Chidchanok Pleesudjai, Carlos A. S. Oliveira, Daniel L. Araujo, Devansh Patel, Moacir Alexandre Souza de Andrade, Romildo Toledo Filho, Barzin Mobasher
{"title":"Efficiency of hybrid reinforced concrete beams with low reinforcement ratios","authors":"Chidchanok Pleesudjai, Carlos A. S. Oliveira, Daniel L. Araujo, Devansh Patel, Moacir Alexandre Souza de Andrade, Romildo Toledo Filho, Barzin Mobasher","doi":"10.1617/s11527-025-02736-4","DOIUrl":"10.1617/s11527-025-02736-4","url":null,"abstract":"<div><p>This research explores the serviceability level characterization of hybrid reinforced concrete (HRC) beams with low reinforcement ratios in the range of 0.052%-0.262% under flexural test. Hybrid reinforced structural members use continuous reinforcement with randomly distributed chopped fibers in the matrix. The study focuses on the immediate post-cracking response of flexural beams to analyze parameters such as stiffness, deflection, strain transfer mechanisms, and ultimate strength response. The influence of steel fibers on flexure performance, ductility, and tensile strain, as well as the sharing of the flexural load are also studied. HRC beams are shown to have a higher first crack strength (15–24%) and stiffness in the serviceability domain compared to conventional RC beams regardless of the reinforcement ratio. The addition of up to 1.25% fibers contributes to the sharing of the flexural load such that reducing longitudinal reinforcement between 50 and 80% was associated with decreasing the ultimate load between 10 and 50% while still increasing the post-crack stiffness. Crack localization was found in both RC and HRC sections within a range of reinforcement ratios. The addition of fiber while maintaining the same reinforcement ratio confirmed the reduction in ductility. However, by adopting a lower limit of 3.0 for the deflection ductility ratio, HRC beams with up to 0.75% of steel fibers were found to be ductile, even despite presented softening behavior after the peak load.</p></div>","PeriodicalId":691,"journal":{"name":"Materials and Structures","volume":"58 6","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145163097","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}
Hao Bao, Ruyu Wang, Yahui Yang, Qing Wang, Gang Xu, Mohamed Saafi, Jianqiao Ye
{"title":"Effect of pore water saturation on the supercritical carbonation of cementitious materials","authors":"Hao Bao, Ruyu Wang, Yahui Yang, Qing Wang, Gang Xu, Mohamed Saafi, Jianqiao Ye","doi":"10.1617/s11527-025-02740-8","DOIUrl":"10.1617/s11527-025-02740-8","url":null,"abstract":"<div><p>The optimization of pore water saturation is essential to improve the supercritical carbonation efficiency of cementitious materials. In this study, a control method was developed to adjust the pore water saturation of cementitious materials to predetermined target values, thereby achieving a uniform distribution of pore water within the specimens. Based on this approach, a systematic supercritical carbonation test was conducted, the effects of pore water saturation and water-cement ratio on carbonation efficiency was researched by measuring carbonation depth, which reaches its maximum at a pore water saturation of 0.50. The effect of pore water saturation on the supercritical carbonation depth was clarified. Additionally, a novel method was proposed to determine the Ca(OH)<sub>2</sub> and C–S–H contents of cementitious materials before carbonation using inverse derivation from the differences in thermogravimetric analysis (TGA) results. Furthermore, microscopic techniques, including scanning electron microscopy (SEM), were employed to investigate the mechanisms of supercritical carbonation in cementitious materials under different pore water saturation levels. The influence of pore water saturation on the carbonation process was thereby elucidated.</p></div>","PeriodicalId":691,"journal":{"name":"Materials and Structures","volume":"58 6","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145161694","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":"Performance evaluation of precast vertical wall connections featuring an innovative locking bar under cyclic loading","authors":"S. Hemamalini, R. Vidjeapriya","doi":"10.1617/s11527-025-02728-4","DOIUrl":"10.1617/s11527-025-02728-4","url":null,"abstract":"<div><p>The incorporation of precast structural wall connections is essential in the construction of buildings, serving to ensure structural stability against lateral forces. To assure the efficiency and permanent performance of these precast structural wall connections, it is imperative to observe appropriate design, detailing, and construction techniques. This study explores four distinct connection designs implemented between shear walls. This specific type of connections presents numerous benefits, such as an ability to bear heavy loads, ease of construction, and enhanced resistance to seismic activity. The purpose of this study is to assess vertical wall-to-wall connectors seismic performance for following four connection methods: (1) Staggered Loop bar with Shear Key (SL-SK), (2) U-bar Hook with Shear Key (UH-SK), (3) U-bar Hook with Locking bar (UH-LB), and (4) U-bar Hook with Shear Key and Locking bar (UH-SK-LB). The research conducted a comparative analysis of the mechanical characteristics, encompassing load bearing capacity, stiffness degradation, hysteretic response, ductility, viscous damping ratio, and energy dissipation for all four connection types. The results indicated that the (SL-SK) specimen demonstrated excellent ductile behavior, a higher ultimate load capacity, and improved energy dissipation performance. These attributes were influenced by the trapezoidal design of the shear key with a 45° tooth angle under cyclic loading conditions. With an average ductility factor exceeding 4, this specimen is recommended for use in high seismic regions.</p></div>","PeriodicalId":691,"journal":{"name":"Materials and Structures","volume":"58 6","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145161695","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":"Application of hybrid alkali-activated binders for chemical realkalization","authors":"Clarissa Glawe, Michael Raupach","doi":"10.1617/s11527-025-02732-8","DOIUrl":"10.1617/s11527-025-02732-8","url":null,"abstract":"<div><p>The repair of reinforced concrete structures affected by carbonation-induced corrosion is essential for the preservation of existing buildings. The chemical realkalization, using cementitious layers applied to the surface of carbonated concrete is a commonly used method to restore the passivity of the embedded steel reinforcement. Despite its practical relevance and low implementation effort, the mechanisms contributing to the realkalization process, especially when using low-CO<sub>2</sub> binders, remain insufficiently understood. In the present study, the applicability of hybrid alkaline-activated binders (HAAB), which enable a reduction of the clinker content while simultaneously adding additional alkaline components through alkaline activation, is investigated. Under defined exposure conditions, realkalization depths of up to 30 mm were achieved using HAAB. The application of alternative pH indicators allows a more precise analysis of the spatial and temporal evolution of the realkalized area, highlighting the critical role of the initial suction phase. The results provide new insights into the interaction between the binder chemistry and the realkalization effectiveness as well as the importance of the availability of alkalis.</p></div>","PeriodicalId":691,"journal":{"name":"Materials and Structures","volume":"58 6","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1617/s11527-025-02732-8.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145160815","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}
Luiz Antonio de Siqueira Neto, O. Burkan Isgor, W. Jason Weiss
{"title":"Modeling fluid absorption in layered anisotropic cement-based materials","authors":"Luiz Antonio de Siqueira Neto, O. Burkan Isgor, W. Jason Weiss","doi":"10.1617/s11527-025-02733-7","DOIUrl":"10.1617/s11527-025-02733-7","url":null,"abstract":"<div><p>The absorption of fluid in cement-based materials is often related to their durability. Current approaches to predict fluid absorption often assume material isotropy, which may not be accurate for layered systems. This paper presents a moisture transport modeling approach to investigate fluid absorption in layered anisotropic cement-based systems. The model is first validated by predicting the moisture profiles obtained from absorption experiments of two mortar samples, at times between 0.5 and 5 h. The model is then used to simulate layered geometries representative of 3D-printed mortar structures, emphasizing heterogeneity between filament and interfacial regions. Simulation results for the validation example match the moisture profiles obtained in the absorption experiments, with a Root Mean Square Percentage Error (RMSPE) of less than 12% in all cases. Simulation results for the layered geometries illustrate the anisotropic nature of fluid absorption in these systems. A layer arrangement parallel to the absorption direction leads to higher fluid uptake than when the layers are perpendicular to the absorption direction, due to lateral fluid transport from interfacial regions to filament regions. The roles of porosity, pore connectivity, and pore size distribution (PSD) are also examined, providing insights into how the microstructure of the material layers may impact fluid ingress. Additionally, it may be possible for material defects in these systems to be designed to control fluid absorption.</p></div>","PeriodicalId":691,"journal":{"name":"Materials and Structures","volume":"58 6","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1617/s11527-025-02733-7.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145160814","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":"Evaluation of high-content warm-mixed rubber modified asphalt: experimental investigation and molecular dynamics simulation","authors":"Jiawei Zhu, Md Sumon Prodhan, Chaoen Yin, Xiaorui Zhang, Xinxing Zhou","doi":"10.1617/s11527-025-02724-8","DOIUrl":"10.1617/s11527-025-02724-8","url":null,"abstract":"<div><p>This study investigates the effects of crumb rubber (CR) content and the activation treatment of CR with aromatic oil and rosin oil on the performance of warm-mixed crumb rubber modified asphalt (WRMA) through laboratory tests and molecular dynamics (MD) simulations. The workability of WRMA decreases notably when CR content exceeds 30%, with optimal high-temperature performance observed at 30% CR but poorer performance at 40%. Additionally, activation of CR with aromatic oil enhances asphalt’s high-temperature performance. Fourier Transform infrared spectroscopy (FTIR) analyses reveal no introduction of new functional groups during CR activation with aromatic and rosin oils, indicating a physically mixed state with asphalt. Increasing CR content reduces WRMA surface roughness by inhibiting the formation of bee-like structures, associated with smaller structure sizes. Moreover, aromatic and rosin oils promote the proximity of aromatic molecules to rubber, impacting asphaltene and resin aggregation. Sasobit demonstrates high mobility, while rosin oil exhibits a distinct peak. Furthermore, diffusion coefficients highlight Sasobit and light component mobility, peaking at 25% CR content for CR and warm-mix agents. However, the addition of aromatic and rosin oils significantly reduces mobility, particularly for rubber molecules. Finally, CR content minimally affects WRMA’s solubility parameters until reaching 40%, where a 2.2% decrease indicates reduced CR-asphalt compatibility.</p></div>","PeriodicalId":691,"journal":{"name":"Materials and Structures","volume":"58 6","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145170915","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}
Farid Shabani, Julia Hylton, Ahmadreza Hedayat, Lori Tunstall, Juan Antonio Vega Gonzalez, Jorge Wilfredo Vera Alvarado, Martin Taboada Neira
{"title":"Mechanical activation of sulfidic mine tailings for use as supplementary cementitious materials","authors":"Farid Shabani, Julia Hylton, Ahmadreza Hedayat, Lori Tunstall, Juan Antonio Vega Gonzalez, Jorge Wilfredo Vera Alvarado, Martin Taboada Neira","doi":"10.1617/s11527-025-02730-w","DOIUrl":"10.1617/s11527-025-02730-w","url":null,"abstract":"<div><p>Mine tailings (MTs) are hazardous waste generated in large volumes and can pose serious environmental risks if not effectively managed. They are typically stored as slurry in ponds, behind tailings dams, or storage facilities. In sulfidic MTs, the high concentration of sulfide minerals makes them prone to acid mine drainage, infiltrating soil and groundwater. Recently, producing supplementary cementitious materials (SCMs) from MTs has been noted as an effective approach for utilizing mining waste while reducing the carbon footprint of concrete. This study assesses the influence of four milling methods, rotary ball mill, planetary ball mill, vibratory ball mill, and vibratory disc mill, on the reactivity of sulfidic MTs. The vibratory-disc-milled MTs revealed higher reactivity with a heat release of 162 J/g, as quantified using the modified R<sup>3</sup> test; this is likely due to their very fine particle size (d<sub>50</sub> = 9.8–14 μm)<i>.</i> Owing to the presence of pyrite in raw materials, its impact on the activity of MTs in cement-tailings mixes was examined, focusing on heat release, hydration, and strength development through morphological, chemical, mineralogical, and mechanical characterization. Furthermore, hyphenated TGA and FTIR was employed to accurately identify the decomposition temperature ranges of chemically bound water and other evolved gas, in specimens made with tailings-based SCMs. A 10% cement substitution with tailings-based SCMs resulted in mortars with the highest strength at early ages, achieving 41.5 MPa at 3 days, which surpassed the 33 MPa strength of the control specimens. Although strength reduction with higher SCM content likely stemmed from pyrite oxidation and the formation of a secondary ettringite phase, up to 30% substitution achieved the required strength activity index per ASTM C618, indicating their potential as suitable SCMs.</p></div>","PeriodicalId":691,"journal":{"name":"Materials and Structures","volume":"58 6","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145171376","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}
Barbara Lothenbach, Miriam E. Krüger, Maxime Ranger, Ana Bergmann, Petter Hemstad, Jan Lindgård, Doug Hooton, Josée Duchesne, Andreas Leemann, Klaartje De Weerdt
{"title":"Report of RILEM TC 301-ASR: relation between pore solution composition and ASR expansion","authors":"Barbara Lothenbach, Miriam E. Krüger, Maxime Ranger, Ana Bergmann, Petter Hemstad, Jan Lindgård, Doug Hooton, Josée Duchesne, Andreas Leemann, Klaartje De Weerdt","doi":"10.1617/s11527-025-02726-6","DOIUrl":"10.1617/s11527-025-02726-6","url":null,"abstract":"<div><p>An important parameter determining the risk of alkali-silica reaction (ASR) in concrete is the availability of alkali ions as they are closely related to the OH<sup>−</sup> concentration in the pore solution. Comparison of concrete or mortar expansion with cement and pore solution composition from literature data showed no obvious relationship of the expansion with the total alkali content of the cement. However, the observed expansion was strongly dependent on the alkali and hydroxide concentrations in the pore solution. At a hydroxide concentration greater than 250 mmol/L in the pore solution or at (Na + K) concentrations greater than 300–400 mmol/L, significant ASR expansion took place for the highly reactive aggregates studied in the laboratory samples exposed at near ambient temperatures (20–40 °C). Less reactive aggregates will have a higher “alkali threshold”. At 60 and 80 °C correlations between pore solution and expansion tend to fall apart as temperature influences many factors that can accelerate or slow down ASR. High Al concentration in the pore solution as well as a low undersaturation with respect to silica have been suggested to slow down ASR formation. Neither the Al concentration in the pore solution nor undersaturation with respect to SiO<sub>2</sub> was found to be selective criteria for ASR expansion. The pH measurements are highly dependent on temperature, difficult to measure, and determined using a variety of techniques that are frequently poorly explained. The pore solution’s pH by itself is therefore not a good way to evaluate the risk of ASR expansion, although this study showed that there is a good correlation between pH and the sum of (Na + K) concentration in the paste pore solution. It is recommended that (Na + K) is used as the most reliable and relatively easily accessible parameter to indicate the potential for ASR in concretes or mortars up to 40 °C.</p></div>","PeriodicalId":691,"journal":{"name":"Materials and Structures","volume":"58 6","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1617/s11527-025-02726-6.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145171375","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":"Preparation and properties of clinker-free cement based on lithium slag and quicklime","authors":"Yu Zhu, Songzhe Zhou, Zhaocai Zhang","doi":"10.1617/s11527-025-02720-y","DOIUrl":"10.1617/s11527-025-02720-y","url":null,"abstract":"<div><p>In order to reduce the environmental harm caused by the production of traditional cement, the feasibility of preparation for clinker-free cement based on lithium slag and quicklime was investigated in this paper. Meanwhile, the effect of Na<sub>2</sub>SO<sub>4</sub> on the reactivity of lithium slag was studied. The hydration degree, hydration products and microstructure of clinker-free cement paste were analyzed by FTIR, XRD, TG-DTG, NMR, and SEM, respectively. The results indicate that lithium slag itself does not have the ability to hydrate. However, the clinker-free cement paste prepared with lithium slag can harden after adding quicklime, due to the formation of hydration products C–(A)–S–H gel and AFt. Adding Na<sub>2</sub>SO<sub>4</sub> can enhance the reactivity of lithium slag, and further increase the amount of hydration products. Moreover, the compressive strength of clinker-free cement paste with lithium slag and quicklime is improved (25.6 MPa at 28 d). This paper not only verifies that lithium slag and quicklime can be used to prepare the clinker-free cement, but also provides a theoretical basis for the addition of Na<sub>2</sub>SO<sub>4</sub> to enhance the reactivity of lithium slag.</p></div>","PeriodicalId":691,"journal":{"name":"Materials and Structures","volume":"58 6","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145168926","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}