Tractebel

Non-destructive techniques such as the contact sponge method (CSM) and the Karsten tube have been developed to assess the water absorption properties of building materials during field measurements. In contrast, laboratory investigations typically rely on capillary rise tests (CR) on centimetric specimens imposing a one-dimensional water flow. Although the results obtained from these methods are qualitatively comparable, a robust quantitative correlation is still lacking. An analytical expression has previously been proposed to estimate the sorptivity from measurements with non-destructive techniques, based on the assumption that the water penetration depth equals the lateral spreading of water on the material surface. In this study, we investigate the water absorption processes induced by the contact sponge method, by combining neutron radiography, which allows direct visualization of water penetration, with conventional capillary rise tests based on gravimetric measurements. Sandstones and limestones with porosities ranging from 10

Earthen construction is gaining popularity because low-carbon, locally produced, and sustainable building materials are needed. However, Compressed Earth Blocks (CEBs) still struggle with strength, water sensitivity, and durability particularly when assessed at the material scale or under insufficient stabilization and moisture-protection conditions. Due to their renewability, quantity, and ability to enhance mechanical and environmental performance, natural fibers are a viable reinforcement strategy. This work goes beyond a state-of-the-art synthesis to examine natural fiber-reinforced CEB studies quantitatively. A comprehensive literature review based-on PRISMA technique and statistical data analysis utilizing R programming associate fiber type, treatment methods, and earth composition with important performance factors. Chemical, physical, and thermal treatments are critically compared for fiber-matrix bonding, mechanical properties, and environmental trade-offs. It also compares fiber integration to cement and lime stabilizers in Life Cycle Assessment (LCA), revealing their sustainability potential. Finally, this study addresses information gaps, including the lack of standardized methods, long-term durability studies under varied climates, and suggests further research and large-scale implementation. This study contributes to the development of performance-enhanced earthen building materials with potentially reduced embodied carbon, based on environmental assessment, quantitative synthesis, and critical evaluation.

A large industrial facility with their inhouse power generating sources, connected to the utility grid via high impedance interconnecting transformers, could experience low frequency oscillations when dispatch changes occur while having one of the interconnecting transformers offline for maintenance. Typical aluminium smelters have their own generators and substations along with high voltage grid connections, a detailed study for an aluminium smelter was conducted involving model reviews, operating condition replication, modal analysis, and RMS dynamic simulations to assess the risk of such oscillations and to analyze the possible measures under both normal and abnormal operating conditions in order to improve the Security of Electricity Supply to the smelter process. This paper presents the main outcomes of a case study and provides a number of recommendations including the need for better observability of oscillations via PMU’s, ensuring a minimum level of system strength, installation of an Out of Step (OOS) Relay, Power Swing Blocking (PSB) and adhering to the system state limits such as maximum power transfer.

In the context of the energy transition, tighter integration of energy production and consumption through multiple energy vectors represents a promising pathway to improve resource utilisation and efficiency. Nuclear Hybrid Energy Systems (NHES), where nuclear reactors are coupled to different end-user segments, are seen as a valuable response.This article presents an overview of the TANDEM Modelica library, an open-source modelling tool developed under the Euratom-funded TANDEM project to support the simulation and analysis of NHES. It is based on the object-oriented language Modelica, which allows assembling NHES simulators from independently developed models through a plug-and-play approach. In this work, we present the objectives and anticipated requirements of the tool, while practical applications showcase the library’s capability to simulate complex dynamics under various operating scenarios. It also outlines the methodological approach to numerically couple dynamic models with external tools (i.e., thermal-hydraulic codes for safety analyses and techno-economic optimisation frameworks).The library proved to be a valuable tool within the broader framework of NHES analysis, which aims at supporting decision-makers evaluating the deployment of such systems in decarbonisation strategies. Future developments aim at expanding the library’s contents in terms of available technologies and assessing model fidelity through verification and validation efforts.

Cette étude propose une méthodologie pour sélectionner des scénarios de sol critiques dans le cadre de la conception géotechnique du projet d’infrastructure Oosterweel, à Anvers (Belgique). En raison de la complexité géologique du site et de la variabilité observée dans les essais CPT (Cone Penetration Test), une approche combinant expertise géotechnique et approche statistique a été mise en œuvre pour identifier les profils de sol induisant les réponses structurelles les plus contraignantes. Des analyses par éléments finis ont été réalisées à l’aide du logiciel Plaxis 2D afin de simuler l’interaction sol-structure à différentes étapes de la construction. Plusieurs scénarios de profil de sol ont été étudiés : des profils de sols meubles, rigides, ainsi que des profils de sols hétérogènes composés de couches alternées. L’analyse s’est concentrée sur les éléments clés du projet, tels que la paroi moulée et les fondations profondes, en évaluant les déplacements et les efforts internes générés dans chaque configuration. Les résultats ont montré que les sollicitations structurelles les plus importantes ne provenaient pas uniquement des sols meubles ou rigides, mais principalement des profils hétérogènes, où la stratification variable du sol provoque des réponses mécaniques complexes. Les plus fortes valeurs de déplacement et de moment de flexion ont été observées dans ce scénario hétérogène. Sur cette base, trois profils critiques ont été retenus – meuble, rigide et hétérogène – en tant que cas de référence pour les modélisations futures. La méthodologie développée permet de mieux anticiper les effets de la variabilité des sols sur la conception, et fournit un cadre rationnel pour le choix de scénarios représentatifs dans des projets d’infrastructure complexes, renforçant ainsi leur robustesse géotechnique.