Materials and Structures最新文献

{"title":"A three-dimensional CFD–DEM model to investigate the fiber orientation and distribution during concrete extrusion in 3D printing","authors":"Yiqing Yan,&nbsp;Xiaonan Zhang,&nbsp;Jiaxu Liu,&nbsp;Xiangyu Xie","doi":"10.1617/s11527-026-03241-y","DOIUrl":"10.1617/s11527-026-03241-y","url":null,"abstract":"<div><p>Steel fibers are a promising reinforcement for 3D concrete printing (3DcP), which enhance post-cracking mechanical strength and fracture resistance. However, during the printing process, fibers tend to align with the printing direction, which exacerbates the inherent anisotropy of 3DcP structural components. Accurate prediction of fiber orientation is therefore essential for mitigating this effect. Traditional numerical approaches, however, are often limited by prohibitive computational costs due to the large number of fibers and the complex fluid–fiber interactions involved. This study proposes a computationally efficient three-dimensional coupled computational fluid dynamics–discrete element method (CFD–DEM) model for the rapid simulation of fiber orientation during the extrusion process. To improve computational efficiency, fluid–fiber interactions are treated using a one-way coupling framework, in which fiber rotation is analytically resolved based on Jeffery’s rotation equations. Validation against experimental measurements demonstrates the reliability of the proposed model. Parametric studies reveal that smaller nozzle openings, longer fiber lengths, and higher printing speeds promote stronger alignment of fibers along the printing direction, whereas the influence of rheological properties is relatively limited. In addition, shear-induced rotation is identified as one of the dominant mechanisms governing fiber orientation during extrusion. Increasing the size of the shear-dominated region near the nozzle exit can therefore improve fiber alignment in the printing direction. Beyond its engineering implications, the proposed modeling framework provides a design-oriented tool for fiber-reinforced 3DcP systems. By enabling the prediction and control of fiber orientation fields, the approach opens opportunities for directionally informed structural design in robotic concrete construction and can be extended to other short-fiber-reinforced material systems.</p></div>","PeriodicalId":691,"journal":{"name":"Materials and Structures","volume":"59 7","pages":""},"PeriodicalIF":3.9,"publicationDate":"2026-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1617/s11527-026-03241-y.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148782617","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":"SCM–EIM coupled model for linking the micro–macro performance of the GO-modified ITZ in recycled aggregate concrete and modulus prediction","authors":"Kai Guo,&nbsp;Fubin Zhao,&nbsp;Lihua Wang,&nbsp;Yichao Zhang","doi":"10.1617/s11527-026-03211-4","DOIUrl":"10.1617/s11527-026-03211-4","url":null,"abstract":"<div><p>This study examines the impact of graphene oxide (GO) on the mechanical properties of recycled aggregate concrete (RAC) and its interfacial transition zone (ITZ). Macroscopic mechanical property and nano-scratch tests were performed on RAC specimens with varying GO doping levels. The results indicated that the optimal GO dosage significantly enhanced the strength and elastic modulus of RAC, with the most notable improvement observed at a doping level of 0.06%. The nano-scratch tests further revealed that the GO modification increased the hardness and friction coefficient of the ITZ, reduced its width, and increased the volume fraction of high-density hydrated calcium silicate in the hydration products. A predictive model for the elastic modulus of composites incorporating ITZ effects was developed by combining equivalent inclusion theory with the self-consistent field method. The model predictions were in good agreement with the experimental results and data from the literature. The results highlight GO’s potential to improve RAC performance.</p></div>","PeriodicalId":691,"journal":{"name":"Materials and Structures","volume":"59 7","pages":""},"PeriodicalIF":3.9,"publicationDate":"2026-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148782520","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":"Lightweight nail-laminated engineered bamboo frame structures in residential construction: a case study","authors":"Zhi Li,&nbsp;Rui Wang,&nbsp;Yan Xiao","doi":"10.1617/s11527-026-03096-3","DOIUrl":"10.1617/s11527-026-03096-3","url":null,"abstract":"<div><p>This study integrates newly developed nail-laminated engineered bamboo (NLB) structural components into conventional light-frame systems and presents a two-story residential demonstration project. The mechanical properties and fabrication details of multidirectional laminated engineered bamboo are provided and compared with those of sawn timber. The connection system linking key structural elements is introduced, with its performance determined by (i) the lateral resistance of bamboo–bamboo, bamboo–timber, and bamboo–steel connections, and (ii) the withdrawal behavior of steel connectors embedded in bamboo. Relevant studies on the above two aspects are reviewed and discussed. Methods for calculating the brittle shear resistance of bamboo connections are also analyzed to determine suitable overstrength factors for capacity-based design. The manufacturing details of main structural elements—bending members, hybrid shear walls, and roof trusses—are described. Experimental evaluations of connector performance in bending members, as well as load-bearing capacities of shear walls and roof trusses, are reported. Finally, the construction and assembly of the full-scale residential building are presented, demonstrating the practical application and promising potential of this nail-laminated bamboo construction method.</p></div>","PeriodicalId":691,"journal":{"name":"Materials and Structures","volume":"59 7","pages":""},"PeriodicalIF":3.9,"publicationDate":"2026-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148782521","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":"Waterglass treatment of cellulose excelsior cement composites for improving mechanical properties and dimensional stability","authors":"Naveen Krishnan,&nbsp;Catherine Lucero,&nbsp;O. Burkan Isgor,&nbsp;W. Jason Weiss","doi":"10.1617/s11527-026-03242-x","DOIUrl":"10.1617/s11527-026-03242-x","url":null,"abstract":"<div><p>Untreated cellulose excelsior (CE) primarily serves as a non-structural filler in cellulose excelsior–cement composites (C3) due to weak interfacial bonding with the cementitious binder. This study evaluated a sodium silicate (waterglass, WG) treatment to enhance CE load transfer and improve flexural strength and elastic modulus. A methodology was developed to produce WG-treated CE with consistent WG residue and moisture conditions. The effect of WG on CE moisture condition, and WG residue, along with CE-binder interfacial hydration, dimensional stability, mechanical performance, and global warming potential (GWP) of WG-treated C3 were evaluated. WG treatment reduced moisture uptake, with moisture content decreasing from ~108 to ~62% as WG concentration increased from 10 to 40%. Thermogravimetric analysis shows that WG residue in CE reached a plateau at 20–40%, indicating a practical upper limit for sodium silicate uptake. C3 samples prepared with 40% WG-treated CE exhibited enhanced pozzolanic reactions at the CE–binder interface, reducing calcium hydroxide by 43% and increasing C-S-H formation. These interfacial changes improved dimensional stability and mechanical performance. At 75% CE volume fraction, WG-treated C3 exhibited approximately two-fold higher flexural strength than untreated systems. A modified rule-of-mixtures model indicated the effective CE contribution increased from 4.2 to 12.0 MPa due to WG treatment. Despite the added embodied emissions from sodium silicate, WG-treated C3 maintained net-negative GWP for 50% PLC/50% fly ash binders above 75% CE contents.</p></div>","PeriodicalId":691,"journal":{"name":"Materials and Structures","volume":"59 7","pages":""},"PeriodicalIF":3.9,"publicationDate":"2026-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148782618","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":"Role of amorphous phase, temperature fluctuations, and vacuum, on the performance of alkali-activated lunar regolith simulants","authors":"Anas Driouich,&nbsp;Ahmad Goudarzi,&nbsp;Francesco Santoro,&nbsp;Maria Chiara Dalconi,&nbsp;Massimo Dau,&nbsp;Carlo Bettanini,&nbsp;Shima Pilehvar,&nbsp;Luca Valentini","doi":"10.1617/s11527-026-03243-w","DOIUrl":"10.1617/s11527-026-03243-w","url":null,"abstract":"<div><p>This study explores the feasibility of using alkali-activated regolith for construction in lunar environment. The composition of the reactive glassy fraction present in lunar regolith simulant is assessed in detail, with the aim of tailoring suitable alkaline activators that can maximise the reactivity of the system without leading to the release of excess alkali in solution or formation of unwanted products such as amorphous silica. The obtained results suggest that the low amount of reactive aluminium present in the regolith can be compensated by either the addition of moderate amounts (&lt; 10 wt%) of metakaolin or the use of a sodium aluminate activator. After ascertaining an adequate mechanical performance in standard terrestrial conditions, we assessed the role of vacuum on the fresh properties, and of combined vacuum and extreme temperature variations (− 50 °C to + 100 °C) on the hardened properties. It was observed that, while the exposure to vacuum and temperature fluctuations after setting did not significantly affect strength and microstructural development, exposure to vacuum when the samples are still in the fresh state leads to significant formation of macropores due to solvent evaporation. This process, however, did not inhibit setting and hardening. Finally, feasibility in a real lunar environment, limitations and future directions are discussed.</p></div>","PeriodicalId":691,"journal":{"name":"Materials and Structures","volume":"59 7","pages":""},"PeriodicalIF":3.9,"publicationDate":"2026-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1617/s11527-026-03243-w.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148782517","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":"Seismic performance of demountable concrete column-beam based on steel corbel connection: T-shaped joint","authors":"Yuqing Zhao,&nbsp;Wenxue Zhang,&nbsp;Zhen Luo,&nbsp;Ying Chen","doi":"10.1617/s11527-026-03173-7","DOIUrl":"10.1617/s11527-026-03173-7","url":null,"abstract":"<div><p>A demountable precast concrete frame joint based on a steel corbel connection was proposed. The joint consists of a precast concrete upper column, lower column, beam-slab and steel corbel, steel wedges, steel buckles. The demountable property of the concrete frame joint makes it suitable for emergency structures and temporary buildings. The seismic performance of the T-shaped joint was primarily investigated. The hysteretic behavior under cyclic horizontal loading at the column top, cyclic vertical loading at the beam end and the damage process were simulated by finite element models. The influence of key parameters on the seismic performance of T-shaped joint were analyzed. The analysis results indicated that T-shaped joint exhibited favorable energy dissipation capacity and ductility. Its deformation comprised the plastic deformation and the relative slip of components. The primary failure modes were bending and shear failure of the steel corbel, combined with compression and shear failure of the concrete in the joint core region. Ensuring that the strength of the steel wedge exceeds that of the steel corbel is beneficial for enhancing the seismic performance of the T-shaped joint. Appropriately increasing the strength of the steel corbel, concrete, or steel wedge can enhance the joint’s seismic performance, while the strength of the steel buckle has minor effect. The influence of the axial compression ratio on the seismic performance of the joint demonstrates distinct patterns under the two loading conditions. As the axial compression ratio increases, the seismic capacity decreases under cyclic horizontal loading at the column top, but improves slightly under cyclic vertical loading at the beam end.</p></div>","PeriodicalId":691,"journal":{"name":"Materials and Structures","volume":"59 7","pages":""},"PeriodicalIF":3.9,"publicationDate":"2026-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148782212","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":"Beneficiation of E-glass textile reinforced cementitious composites through carbonation","authors":"Sunitha K. Nayar,&nbsp;P. Saranya,&nbsp;Sai Sri Kusumanchi,&nbsp;Ravindra Gettu,&nbsp;Amritha Raj","doi":"10.1617/s11527-026-03234-x","DOIUrl":"10.1617/s11527-026-03234-x","url":null,"abstract":"<div><p>Textile reinforced concrete (TRC) is an emerging technology considered as a sustainable alternative to traditional concrete composites on account of the material efficiency and extended service life, limited mostly by the higher economic implications. Although E-glass textiles offer a cost-effective option in place of the conventional AR glass based TRC, its long-term performance is compromised by its degradation in highly alkaline cementitious environment. This study proposes a strategy to improve the durability of E-glass based TRC through low-pH matrices enhanced with accelerated carbonation. The investigation is structured as four phases: (1) Development of highly-carbonatable matrix using ternary blends such as OPC-fly ash-silica fume (OFAS-CS), OPC-GGBS-silica fume (OGSS-CS), and OPC-limestone-calcined clay (OLC2-CS); (2) Evaluation of the mechanical performance of E-glass yarns under various pH conditions; (3) Assessment of Mechanical performance of TRCs incorporating E-glass textiles and developed matrices; and (4) Finally, understanding the influence of carbonation on the long-term durability of the developed TRC composites. The developed mixes incorporate locally-available crushed sand, enabling a shift from more expensive fine-grained quartz for the TRC matrices. From the results of the study, it is clear that the composites developed with different binder compositions have shown no significant change in the tensile behaviour. Moreover, an alkaline environment having a pH of about 10 appears to be the suitable for coated E-glass textiles, which is achieved in the matrix through accelerated carbonation. Uncarbonated composites, exposed to accelerated aging, exhibited a loss of about 11% in tensile strength, whereas the loss is less than 5% in the case of carbonated composites. The effect on work to fracture characteristics of the various composites with and without carbonation, after degradation also supports the synergistic impact of coupling low carbon binders with carbonation in improving the long-term performance of E-glass TRC. This work establishes a clear pathway towards durable, low-cost, and sustainable TRC systems using widely-available materials, marking significant advancement in the field of composite material durability.</p></div>","PeriodicalId":691,"journal":{"name":"Materials and Structures","volume":"59 7","pages":""},"PeriodicalIF":3.9,"publicationDate":"2026-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148782237","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":"Influence of concrete type on the structural performance of timber-concrete composite T-beams using adhesively bonded perfobond connections: experimental and analytical evaluation","authors":"Elif Appavuravther,&nbsp;Bram Vandoren,&nbsp;Jose Henriques","doi":"10.1617/s11527-026-03239-6","DOIUrl":"10.1617/s11527-026-03239-6","url":null,"abstract":"<div><p>Timber-concrete composite (TCC) systems are increasingly adopted in structural applications, placing greater emphasis on the performance of shear connection systems. In this study, the performance of a novel type of connector in TCC systems, the perfobond shear connector, is experimentally investigated in full-scale TCC T-beams in which two concrete types are considered, lightweight and normal weight concrete. The structural response is evaluated through force–deflection behaviour and failure modes. In all cases, connection failure precedes tensile bending failure of the timber member. Replacing normal weight concrete with lightweight concrete reduces self-weight, resulting in a slight decrease in bending stiffness and yield load due to reduced density. The experimental results are used to assess the applicability of the Gamma method, revealing deviations. An alternative approach proposed by Girhammar is therefore evaluated. A comprehensive comparison, including literature data, indicates that the Gamma method should be limited to connection spacings up to 4% of the span, while the Girhammar method provides a suitable alternative for larger spacings.</p></div>","PeriodicalId":691,"journal":{"name":"Materials and Structures","volume":"59 7","pages":""},"PeriodicalIF":3.9,"publicationDate":"2026-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148752322","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":"Reinforced wide concrete corbel: design problems and numerical analysis","authors":"Andrzej Ambroziak,&nbsp;Krystyna Nagrodzka-Godycka","doi":"10.1617/s11527-026-03238-7","DOIUrl":"10.1617/s11527-026-03238-7","url":null,"abstract":"<div><p>The paper presents structural analysis of reinforced wide concrete corbel. The article may be considered part of expert bearing capacity assessment of reinforced wide concrete corbel. The term wide corbel here is related to a corbel whose width is more than one and a half times its height. Wide corbels, due to width effects that affect the 3D stress distribution, require appropriate central part reinforcement. Wide corbel indicates incorrect reinforcement placement due to design deficiency. The paper starts with a literature survey on chosen investigations into reinforced concrete corbels. Next, analytical and numerical modelling of reinforced concrete corbel through 3D models are presented. The description of the reinforced concrete corbel, including basic details and the results of structural analysis, is addressed too. Comparison of analytical results (Franz [1], Hagberg [2], Nagrodzka-Godycka [3]) and selected standards (PN-B-03264 [4], EN-1992-1-1 [5], ACI318-19 [6]) is also regarded. Finally, the conclusions are presented. Reinforcement bars of wide corbels should be designed properly across the corbel width, to distribute the primary and secondary reinforcement in a repetitive, overlapping and interchangeable way to ensure that the main bars and stirrups are located within an entire corbel core. It is recommended to introduce guidelines into standards for reinforcement bar layout to ensure a uniform primary reinforcement layout in the cross-section of wide corbels. This paper provides scientists, engineers and designers with a background for structural analysis of reinforced concrete corbels.</p></div>","PeriodicalId":691,"journal":{"name":"Materials and Structures","volume":"59 7","pages":""},"PeriodicalIF":3.9,"publicationDate":"2026-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148751905","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":"Tensile creep behaviour of cracked textile reinforced concrete","authors":"Ramakrishna Samanthula,&nbsp;Ravindra Gettu","doi":"10.1617/s11527-026-03203-4","DOIUrl":"10.1617/s11527-026-03203-4","url":null,"abstract":"<div><p>This study investigates the tensile creep behaviour of cracked Textile Reinforced Concrete (TRC), as well as the textile yarns. Single yarns were subjected to sustained loads of about 70 and 30% of the rupture load. The findings reveal that the yarns at the higher creep stress exhibited rapid creep strain accumulation and failure as early as 25 min. In contrast, the yarns loaded at 30% failure stress demonstrated stable creep evolution for more than 4 h, confirming a static fatigue stress limit. On the other hand, TRC panels were pre-cracked under monotonic tensile loading to strains of about 0.2 and 0.4%, and subsequently subjected to constant stresses, corresponding to about 40 and 70% of the monotonic failure stresses. The specimens loaded at 0.4% strain developed about 50% of their maximum creep strains within the first 3 days, with creep rupture occurring in some cases as early as 30 days. As most of the load is carried by textiles, the creep strains are significant and result in failure, as the static fatigue limit of the glass textiles is exceeded. However, the panels pre-cracked to 0.2% strain exhibited much lower creep strains with diminishing creep rates, and survived for more than 500 days. In this case, approximately 80% of the one-year creep strain occurred within the first two weeks, followed by slower creep rates. This creep response correlates well with that of yarns at creep stresses below the static fatigue limit of glass textiles. Finally, creep modelling performed with the double-power logarithmic law demonstrates satisfactory correlation with the experimental data, enabling reliable prediction of long-term tensile creep in cracked TRC.</p></div>","PeriodicalId":691,"journal":{"name":"Materials and Structures","volume":"59 7","pages":""},"PeriodicalIF":3.9,"publicationDate":"2026-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148751907","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}