bluuebunny/crossref_metadata_2025 huggingface dataset:
Strengthening of Precast Segmental Bridge built in 1960s using External Tendons
Authors: Moravcik Martin , Bujnakova Petra , Kralovanec Jakub
Published: September 2023

Recently more attention has been paid to ageing infrastructure under increased traffic on the roads in Slovakia. As a result, selected prestressed concrete bridges have been inspected. Evidence of their poor technical condition has been discovered including serious faults such as large permanent deflection, wide cracks, extensive prestressing degradation, and others. The original conceptual design and poor quality of prestressing steel protection are often the decisive factor. This paper provides an example of bridge rehabilitation design of the concrete precast segmental bridge in an emergency condition. The bridge in question which is located over the water reservoir Ruzin was built in 1967 as one of the first‐generation precast segmental bridges in Slovakia. Its service life was successfully extended using structural system modification and strengthened using external prestressing. The initial assumptions for the rehabilitation have been based on the detailed analysis of the defects, and assessment of existing conditions including the analytical approach of residual prestressing determination. This concept represents the potential solution for achieving enhanced service life of similar bridges.
On Mathematical Models of Degradation Processes According to ISO 16204 and fib Model Code
Authors: Šomodíková Martina , Doležel Jiří , Lehký David
Published: September 2023

The main factors affecting the service life of concrete structures are the presence of chloride ions and carbon dioxide, alternating frost action and mechanical stresses on the structure. In practice, these effects can be taken into account by using mathematical modelling of these phenomena. In this contribution, the authors focus on the processes of chloride ions and carbon dioxide (carbonation process) diffusion through concrete and the associated subsequent corrosion of reinforcement. Mathematical models recommended by the fib Model Code and ISO 16204 are described and the effect of simultaneous environmental and mechanical load on the service life of the structure is discussed. The models are used to study the residual service life of a simple reinforced concrete frame bridge based on the percentage loss of reinforcement area analysis over time.
Inspection and maintenance KPIs to support decision making integrated into Digital Twin tool
Authors: Stipanovic Irina , Palic Sandra Skaric , Casas Joan Ramon , Chacón Rolando , Ganic Emir
Published: September 2023

In the H2020 European project ASHVIN “Assistants for Healthy, Safe, and Productive Virtual Construction Design, Operation & Maintenance using a Digital Twin”, a set of Key Performance Indicators (KPIs) and Performance Indicators (PIs) to plan and control productive, resource efficient, and safe maintenance are being developed for transport infrastructure. This paper is presenting PIs and KPIs for the assessment and monitoring of the following aspects: Productivity, Resource Efficiency, Cost, Health & Safety during the operational life cycle stage, which is mainly focusing on the inspection and maintenance planning. Quantifiable and measurable PIs and KPIs are proposed and applied on two demonstration projects, highway bridge in Spain and airport runway in Croatia, as part of transportation infrastructure. Proposed PIs and KPIs are integrated into digital twins of the analyzed assets and into decision making tools for risk based maintenance planning. This paper presents the overview of the proposed digital PIs and KPIs applied on two demonstration projects and the integration into decision support tools for efficient and sustainable maintenance planning.
Towards standardized guidelines in digital data acquisition for monitoring and maintenance of European transport infrastructures
Authors: Justo Andrés , Sánchez‐Rodríguez Ana , Varela María , Arias Pedro
Published: September 2023

The digital transformation of the architecture, engineering, and construction sector is associated with an enormous production of data. The appearance of new technologies is leading the way for more sustainable and interconnected infrastructures. Therefore, data analytics is crucial to know the current state of infrastructure and will help towards the efficient management of assets. The main issue is how to collect and exploit meaningful data throughout the lifecycle of infrastructure assets to further allow human experts and computers to make accurate diagnostics, predictions, and decisions. This contribution presents the insights gained in the course of IM‐SAFE project, showing the strategy followed to create guidelines for data collection to monitor and maintain critical assets in the infrastructure network (bridges and tunnels). It tackled a variety of surveying technologies, from destructive and non‐destructive, to chemical methods, among others. The results obtained will support the European Committee for Standardization (CEN) in the standards for monitoring and maintenance of bridges and tunnels, accelerating the adoption of new standards by public authorities and stakeholders in transport infrastructure.
Model updating of in‐service bridges using multidisciplinary research ‐ case studies in Spain
Authors: Riveiro Belen , Bouzas Óscar , Barros Brais , Conde Borja , Cabaleiro Manuel , Rodríguez Ana Sánchez , Arias‐Sánchez Pedro
Published: September 2023

This paper presents several experiences focused to create and update accurate numerical models of ageing bridges in Spain. The experimental campaigns included integration of various NDT technologies such as laser scanning, ultrasounds, etc., combined with vibration‐based methods such as Operational Modal Analysis. From these multi‐source data it was possible to create an accurate numerical model of each structure, which was lately subjected to a calibration using the actual dynamic response of the structure. Thus, the updated structural model presents the same behaviour as the real construction, offering a powerful tool to more accurately predict the safety level of the structure. On the other hand, structural assessments based on reliability analysis has been proved to improve the quality and accuracy of safety analysis due to the consideration of the possible deviations presented in the parameters of a structure. These works were compiled as case‐studies in Spain within IM‐SAFE project.
FRAMEWORK FOR PROACTIVE MAINTENANCE PRACTICES FOR TRANSPORT INFRASTRUCTURES
Authors: Daró Paola , Alovisi Isabella , Mancini Giuseppe , Negri Serena , Vliet Agnieszka Bigaj‐van , van Meerveld Hendrik
Published: September 2023

The intensive use, as well as climate change, accelerates structural deterioration of transport infrastructure, leading to an increased risk level. Hence, well‐founded procedures to improve asset management and optimize utilization of the limited resources for conservation are needed. The foreseen harmonization of standards at European level aims to facilitate the transition from traditional maintenance approaches (corrective and time‐based maintenance) towards a risk‐based approach to maintenance decision‐making. The condition‐based maintenance strategy is favored since enables early identification of risks. Analysis of best practices show that the acceptance and use of preventive maintenance strategies in the current practice is increasing. Therefore, it is essential to provide an harmonized basis for decision‐making concerning the implementation of maintenance strategies in asset management. This contribution summarizes the lessons learned and explores the vision developed in H2020 CSA IM‐SAFE project, which envisages the use of risk‐based maintenance management system and employing condition‐based maintenance strategies supported by inspection, testing and monitoring to ensure reliability, safety, availability and economical operation over the assets' lifetime.
Electromagnetic testing of multi‐strand stay cables: novel technique and instrumentation
Authors: Semenov Alexey , Slesarev Dmitry
Published: September 2023

Steel stay cables are widely applied in various civil constructions. In recent decades, the so‐called multi‐strand stay cables have become widely used, particularly in the construction of cable‐stayed bridges. Conventional method of stay‐cable diagnostics utilizes magnetic rope testing instruments. However, because of the large diameter of multi‐strand stay cables, the appropriate magnetic instrument should have an inappropriate high mass and create a significant force of attraction between the magnetic head and the stay cable, which likely would cause damage to the cable's outer protective shell. Alternatively, the eddy current method can be used for testing of stay cables. The special probe was developed that provides equal sensitivity to surface and subsurface breaks of the strands and reduces a disturbance of irregularity of magnetic properties along the cable. On the basis of this probe, a specific electromagnetic instrument was designed for nondestructive testing of multi‐strand stay cables. The instrument was tested on a multi‐strand mock‐up and applied for inspection of the stay cables of bridges. Results of this are discussed in the article.
Guideline on NDT‐supported reliability assessment of existing structures ‐ Current developments in Germany
Authors: Küttenbaum Stefan , Braml Thomas , Heinze Marco , Kainz Christian , Keuser Manfred , Kotz Peter , Lechner Thomas , Maack Stefan , Reinke Klaus‐Dieter , Schulze Sebastian , Soukup Alexander , Stettner Christian , Taffe Alexander , Wöstmann Jens
Published: September 2023

Information about an existing structure can be collected at certain costs to evaluate the reliability and condition as realistically as necessary. This information can be relevant or irrelevant, true or biased, precise or imprecise. The incorporation of relevant and quality‐assessed measured information into reliability reassessment offers the chance to extend remaining lifetimes and support decision making about optimal actions or maintenance strategies. This paper shows recent developments in a national research project that aims to produce a guideline on the NDT‐based, structure‐specific modification of partial safety factors. The general methodology, results from recalculations according to the Eurocodes and metrologically solvable testing tasks relevant in the recalculation of the concrete bridges are shown and compared with the non‐destructive testing methods applicable to concrete bridges. A case study is used to demonstrate that as‐built drawings, in this case of the positions of tendons and shear reinforcement, can be verified using the radar method.
A Unified concrete damage model for monotonic loading and fatigue loading
Authors: Guo Chenggong , Li Jie
Published: September 2023

In this work, a unified damage model is proposed for describing the mechanical behavior of concrete under monotonic loading and fatigue loading. Based on the micro‐meso stochastic fracture model (MMSF), the multiscale energy dissipation within the microspring is investigated. The rate process theory and a crack hierarchy model are employed to describe the nanocrack growth rate and crack number, respectively. It is found out that the fracture strain of the microspring can be derived from the energy dissipation analysis. The expression of the stochastic damage evolution law is changed to “energy dissipation threshold” instead of “fracture strain.” The new model can describe different damage evolution forms under monotonic and fatigue loading with the same parameters. The mechanisms of different damage evolution laws under different loading modes are analyzed in detail. Finally, a numerical example is presented to verify the proposed model.
Low frequency Piezoelectric Micromachined Ultrasonic Transducers optimized for concrete structures.
Authors: Sammut Stephen , Gatt Edward , Borg Ruben Paul
Published: September 2023

Embedded sensors operating within a reinforced concrete structure enable the timely detection of structural degradation causes, such as chloride ions present in the pore solution. The best communication protocol to use for inter‐device communication within the concrete structure would ideally be wireless such as an ultrasonic system. Concrete is a composite material which imposes constraints on ultrasonic transmission, especially when operating at frequencies above 100kHz where incident radiation is scattered by the aggregate. Furthermore, for an effective coupling mechanism, a liquid with high acoustic impedance is required to reduce energy reflection at the interface. This paper outlines the design, construction, and characterisation of a range of Piezoelectric Micromachined Ultrasonic Transducers (PMUTs) which are specifically designed to operate in liquids, at frequencies near or below 100kHz. The PMUT devices described in this paper have diaphragm diameters ranging between 550μm and 2,000μms which sizes are needed for PMUTs to resonate at the required low frequency. This paper outlines the device geometry calculations and the design and fabrication of the prototype devices. The resonant frequencies were determined using a laser vibrometer.
Flood vulnerability assessment: an effective tool to evaluate the lifecycle risk analysis of bridges.
Authors: Kosič Mirko , Anžlin Andrej , Bau' Valentina
Published: September 2023

From a lifecycle perspective, assessing bridge vulnerability is a key element of implementing effective risk mitigation and management strategies. This study offers an integrated and computationally efficient approach to evaluate bridges' vulnerability to failure due to hydrodynamic and wood debris forces and the concurrent action of local scour. The vulnerability analysis follows a stochastic approach and is developed through a case‐study analysis of a bridge that has a high proneness to flood‐related hazards. The modelling of the wood debris accumulation is accomplished based both on a Standard approach and on findings drawn from up‐to‐date research data. It is found that the shape of wood debris accumulation envisioned in the first approach has a particularly adverse effect on the bridge's vulnerability, exposing its limitations. A detailed and comprehensive methodology for assessing the risk related to flood hazards on bridges is also presented. It is perceived that not only will this new tool be valuable in estimating the flood loss assessment on bridges, but it will also be beneficial for facilitating decision‐making processes and in finding effective countermeasures for risk mitigation of flood‐related hazards.
Drive‐by frequencies extraction by means of synchrosqueezed wavelet transform
Authors: Benedetti Lorenzo , Bernardini Lorenzo , Argentino Antonio , Cazzulani Gabriele
Published: September 2023

Bridges and viaducts are facing growing traffic, increasing loads as well as ageing and deterioration. Nowadays, vibration‐based Structural Health Monitoring (SHM) represents an effective solution to extract quantitative information regarding bridge structural condition. Bridge frequencies are fundamental parameters capable to reflect and summarize bridge dynamics and health condition. Typically, their identification is performed by direct approaches, which rely on the use of sensors installed on the structure under analysis. A cost‐efficient, movable, and flexible alternative is offered by drive‐by methods, consisting in the use of instrumented vehicles to extract bridge frequencies. This paper presents an experimental campaign carried out on a multiple‐span mixed railroad bridge, with the aim to identify its frequencies through onboard measurements. A set of MEMS wireless accelerometers is deployed on the vehicle, firstly allowing for vehicle pitch component mitigation. Vehicle accelerations were then used to extract bridge frequencies, by means of a Most Probable Modal Frequencies approach, relying on synchrosqueezed wavelet transform. At a cruise speed of 30 km/h promising results in terms of indirect frequency estimation were found, with no traffic disruption.
Key Performance Indicators for Building Assessment. A case study on an R/C Building in Greece.
Authors: Markogiannaki Olga , Stefanidou Sotiria
Published: September 2023

The acquisition of data regarding the performance of buildings and the use of metrics to understand their performance level are critical for efficient building management. Performance indicators are key elements in this process. They shall be clearly defined and provide the means for easily measuring building performance. These performance indicators should cover all aspects of a building's life cycle including safety, operability and sustainability. To facilitate such a process, it is preferable to group the performance indicators into categories, namely the key performance indicators. In this paper, the key performance indicators for buildings are determined by compiling the identified critical ones in the literature. A case study of an R/C building in Greece is used to quantify the presented metrics focusing mainly on safety. The reliability index indicator is calculated based on the simulation and analysis of a building subsystem. Other key performance indicators relevant to building maintenance are considered on scenario basis. The study has been conducted as part of the IABSE Task Group 5.2. – “Key Performance Indicators: Definition” and provides valuable insight into using quantified metrics for decision‐making in building management.
Structural Health Monitoring of a steel truss railway bridge studying its low frequency response
Authors: Radicioni Luca , Bernardini Lorenzo , Bono Francesco Morgan , Anghileri Mattia , Capacci Luca , Cazzulani Gabriele , Somaschini Claudio , Pande Aniket Ketan , Biondini Fabio , Cinquemani Simone , Belloli Marco
Published: September 2023

In the framework of direct Structural Health Monitoring approaches, this paper presents a low frequency range analysis performed on a steel truss bridge designed in 1946 and built up in Northern Italy. The bridge is instrumented with a permanent structural health monitoring system, that guarantees a continuous flux of data and information from a heterogeneous set of sensors. In this analysis, static and quasistatic bridge responses are considered. These experimental data are merged with the analogous outputs obtained from numerical simulations, performed on FE models representative of the actual bridge, with the purpose of identifying damage‐sensitive indexes. Simulations are performed considering the healthy structure and modelling different damage scenarios. The static analysis consists in the construction of a regressive model able to estimate sensor output responses starting from environmental measurements, with the primary purpose to reduce the effect of temperature over measured static response. This procedure allows to relate the damages simulated by means of a numerical model with the real data, so that the monitoring rules can effectively defined.
Digital Life‐Cycle and Asset‐Management for Steel Bridges
Authors: Geβler Achim , Hoffmeister Benno , Geers Thorben
Published: September 2023

(Steel) bridges have well‐known issues with regard to fatigue problems causing a lot of the existing infrastructure to be urgently being strengthened or even being replaced. To supervise and investigate all bridges it is state of the art that on a regular basis these bridges have to be inspected by experts (German DIN 1076). In particular with regard to those already known issues a research consortium has set up a collaborative research project together with partners from the road authorities with the aim to provide a data system for an asset‐management for such bridges.

The partners and road authorities have selected some typical bridges with regard to those particular structural details:

• Cluster 1: „Coupling joints“ (Pretensioned Concrete bridges)

• Cluster 2: „Orthotropic steel decks“

• Cluster 3: „Hangers/Cables“ (Suspension bridges and steel arch bridges)

This contribution will demonstrate that for six selected bridges of cluster 2 and 3 RWTH Aachen has developed detailed numerical models, investigated those critical details with regard to fatigue and proposed monitoring specifications.

The relevant design checks of those critical details follow the design rules (in particular fatigue load model 3 of Eurocode) and with the installation of those monitoring concepts the evaluation of the fatigue critical details can be matched using hotspot analysis.
BIM‐models of bridges in the operational phase: use cases, phase model and reference architecture
Authors: Jäkel Jan‐Iwo , Klemt‐Albert Katharina
Published: September 2023

For several years, the use of the BIM method has been mandatory for public new construction and replacement projects of the transport infrastructure in the Federal Republic of Germany. As a result, about 20 use cases (UC) for the application of digital models have been defined. Most of them focus on the planning and execution phase. Despite the importance and long duration of the operational phase, there are isolated definitions for use case for operational phase and therefore underrepresented in the overall context. Moreover, none of the published use cases so far consider the specifics of bridge structures. For this reason, a further definition of specific BIM use cases for the operation of bridge structures is needed. In this article, BIM use cases for the use of digital models of bridge structures in the operation and maintenance phase are defined based on a qualitative empirical study. First, the current state of the art is elaborated by means of a literature analysis. Based on this, a expert interviews are conducted and systematically evaluated. The BIM use cases for operation are derived from the results. In addition, requirements and artifacts are defined. This results in a further specification of the use of BIM models in the operational phase of bridge structures and promotes the digitalization of maintenance management.
The holistic multi‐level approach of recent Italian Guidelines applied to the bridges of Caserta
Authors: Bencivenga Pasquale , Zizi Mattia , Palmieri Gerardo , De Matteis Gianfranco
Published: September 2023

Recent Italian Guidelines provide a possible solution for mitigating the structural risk of existing bridges. The procedure, which entails a multi‐level approach, from census of the structures to the resilience assessment of the road network, is being applied in several portions of the Italian territory with reference to bridges managed by different administrative bodies and private companies. In this paper, the application of the Italian Guidelines to a stock of 150 in‐service road bridges of the Province of Caserta is addressed. The application refers to the level 2 of the procedure and aims at estimating the structural/foundational and seismic attention class of the considered structures. The obtained results are then discussed, and a preliminary statistic elaboration of the results aimed at highlighting the most influencing parameters of the whole procedure is provided.
SAFOTEB project: towards new approaches for the reliability assessment of existing prestressed bridge
Authors: Micozzi Fabio , Poeta Alberto , Gioiella Laura , Natali Agnese , Celati Simone , Mazzatura Isabella , Salvatore Walter , Meoni Andrea , Ierimonti Laura , Venanzi Ilaria , Ubertini Filippo , Ranaldo Antonella , D'Amato Michele , Cattaneo Sara , Pettorruso Carlo , Quaglini Virginio , Rossi Dalila , Titton Michele , Dall'Asta Andrea
Published: September 2023

This paper presents the structure of new collaborative research project entitled SAFOTEB “A reviewed SAfety FOrmat for structural reliability assessment of post‐TEnsioned concrete Bridges”. The research aims at assessing the reliability of the current safety format and developing specific suggestions for existing concrete bridges with post‐tensioned cables. To date, no European code provides specific guidance for such a purpose. Indeed, the status of conservation and possible defects of the cables may be hidden, enlarging the uncertainties in the structural assessment of such constructions. The basic steps of the research are: (i) definition of the probabilistic models for the main variables concerning the assessment of existing post‐tensioned prestressed concrete bridges; (ii) reliability assessment and calibration of updated safety coefficients for the partial factors method; (iii) evaluation of the residual life and model updating through real‐time continuous monitoring systems. The full procedure will be applied on existing case study structures used as benchmarks. The project is funded by FABRE, an Italian research consortium composed by universities and research institutions aimed at the evaluation and monitoring of bridges, viaducts, tunnels and other structures.
Investigation of the unusual deformations of external tendons in concrete highway bridges
Authors: Švraka Ratko , Bevc Lojze , Vezočnik Rok , Hekič Doron , Anžlin Andrej
Published: September 2023

During a regular inspection of a multi‐span highway bridge, an unusual deformations of external post‐tensioned tendons were observed. These deformations were not noticed or recorded during the previous main inspections. A detailed visual inspection of the condition of external tendons was performed on all bridges with external tendons by mapping the location and extent of unusual deformation. Based on this, several non‐destructive tests were performed, where deformations were first noticed, from magnetic‐flux leakage to radiographic screening. Some local destructive investigations were subsequently carried out at several locations in two bridges, i.e. opening the tendons. The result of the tendons opening showed the presence of foreign objects and non‐tensioned strands, the latter being a possible cause for the deformations of that tendon. In both locations, the injection mass was compact with only hairy transverse cracks, both on the undeformed part as well as on the moderately deformed part of the tendon. In this paper, the latest results from this study are presented in detail.
Sensory monitoring system of the post‐tensioned concrete bridge over the Odra River in Poland
Authors: Kużawa Mieszko , Bień Jan
Published: September 2023

The paper presents the Structural Health Monitoring system installed on the posttensioned concrete road bridge over the Odra River in Poland. The bridge superstructure has a form of the 5‐span box girder with skewed supports, built using the cantilever method. During operation of the bridge (since 2010) many cracks arrived in the superstructure, mainly within the main bridge span with a length of 140 m. Therefore, as a part of a complex diagnostic process, the monitoring system were incorporated for assessment of the bridge performance and for observing further propagation of damage. The implemented monitoring system utilizes Fiber Bragg Grating (FBG) technique for measuring of strains, changes of cracks width and angular displacements of concrete box girder for various operating conditions of the structure including effects of regular road traffic, environmental influences and rheological phenomena. The paper presents applied testing and measuring procedures as well as results of the monitoring. Conclusions regarding effectiveness of the applied testing method in identification of the bridge condition are formulated and discussed.
Identification of influencing factors on bridge damages using Bayesian network
Authors: MIYAKAWA Teruyuki , NAKAMURA Shozo , NISHIKAWA Takafumi
Published: September 2023

In Japan, bridge inspections are compulsorily performed in 5‐year cycles. With the institutionalization of the inspection cycle, essential data have been continuously accumulated. However, effective data utilization requires trend analysis and causal analysis for a group of bridges. In this study, a method for determining factors affecting deterioration is established. The analysis is performed for concrete and steel bridges with Bayesian networks by utilizing data on bridge inspection and repair, and open data such as traffic census and rainfall. For concrete and steel bridges, the target members are the deck slab and main structural members, whereas the damage type is “Delamination/rebar exposure” and “corrosion,” respectively. The validity of the selected explanatory variables is verified by crossvalidation using separately prepared test data; evidently, the maximum damage rating prediction accuracy is 86%. Furthermore, the influencing factors extracted in this study are reasonable for the two damages, thus indicating the possibility of probabilistically extracting influencing factors for specific damages by Bayesian networks.
Integration of measured data for the seismic fragility assessment of deteriorated bridges
Authors: Fragiadakis Michalis , Prentzas Ioannis , Georgioudakis Manolis , Diamantopoulos Spyridon , Markogiannaki Olga , Stefanidou Sotiria
Published: September 2023

The reliable assessment of bridge capacity is necessary in order to ensure the functionality of the roadway network under normal, or emergency operating conditions. Damage due to the interaction with the environment (e.g., corrosion of coastal reinforcement) has been observed in many cases, even in newly built interurban road networks. Therefore, the need for obtaining and including measured data in fragility assessment analysis has emerged. In line with the above, the proposed research introduces a framework for the assessment of bridges considering integrating data obtained with NDTs. The scope of NDTs is to track down the evolution damage on bridges and determine its risk of failure. The work presents a structural damage identification approach that successfully updates a digital twin of the structure. Subsequently the digital twin is used in order to determine the bridge fragility. Fiber modeling is used for creating the digital twin of the structure. Modified uniaxial material laws are applied for the fragility assessment of a deteriorated case study bridge also providing comparative assessment results for the pristine bridge, i.e. without damage.
Development of a new high‐speed train load model for dynamic calculation of railway bridges
Authors: Reiterer Michael , Kwapisz Maciej , Firus Andrei , Rupp Maximilian , Lombaert Geert
Published: September 2023

Dynamic calculations of train crossing of railway bridges must be carried out in Europe in accordance with current valid standards for both new and existing bridges. The high‐speed load model (HSLM) trains to be used are defined in the Eurocode, denoted as HSLM‐A1 to ‐A10. In the near past, the results gained from these dynamic calculations of train crossing have shown, that the current valid HSLM model trains do not cover the bridge vibration response level for certain real operating trains. It turned out that the application of the HSLM‐A trains might lead to an unsafe design of new railway bridges and destabilization of the ballast layer may occur, leading to safety critical track position defects and eventually to train derailments. Hence, in 2019 the consortium TU Darmstadt, KU Leuven, Austrian Institute of Technology and REVOTEC was commissioned by the German Federal Railway Authority to develop a completely new European high‐speed train load model for dynamic calculations of railway bridges that should account for almost all current running operating trains in the European railway network. The project ended in June 2023 and this paper presents the steps carried out to develop the high‐speed train load model, denoted as HSLM‐C, and the results of validation calculations considering more than 300 existing railway bridges of different construction type.
Semantic knowledge models for decision making in asset management: IM‐SAFE Knowledge Base
Authors: Bektas Esra , Oord Erwin , Kohler Jochen , Sánchez‐Rodríguez Ana
Published: September 2023

Against the backdrop of physical ageing, asset management organizations not only struggle with scattered object‐related data across incompatible software and models, but also dispersed, often missing, insights from domain experts. There is a large volume of data already available particularly at National Road Authorities i.e. object characteristics, inspection and measurement results, usage records. Yet this data is distributed, has complex and varying structures, it takes cumbersome effort to find and obtain for a particular asset management decision. Semantic knowledge models aim to capture domain information and represent it via class definitions, their attributes, relationships and in instances. Such models are used to create knowledge bases, where different technologies are utilized. In the IM‐SAFE project, a knowledge base is created based on a Semantic Wiki Platform. It captures asset information concerning their structural analysis and state on 99 civil structures across Europe. In this paper, a step‐by‐step methodology is provided to build the knowledge base. The paper involves knowledge acquisition, data collection, knowledge modelling, populating datasets and quality assurance steps. It will conclude future implications to make the base expandable and widely used for asset management.
Validating the performance of direct fastening (PAF) into concrete with high‐speed measuring technology
Authors: Scholz Ronja , Franck Pascal , Yousef Alhussain , Spyridis Panagiotis , Walther Frank
Published: September 2023

In recent years, attention has been driven to the direct fastening technology by use of power actuated nail‐type fasteners (PAFs) set in concrete. By means of the series of tests shown in this paper and the high‐speed measuring equipment used, a first approach to the possibility of evaluating the setting performance is demonstrated. The difficulty is to judge whether the operation was successful and whether the fastening can bear the required force, since it is not possible to look into the concrete. For example, it remains hidden whether and, if so, how much the nail was deflected and bent by the concrete. Furthermore, it is unknown how the surrounding concrete was affected by occurring strains and heating as a result of friction. Since the setting process is very fast, it is necessary to use high‐speed measurement technology. In the case of the studies conducted, both digital image correlation (DIC) and thermography were used to record material responses. Following the setting process, the nails and the surrounding concrete were separated and examined with computer tomography (CT). The CT provides the information on the inside of the concrete and one can see cracks and other reactions to the setting process.
Experimental verification of FRP bridge deck's monitoring system based on DFOS sensors
Authors: Kulpa Maciej , Rajchel Mateusz , Siwowski Tomasz , Howiacki Tomasz
Published: September 2023

The paper presents the smart FRP composite bridge panel called „OptiDeck“ with integrated distributed fibre optic sensors (DFOS), to monitor the panel's behavior. The panel is intended for use in newly build and refurbished road bridges. From structure point of view the uniqueness of the presented solution results from innovative technological production process to create a honeycomb core in thick sandwich panel. In order for the monitoring system to cover the entire surface of the panel and to detect local damage, it was necessary to use a modern solution based on geometrically continuous DFOS system. The DFOS system serves as the structure health monitoring (SHM) system, which has been tested during the production and laboratory testing of a prototypes in natural scale. The advantages of DFOS measurements are well known and applied in many civil engineering applications. However, the potential benefits are still not fully utilized. Finally the experimental verification of the DFOS system integrated with the FRP deck panel is presented.
Steel‐Concrete Composite Bridge Diagnostics and Reconstruction
Authors: Vanova Patricia , Kusnir Stefan , Dubecky Daniel , Harabinova Slavka , Orolin Peter , Kvocak Vincent , Lavko Martin
Published: September 2023

Many bridges in Slovakia are reaching their designed life span these days. Due to frequent errors during the construction of those bridges as well as bad maintenance, steel‐concrete bridges are now in a critical state and urgent repairs of those structures are needed. In this article progressive methods of retrofitting existing concrete bridges are shown. In the presented method, the original pillars and original bridge deck will remain in their place, and on the existing deck new composite, steel‐concrete bridge deck with encased steel members of progressive shape will be created. This method brings significant cost reduction for such retrofitting and enables the application of increased loads on the bridge.
An In Situ Fabricated Hydrogel Polymer – Palladium Nanocomposite Electrocatalyst for the HER: Critical Role of the Polymer in Realizing High Efficiency and Stability
Authors: Bovas Anu , Thangavelu Dhanasekaran , Pillai K. Vijayamohanan , Radhakrishnan T. P.
Published: September 2023

Development of general and simple designs of catalytic electrodes for the hydrogen evolution reaction (HER) is critical. The present work demonstrates the multiple roles played by a hydrogel polymer in the fabrication and activity enhancement of the nanoelectrocatalyst. A nanocomposite thin film of Pd with the insulating hydrogel, poly(2‐hydroxyethyl methacrylate) (PHEMA), is fabricated through a facile in situ process, the polymer itself functioning as the reducing/stabilizing agent in the formation of Pd nanoparticles. Pd‐PHEMA on Ni foam enables efficient HER in alkaline medium with a low overpotential; the polymer enables the electrocatalysis by its swelling and confinement of the electrolyte. Most significantly, when the electrode is subjected to an optimized cycling protocol, the overpotential decreases steadily, reaching an impressively low value of 36 mV (@10 mA cm−2). A low Tafel slope (68 mV dec−1), high exchange current density, Faradaic efficiency and TOF (3.27 mA cm−2, 99 %, 122.7 h−1), and extended stability are achieved. Detailed investigations reveal the active role of the polymer in the evolution of the nanocatalyst, itself undergoing favorable morphological changes. The study illustrates the widened scope for developing efficient and stable catalytic electrodes with hydrogel polymers and unique features that promote the generation of green hydrogen.
Optimization of a 1,4,7‐Triazacyclononane‐1,4‐diacetic acid (NODA) Derivative Radiofluorination by Al18F Complexation Using a Design of Experiments Approach
Authors: San Carine , Hosten Benoît , Vignal Nicolas , Beddek Meriem , Pillet Maurice , Sarda‐Mantel Laure , Port Marc , Dioury Fabienne
Published: September 2023

Fluorine‐18 (18F) is the most favorable positron emitter for radiolabeling Positron Emission Tomography (PET) probes. However, conventional 18F labeling through covalent C−F bond formation is challenging, involving multiple steps and stringent conditions unsuitable for sensitive biomolecular probes whose integrity may be altered. Over the past decade, an elegant new approach has been developed involving the coordination of an aluminum fluoride {Al18F} species in aqueous media at a late‐stage of the synthetic process. The objective of this study was to implement this method and to optimize radiolabeling efficiency using a Design of Experiments (DoE). To assess the impact of various experimental parameters on {Al18F} incorporation, a pentadentate chelating agent NODA‐MP‐C4 was prepared as a model compound. This model carried a thiourea function present in the final conjugates resulting from the grafting of the chelating agent onto the probe. The formation of the radioactive complex Al18F‐NODA‐MP‐C4 was studied to achieve the highest radiochemical conversion. A complementary “cold” series study using the natural isotope 19F was also conducted to guide the radiochemical operating conditions. Ultimately, Al18F‐NODA‐MP‐C4 was obtained with a reproducible and satisfactory radiochemical conversion of 79±3.5 % (n=5).
Cytopathologic diagnosis of extragonadal germ cell tumors: A 10‐year institutional review
Authors: Geisler Daniel L. , Marshall Mason , Bastacky Sheldon I. , Khader Samer N.
Published: September 2023

Background

The occurrence of extragonadal germ cell tumors (EGGCTs), either as primary tumors or metastatic disease, is rare. Forms of cytologic sampling, including fluid analysis, fine‐needle aspiration, and/or small‐core needle biopsy, have been shown to be reliable methods for the diagnosis of germ cell tumors. This study aims to investigate the utility of cytopathologic techniques in the diagnosis of EGGCTs at the authors’ institution.

Methods

The laboratory information system was queried over a period of 10 years (2012–2022) to identify all cytology cases diagnosed on fluid cytology, FNA, and/or small‐core biopsy as germ cell tumors in extragonadal locations. Patient demographics, tumor location, serum tumor marker levels, cytopathologic diagnosis, and follow‐up surgical resection data were reviewed and correlated.

Results

A total of 35 cases from 32 patients (all males) were identified. Thirty specimens contained satisfactory material for diagnosis (86%) and five were less than optimal for evaluation (14%). Despite this, all cases had clinically useful cytopathologic diagnoses. A total of 19 cytology cases (16 patients) had follow‐up resection specimens available. Of these, 11 patients underwent preoperative chemotherapy. Nine patients showed no evidence of residual tumor and two showed histologic concordance. Of the five patients who did not have preoperative chemotherapy, all showed concordant histologic diagnoses.

Conclusions

Cytology can provide a reliable, accurate method for diagnosing EGGCTs. The practice of preoperative (neoadjuvant) chemotherapy places an extreme importance on the initial cytopathologic diagnosis because the majority of patients with follow‐up resection in this series showed no residual tumor.
mRNA Synthesis and Encapsulation in Ionizable Lipid Nanoparticles
Authors: McKenzie Rebecca Elizabeth , Minnell Jordan James , Ganley Mitch , Painter Gavin Frank , Draper Sarah Louise
Published: September 2023

mRNA vaccines have recently generated significant interest due to their success during the COVID‐19 pandemic. Their success is due to advances in mRNA design and encapsulation into ionizable lipid nanoparticles (iLNPs). This has highlighted the potential for the use of mRNA‐iLNPs in other settings such as cancer, gene therapy, or vaccines for different infectious diseases. Here, we describe the production of mRNA‐iLNPs using commercially available reagents that are suitable for use as vaccines and therapeutics. This article contains detailed protocols for the synthesis of mRNA by in vitro transcription with enzymatic capping and tailing and the encapsulation of the mRNA into iLNPs using the ionizable lipid DLin‐MC3‐DMA. DLin‐MC3‐DMA is often used as a benchmark for new formulations and provides an efficient delivery vehicle for screening mRNA design. The protocol also describes how the formulation can be adapted to other lipids. Finally, a stepwise methodology is presented for the characterization and quality control of mRNA‐iLNPs, including measuring mRNA concentration and encapsulation efficiency, particle size, and zeta potential. © 2023 The Authors. Current Protocols published by Wiley Periodicals LLC.

Basic Protocol 1: Synthesis of mRNA by in vitro transcription and enzymatic capping and tailing

Basic Protocol 2: Encapsulation of mRNA into ionizable lipid nanoparticles

Alternate Protocol: Small‐scale encapsulation of mRNA using preformed vesicles

Basic Protocol 3: Characterization and quality control of mRNA ionizable lipid nanoparticles
Flow‐Integrated Preparation of Norbornadiene Precursors for Solar Thermal Energy Storage
Authors: Baggi Nicolò , Hölzel Helen , Schomaker Hannes , Moreno Kevin , Moth‐Poulsen Kasper
Published: September 2023

Molecular solar thermal (MOST) energy storage systems are getting increased attention related to renewable energy storage applications. Particularly, 2,3‐difunctionalized norbornadiene‐quadricyclane (NBD‐QC) switches bearing a nitrile (CN) group as one of the two substituents are investigated as promising MOST candidates thanks to their high energy storage densities and their red‐shifted absorbance. Moreover, such NBD systems can be prepared in large quantities (a requirement for MOST‐device applications) in flow through Diels‐Alder reaction between cyclopentadiene and appropriately functionalized propynenitriles. However, these acetylene precursors are traditionally prepared in batch from their corresponding acetophenones using reactive chemicals potentially leading to health and physical hazards, especially when working on a several‐grams scale. Here, we develop a multistep flow‐chemistry route to enhance the production of these crucial precursors. Furthermore, we assess the atom economy (AE) and the E‐factor showing improved green metrics compared to classical batch methods. Our results pave the way for a complete flow synthesis of NBDs with a positive impact on green chemistry aspects.
Top‐down effects of filter‐feeding fish and bivalves moderate bottom‐up effects of nutrients on phytoplankton in subtropical shallow lakes: An outdoor mesocosm study
Authors: Zhang You , Shen Ruijie , Li Kuanyi , Li Qisheng , Chen Huihui , He Hu , Gu Xiaohong , Mao Zhigang , Johnson Richard K.
Published: September 2023

Biomanipulation has been widely used in the ecological restoration of eutrophic lakes for decades. However, biomanipulation is prone to failure if external nutrient loads are not reduced. In order to explore the importance of filter‐feeding fish and bivalves on algal control, an outdoor mesocosm experiment was conducted using different nutrient concentrations. Four treatments simulating daily loads of nutrients in Lake Taihu were studied: current, two times, and three times average daily loads of nutrients with both fish (Aristichthys nobilis) and Asian clam (Corbicula fluminea) and as a control current daily loads without fish or bivalves. Results showed that stocking of filter‐feeding fish and bivalves (80 g m−3 bighead carp; 200 g cm−2 clams) at two times daily nutrient loads could effectively control water column Chl a concentrations and phytoplankton biomass. At higher nutrient concentrations (TN ≥ 260 μg L−1 d−1; TP ≥ 10 μg L−1 d−1), top‐down control of filter‐feeding fish and bivalves was less effective and bottom‐up effects resulted in significant increases of Chl a concentration. Thus, as phytoplankton biomass in freshwater ecosystems is determined by both the top‐down effects of predators and the bottom‐up effects of nutrients, external loadings should be controlled when filter‐feeding fish and bivalves are used for algal control to ensure the efficacy of biomanipulation.