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Ulfberg, A., Gonzalez-Libreros, J., Westberg Wilde, M., Johansson, F. & Sas, G. (2027). Reliability and sensitivity analysis of global failure modes of concrete buttress dam monoliths. Reliability Engineering & System Safety, 277, Article ID 113175.
Open this publication in new window or tab >>Reliability and sensitivity analysis of global failure modes of concrete buttress dam monoliths
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2027 (English)In: Reliability Engineering & System Safety, ISSN 0951-8320, E-ISSN 1879-0836, Vol. 277, article id 113175Article in journal (Refereed) Published
Abstract [en]

Research interest in reliability and sensitivity analyses of concrete dams has grown in recent decades, yet existing studies remain largely limited to gravity and arch dams and to case studies focused on earthquake events. To address this gap, this study aims to evaluate the reliability and sensitivity of concrete buttress dam monoliths using a simulated population based on existing Swedish designs with varying geometric properties such as height and width. Three failure modes, sliding, overturning, and combined sliding and overturning, were assessed under ice load and overtopping conditions. Reliability indices and local sensitivity measures were first estimated using first-order reliability analysis, after which polynomial chaos expansion metamodels were constructed to facilitate global sensitivity analyses. The results show that sliding has the lowest reliability, whereas overturning exhibits very high reliability and is generally not governing. Local sensitivity analyses indicate that rock-concrete interface friction dominates sliding and the combined failure mode, while concrete density is most influential for overturning. Global sensitivity analyses show that sliding reliability is primarily affected by front plate inclination, while overturning is mainly relevant for low monoliths or those with near-vertical front plates, and the combined mode is mainly influenced by asperity and front plate inclinations.

Place, publisher, year, edition, pages
Elsevier Ltd, 2027
Keywords
Buttress dams, Reliability analysis, Sensitivity analysis, First-order reliability method, Polynomial chaos expansion
National Category
Infrastructure Engineering
Research subject
Structural Engineering
Identifiers
urn:nbn:se:ltu:diva-119403 (URN)10.1016/j.ress.2026.113175 (DOI)001836092000001 ()2-s2.0-105045593121 (Scopus ID)
Funder
Swedish Research Council Formas
Note

Funder: the Swedish Centre for Sustainable Hydropower (SVC);

Available from: 2026-08-18 Created: 2026-08-18 Last updated: 2026-08-18Bibliographically approved
Fang, M., Huang, H., Guo, T., Li, Y., Wang, C., Ji, Y., . . . Sas, G. (2026). Atomic insights into asymmetric wetting and water retention in cementitious composites with high-siliceous ZSM-5 zeolite. Journal of Building Engineering, 128, Article ID 116527.
Open this publication in new window or tab >>Atomic insights into asymmetric wetting and water retention in cementitious composites with high-siliceous ZSM-5 zeolite
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2026 (English)In: Journal of Building Engineering, E-ISSN 2352-7102, Vol. 128, article id 116527Article in journal (Refereed) Published
Abstract [en]

Water retention capacity of zeolite allows strategic water release to mitigate shrinkage effects of cement-based materials. This study employed molecular dynamics simulations to explore the asymmetric wetting behaviors of corrosive salt solutions within pore models combined with different ZSM-5 facets and C-S-H surfaces. Results demonstrate that compared to the consistent hydrophilic C-S-H surface, variations of the zeolite facets influence the water retention capacity of zeolites and lead to differing degrees of solution transport unevenness. At discontinuous cavities, the solution fills first and the contact angle shows a horizontal trend or hysteresis behavior. Hydroxyl groups at the cavity distal ends then attract water molecules to form a hydrophilic contact angle. The favorable void exposure enables the highest water storage capacity of zeolite (0 0 1) facet, followed by (1 0 0) and (0 1 0) facets. While the continuous (0 1 0) facet shows superior hydrophilicity for rapid solution transport. Transport behaviors are similar for pure water and NaCl, but ion clusters in Na2SO4 solution reduce transmission rates and hinder water entry into zeolite channels. These findings provide an atomic-level perspective of zeolite applications for enhancing water storage and durability in cement-based materials.

Place, publisher, year, edition, pages
Elsevier Ltd, 2026
Keywords
Asymmetric wetting, Water retention, Composite pores, ZSM-5, Calcium silicate hydrate
National Category
Materials Chemistry Physical Chemistry
Research subject
Structural Engineering
Identifiers
urn:nbn:se:ltu:diva-118698 (URN)10.1016/j.jobe.2026.116527 (DOI)2-s2.0-105041319224 (Scopus ID)
Note

For funding, see link: https://www.sciencedirect.com/science/article/pii/S2352710226013483?via%3Dihub#ack0010

Available from: 2026-06-25 Created: 2026-06-25 Last updated: 2026-06-25Bibliographically approved
Ulfberg, A., Gonzalez, J., Westberg Wilde, M., Johansson, F. & Sas, G. (2026). Behavior and failure mechanism of scale model buttress dams with large-scale asperities in the rock-concrete interface. Engineering structures, 358, Article ID 122645.
Open this publication in new window or tab >>Behavior and failure mechanism of scale model buttress dams with large-scale asperities in the rock-concrete interface
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2026 (English)In: Engineering structures, ISSN 0141-0296, E-ISSN 1873-7323, Vol. 358, article id 122645Article in journal (Refereed) Published
Abstract [en]

The stability of concrete dams is commonly evaluated in terms of sliding, overturning, and bearing capacity. Although these failure modes are simple to evaluate analytically, they may not accurately reflect a dam’s actual failure behavior because of inherent idealizations and assumptions. Previous studies have shown that the failure mechanism for dams often involves both sliding and overturning, particularly in dams with uneven rock-concrete interfaces and large-scale asperities. This article presents results from 1:5 scale model tests of a buttress dam, conducted to investigate the behavior and failure mechanism of dams featuring large-scale asperities in the rock-concrete interface. Each of the twelve scale models incorporated a specific combination of interface geometry, rock bolts, reinforcement, and rock joints. The results were compared with FEA and analytical estimates for sliding, overturning, and combined sliding and overturning failure. The scale models failed through a combination of sliding and overturning, with significant strain concentrations observed at the asperities’ upstream faces and the toe at peak load, indicating reliance on these regions for force transfer. The presence of rock bolts and a rock joint altered the load capacity but generally did not affect the overall failure mechanism. The results indicate that dams with irregular interfaces may exhibit significant overstrength compared to current assessment practices in dam safety guidelines.

Place, publisher, year, edition, pages
Elsevier, 2026
Keywords
Concrete dams, Scale model tests, Buttress dams, Sliding, Overturning
National Category
Water Engineering
Research subject
Structural Engineering
Identifiers
urn:nbn:se:ltu:diva-115529 (URN)10.1016/j.engstruct.2026.122645 (DOI)001738313300001 ()2-s2.0-105034744392 (Scopus ID)
Funder
Swedish Research Council Formas
Note

Full text license: CC BY 4.0;

Funder: Swedish Centre for Sustainable Hydropower 

Available from: 2025-11-24 Created: 2025-11-24 Last updated: 2026-06-30Bibliographically approved
Bertola, N., Bhowmick, A., Casas, J. R., Chacon, R., Cousins, D., Grimson, J., . . . Žnidarič, A. (2026). Bridge load testing for assessment: recent advances in application, collaboration, codes, and research. Structure and Infrastructure Engineering, 22(5–6), 862-887
Open this publication in new window or tab >>Bridge load testing for assessment: recent advances in application, collaboration, codes, and research
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2026 (English)In: Structure and Infrastructure Engineering, ISSN 1573-2479, E-ISSN 1744-8980, Structure and Infrastructure Engineering, ISSN 1573-2479, Vol. 22, no 5–6, p. 862-887Article, review/survey (Refereed) Published
Abstract [en]

As the bridge stock in many countries is ageing, the topic of bridge assessment is gaining more importance. Bridge load testing is one of the tools that can be used to assess existing bridges. Over the past decade, assessment, and by extent, bridge load testing, have been applied, studied, and improved in various countries. This paper provides an international overview of bridge assessment practices, load testing practices, and recent research insights. Moreover, synergies in the research activities, collaboration efforts via technical committees, and recently published codes and guidelines are highlighted. The major topics of importance identified are linking load testing to global and element structural behaviour, improved on-site sensing techniques, incorporating load testing with structural monitoring, non-destructive evaluation, numerical modelling, probabilistic analysis, and leveraging the use of digital tools for embedding detailed load testing insights into modern bridge management systems. It can be concluded that bridge load testing is a dynamic field of application and research, for which international collaboration and comparing best practices is essential.

Place, publisher, year, edition, pages
Taylor & Francis, 2026
Keywords
Bridge assessment, diagnostic load testing, international collaboration, measurement techniques, monitoring, proof load testing, state-of-the-practice, stop criteria, structural reliability, technical committees
National Category
Infrastructure Engineering
Research subject
Structural Engineering
Identifiers
urn:nbn:se:ltu:diva-116218 (URN)10.1080/15732479.2025.2594077 (DOI)001631333000001 ()2-s2.0-105024885443 (Scopus ID)
Note

Funder: Ministry of Infrastructure and the Environment of the Netherlands; Italian High Council of Public Works; ReLUIS Consortium; ASHVIN project; ADIF

Available from: 2026-01-28 Created: 2026-01-28 Last updated: 2026-08-25Bibliographically approved
Wang, T., Fang, M., Guo, T., Qin, L., Tu, Y., Wang, C. & Sas, G. (2026). Bridging molecular dynamics simulations and experimental results via peridynamics for multiscale analysis of geopolymer mechanics. Geomechanics for Energy and the Environment, 46, Article ID 100841.
Open this publication in new window or tab >>Bridging molecular dynamics simulations and experimental results via peridynamics for multiscale analysis of geopolymer mechanics
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2026 (English)In: Geomechanics for Energy and the Environment, ISSN 2352-3808, Vol. 46, article id 100841Article in journal (Refereed) Published
Abstract [en]

Geopolymers are promising sustainable materials for structural and geotechnical applications. However, their pronounced multiscale structural heterogeneity complicates the direct linkage between atomistic mechanisms and macroscopic mechanical performance. In this study, a hierarchical multiscale molecular dynamics (MD) —peridynamics (PD) framework is developed, in which PD serves as an intermediate bridge connecting MD simulations with experimental observations of geopolymer mechanics. This framework enables the transfer of material characteristics across scales and allows the effects of Si/Al ratio and porosity on mechanical behavior to be systematically evaluated. The simulations indicate that Young’s modulus decreases with increasing Si/Al ratio, while the maximum tensile strength is achieved at a Si/Al ratio of 2. Under zero-porosity conditions, the PD-predicted Young’s modulus closely matches the MD results, whereas in the presence of porosity, the PD predictions fall within the experimental range. These findings demonstrate that PD effectively extends the applicability of MD simulations to the mesoscale and provides a practical multiscale framework for the design and optimization of geopolymers.

Place, publisher, year, edition, pages
Elsevier Ltd, 2026
Keywords
Molecular dynamics, Peridynamics, Multiscale modeling, Si/Al ratio, Porosity
National Category
Applied Mechanics
Research subject
Structural Engineering
Identifiers
urn:nbn:se:ltu:diva-117724 (URN)10.1016/j.gete.2026.100841 (DOI)2-s2.0-105039003471 (Scopus ID)
Note

For funding, see link: https://www.sciencedirect.com/science/article/pii/S2352380826000560?via%3Dihub#ack0005

Available from: 2026-06-01 Created: 2026-06-01 Last updated: 2026-06-01Bibliographically approved
Guo, X., Jing, J., Guo, T., Feng, J., Wang, C., Ji, Y., . . . Sas, G. (2026). Corrosion inhibition mechanisms of salicylic acid and cinnamaldehyde on stainless steel passive films in sulfuric acid: a reactive force field molecular dynamics study. Applied Surface Science, 748, Article ID 167830.
Open this publication in new window or tab >>Corrosion inhibition mechanisms of salicylic acid and cinnamaldehyde on stainless steel passive films in sulfuric acid: a reactive force field molecular dynamics study
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2026 (English)In: Applied Surface Science, ISSN 0169-4332, E-ISSN 1873-5584, Vol. 748, article id 167830Article in journal (Refereed) Published
Abstract [en]

Understanding how organic inhibitors regulate oxide surfaces in acidic environments requires connecting adsorption strength with dynamic interfacial transport. Here, reactive force field molecular dynamics (ReaxFF MD) simulations were used to compare salicylic acid (SA) and cinnamaldehyde (CA) on Cr2O3 passive films in sulfuric acid solution. Adsorption configurations, interfacial water structure, ion distribution, hydrogen bonding, and proton-accessibility descriptors were analyzed at the atomic scale. Both inhibitors chemisorb strongly on Cr2O3, but their protective functions differ substantially. SA anchors through localized carboxyl and hydroxyl coordination, forming a discontinuous and relatively hydrophilic adsorption layer that permits water accumulation and proton access. By contrast, CA adopts a surface-parallel configuration stabilized by aldehyde coordination and extended π-metal interactions, producing a compact hydrophobic layer that depletes interfacial water and suppresses proton approach to surface oxygen sites. The results show that corrosion inhibition is governed not only by adsorption energy but also by molecular planarity, lateral packing, interfacial water exclusion, and suppression of proton transport. This work provides an atomistic design framework for organic inhibitors targeting stainless-steel passive films in acidic sulfate environments.

Place, publisher, year, edition, pages
Elsevier B.V., 2026
Keywords
Organic corrosion inhibitors, ReaxFF molecular dynamics, Chromium oxide passive film, Adsorption mechanism, Proton transport
National Category
Surface- and Corrosion Engineering
Research subject
Structural Engineering
Identifiers
urn:nbn:se:ltu:diva-119262 (URN)10.1016/j.apsusc.2026.167830 (DOI)001827526500001 ()2-s2.0-105045010313 (Scopus ID)
Note

Funder: Key project supported by the Joint Funds of the National Natural Science Foundation of China (U23A20661); the National Natural Science Foundation of China (22478069); the National Science Fund for Distinguished Young Scholars (52125802); the Fundamental Research Funds for the Central Universities (2242022k30030; 2242022k30031); the SEU Innovation Capability Enhancement Plan for Doctoral Student (CXJH_SEU 25102);

Available from: 2026-08-12 Created: 2026-08-12 Last updated: 2026-08-12Bibliographically approved
Liu, D., Wang, C., Gonzalez-Libreros, J., Andersson, A., Elfgren, L. & Sas, G. (2026). Dynamic behavior of steel post/wood panel railway noise barriers under aerodynamic loads induced by high-speed trains. Railway Engineering Science, 34(1), 55-84
Open this publication in new window or tab >>Dynamic behavior of steel post/wood panel railway noise barriers under aerodynamic loads induced by high-speed trains
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2026 (English)In: Railway Engineering Science, ISSN 2662-4745, Vol. 34, no 1, p. 55-84Article in journal (Refereed) Published
Abstract [en]

Railway noise barriers are an essential piece of infrastructure for reducing noise propagation. However, these barriers experience aerodynamic loads generated by high-speed trains, leading to dynamic effects that may compromise their fatigue capacity. The most common structural design for railway noise barriers consists of vertical configurations of posts and panels. However, there have been few dynamic analyses of steel post/wood panel noise barriers under train-induced aerodynamic loads. This study used dynamic finite element analysis to assess the dynamic behavior of such noise barriers. Analysis of a 40-m-long noise barrier model and a triangular simplified load model, the latter of which effectively represented the detailed aerodynamic load, were first used to establish the model and input of the moving load during dynamic simulation. Then, the effects of different parameters on the dynamic response of the noise barrier were evaluated, including the damping ratio, the profile of the steel post, the span length of the panel, the barrier height, and the train speed. Gray relational analysis indicated that barrier height exhibited the highest correlations with the dynamic responses, followed by train speed, post profile, span length, and damping ratio. A reduction in the natural frequency and an increase in the train speed result in a higher peak response and more pronounced fluctuations between the nose and tail waves. The dynamic amplification factor (DAF) was found to be related to both the natural frequency and train speed. A model was proposed showing that the DAF significantly increases as the square of the natural frequency decreases and the cube of the train speed rises.

Place, publisher, year, edition, pages
Springer Nature, 2026
Keywords
Aerodynamic load, Dynamic amplifcation factor, Dynamic behavior, Finite element analysis, High-speed train, Railway noise barrier
National Category
Infrastructure Engineering
Research subject
Structural Engineering
Identifiers
urn:nbn:se:ltu:diva-112214 (URN)10.1007/s40534-025-00377-5 (DOI)001448881100001 ()2-s2.0-105000502708 (Scopus ID)
Funder
Swedish Transport Administration, BBT-2019-022Swedish Transport Administration, BBT-TRV 2024/132497
Note

Full text license: CC BY 4.0;

Available from: 2025-04-02 Created: 2025-04-02 Last updated: 2026-06-30Bibliographically approved
Fang, M., Wang, T., Guo, T., Jiang, B., Guo, X., Wang, C., . . . Sas, G. (2026). Effects of water on the early-stage competitive adsorption of carbon dioxide within cement hydrate pores. Physical Chemistry, Chemical Physics - PCCP
Open this publication in new window or tab >>Effects of water on the early-stage competitive adsorption of carbon dioxide within cement hydrate pores
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2026 (English)In: Physical Chemistry, Chemical Physics - PCCP, ISSN 1463-9076, E-ISSN 1463-9084Article in journal (Refereed) Epub ahead of print
Abstract [en]

The pursuit of carbon neutrality has intensified interest in carbon utilization. Understanding the diffusion and adsorption mechanisms of CO2 and H2O within calcium silicate hydrate (C–S–H) is critical for assessing the carbonation durability of cement-based materials. In this study we used molecular dynamics to explore the transport and adsorption of H2O, CO2 fluid, and their mixtures in C–S–H nanopores. Water content was varied based on the fixed CO2 amount (0%, 25%, 50%, 75%, and 100%) to assess its impact on CO2 dynamics behaviors. The results indicate that CO2 exhibited greater mobility and density change compared to H2O which moved slowly. The presence of water suppresses initial CO2 diffusivity, an effect that intensified with increasing water content. CO2 initially undergoes dynamic adsorption–desorption cycles on the C–S–H surface but is progressively displaced as infiltrating water molecules establish a stable hydration layer that blocks further CO2 access to adsorption sites. The cohesive nature of the aqueous solution promotes multilayer-to-monolayer adsorption, whereas CO2 remains more evenly distributed yet exhibits a markedly lower adsorption capacity than water molecules. This study offers an atomic-level perspective of early dynamic behaviors of CO2 and H2O within C–S–H pores and thereby provides insights into the subsequent carbonation phenomena in cementitious systems.

Place, publisher, year, edition, pages
Royal Society of Chemistry, 2026
National Category
Physical Chemistry Materials Chemistry
Research subject
Structural Engineering
Identifiers
urn:nbn:se:ltu:diva-119618 (URN)10.1039/d6cp02160c (DOI)001852486500001 ()42614104 (PubMedID)2-s2.0-105047962104 (Scopus ID)
Note

Funder: National Natural Science Foundation of China (22478069, U23A20661); National Science Fund for Distinguished Young Scholars (52125802); Central Universities (2242022k30030, 2242022k30031);

Available from: 2026-09-03 Created: 2026-09-03 Last updated: 2026-09-03Bibliographically approved
Coric, V., Gonzalez-Libreros, J., Wang, C. & Sas, G. (2026). Environmental Anomaly Identification in Time Series Data for Prestressed Concrete Bridges. In: Ravdeep Kour, Ramin Karim, Uday Kumar, Diego Galar, Veronica Jägare (Ed.), International Congress and Workshop on Industrial AI and eMaintenance 2025: . Paper presented at International Congress and Workshop on Industrial AI and eMaintenance, May 13–15 2025, Luleå, Sweden (pp. 503-515). Springer Nature
Open this publication in new window or tab >>Environmental Anomaly Identification in Time Series Data for Prestressed Concrete Bridges
2026 (English)In: International Congress and Workshop on Industrial AI and eMaintenance 2025 / [ed] Ravdeep Kour, Ramin Karim, Uday Kumar, Diego Galar, Veronica Jägare, Springer Nature, 2026, p. 503-515Conference paper, Published paper (Refereed)
Place, publisher, year, edition, pages
Springer Nature, 2026
Series
Lecture Notes in Mechanical Engineering, ISSN 2195-4356, E-ISSN 2195-4364
National Category
Infrastructure Engineering
Research subject
Structural Engineering
Identifiers
urn:nbn:se:ltu:diva-117024 (URN)10.1007/978-3-032-03725-1_35 (DOI)
Conference
International Congress and Workshop on Industrial AI and eMaintenance, May 13–15 2025, Luleå, Sweden
Note

ISBN for host publication: 978-3-032-03724-4, 978-3-032-03725-1;

Available from: 2026-04-08 Created: 2026-04-08 Last updated: 2026-04-08Bibliographically approved
Li, H., Jiang, J., Qin, L., Wang, T., Zang, H., Wang, C., . . . Sas, G. (2026). Failure criteria and constitutive model analysis of coral aggregate concrete under conventional triaxial loading based on physics-informed neural networks. Computers & structures, 330, Article ID 108326.
Open this publication in new window or tab >>Failure criteria and constitutive model analysis of coral aggregate concrete under conventional triaxial loading based on physics-informed neural networks
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2026 (English)In: Computers & structures, ISSN 0045-7949, E-ISSN 1879-2243, Vol. 330, article id 108326Article in journal (Refereed) Published
Abstract [en]

Coral aggregate concrete is a potential alternative to natural aggregate concrete for coastal building structures. Given that coastal structures often experience triaxial stress states, conventional empirical models rely on extensive experimental data, and their limited physical interpretability can hinder reliable prediction of coral aggregate concrete behavior when data are sparse. This study proposes a physics-informed neural networks framework embedding the unified five-parameter or modified unified twin-shear strength theory failure criteria, modified Guo’s piecewise constitutive model, and geometric boundary constraints to enable parameter inversion and stress–strain reconstruction. Conventional triaxial compression tests were conducted on coral aggregate concrete across varying strength grades, coral aggregate replacement rates, and confining pressure ratios. Experimental results show that higher confinement shifts failure from axial splitting to ductile oblique shear, increases peak stress, and alleviates post peak softening. Meanwhile, increased coral aggregate replacement rates intensify structural crushing. The developed framework accurately predicts multiaxial peak stress and reconstructs full stress-strain curves from sparse data. Validations demonstrate excellent predictive accuracy, achieving determination coefficients exceeding 0.97 and mean absolute percentage errors below 5 %. The framework maintains robust accuracy under 20 % data noise. This study provides an efficient and interpretable computational approach for characterizing the nonlinear mechanics of emerging engineering materials.

Place, publisher, year, edition, pages
Elsevier Ltd, 2026
Keywords
Physics-informed neural networks, Coral aggregate concrete, Triaxial compression, Failure criterion, Constitutive model
National Category
Infrastructure Engineering
Research subject
Structural Engineering
Identifiers
urn:nbn:se:ltu:diva-118758 (URN)10.1016/j.compstruc.2026.108326 (DOI)2-s2.0-105041562043 (Scopus ID)
Note

Funder: National Natural Science Foundation of China (U23A20661, 22478069); National Science Fund for Distinguished Young Scholars (52125802); Fundamental Research Funds for the Central Universities (2242022k30030, 2242022k30031); SEU Innovation Capability Enhancement Plan for Doctoral Students (CXJH_SEU 25086)

Available from: 2026-06-24 Created: 2026-06-24 Last updated: 2026-06-24Bibliographically approved
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