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This contribution describes the architectural and structural solutions of a unique pedestrian footbridge in Hradec Králové. The new significant construction was built over the Elbe River in the pedestrian area. The bridge design was challenging for architects, planners even though contractors, especially due to accounting for the influence of shipping traffic. Completed structure has two asymmetrical spans, whereas the main span across the river is 69 m long. In the final static scheme, the structure forms a virtual Vierendeel truss of variable height. A slender UHPFRC bridge deck supported by a pair of cables through thin steel crossbars creates a delightful bridge, which has become a new symbol of the city. [ABSTRACT FROM AUTHOR]

Shui Su Ravine Bridge is built in Bai Shui County in Shaanxi Province, which is a part of the highway linking Heyang and Tongchuan. The bridge has been designed as a composite steel‐concrete truss bridge with 3 spans in total of 240 meters and a deck of 4 lanes. To meet the harsh environmental demand and lessen the future maintenance, the solution adopts the weathering steel Q420qENH similar strength as S420NL in European code. The bridge is erected by incremental launching and post‐installation of the pre‐cast concrete slab. Since the truss segment is all welded, two‐step models have been developed to evaluate the fatigue performance of the steel truss joint. In the simplified two‐dimensional model, Phase‐Field (PF) approach has been implemented to make a full fatigue evaluation of crack propagation in the truss. [ABSTRACT FROM AUTHOR]

Once constructed, the Baku White City pedestrian bridge will be a landmark for the newly developed White City district in the east of the Capital. Designed by UNStudio, the bridge crosses the highway of 8th November Avenue and connects the newly build city to the seaside, forming a wide promenade. Due to the pending construction of the mall as future bridge support, the bridge had to be redesigned. A cantilevering viewing platform will highlight the bridge's ending. This paper covers the structural design of the architecturally shaped cable stayed bridge, supported through a 46 m high A‐shaped, slightly curved pylon. Based on 3‐D modelling in Rhino® and Grasshopper®, the FE‐software SOFISTIK® is used both for cable force finding and bridge design. The structural system, steel structure's specific detail for cable connection and its design approach have been documented. [ABSTRACT FROM AUTHOR]

A novel prefabricated steel‐concrete composite girder is proposed, which aims to provide an economic and sustainable solution for small bridge construction. The girder consists of composite dowels and concrete slabs. The depth of composite girder is analyzed in a span range of 8‐20m. A continuous deck joint between the simply supported bridge is proposed to enhance the durability of the girder. Carbon emissions from construction materials are compared between different schemes. The efficiency of the schemes is evaluated through Live Load Structural Index. [ABSTRACT FROM AUTHOR]

Responsible for 70% of the global CO2 emissions, infrastructure has a significant impact on our climate and the related consequences. Bridges are a major keystone of the infrastructure and take a leading position in its decarbonization. In this framework, low‐carbon emission steels play an important role. Low‐carbon emission steels, like ArcelorMittal's XCarb® recycled and renewably produced steels, are already available on the market. Combining scrap and renewable electricity, it offers very low levels of CO2 emissions per ton of finished steel. The present paper describes how different steel solutions can be combined to lower the material input, to simplify the construction process and to reduce the maintenance efforts in bridge construction. The impact of efficient design has been assessed by a Life‐Cycle Assessment (LCA) for bridge solutions with small and medium spans of up to 40 m. The paper concludes with a summary of recently realized bridge projects in Poland. [ABSTRACT FROM AUTHOR]

This paper presents the shake table testing and finite element (FE) modeling of a modular prefabricated concrete bridge‐like specimen. The specimen comprised four equal‐height cylindrical reinforced concrete (RC) columns capped with an RC slab. The structural connections were non‐monolithic. Hence, controlled relative motion of the members, including rocking (uplift) of the piers, was allowed. The columns were connected to the slab with stiff tendons that provided positive post‐uplift stiffness. The specimen was subjected to 184 triaxial shake table tests, so that a statistical validation of numerical models can be performed. Subsequently, a detailed three‐dimensional FE model of the bridge was developed. The objectives of the present study were to: i) investigate the shake table response of a modular bridge with positive post‐uplift stiffness under multiple ground motions, ii) develop an FE model of the proposed structural system, iii) investigate the influence of geometrical imperfections on rocking bridges, and iv) evaluate the efficiency of using additional dissipative rebars. After being subjected to 184 shake table tests, the specimen showed zero damage, moderate displacements and tendon forces (TFs), low slab torsion, and zero residual displacements. The shake table tests were practically repeatable. The proposed FE model accurately captured the experimental results. Geometrical imperfections heavily affect the response of negative stiffness systems. However, they have a marginal influence on positive stiffness systems. When comparing systems with equivalent uplift resistance and post‐uplift stiffness, the use of additional dissipative rebars results in lower slab torsion and TFs, provided that the rebars do not fracture. [ABSTRACT FROM AUTHOR]

Translation abstract On the load bearing and fatigue behaviour of headed anchor studs with defective weldsThe welding of headed anchor studs (KBD) is a technically demanding process. The main difficulty for contractors is that it is not yet possible to provide non‐destructive evidence that the product is free of defects. The publication of Allgemeines Rundschreiben Straßenbau (ARS) No. 18/2019 on quality assurance when welding headed stud dowels in bridge construction has significantly tightened the requirements for headed stud dowel welding. Since a company owes a defect‐free trade at the time of handover, but the freedom from defects of headed anchor studs can currently only be proven by means of destructive testing, this creates a considerable entrepreneurial risk for the practice. Although the standards and guidelines provide information on the procedure that can be used to ensure defect‐free bolts, there is no guarantee of success. For this reason, companies had to rely on the tolerance of the acceptance criteria provided by the current standards for headed anchor studs. This article deals with faulty headed anchor stud welds as well as repair methods commonly used in practice to gain initial insights into whether the tightening within the framework of the document Allgemeines Rundschreiben Straßenbau No. 18/2019 was expedient or necessary. Initial results from the PAUT (Phased Array Ultrasound) method will also be examined to determine whether it may be possible in the future to use this method to enable non‐destructive testing of headed anchor studs. [ABSTRACT FROM AUTHOR]

Translation abstract Evaluation and strengthening of existing bridges – historical outlines and findings regarding the Hessian road bridge inventoryTwo short histographical sketches introduce the concepts of refurbishment, condition and load‐bearing capacity assessment between 1700 and 2010 and take a look at the development of the recalculation of existing bridges. Based on project sketches, the hidden safety features of existing road bridges are worked out and procedures for achieving efficient structural bridge strengthening are presented. The focus is on the determination of real object‐specific traffic load models, calibrated structural analyses and additive and non‐destructive strengthening methods. Some critical comments on planning acceleration and the current approval system, together with the demand that bridge construction should be reflected in the common objective of “traffic”, broaden the definition of strengthening holistically. This offers the opportunity to stimulate a discussion about the sensible handling of existing bridges as part of our road infrastructure. [ABSTRACT FROM AUTHOR]

The International Federation for Structural Concrete (fib) offers various publications and resources for those interested in concrete structures. One publication, fib Bulletin 111, focuses on modeling the performance of existing concrete structures, considering factors such as increased traffic loads and material deterioration. The fib Model Code (2020) provides comprehensive guidelines for planning, designing, and constructing concrete structures. The fib also recognizes and promotes innovative design and construction practices through awards and symposiums. The document also highlights the career and contributions of Peter Marti, a professor at ETH Zurich, who has made significant contributions to the field of structural engineering. Lastly, the document mentions upcoming congresses and symposia related to structural concrete. [Extracted from the article]

As the prefabrication construction method plays an increasingly important role in the construction of cross‐sea bridges, coordinating the schedule between off‐site prefabrication and on‐site assembly becomes crucial and challenging. This paper studies a just‐in‐time single‐machine scheduling problem with due windows and release dates, which originates from the production and supply process of large segments of precast steel box girders in bridge construction. To solve this problem, we equivalently decompose it into the independent and same type of subproblems and formulate a mixed‐integer linear mathematical programming model. Furthermore, we propose a branch‐and‐bound algorithm with the initialization of a novel linear early and tardy dispatching rule with due windows to solve the problem exactly. The dispatching rule, based on the local dominance criteria with due windows, is designed and used to improve the upper bound. Moreover, a lower bound is obtained by further decomposing and relaxing the subproblems. Finally, the parameter of the dispatching rule is calibrated, and the best search strategy of the branch‐and‐bound algorithm is determined. The comprehensive computational experiments carried out show the efficiency and effectiveness of the proposed branch‐and‐bound algorithm. [ABSTRACT FROM AUTHOR]

Metal‐halide perovskite solar cells (PSCs) have emerged as a promising photovoltaic technology. Fabricating PSCs in ambient air can accelerate their low‐cost commercialization, since it can remove the reliance on atmosphere‐controlled equipment. However, the power conversion efficiency (PCE) of air‐fabricated PSCs still lags behind those fabricated in glovebox. Here, based on a technology to fabricate high‐quality perovskite film in ambient air, a compatible optimization is performed on electron transport layer (ETL) to further enhance the photovoltaic performance of PSCs. A soft‐templated deposition strategy is proposed that utilizes tetrasodium glutamate diacetate (GLDA) to finely regulate the chemical bath deposition process, leading to an ideal SnO2 ETL with no additive residual. Adopting this feature of no residual, a molecular bridge using β‐guanidinopropionic acid (βA) is constructed at the buried interface (SnO2/perovskite), which effectively enhances the electron extraction and decreases electron losses. The resulting PSCs (0.08 cm2) achieve an impressive PCE of 25.74% (certificated 25.43%), which is the highest among the air‐fabricated PSCs reported to date. A PCE of 24.61% in 1 cm2‐PSCs is also obtained, exhibiting the scalable potential of the technology. In addition, the excellent operational stability of these PSCs is also demonstrated. [ABSTRACT FROM AUTHOR]

Prefabrication has been widely used in bridge construction, for which precast beams are produced from a beam yard and constructed with a cast‐in‐suit bridge deck. The developments recently are focusing on large dimensions or large quantities of beam units, which leads to the inevitable challenge of beam quality control. Among them, beam surface flatness as one of the important indicators for manufacturing quality needs to be strictly controlled to ensure structural performance. However, the commonly used methods still rely heavily on manually contact‐based inspection, which is not only time‐consuming but also error‐prone. This paper presents an automated flatness assessment for large quantities of full‐scale precast beams by using terrestrial laser scanning techniques. Through axis calibration, target surface segmentation, and flatness deviation calculation, flatness deviations of the segmented surfaces from the point cloud of the entire beam are calculated, and colored maps are generated to visually assess the flatness quality. The proposed approach was applied to numerical simulated models as well as laboratory‐scale specimens for accuracy validation. Besides, its processing time was also compared to conventional contact‐based inspection during a field test. Moreover, efforts are devoted to applying the proposed method on nearly a thousand precast beams in an in‐field bridge construction project. Results can demonstrate its outperformance not only on accuracy but also the efficiency and practicality when applied to large quantities of full‐scale precast beams. [ABSTRACT FROM AUTHOR]

Accelerated bridge construction, with innovative connection details and construction technologies, has been extensively investigated and put into practical application for years. Nowadays, there are three commonly used connection methods of accelerated bridge construction technology, namely, lap‐spliced connection, sleeve connection, and socket connection. Due to the convenience of construction and lower requirements of construction accuracy, the socket connection is more suitable for reconstruction and expansion projects of traffic infrastructure, which could minimize the impact on traffic and accelerate construction progress. According to the structural characteristics of the socket connection, there are some design parameters that may significantly affect the seismic resistance of the structure, such as socket embedment length, fabrication of the shear key, and grouting material strength. To fully study the influence of different design parameters on structural performance, an experiment was carried out to investigate the seismic behavior of the precast pier‐footing socket connections with different design parameters. Five 1:2 scale reinforced concrete precast pier‐footing socket connection specimens with different design parameters were designed and tested under cyclically reversed horizontal loads. The development of hysteresis features, failure mode, load‐bearing capacity, stiffness degradation, structural ductility, energy dissipation capacity, and residual drift are analyzed to reveal the influence of the different design parameters on the seismic behavior of the precast pier‐footing socket connection. The seismic behavior of the precast pier‐footing socket connection was significantly influenced by the embedment length especially when the embedment length was less than 1.0bc. When the embedment length was 0.5bc, the failure mode changed from bending damage at the bottom of the precast pier to the anchorage failure of the precast pier‐footing socket connection. When the embedment length was 1.5bc, the fabrication of the shear key had limited improvement on the seismic performance of the specimen, while reducing the ductility of the specimen. When the embedment length was 1.0bc, the grouting material with a strength grade of C60 could be used in the socket connection between the precast pier and footing. The research presented in this paper provides some design suggestions and a technical basis for evaluating the seismic behavior of precast pier‐footing structures with socket connection. [ABSTRACT FROM AUTHOR]

On the shear load‐bearing capacity of thin‐walled box girders with unreinforced joints in the webs As part of the LT bridge construction method (L: Longitudinal, T: Transversal), which is being developed at TU Wien, thin‐walled hollow concrete box girders are used longitudinally and are combined with deck slab elements and in‐situ concrete. Due to the construction process, unreinforced joints remain in the webs of these box girders, while the bottom and deck slabs can be continuously reinforced due to the in‐situ concrete layers. The question arose as to how this joint configuration affects the shear load‐bearing capacity of the box girders. In order to gain a fundamental understanding, two large‐format test specimens, one with joints in the webs and one without, were investigated experimentally. The shear force capacity of the girder with joints corresponded approximately to the one of the girder without joints, showing that it was possible to transfer significant shear forces despite the joints. The joint opening proved to be characteristic for the shear load‐bearing behaviour, as the stirrups adjacent to the joint act like a suspension reinforcement. A local increase in the stirrup reinforcement in this area is therefore recommended. Non‐linear finite element analyses were carried out to analyze the effects of post‐tensioning, as used in the LT method, on the load‐bearing behavior. It was shown that the load‐bearing behavior of the post‐tensioned girder with joints largely corresponds to the one without joints. [ABSTRACT FROM AUTHOR]

The LT‐bridge construction method for the material‐saving and fast construction of post‐tensioned concrete bridges Owners of infrastructure buildings will face enormous challenges in the coming years. Many engineering structures, especially bridges, need to be renovated or rebuilt. They are either no longer able to withstand the current loads or have developed durability problems. Discussions with owners have shown that rapid construction progress is crucial for bridge replacements. The construction sites should disrupt the normal flow of traffic as little as possible. As a result, a new, resource‐saving, and fast construction method for bridges has been developed. Innovative prefabricated elements for the longitudinal girders and the deck slab were developed to fulfill these requirements. The prefabricated elements are connected by reinforcement and an in‐situ concrete layer at the construction site. A comparison of the environmental impact based on the construction materials (life cycle phases A1–A3) between a construction section of an LT‐bridge and a typical German motorway bridge shows a lower global warming potential for the new bridge construction method due to the savings in construction materials. The feasibility of this new construction method was demonstrated by a pilot project in Austria. [ABSTRACT FROM AUTHOR]

Stretchable displays based on conventional materials exhibit a trade‐off relationship between the pixel density and the stretchability. In this paper, we have demonstrated overcoming the technological limitations of stretchable displays through the optimization of serpentine‐shaped bridge design and the application of stretchable metal electrodes. The application of stretchable electrodes has increased stretchability by over 30% without compromising pixel density. [ABSTRACT FROM AUTHOR]

This article presents the design and experimental validation of a novel semiconductor area optimised 3300 V half bridge with Silicon Carbide (SiC) MOSFETs for HVDC converters. Based on a loss simulation, the problem statement is provided. On this results, a mathematical derivation for the optimised semiconductor area design is executed. After this step, a system loss simulation shows the performance in efficiency and specific output power. Finally, a proof of concept was provided by a scaled hardware test setup to characterise the dynamic behaviour of the novel SiC half bridge design compared to the conventional SiC half bridge. [ABSTRACT FROM AUTHOR]

Model‐based development and implementation of the digital building file – BIM from construction to operation The use of BIM in bridge construction is currently limited to the design and construction phases, but BIM can be particularly useful for the operation of structures. The basis for the use of BIM in the operation life cycle phase is the transfer of relevant information from the planning and construction life cycle phases to operation. The creation of a model‐based digital building file enables the transfer of relevant information for operation. The article classifies the creation and use of model‐based digital construction files both in the scientific context and in the current working methodology with analog construction files and construction files. It also includes the practical implementation of a specific project. Furthermore, the reference to the standardized use cases 190 "Project and building documentation" and 200 "Use for operation and maintenance" is presented. The implementation of the model‐based digital construction file is demonstrated using the example of the Cologne Heumar highway interchange. The objectives and principles associated with the use of BIM, the project development and the background are discussed. The implementation and handover of the model‐based digital construction file is described in detail for the practical example. [ABSTRACT FROM AUTHOR]

Concept of a digital twin for bridges in the operational phase The concept of the digital twin is also finding its way into bridge construction. In future, the aggregated data collected during the operating phase from inspection, structural health monitoring and diagnostics will form the basis for transforming the current reactive maintenance into predictive maintenance. This article presents a concept for an object twin with the degree of connectivity of a digital shadow at maturity level 2. It lists criteria for a precise definition of the term digital twin, defines BIM use cases for the operational phase of bridges and derives the necessary models. With regard to the IDA‐KI research project, requirements for the digital twin are established and a software concept is developed to fulfill them. Particular focus is put on the provision of the IFC models in a CDE as well as on the refinement process of monitoring data. [ABSTRACT FROM AUTHOR]

Parametric modeling and generative deep learning for bridge design Given the significant environmental impact of the construction industry, the analysis and, above all, optimization of the sustainability of structures while maintaining established levels of reliability are becoming increasingly important. While there are initial tools for life cycle analysis in the building sector, these are not directly transferable to bridge structures. This paper introduces a deep learning‐based approach to explore and model the design space of parametric bridge models and their performance evaluations, illustrating its application for multi‐objective optimization of reinforced concrete frame bridges. Initially, data is synthetically generated using a parametric bridge model and coupling analysis software, followed by training a conditional variational autoencoder (CVAE) as a metamodel. In the context of conceptual bridge design, the CVAE serves as an efficient co‐pilot for both forward and inverse analysis. The sensitivity analysis performed with the CVAE reveals relationships between design parameters and/or performance metrics, highlighting optimization potentials. The integrated framework presented here has the potential to realize efficient bridge design, particularly focusing on sustainability and structural safety criteria, and can be easily extended to other parametric inquiries. [ABSTRACT FROM AUTHOR]

openLAB – A research bridge for developing a digital twin of bridges Within the IDA‐KI project, a research bridge (openLAB) is being built and loaded up to the level of severe damage. This will be accompanied by extensive measurements and investigations, thus creating a unique database for the validation of damage detection and evaluation methods under real environmental conditions using a large‐scale model. This article presents the project idea, the research bridge currently under construction, and the monitoring system installed at the bridge. The methods implemented for automated data analysis and fault detection in the monitoring data are presented and validated through load tests in the openLAB. First measurements recorded during the production process of the precast girders of the research bridge underline the potential of distributed fiber optic sensors for a monitoring from day one. The information gained from the construction and operation of the bridge is provided in a digital model. The conceptualization of the so‐called "as maintained" model and the data management will be presented. [ABSTRACT FROM AUTHOR]

The eastern oyster (Crassostrea virginica), has experienced dramatic declines throughout its range, and most U.S. states along the Atlantic and Gulf of Mexico coasts have restoration programs. Oyster restoration in the Hudson River Estuary has been a focus of management agencies for over two decades. The present project was initiated in 2013 after sampling for replacement of the Tappan Zee bridge determined live oysters would be lost during bridge construction, thus requiring mitigation measures. Preliminary studies identified three areas for pilot studies to inform the design of full‐scale efforts. A pilot study involving deployment of oyster shell‐filled gabions and two styles of Reef Balls, found all substrates supported oyster recruitment and growth but there were higher oyster densities on gabions. Some of the gabions, however, failed structurally necessitating a need for new design. For full‐scale restoration, a total of 422 modified gabions and 881 Mini‐Bay style Reef Balls were deployed across three sites which totaled approximately 2.4 ha (6 ac) in seafloor area. Both substrate types were heavily colonized by oysters and several other species at all three sites, essentially duplicating the findings of the pilot study. The final monitoring event in 2020 indicated a total of approximately 5.8 million live oysters were on the substrates deployed in 2018. This mitigation effort was the largest oyster habitat restoration project in, or north of, the New York Harbor region in recent decades based on restoration area and several oyster metrics of early success. [ABSTRACT FROM AUTHOR]

The recent development of aero‐structural optimization methods provides a powerful tool to achieve cost‐effective and safe designs for wind‐sensitive structures. However, pursuing holistic formulations involves adopting many design variables and constraints, which increases the computational burden preventing the application of nonlinear methods for accurately assessing aeroelastic responses. This paper proposes a sequential aero‐structural optimization (SASO) method to improve the efficiency of holistic wind‐resistant design optimization of wind‐sensitive structures. The original problem is uncoupled into two standalone optimization problems: a structural size optimization and an aeroelastic shape optimization, linked by an adaptive mapping surrogate and an outer loop. This strategy permits the design‐space dimensionality reduction and avoids the computation of multiple sensitivities with low influence on the design decisions. A long‐span bridge is successfully optimized. The convergence is drastically accelerated by minimizing the number of aeroelastic evaluations, opening the way to implement nonlinear aeroelastic performance‐based design optimization frameworks. [ABSTRACT FROM AUTHOR]

In bridge engineering, the use of precast post‐tensioned segmental (PPS) piers is increasingly expanding due to the Accelerated Bridge Construction viewpoint. Recent experimental and numerical researches have studied general seismic performance and nonlinear behavior of PPS piers without much attention to segment arrangements or joint openings. The aim of this paper is to utilize innovative segment arrangements to reduce the residual deformation, without reducing the energy dissipation capacity of PPS piers with internal energy dissipation (ED) bars. For this purpose, nonlinear rocking dynamics of a multiple‐block assembly of tied rigid rocking blocks equipped with ED bars at joints are firstly developed so that uplift moment for each joint is derived to obtain the threshold joint opening height (height above which no joint opens). Then, nonlinear static, quasi‐static, and dynamic analyses are conducted on different segment arrangements of finite element models of PPS piers. It is proposed to place more segments within the threshold joint opening height by using unequal segments so that the total rotation is shared among critical joints (joints that open), and the nonlinear extent of ED bars at the bottom joint is reduced, resulting in the reduced residual deformation. It is also proposed to place a lower ratio of ED bars at the critical intermediate joints or place ED bars of a lower yield stress there so that the intermediate joints can be more effective even with small rotations. Results indicate that using the proposed segment arrangement, enhances both seismic and post‐earthquake performance of PPS piers. [ABSTRACT FROM AUTHOR]

With the advancement in the concrete technology, the application of precast concrete elements in the buildings and road infrastructures is increasing very rapidly. One of such applications is the use of precast hollow concrete elements in the bridge construction. As the conventional steel reinforcement is highly susceptible to corrosion, the use of non‐corrosive reinforcement in precast hollow concrete piers and piles of bridges could be a good option for the durability of bridge structures., In this regard, hollow concrete columns reinforced with fiber‐reinforced polymer (FRP) have been considered as a potential solution to overcome the structural deterioration due to corrosion. In the past, limited studies have been carried out on hollow concrete columns reinforced with FRP, consequently, the behavior of such columns is not fully understood. Therefore, to comprehensively evaluate the behavior of hollow concrete columns for various design parameters, a finite element model (FEM) was developed in this study using the commercial tool "Abaqus". The model was developed and verified based on the experimental results of studies conducted by two independent research groups on circular concrete columns. The proposed model well predicted the peak loads with an error less than 10% and the failure modes of the tested columns. The verified constitutive relation and establishing method were further employed to conduct parametric evaluations to observe the influence of different parameters, such as inner‐to‐outer diameter ratio, longitudinal reinforcement ratio, lateral reinforcement ratio, and concrete strength, on the behavior of hollow concrete columns. Parametric analyses show that reduced inner‐to‐outer diameter ratio and larger longitudinal or lateral reinforcement may lead to higher peak load and confined concrete strength. Finally, based on the experimental and FEM evaluations, the strength prediction equations were developed for the analysis and design of hollow concrete columns reinforced with GFRP bars. [ABSTRACT FROM AUTHOR]

Faster construction in existing buildings – challanges and opportunities The Federal Ministry's assessment from 2022 shows that around 11,000 sections of the federal trunk road network need to be modernised. The aim of the modernisation measure replacement construction is to carry out the reconstruction and new construction with a minimum of traffic restrictions. It is therefore necessary to utilise all possibilities for faster construction in existing structures. 81 % of the substructures in the motorway modernisation network are between 2 m and 30 m in length. This clearly demonstrates the standardisation potential for new replacement structures. The aspects of standardised structures and demolition of existing bridges are highlighted. Research projects are presented that show ways to innovative, modular and thus also sustainable new replacement construction. In addition, results from the research project "Prefabricated components made of high‐strength concrete" will be presented, which will significantly expand the range of applications for prefabricated components in bridge construction. Finally, the topics of digitalisation and contract design, which also offer potential for faster construction, will be discussed. Great efforts are required from all stakeholders in order to fulfil this immense task. [ABSTRACT FROM AUTHOR]

CO2 balancing of bridges with structure lengths up to 40 m As part of a research project, funded by the Gesellschaft für Energie und Klimaschutz Schleswig‐Holstein GmbH (EKSH), CO2 balancing was carried out on a total of 34 real and several hundred generated bridge constructions. The objectives were to develop empirical data, how much CO2 bridge constructions emit and to develop suggestions on how CO2 emissions can be reduced. [ABSTRACT FROM AUTHOR]

Study on variation of concrete compression strength in the construction of new bridges In the design of new structures and the assessment of existing buildings or bridges, factors with variation such as material properties and component dimensions are represented by representative calculation values. It has long been known that concrete compressive strength is not a constant value but a variable factor. Smaller variations allow for the use of more favorable material properties due to reduced uncertainties. About 50 years ago, the variability characteristics were extensively researched and the results were subsequently incorporated into national and international standards. Many involved in construction have reported about a personal feeling of significant increases in actual concrete strength and more consistent properties in recent decades. Because of improved production conditions and the urgent need for resource conservation, this article examines, based on several recent bridge construction projects in southern Germany, to what extent the variability of concrete compressive strength has changed compared to previous assumptions. To do this, the results of compressive strength tests on nearly 600 specimens are statistically analyzed. The analysis reveals a much smaller variability than previously assumed for current bridge construction projects. Finally, this result is placed in historical context and potential reasons for this results are explained. [ABSTRACT FROM AUTHOR]

Experimental investigation on the fatigue behavior of spot‐welded reinforcement – Applications of semi‐precast elements in bridge construction In recent years, various applications for semi‐precast elements in bridge construction have been developed at the Institute for Structural Engineering at TU Wien. As in most cases spot‐welded reinforcement is used within the elements and special attention must be paid to material fatigue in bridge construction, an investigation thereof is of highest importance. After a brief overview of the possible implementations of the elements as well as standards regarding material fatigue, the experimental investigations on the fatigue behavior are presented. The experimental program consists of the testing of 18 axial‐loaded reinforcement bars with spot‐welded transverse elements as well as 12 large‐scale cycling bending tests. The findings confirm the existence of a residual phase in the realistic large‐scale system, resulting in a time period between the first rupture of a reinforcement bar and the total collapse of the system. This behavior is seen as advantageous for the application in practice, as it results in an additional reaction time for possible construction measures. [ABSTRACT FROM AUTHOR]

Basic and detail design of the Ruhr‐ und Harborcanal bridge in Duisburg The Oberbürgermeister Karl Lehr bridgesection in Duisburg is one of the four Ruhr crossings and has an overarching function for urban traffic and in particular for the industrial location around the port of Duisburg. As a result of the increased load from general traffic and freight traffic from the port, the bridge turned into a bottleneck. In order to cope with the increasing traffic load and increase its capacity, the existing traffic areas of the bridges needed to be expanded. A basic overhaul and extension of the existing, partly very old bridge structures, was ruled out due to their design and structural condition. Therefore, all structures along the bridge section will be replaced by new structures in the same position. This article explains the key aspects of the design and execution planning of the Ruhr and Harborcanal bridges, provides insights into the structural implementation and provides compact information about the overall project. [ABSTRACT FROM AUTHOR]

Integral truss arch bridge over the A3 at the Fürth/Erlangen motorway junction – sustainability and efficiency achieved by combining traditional structural systems The widening of the A3 between the Fürth/Erlangen and Biebelried motorway junctions to six lanes prompted the construction of a 70 m flyover structure without any intermediate supports. From the submissions to a design competition, an integral truss arch bridge design was chosen for the structure. The innovative combination of arch and truss resulted in a highly efficient and robust structure and an extremely flat bridge spanning the motorway. All sustainability aspects were considered in the design – economic efficiency, durability, environmental friendliness and aesthetics. Innovative details such as linear drainage and an exceptional soffit with a special design of haunched precast elements resulted in maximum functionality and durability in addition to the beautiful design of the bridge. Due to its novel shape, which contributes to the variety in today's bridge construction, the structure was awarded the Deutscher Ingenieurpreis Straße und Verkehr in the category Baukultur. [ABSTRACT FROM AUTHOR]

The article provides information on the availability of the fib Bulletin 109, which focuses on the management, testing, and monitoring of existing concrete structures. It emphasizes the importance of maintaining aging infrastructure to ensure safety and functionality. The bulletin offers guidelines for data acquisition, condition assessment, performance prediction, and decision-making for existing structures. The article also mentions the upcoming fib Bulletin 110, which will address the management of post-tensioned bridges. It highlights the fib Symposium in Christchurch, New Zealand, which will showcase resilience to natural hazards and sustainable design in concrete structures. The article concludes with details about the fib PhD Symposium in Budapest and the International Conference on Concrete Sustainability in Guimarães, Portugal. It briefly introduces Aurelio Muttoni, a civil engineer with expertise in structural concrete and bridge design, who has made significant contributions to the field and received multiple awards. [Extracted from the article]

Ultra‐high performance concrete (UHPC) prefabricated beams are competitive in accelerated bridge construction. However, their broader application has been hindered by limited large‐scale tests and inaccurate design methods. To fill this gap, the authors conducted an experimental investigation on the shear and flexural performance of UHPC pi‐beams using two full‐scale specimens. One specimen was a precast UHPC beam, while the other was a composite beam with a normal concrete slab on the UHPC beam. The primary focus was on crack propagation, ultimate capacities, and failure modes. To complement the experimental findings, the extended finite element method (XFEM) was developed as a numerical approach. Nevertheless, relying solely on XFEM to understand real structural behavior is prone to misinterpretations. Moreover, the shear and flexural capacities were evaluated using existing codes and compared with the experimental results. The comparisons revealed that the predictions of shear capacities were at least 15% lower than the experimental values, whereas the flexural capacities showed acceptable agreement. To address this, the authors introduced the limit equilibrium method, leading to a more accurate prediction of shear capacity for UHPC beams with a deviation of <2%. [ABSTRACT FROM AUTHOR]

Studies have shown that in structures isolated with spherical sliding bearings, the seismic base shear increases when the vertical component of ground shaking is explicitly considered, since the dynamic variation of bearing axial force is passed on to the base shear due to the friction mechanism. In this paper, the effect of vertical shaking is systematically investigated in multi‐span concrete box‐girder highway bridges isolated with triple pendulum bearings. Grounded in the theory of bearing mechanics, a simplified method to predict the amplification of base shear with vertical ground shaking intensity in such bridges is developed and evaluated. The simplified approach is potentially applicable for bridge design based on equivalent static analysis. At low to moderate vertical intensities, the simplified method can capture the observed variation in the base‐shear coefficient with isolation system parameters. The differences in base‐shear amplification for bridge superstructure parameter variations are insignificant, and thus the method is widely applicable. At high intensity vertical ground shaking, the base shear coefficient can be affected by an uplift and impact phenomenon. Thus, application of the simplified method should be limited to motions with peak vertical acceleration up to 1 g; simulation with 3D motions is recommended for intensities beyond 1 g. [ABSTRACT FROM AUTHOR]

Effectively integrating and correlating multisource data involved in the bridge construction process is crucial for the improvement of the bridge informatization level. In the current issues of dynamic numerous data and low information sharing between different engineering departments, the traditional information management methods are inefficient in providing comprehensive and accurate data support for construction safety. Focusing on the bridge construction stage, this article proposes a dynamic data‐driven construction method of railway bridge construction knowledge graph (KG) in combination with dynamic data (materials, personnel, equipment and sensors) in the construction process and KG technology. By taking a railway bridge as a case, the study develops a prototype system and analyzes the effectiveness of bridge construction KG in material traceability, personnel and equipment management and construction safety guidance, which can provide comprehensive and accurate data support for bridge construction management and construction optimization. The results show that: (1) bridge construction KG that takes into account the dynamic features of bridge projects can effectively integrate multiple elements; (2) the bridge construction KG is dynamically updated through real‐time comparison and advance prediction based on the dynamic data collected by multi‐sensing equipment at the construction site, and can provide effective data support for guiding bridge construction safety; and (3) the construction management prototype system based on railway bridge construction KG can provide accurate data support for material traceability, personnel and equipment management and assisted risk event decision‐making. The results of the comparative experiment between the KG group and the spreadsheet group showed that utilizing the KG saved approximately 50% of time and achieved a 20% higher accuracy rate in the material traceability task compared to the spreadsheet group. In general, this study proposes a dynamic data‐driven construction method of railway bridge construction KG, which can effectively realize the effective integration and management of multisource data in the bridge construction process, provide the necessary scientific basis for fine bridge management, and help to improve bridge informatization management level. [ABSTRACT FROM AUTHOR]

Use case‐based utility analysis of acquisition technologies in bridge construction BIM‐based project management is currently still under development in infrastructure and engineering, especially in bridge construction. Particularly in the execution phase, only research has been done on how information may be acquired digitally and automatically at the construction site. Automated data acquisition may greatly facilitate the acquisition of relevant data and information during the construction phase, it may increase safety and make more efficient use of personnel at a construction site, reduce workloads and ensure a short‐cycle information provision, thus optimizing costs. Basically, each data acquisition should serve a specific use case and be triggered according to the lean philosophy and the pull principle. So far, there is no standard or recommendation for the decision‐making process, which acquisition technology should be used for which use case in order to generate the greatest benefit. In this paper, a use case based utility analysis for data acquisition technologies in bridge construction is presented. Blind spots of previous research are addressed to ensure a structured and transparent decision‐making process. [ABSTRACT FROM AUTHOR]

UHPFRC Precast Segments for Sustainable and Resource‐Efficient Concrete Bridge Construction Many of the concrete bridges currently in use in Germany are in a deficient condition due to their age or design. However, increased traffic loads also highly contribute to the fact that many of the existing bridges will have to be replaced in the medium term. Due to the many advantages of concrete structures, it can be assumed that concrete bridges will continue to be designed and built in the future. In the light of the increasing consequences of climate change and the pressing need to reduce CO2 emissions also in the building industry as well, there is an urgent need for research into climate‐ and resource‐friendly as well as sustainable but also economical concrete construction methods. A promising approach to fast, effective and resource‐optimized as well as CO2‐efficient construction is the use of high‐performance materials such as UHPFRC in combination with precast segmental construction. In this paper, starting from a monolithic box girder bridge made of normal strength concrete, numerical calculations are used to investigate how much material can be saved in segmented box girder bridges by varying the concrete compressive strength (normal and high‐strength concrete as well as UHPFRC). The life cycle assessment subsequently carried out on this basis for life cycle phases A1 to A3 showed that, when the material is fully utilized, the use of UHPFRC leads to very resource‐efficient and sustainable structures compared with normal‐ and high‐strength concretes. [ABSTRACT FROM AUTHOR]

The demolition of old bridges and the construction of new bridges are obviously not as good as retaining old bridges through the transformation in a short period of time. To continue using the old bridge and implement the new bridge and the old bridge at the same elevation, the old bridge overall jacking of 2.57 m is the only feasible plan (Figure 2). The old bridge in the middle is retained and still used, and the new bridge on both sides is adopted to broaden the bridge. [Extracted from the article]

ÖBB trough bridges with UHPFRC‐composite slab In the railway system of the Austrian Railway Association there are a lot of single span steel bridges with short span (<20 m) and without ballast bed. One of these bridges was the Auenbachbrücke, situated on the railway track Zeltweg–St. Paul in the Lavanttal (Kärnten, Austria), which should be replaced by a modern bridge structure with ballast bed. The main task in the design of the bridge construction was to maintain the existing top of the rails as well as the bottom height of the construction due to flood prevention issues. This task could be solved by using a steel trough bridge with transversal orientated UHPFRC‐composite slab, as shear connection crown dowels were used. In the present paper, the bridge construction is presented and the statically calculation as well as the corresponding testing are introduced. [ABSTRACT FROM AUTHOR]

Ambient vibration tests and operational modal analysis are commonly adopted worldwide to identify the dynamic behaviour of structures because they offer several advantages such as the use of portable light equipment, the possibility to be performed without interruptions of the structure serviceability, and the use of ambient noise to globally excite the construction. Ambient vibration tests are also usually adopted in structural health monitoring systems to control changes in the dynamic behaviour of structures over the time. In this paper the dynamic identification of two multi‐span simply supported prestressed RC deck bridges in Central Italy is presented. The modal parameters of the structures are identified adopting operational modal analyses based on in‐situ ambient vibration measurements. The experimentally identified dynamics is adopted to assess the bridges' seismic retrofitting works and to investigate their dynamic behaviour in the retrofitted state. [ABSTRACT FROM AUTHOR]

The use of small‐sized box girders has shown to bring numerous benefits in the design of bridges with short to medium spans. Therefore, it has become an established construction method in Germany. However, the beams are not accessible for inspection due to their small size, requiring the girder to be welded airtight. The limited accessibility also has consequences on the manufacturing process. Two of the four longitudinal fillet welds can only be executed from outside resulting in single‐sided fillet welds. As a result of the airtight construction, temperature actions lead to fluctuation of the internal pressure of the box. The single‐sided fillet welds are consequently subjected to unscheduled bending stress, which has an unclear impact on the weld. Subject of the research project, presented in this paper, is the influence of this unscheduled load case on the load‐bearing capacity of the girder. To quantify the temperature which leads to changes of the internal pressure, numerical studies based on meteorological data are performed. The load‐bearing behavior of single‐sided fillet welds is investigated in experiments. It can be shown that the load‐bearing capacity is underestimated by simplified calculation methods. [ABSTRACT FROM AUTHOR]

Steel plate girders with I‐section are frequently used in industrial buildings and bridge design as prismatic members that means as members with parallel flanges and rectangular webs. The structural efficiency can significantly be achieved if such members are designed with tapered webs that means with non‐rectangular webs. Depending on the flange inclination and the moment diagram, the stress in the webs of tapered plate girders is significantly affected also as known as Résal effect. Furthermore, the structural efficiency of plate girders can be improved if the flat webs are replaced by corrugated webs. The gain in out‐of‐plane stiffness due to the corrugated webs reduces the buckling sensitivity of the web. As tapered plate girders with sinusoidally corrugated webs under shear forces have not been subject of research up to now, a numerical investigation on the shear force resistance of such girders has been made. The most important findings are presented. It can be stated that the shear force resistance of tapered girders with corrugated webs cannot accurately be predicted by the existing calculation models for prismatic members. [ABSTRACT FROM AUTHOR]

To satisfy the sustainability criteria, a bridge design must be economically viable during its entire service life with a minimal impact on the environment. While stainless steel is known for its excellent life cycle performance, its high cost prevents it from being used in bridges to a larger extent. This study evaluates a new design solution that takes advantage of using corrugated web in bridge girders to overcome this issue. Three design concepts are evaluated for a three‐span case‐study bridge. These include a bridge with carbon steel flat web, stainless steel flat web, and stainless‐steel corrugated web girders. Each design is optimized using a genetic algorithm. The three optimal solutions are then evaluated in terms of investment costs, life cycle costs (LCC) and life cycle impact. The results show that the investment costs in a flat web girder bridge increase by 27% when stainless steel is used instead of C‐Mn (carbon) steel. However, this increase is only 10% when corrugated web girders are used. On the other hand, the LCC savings increase from 6% to 18% for corrugated web girders. Finally, the use of corrugated web in stainless steel leads to a reduction in the climate impacts of up to 32% compared to carbon steel for the studied bridge. [ABSTRACT FROM AUTHOR]

To move up the circular economy hierarchy steel profiles should be reused instead of recycled. To efficiently utilise the limited availability of reclaimed steel elements in new structures, a different approach is required: form follows availability. This paper presents an algorithm for generating truss bridge designs using only reclaimed steel, which optimises material efficiency and avoids cut‐off waste. The algorithm does not require an initial design or a grid of possible positions like the commonly used ground structure method. Instead, it lets a truss geometry grow from start to end. The algorithm was developed using Python in Grasshopper, resulting in a user‐friendly parametric design process. By defining the width and span of a truss bridge and providing a stock of reclaimed elements, a solution cloud of locally optimal truss bridge designs in terms of capacity utilisation is generated, which comply to Eurocode provisions. An optimal design can be selected with given objectives, e.g. the lowest environmental impact. A case study showed that the developed growth method can lead to a truss with 63% less embodied carbon than conventionally designed new steel trusses and 17% less embodied carbon than optimised standard truss designs with retrofitted reclaimed steel elements. [ABSTRACT FROM AUTHOR]

In 2020, 37% of the global share of CO2eq. emissions were attributed to the construction sector. More recently, awareness has been raised on embodied carbon, where emissions from materials and products must be urgently addressed to ensure sustainable constructions. To assess the environmental impacts of a project, a Life‐Cycle‐Assessment (LCA) can be applied: it is a science‐based standardized methodology for quantifying the environmental impacts. It can be used to measure and provide insights to reduce the embodied carbon of constructions over their life. The present publication details the LCA of a wildlife bridge built in France. In addition to the original bridge structure, other structural systems are considered including different materials such as steel and reinforced concrete. The boundary of the LCA is a cradle‐to‐cradle analysis. The life cycle inventory (LCI) is composed of environmental product declarations (EPD) according to EN 15804. The influence of the structural design on the bridge's global warming potential (GWP) emissions and the influence of LCA assumptions (for example, EOL scenarios) are analyzed. This publication aims to support a holistic approach for bridge LCA and help identify the opportunities that can result from implementing sustainable construction strategies. [ABSTRACT FROM AUTHOR]

Fillet welds of airtight welded hollow boxes In steel and steel composite bridge construction, inaccessible box girders provide filigree and resource‐efficient structures. However, due to limited accessibility, inspecting the interior of these girders poses difficulties. As a result, it is necessary for the inaccessible hollow boxes to be airtight welded. This results in pressure variations within the box girder that are influenced by daily and seasonal temperature changes. Furthermore, due to geometric constraints, only two of the four longitudinal welds can be welded from the inside and the outside of the beam. As a result, two of the welds can only be made from the outside, resulting in a single‐sided fillet weld. These one‐sided fillet welds are subjected to unexpected bending stresses due to pressure variations. As part of a research project, numerical and experimental investigations are being conducted to examine the effects of internal pressure and determine the load‐bearing capacity of single‐sided fillet welds. A numerical model is generated and validated, and investigations are carried out using data from weather stations to determine the characteristic value of the internal pressure. Additionally, an initial series of experiments has been conducted to investigate the load‐carrying and rotational capabilities of single‐sided fillet welds. These experiments have shown a significant rotational capacity and increased load‐bearing capacity for the single‐sided fillet welds. [ABSTRACT FROM AUTHOR]

Precast segmental construction can shorten the construction time of the bridge and reduce the impacts on traffic and environment. Thus, this approach has been widely used in many countries. The relevant literature suggests that in the existing segmental precast bridges, nearly all of the centerlines of the girders are aligned with the centerline of the bridge piers. This paper introduces a wide urban viaduct comprising twin separate box girder cells using segmental prefabrication. To save space under the bridge, the bridge has only one row of piers and long cantilever crossbeams are set at the top of each pier. Additionally, the centerline of the girder and the centerline of the pier do not overlap. To prevent eccentric loading and improve the construction speed, two bridge erection gantries are used for synchronous construction. This study is a pioneering attempt at bridge construction with a precast segmental twin‐deck box girder bridge simultaneously erected with double gantries. To investigate the stress state of the whole system (crossbeam, gantries, and box girder segments) during construction and demonstrate the feasibility of the construction method, a real bridge was used. The test results provide a reference for the design and construction of similar projects. [ABSTRACT FROM AUTHOR]

Despite the good balance between notable mechanical properties and a reasonable cost, high‐performance fiber reinforced concrete (HPFRC) is not widely employed in the construction of bridges. This work is part of a larger research addressed at exploring the potential of this material for replacing standard concrete in the construction sector. Specifically, this paper focuses on the use of HPFRC to build precast simply supported I‐girders for road bridges. This work investigates the influence of several design variables on the material consumption to identify the key features that can lead to possible material savings. The variables, explored through a parametric analysis, are: (i) the concrete class (C80/95, C100/115, and C120/140); (ii) the number of beams to form the deck (from 3 to 5); (iii) the girder span‐to‐depth ratio (17, 20, and 23); (iv) the bridge span (L) (20, 40 and 60 m). One specific case of study is described in detail, and then the same procedure is applied to all the case studies. In addition, the effect of different hypotheses and formulations for the bending and shear verifications are analyzed. The results shed light on the relevance that these variables play in the final solution and how they affect the dimensioning of these elements. As main finding, this work proves that the use of HPFRC represent a material‐efficient solution for slender and long‐span precast I‐girders. [ABSTRACT FROM AUTHOR]

Hot‐dip galvanized steel structures are well established and state of the art for public and industrial buildings. They can achieve a corrosion protection period in the magnitude of the lifetime of the structures (≥100 years). The application of this corrosion protection system would also have great potential in bridge construction. Economic efficiency and sustainability in bridge construction are, in addition to the cost of new building, determined by the incurred maintenance costs. Various research projects demonstrate hardly any losses on the fatigue strength compared to the non‐galvanized steel components. Large bridge structures must be designed with assembly joints. Welded site joints of hot‐dip galvanized components require a complex pre‐ and post‐treatment of the corrosion protection. Nevertheless, on‐site applied corrosion protection cannot reach the protection durability of a hot‐dip galvanizing. This technological restriction can be avoided by the use of hot‐dip galvanized bolted connections. Slip‐resistant pre‐stressed connections are proved successful in steel bridge construction. Major scientific investigations are not yet available for the use of slip‐resistant connections for hot‐dip galvanized joints. Technical and scientific foundations for the application of hot‐dip galvanized bolted connections in cyclically loaded steel and composite bridge constructions, based on the European standard for steel constructions, are investigated within the scope of this research project. Construction and design recommendations are provided. [ABSTRACT FROM AUTHOR]

Bridges over the Kiel Canal – evidences of the art of bridge construction in the field of tension between preservation or replacement The article presents several high bridges over the Kiel Canal, for which the fundamental decision to strengthening or replacement was made in a differentiated manner. This shows the difficult boundary conditions in which the authorities often find themselves today with regard to ensuring the functionality of the infrastructure, condition and calculated assessment. With the railway bridges Rendsburg and Hochdonn, two structures are presented which have with more than 110 years already exceeded their normative useful life and can still be used economically for a long time after their strengthening. Furthermore, the Rader highway bridge and the combined road and railway bridge Levensau are explained, which mark the two border areas for the determination of a replacement. The highway bridge is simply no longer usable for the heavy road traffic loads of the A7 after only 50 years of use, on the other hand the Levensau bridge with rather moderate road and rail traffic has long since reached its planned service life, but has to be rebuilt because of the necessary widening of the Kiel Canal. [ABSTRACT FROM AUTHOR]