi":"10.1617/s11527-026-03307-x","DOIUrl":"10.1617/s11527-026-03307-x","url":null,"abstract":"<div><p>This study investigates the combined effects of superplasticizer (SP) and hydroxypropyl methylcellulose (HPMC) on the rheological behavior and printability of extrusion-based 3D concrete printing. A series of indirect rheological tests, including slump, slump flow, and slug tests, as well as printability tests comprising extrudability and buildability tests, were conducted. The results identified three distinct rheological regimes governed by the competitive adsorption of SP and HPMC on cement particle surfaces. In the SP-dominated regime, dispersion reduces both yield stress and plastic viscosity, resulting in increased slump and slump flow. In contrast, the HPMC-dominated regime is characterized by hydrogen-bond-driven structuration, which decreases slump and slump flow. Between these regimes, a transitional co-assembly stage is observed, where competing mechanisms produce a decoupled response, in which slump increases due to SP-induced dispersion, while slump flow decreases due to HPMC-induced agglomeration. Optimal printability is achieved only within a narrow dosage range where both admixtures are balanced, corresponding to a defined printability window in terms of slump and slump flow. Based on these relationships, a simplified mix design approach is proposed, enabling adjustment of admixture dosages to achieve target printability. The method was validated through iterative refinement, successfully producing the printable mixtures within two iterations.</p></div>","PeriodicalId":691,"journal":{"name":"Materials and Structures","volume":"59 9","pages":""},"PeriodicalIF":3.9,"publicationDate":"2026-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149189264","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An experimental study on the effects of mix design parameters, test methods, and time-dependence of chloride penetration in concrete","authors":"Michele da Cruz Larrossa,&nbsp;Gustavo Bosel Wally,&nbsp;Mauro de Vasconcellos Real,&nbsp;Fábio Costa Magalhães,&nbsp;César Antonio Oropesa Avellaneda","doi":"10.1617/s11527-026-03264-5","DOIUrl":"10.1617/s11527-026-03264-5","url":null,"abstract":"<div><p>Prescriptive durability approaches have proven insufficient to ensure the designed service life of reinforced concrete structures, particularly in highly aggressive environments. Consequently, several codes introduced performance-based specifications to promote more durable designs. These approaches rely on assessing concrete durability-related properties that reflect how the material performs under specific exposure conditions, known as durability indicators. Such parameters are directly influenced by the concrete constituent materials and mix design parameters. Understanding the effects of these factors is therefore essential for developing designs that enhance structural performance and durability. This paper assesses the behavior of 28 concrete mixes produced with different materials and specifications. The influences of various binder systems and mix design parameters on properties directly related to resistance to chloride ingress are evaluated, including chloride migration, electrical resistivity, and water absorption. Different cement types, mineral additions, water/cement and water/binder ratios, and dry mortar contents are adopted. The results show that prescriptive parameters are relevant for concretes with similar binder systems, while differences between distinct binder groups are mainly controlled by the chemical properties of the binders. In this sense, the findings contribute to bridging prescriptive mix design parameters and performance-based durability approaches, highlighting the importance of binder characteristics for a more consistent interpretation of concrete durability indicators under chloride penetration.</p></div>","PeriodicalId":691,"journal":{"name":"Materials and Structures","volume":"59 9","pages":""},"PeriodicalIF":3.9,"publicationDate":"2026-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1617/s11527-026-03264-5.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149189287","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mitigating ageing-induced stiffening in asphalt mixtures using zinc diethyldithiocarbamate: mechanical performance, digital image correlation, and inter-laboratory validation","authors":"Antonio Roberto,&nbsp;Walid Boughalem,&nbsp;Anand Sreeram,&nbsp;Justine Cantot,&nbsp;Yongping Hu,&nbsp;Georgios Pipintakos","doi":"10.1617/s11527-026-03313-z","DOIUrl":"10.1617/s11527-026-03313-z","url":null,"abstract":"<div><p>While antioxidant additives have shown promising results to mitigate oxidative ageing at the binder scale, their effectiveness at the asphalt mixture level and their reproducibility across different laboratories remain insufficiently understood. This study evaluates the potential of zinc diethyldithiocarbamate (ZDC) to mitigate ageing-induced stiffening in asphalt mixtures through a comprehensive mechanical characterisation and an inter-laboratory validation campaign. Asphalt mixtures containing 3% and 5% ZDC by binder weight, together with an unmodified reference mixture, were subjected to unaged, short-term (ST) aged, and long-term (LT) aged conditions. Mechanical performance was assessed using dynamic modulus, semi-circular bending (SCB), indirect tensile strength (ITS), and digital image correlation (DIC). To account for differences in mixture composition among laboratories, normalised ITS Ageing Indices (IAI) were introduced and statistically analysed. The results showed that ZDC effectively mitigated ageing-induced stiffening. Dynamic modulus testing indicated that 5% ZDC reduced the ageing susceptibility of the mixtures by approximately 30% compared with the control mixture, while SCB, ITS, and DIC analyses demonstrated improved cracking resistance, enhanced ductility, and reduced strain localisation after ageing. Despite differences in mixture composition and gradation, the inter-laboratory analysis confirmed a statistically consistent antioxidant effect (<i>p </i>&gt; 0.05), with the most pronounced benefits observed at low temperatures for mixtures containing 5% ZDC. Overall, ZDC proved effective in mitigating ageing-induced stiffening and cracking susceptibility, supporting its potential as a practical strategy to improve the long-term durability of asphalt pavements.</p></div>","PeriodicalId":691,"journal":{"name":"Materials and Structures","volume":"59 9","pages":""},"PeriodicalIF":3.9,"publicationDate":"2026-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1617/s11527-026-03313-z.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149189286","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Refined in-plane strut-and-tie model for reinforced concrete squat walls with and without openings","authors":"Syed Aqeel Shah,&nbsp;Azam Khan,&nbsp;Moiz Tariq,&nbsp;Arbaz Khan,&nbsp;Arshad Hussain","doi":"10.1617/s11527-026-03270-7","DOIUrl":"10.1617/s11527-026-03270-7","url":null,"abstract":"<div><p>Squat shear walls or short walls are particularly relevant in middle to low-rise buildings that are prone to seismic activity. The behavior of these low aspect ratio walls becomes more complex when openings are introduced to cater for doors, windows, ventilation, or some architectural requirements. The present study is aimed at developing two modified strut-and-tie models (STM) to determine the respective shear capacities of solid squat walls and squat walls with a central opening of any aspect ratio. The proposed STMs are characterized by Mohr-Coulomb strut-softening behavior incorporating a triangular distribution of in-plane stress. The proposed first model is verified against the existing experimental database of 611 solid squat wall specimens. Subsequently, the second model is applied to two squat walls having a central opening with various aspect ratios. This time, the results are numerically and experimentally verified against a finite element model developed in ABAQUS, which has been able to yield realistic predictions. Overall, both STM models predict the shear capacity of squat walls with reasonable accuracy.</p></div>","PeriodicalId":691,"journal":{"name":"Materials and Structures","volume":"59 9","pages":""},"PeriodicalIF":3.9,"publicationDate":"2026-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149189054","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Traffic speed deflectometer data interpretation using the falling weight deflectometer-based structural indicators to assess full-depth asphalt pavements","authors":"Bongsuk Park,&nbsp;Seonghwan Cho,&nbsp;Cheng Zhang,&nbsp;Tommy E. Nantung,&nbsp;John E. Haddock","doi":"10.1617/s11527-026-03318-8","DOIUrl":"10.1617/s11527-026-03318-8","url":null,"abstract":"<div><p>This study focused on identifying appropriate structural indicators for traffic speed deflectometer (TSD) measurements to accurately assess the structural conditions of full-depth asphalt pavements. Comparative studies were conducted to evaluate the agreement between TSD and falling weight deflectometer (FWD). Results show the effective structural number (SN_eff) exhibited a smaller mean difference and a narrower range for the limits of agreement between TSD and FWD. Since the SN_eff appears to reflect the effect of pavement thickness, the SN_eff may provide improved agreement between TSD and FWD. Consequently, SN_eff was recommended for interpreting TSD data to assess full-depth asphalt pavements.</p></div>","PeriodicalId":691,"journal":{"name":"Materials and Structures","volume":"59 9","pages":""},"PeriodicalIF":3.9,"publicationDate":"2026-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149189132","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A new integrated framework for the construction of free-form concrete shell structures with thermoplastic-coated textile reinforcements","authors":"Bedirhan Enes Kelek,&nbsp;Thomas Henzel,&nbsp;Muhammed Maraşlı,&nbsp;Serdar Soyöz,&nbsp;Nilüfer Özyurt,&nbsp;Esat Selim Kocaman","doi":"10.1617/s11527-026-03310-2","DOIUrl":"10.1617/s11527-026-03310-2","url":null,"abstract":"<div><p>Free-form concrete shell structures have attracted significant attention due to their distinctive aesthetics and structural performance. However, physical realisation of these innovative structures remains limited particularly due to the shaping of the reinforcements into curved geometries. To address this, we explored an innovative composite reinforcement, i.e., thermoplastic-coated textiles that can be practically thermoformed into various free-form geometries. In this study, a comprehensive framework was developed for the realization of free-form shell structures reinforced with these novel textiles, which was verified through the construction of a prototype structure. Key challenges and considerations were identified, and the feasibility of this novel reinforcement system was demonstrated. The critical steps of the framework included the textile positioning based on a finite element model, topology partitioning for textile placement, textile thermoforming for free-form topologies, overlap length determination, prototype construction and testing. A practical methodology was proposed for the topology partitioning stage whereby free-form drapability limitations of the textile parts were obtained. An ideal length between the textile parts was determined based on flexural testing. Critical factors and parameters that influence the free-form thermoforming of thermoplastic-coated textiles were revealed for future improvements. Thermal resilience of the knitting yarns, thermoforming characteristics of the thermoplastic coating and heater capacity were identified as pivotal factors for ideal free-form thermoforming and successful construction, significantly influencing the process parameters and times. Overall, the proposed methodology bridges digital design and physical realisation, thereby paving the way for translating free-form geometries of computational design into real-world complex shell structures with novel reinforcements.</p></div>","PeriodicalId":691,"journal":{"name":"Materials and Structures","volume":"59 9","pages":""},"PeriodicalIF":3.9,"publicationDate":"2026-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149189041","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}