{"title":"Effect of sulfate in cement and environment on the leaching behavior of Cr(VI) immobilized in cement paste","authors":"Yuan Wang, Zhi Wang, Linbo Jiang, Jincheng Yu, Jinghang Niu","doi":"10.1617/s11527-025-02774-y","DOIUrl":"10.1617/s11527-025-02774-y","url":null,"abstract":"<div><p>Sulfate in cement and the environment can affect leching of Cr(VI) immobilized in cement paste according to the immobilization mechanism of Cr(VI) in cement paste. In this study, the influence of sulfate in cement and environment on the leaching behavior of Cr(VI) immobilized in cement paste was studied, and the mechanism of the influence of leaching behavior was analyzed by XRD, FTIR and SEM–EDS. Results: The sulfate in cement will affect the adsorption amount of Cr(VI) by C–S–H, which eventually leads to Cr(VI) leaching; The sulfate in the environment will enter the AFt phase, displacing the Cr(VI) that is solidified in the AFt (ettringite, 3CaO·Al<sub>2</sub>O<sub>3</sub>·3CaSO<sub>4</sub>·32H<sub>2</sub>O) phase, resulting in an increase in the leaching amount of Cr(VI) that is immobilized in the hydration product in the sulfate environment. When both sulfate ions (SO<sub>4</sub><sup>2−</sup>) and magnesium ions (Mg<sup>2+</sup>) are present in the environment, the sulfate ions and calcium ions (Ca<sup>2+</sup>) will form gypsum, which will reduce the loss of hexavalent chromium (Cr(VI)); The research found that the Cr(VI) that is solidified in cement shows a trend where its leaching amount increases initially and then decreases as the pH value in the environment decreases. The Cr(VI) that is solidified in C–S–H is leached first, while the Cr(VI) that is solidified in AFt is leached later. It is necessary to consider the sulfates in the cement and the environment for the Cr(VI) immobilized in the cement paste.</p></div>","PeriodicalId":691,"journal":{"name":"Materials and Structures","volume":"58 9","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145316517","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":"Experimental modal analysis for fast monitoring of earthen samples drying-induced stiffness changes","authors":"Marie-Sarah Force, Stéphane Hans, Antonin Fabbri","doi":"10.1617/s11527-025-02798-4","DOIUrl":"10.1617/s11527-025-02798-4","url":null,"abstract":"<div><p>This paper presents the investigation for the development of a characterization method for rammed earth samples. This method is based on modal analysis of the frequency spectral response of samples to an excitation by impulse shock method. This allows for the estimation of elastic parameters, particularly the Young’s modulus of materials in a non-destructive manner, by identifying the specimens’ resonance frequencies. The preparation of specimens, the development of the test protocol, and the pre-processing of modal analysis methods are briefly presented. The development of this method enabled the implementation of a consecutive measurement campaign on the same samples, allowing us to monitor the evolution of their Young’s modulus during the drying phase. The primary results of these tests are presented, along with a preliminary positive conclusion regarding the repeatability of the non-destructive characterization method.</p></div>","PeriodicalId":691,"journal":{"name":"Materials and Structures","volume":"58 9","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145315981","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":"Discrete modeling of cracking in reinforced concrete structures: formulation, size effect, and parameter sensitivity","authors":"Vladislav Gudžulić, Günther Meschke","doi":"10.1617/s11527-025-02815-6","DOIUrl":"10.1617/s11527-025-02815-6","url":null,"abstract":"<div><p>This paper presents a discrete fracture modeling approach for simulating cracking in reinforced concrete (RC) structures. Cracks are represented using cohesive zero-thickness interface elements, with a traction-separation law by Snozzi and Molinari (Int J Numer Meth Eng 93(5):510–526, 2013. https://doi.org/10.1002/nme.4398) extended to account for frictional sliding and crack-roughness-induced dilatancy. An effective failure surface is derived from the extended constitutive relation. Reinforcement is modeled using elastoplastic Timoshenko beam elements, and bond behavior is modeled using coupling elements governed by an elastoplastic bond-slip law. The model is validated through simulations of size effect experiments on RC beams under four-point bending (Syroka-Korol and Tejchman in Eng Struct 58:63–78, 2014. https://doi.org/10.1016/j.engstruct.2013.10.012). These tests exhibit consistent shear failure modes across all sizes and serve as a reference for evaluating fracture models proposed by Bažant and Nguyen (J Eng Mech 149(8):04023047, 2023. https://doi.org/10.1061/JENMDT.EMENG-6887). Simulations reproduce size-dependent peak loads, crack patterns, and failure modes using material parameters derived from design codes and literature. A mesh sensitivity analysis and a parametric study on mixed-mode fracture parameters (shear strength, friction coefficient, and dilatancy) are conducted. The results highlight the importance of these parameters in capturing shear-dominated failure mechanisms and reveal the possible impact of uncertainties linked to material property identification on the model predictions. The proposed approach provides a robust, physically motivated, and modular framework for analyzing both serviceability and failure in RC structures. The model demonstrates good predictive capability, but also shows sensitivity to mixed-mode fracture properties. This result highlights the importance of advancing and more widely applying experimental methods for characterizing these parameters, which are currently difficult to obtain and rarely addressed in standard testing protocols.</p></div>","PeriodicalId":691,"journal":{"name":"Materials and Structures","volume":"58 9","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1617/s11527-025-02815-6.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145315982","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}
Lorena Skevi, Xinyuan Ke, Stéphane Ginestet, Claudiane Ouellet-Plamondon, Fernando Gomes, Martin Cyr
{"title":"Reviewing experimental studies on chemical thermal energy storage in Cementitious composites: report of the RILEM TC 299-TES","authors":"Lorena Skevi, Xinyuan Ke, Stéphane Ginestet, Claudiane Ouellet-Plamondon, Fernando Gomes, Martin Cyr","doi":"10.1617/s11527-025-02803-w","DOIUrl":"10.1617/s11527-025-02803-w","url":null,"abstract":"<div><p>Thermochemical energy storage (TCES) is a method of storing energy by using reversible chemical reactions to absorb and release heat. TCES materials generally possess the highest volumetric energy density and negligible heat losses during cyclic charging/discharging when compared with sensible and latent heat storage materials. The controllable charging/discharging processes in the TCES materials make them suitable for long-term or seasonal thermal energy storage, which can help improve the resilience of the existing energy system and built environment. In recent years, there has been a growing number of studies on the use of cementitious materials as low-cost and low-carbon thermochemical energy storage materials, including ettringite, calcium aluminate cements, and geopolymers. In this study, the state-of-the-art development using cementitious materials for thermo-chemical energy/heat storage applications is reviewed and systematically compared in terms of their compositions, energy storage operating conditions, and energy storage performance. Technical recommendations are proposed for standardised characterisation and testing protocols of these cementitious (composite) materials used for thermochemical heat storage. The current research challenges and future research needs in this field are also discussed.</p></div>","PeriodicalId":691,"journal":{"name":"Materials and Structures","volume":"58 9","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12518393/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145298020","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}
Stefan Werkovits, Georgios Pipintakos, Aditi Sharma, Pejoohan Tavassoti, Johannes Mirwald, Aikaterini Varveri, Bernhard Hofko
{"title":"Recommendation of RILEM TC 295-FBB: Implementing a systematic approach to fingerprint bituminous binders using proton nuclear magnetic resonance spectroscopy (1H-NMR)","authors":"Stefan Werkovits, Georgios Pipintakos, Aditi Sharma, Pejoohan Tavassoti, Johannes Mirwald, Aikaterini Varveri, Bernhard Hofko","doi":"10.1617/s11527-025-02799-3","DOIUrl":"10.1617/s11527-025-02799-3","url":null,"abstract":"<div><p>This recommendation is an output of a small-scale round-robin test involving three different laboratories from TG2 of the RILEM TC 295-FBB: “Fingerprinting bituminous binders using physico-chemical analysis” concerning the use of <sup>1</sup>H-NMR for fingerprinting of bituminous binders. It demonstrates the full capabilities of <sup>1</sup>H-NMR as a robust characterisation tool for complex organic materials, like bituminous binders, to examine their molecular composition in a reproducible way and with the best possible detail. This recommendation documents the key factors in sample preparation and the sensitivity of data post-processing steps. It concludes with best practices and a case study examining the effect of laboratory ageing on two bituminous binders. Overall, it highlights the potential, to the broader scientific community, of another efficient chemometric tool for bituminous binders.</p></div>","PeriodicalId":691,"journal":{"name":"Materials and Structures","volume":"58 9","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145316032","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":"Quantitative characterization of pore properties of concrete under on-site curing pressure","authors":"Bei Tang, Wei Cui, Bao-zeng Zhang, Zhi-an Jiang","doi":"10.1617/s11527-025-02812-9","DOIUrl":"10.1617/s11527-025-02812-9","url":null,"abstract":"<div><p>Concrete cured within curing pressure is a universal phenomenon for underground concrete structures. Most researches mainly focused on the effect of pressure total porosity and simple surface morphology of the pores in concrete. However, there is a lack of full understanding regarding the pore characteristics of concrete under ultra-deep formation condition (over 100 m). This study aims to investigate the impact of on-site curing pressure on the internal pore structure of concrete. This study analyzed the pore spatial distribution, the pore size-based characteristics, the pore shape-based characteristics and the pore tortuosity properties of concrete sample under varying curing pressure. The result shows that internal pore structure of concrete sample exhibited remarkable uniformity and well-dispersed network under high curing pressure. With curing pressure increased from 0 to 2 MPa, it could be observed that there was a more homogeneous pore spatial distribution, high small-sized pores fraction and uniform equivalent pore diameter in concrete. The curing pressure also could inhibit the development of flattened and elongated pores in the concrete system. The pressurized sample exhibited a more tortuous path on the horizontal direction and vertical direction. This suggests that the concrete samples cured in high curing pressure would present a better structural integrity and durability.</p></div>","PeriodicalId":691,"journal":{"name":"Materials and Structures","volume":"58 9","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145316169","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}
Robert Wegner, Larissa Born, Michelle Engert, Kim T. Werkle, Hans-Christian Möhring, Götz T. Gresser
{"title":"Determination of the mechanical properties of prestressed fiber-reinforced polymer concrete","authors":"Robert Wegner, Larissa Born, Michelle Engert, Kim T. Werkle, Hans-Christian Möhring, Götz T. Gresser","doi":"10.1617/s11527-025-02814-7","DOIUrl":"10.1617/s11527-025-02814-7","url":null,"abstract":"<div><p>Polymer concrete is increasingly used in high-precision machine tools due to its excellent damping properties, thermal stability, and reduced environmental impact. However, its low tensile strength and stiffness limit its use in structural or dynamically loaded components. This study examines the mechanical enhancement of polymer concrete through the integration of prestressed continuous carbon fiber reinforcements. Specimens with embedded carbon fiber rovings prestressed up to 470 MPa were fabricated and tested under three-point bending and uniaxial compression loading. Bending strength increased by up to 35 % and bending stiffness by 16 %, with significant gains occurring beyond a prestress level of 70 – 110 MPa. CT imaging confirmed that prestressing delayed crack initiation and limited propagation. Under compressive loading parallel to the fiber direction, strength increased by up to 8 %, though the effect diminished at higher prestress levels. A reduction in compressive strength was observed for transverse loading, attributed to matrix discontinuities and stress redistribution. The results demonstrate that prestressed fiber integration significantly improves the structural performance of polymer concrete, offering enhanced load capacity and failure resistance. These findings lay the foundation for broader application of polymer concrete in load-bearing components and support the development of hybrid systems combining mechanical efficiency with design flexibility.</p></div>","PeriodicalId":691,"journal":{"name":"Materials and Structures","volume":"58 9","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1617/s11527-025-02814-7.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145316170","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}
Belkis Selma Aouichat, Masoud Hosseinpoor, Ammar Yahia, Mario Dupuis
{"title":"Dispersion of cellulose nanocrystals and cellulose nanofibers in aqueous suspensions: synergistic effect of concrete superplasticizers","authors":"Belkis Selma Aouichat, Masoud Hosseinpoor, Ammar Yahia, Mario Dupuis","doi":"10.1617/s11527-025-02811-w","DOIUrl":"10.1617/s11527-025-02811-w","url":null,"abstract":"<div><p>Achieving optimal dispersion of cellulose nanomaterials (CNMs) is crucial for unlocking their potential to enhance the performance of cement-based materials. This study investigates the synergistic effects of concrete superplasticizers (SPs) in dispersing CNMs within aqueous suspensions. The CNMs examined include cellulose nanocrystals (CNC) and cellulose nanofibers (CNF), each paired with one of three different SPs: polycarboxylate ether (PCE), linear polycarboxylate (PCL), and polynaphtalene sulfonates (PNS). The study primarily evaluated the apparent viscosity (<i>η</i><sub>app</sub>) and storage modulus (<i>G</i>′) to assess dispersion effectiveness. Mechanical stirring proved effective in preparing clean, accessible hydroxyl groups (OH<sup>−</sup>) on the CNMs for chemical modification. Depending on the type of CNMs, mechanical stirring induced distinct rheological behaviors that influenced their dispersion. Moreover, SPs successfully dispersed the investigated CNMs. The surface charge of CNMs governed the adsorption of SPs, which was influenced by the chemical structure of the SPs. Additionally, the aspect ratio of CNMs affected the effectiveness of steric hindrance or electrostatic repulsion in achieving proper dispersion. The findings provide valuable insights and recommendations for dispersing CNMs using concrete SPs.</p></div>","PeriodicalId":691,"journal":{"name":"Materials and Structures","volume":"58 9","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145315767","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}
Saeid Ghasemalizadeh, Ahmed G. Mehairi, Diandian Zhao, Rahil Khoshnazar
{"title":"Combination of ultrafine granulated blast furnace slag and metakaolin in low portland cement clinker cementitious mixtures","authors":"Saeid Ghasemalizadeh, Ahmed G. Mehairi, Diandian Zhao, Rahil Khoshnazar","doi":"10.1617/s11527-025-02822-7","DOIUrl":"10.1617/s11527-025-02822-7","url":null,"abstract":"<div><p>Effective utilization of supplementary cementitious materials to substitute high Portland cement contents in cementitious systems is a promising approach towards decarbonizing the cement and concrete industry. In this study, ultrafine ground granulated blast furnace slag (UFS) was combined with a locally available and medium-grade metakaolin (MK) to prepare low-Portland cement content binders. First, UFS was obtained from ultrafine grinding of a commercial slag, and analyzed for amorphous content, surface chemistry, and reactivity using R<sup>3</sup> method. MK and UFS blends at MK/UFS ratios of 80/20, 70/30, and 60/40 were used to replace 50 and 60 wt% of Portland cement in mortars and pastes. The compressive strength of mortars was monitored from 1 to 91 d. The heat evolution of pastes was recorded by isothermal calorimetry, and the microstructure of selected pastes was analyzed through thermogravimetric analysis, quantitative X-ray diffraction, and scanning electron microscopy. The results showed that ultrafine grinding of slag induced changes in its size, surface area, amorphous content, and surface chemistry, leading to higher reactivity of UFS compared to slag. Using MK-UFS blends with MK/UFS of 70/30 and 60/40 in mortars provided comparable 3-d, and higher 28- and 91-d, compressive strengths compared to the mortar made with Portland cement only. Formation of more reaction products, such as calcium–(alumino)–silicate-hydrates (C–(A)–S–H) and carboaluminates, and refinement of the microstructure in the mixtures containing MK-UFS contributed to the enhanced strength development of these mixtures.</p></div>","PeriodicalId":691,"journal":{"name":"Materials and Structures","volume":"58 9","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145256694","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":"Iron tailings-carbon fiber synergy in geopolymer composites: multi-objective optimization of self-sensing mortar","authors":"Ning Zhang, Weikun Zhai, Zexuan Cheng, Yue Geng, Yongqiang Li, Weijun Mi, Shiyang Yin","doi":"10.1617/s11527-025-02746-2","DOIUrl":"10.1617/s11527-025-02746-2","url":null,"abstract":"<div><p>This study proposes a multi-phase synergistic conductive network design strategy, innovatively utilizing industrial solid waste iron tailings sand (ITs) as a low-cost, eco-friendly conductive phase alongside carbon fibers (CFs) within an alkali-activated geopolymer matrix. This approach develops geopolymer mortar (TCAGM) with integrated superior mechanical properties and self-sensing functionality. Through Response Surface Methodology-Box-Behnken Design (RSM-BBD), the alkaline activator modulus (A), sol–gel ratio (B), and CF volume fraction (C) were optimized, overcoming the performance-cost-sustainability trade-off inherent in conventional self-sensing materials. The optimal mix proportion (A = 1.42, B = 0.82, C = 0.4%) achieves high electrical conductivity (1.98 × 10<sup>−2</sup>(Ω ·cm)<sup>−1</sup>, stable without degradation) and piezoresistive performance (− 0.0157 MPa<sup>−1</sup>, fluctuation within ± 5%). The multi-scale conductive network (long-range CF pathways + short-range ITs electron hopping + ionic transport) not only reduces CF dosage by 20–60% and raw material costs by 20% through ITs substitution but also enhances electromechanical performance. This work establishes a sustainable paradigm for high-performance, low-environmental-impact intelligent construction materials.</p></div>","PeriodicalId":691,"journal":{"name":"Materials and Structures","volume":"58 9","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145256692","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}