Current Issue : October-December Volume : 2026 Issue Number : 4 Articles : 5 Articles
This paper evaluates basalt aggregates from the Diack quarry and develops two concrete mixes for bridge construction in an XS1 saline environment. The study applies the Dreux-Gorisse and Féret-Bolomey mix design methods to a conventional C35/45 concrete and a self-compacting C35/45 concrete using CEM III/B cement. The reported aggregate properties meet the cited compliance limits, and both proposed mixes satisfy the prescriptive binder-content and effective water-to-cement ratio requirements for XS1 exposure. Basalt aggregates from the Diack quarry were characterized for physical properties (particle size distribution, specific gravity, bulk density, water absorption) and mechanical properties (Los Angeles and Micro-Deval coefficients) in accordance with applicable NF EN standards. All reported aggregate test results were within NF EN 12620 compliance limits. Two concrete formulations were derived: a conventional structural concrete B40 (C35/45) using the Dreux-Gorisse method, and a Self-Compacting Concrete (BAP, C35/45) using the Féret and Bolomey approaches, both incorporating slag cement CEM III/B 42.5 N-SR and a polycarboxylate superplasticizer. All granular fractions were used in saturated surface-dry (SSD) conditions, and effective water contents were corrected for aggregate absorption prior to mix proportioning. The resulting mix designs achieved effective water-to-binder ratios of 0.449 (B40) and 0.376 (BAP), satisfying the XS1 class requirements for minimum binder content (≥330 kg/m3) and maximum w/c ratio (≤0.55). Fresh-state performance targets for the BAP (slump flow ≥ 650 mm, yield stress τ 0 < 50 Pa, plastic viscosity η < 20 Pa·s) and an estimated service life exceeding 100 years under DuraCrete assumptions represent design objectives that require experimental validation prior to site implementation. The study demonstrates that locally sourced basalt aggregates are suitable for high-performance bridge concrete in estuarine West African environments, provided appropriate cement selection and admixture optimisation are applied....
The increasing frequency of extreme climate events poses significant risks to slope infrastructure, while traditional inspection methods are often inefficient and unsafe. Although unmanned aerial vehicles (UAVs) combined with structure-from-motion (SfM) provide high-fidelity 3D models, they lack the semantic understanding necessary for automated damage assessment. This study addresses this gap by developing and validating an anomaly-enhanced digital twin (AEDT) framework. The proposed system integrates multiview UAV imagery, SfM-based 3D reconstruction, and a convolutional neural network (CNN) for automated anomaly classification. This information is then fused into an interactive, geographic information system (GIS)-compatible DT platform for lifecycle management. A case study on a soil and water conservation (SWC) structure in central Taiwan was conducted for verification. The deep learning module achieved a macroaverage F1-score of 0.81, demonstrating balanced performance across erosion, spalling, siltation, and collapse classes. This was validated on a held-out test set derived from a total of 2000 annotated images spanning four anomaly types with three severity levels. Furthermore, the AEDT-based workflow reduced onsite inspection time by ~63% compared to conventional manual methods. The resulting AEDT model provides a dynamic, semantically enriched 3D representation of the infrastructure, linking geometric data with damage attributes and historical maintenance records. This research demonstrates a feasible and scalable solution for intelligent infrastructure monitoring, offering a robust tool for enhancing climate resilience and enabling proactive asset management....
Auxetic metamaterials have attracted substantial attention as core materials for sandwich structures for advanced lightweight applications due to their unconventional deformation behavior. This investigation studies the nonlinear dynamic response of re-entrant auxetic sandwich panels with various core designs subjected to three-point bending. The examined core designs include pure auxetic and gradient variations of the unit cell wall thickness -vertically and horizontally- across the core. Acrylonitrile Butadiene Styrene (ABS) polymer is chosen as the overall material, due to its high toughness, impact resistance, good processability and suitability for additive manufacturing processes. Finite element simulations were conducted in Abaqus/CAE to evaluate the influence of auxetic core geometry on load distribution, failure behavior, and energy absorption capacity. The numerical models were validated using previously published experimental data from the literature. The results showed that the graded designs improved the distribution of loads and postponed localized failure, thus improving maximum load bearing capacity and energy absorption resulting in enhanced bending performance. The horizontal internal graded configuration exhibited the best mechanical response, achieving a 23.2% increase in maximum load capacity and a 32.8% increase in energy absorption relative to the uniform auxetic core. Furthermore, the gradient effect introduced a progressive deformation mechanism, which induced smoother force-displacement responses alongside decreased stress concentrations. These findings demonstrate that graded auxetic core architectures provide an effective approach for enhancing the mechanical performance of sandwich structures in lightweight engineering applications....
In order to investigate the mechanical properties and supporting effect of the rapidly assembled lattice beam supporting structure in slope engineering, an indoor physical model test based on a scale ratio of 1:2 was carried out to simulate the typical landslide geological conditions of a highway slope. The structural design, construction technology and mechanical response characteristics of the assembled lattice beam under different loads were systematically studied. The stress process of the slope was simulated by the graded vertical loading method, and the evolution law of the soil pressure at each measuring point of the lattice beam cross beam and vertical beam was monitored. The test results show that the assembled lattice beam does not significantly participate in the load transfer of the soil at the initial loading stage. As the load gradually increases, its load-bearing capacity is significantly improved, and the supporting effect is obvious. The earth pressure of the cross beam is non-uniformly distributed along the length direction, and the force near the node and the edge area is significantly higher than that in the mid-span position. The earth pressure of the vertical beam shows a decreasing trend along the height direction, which reveals its transfer law to the concentrated load. The test results can provide a theoretical basis and experimental reference for the design and optimization of a bolt-fabricated lattice beam structure under complex geological conditions....
This study examines the harvesting of electrical energy from civil structures by means of electrodynamic transducers. First, the equations of motions of the electromechanical system are derived based on the modal properties of the structure. For large-mass civil structures such as bridges or slabs, the mechanical and the electrical domains can be decoupled. This allows the induced voltage in the transducer and the accompanying harvester circuit to be analyzed separately once the vibration response of the mechanical system is obtained. The harvested voltage is investigated experimentally using low-budget electromagnetic transducers (woofer drivers) attached to a cross-laminated timber plate and a rectifier with a smoothing capacitor to verify the derived equations. To accurately predict the harvested voltage across the capacitor, a simulation model in the software Simscape Electrical is used, which models the nonlinear behavior of the rectifier diodes in more detail. A numerical case study of applying electrodynamic energy harvesting to a bridge model based on real measurement data and realistic traffic loads reveals the energy harvesting potential of the considered systems. For transducers with typical properties, however, this potential is limited to low-power applications, such as wireless sensor nodes. To maximize voltage output, custom-made transducers with large transducer constants and low damping should be used....
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