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Translation abstract Deformation monitoring of bridges applying remote sensing satellite radar measurementsDeformations of the Earth's surface can be measured from space using remote sensing radar interferometry (InSAR). This paper demonstrates the use of these data for deformation monitoring on the Schottwienbrücke‐S6 Semmering motorway. The European Space Agency (ESA) recently began providing free research satellite data from the Sentinel‐1 mission. The approach uses historically recorded natural reflection points as well as corner reflectors artificially attached to the structure. These are measured coordinately and analyzed using remote sensing methods. Thermal displacements of the structure are compensated to increase accuracy. A new model predicts the temperature of the structure based on network weather data. This means that the deformation measurements from the satellites can be analyzed and thermally compensated without sensors on the building, and the deviations can be more than halved. The recorded and processed annual measurements from 2022 onwards show a standard deviation of 1.7 to 3.0 mm compared to the reference system (Liquid Leveling System). Good agreement with the long‐term settlement behavior of the bridge was also found for natural reflection points. Satellites can also be used to simultaneously record different structures at 6‐day intervals up to 2016. Due to the time‐delayed processing, they are currently well suited for long‐term deformation monitoring of long‐span bridges. [ABSTRACT FROM AUTHOR]

Image‐based quality control – part 2: granulometric properties The changes in concrete technology necessary to achieve the climate protection targets will lead to a significant change in the concrete mixtures typically used. The raw materials used are becoming more diverse and complex. The use of recycled raw materials will also significantly increase the fluctuations in the properties of the raw materials. An Accurate and time‐efficient determination of the granulometric properties of the aggregate is of crucial importance, especially for "eco‐concretes", in order to ensure consistent quality characteristics. As a natural raw material, the aggregate is subject to certain fluctuations to which such optimized concrete compositions can react relatively sensitively. In the future, it will be necessary to determine possible quality deviations of the fresh concrete resulting from fluctuations in the raw materials in a time‐efficient manner in order to be able to make appropriate adjustments in the production process as quickly as possible. This paper presents an image‐based quality control for the digital evaluation of granulometric properties of the aggregate as a part oft he flow table test. Accordingly, the range of properties of the image‐based method already presented in Part 1 of this paper is extended to a fully comprehensive digital quality control. This paper presents the image‐based determination of the granulometric properties of the aggregate as a part oft he flow table test. The determination is based on the image‐based quality control described in part 1 of this paper. [ABSTRACT FROM AUTHOR]

Free‐form reinforced concrete, prestressed concrete and composite components: Calculation of cross‐section values A resource‐efficient use of concrete as a construction material can be achieved by adapting the individual shape of a component under consideration to the stresses that occur and by arranging composite construction materials (e. g. reinforcing steel, prestressing steel or structural steel) in suitable areas of the component. Due to the advancing digitalisation in the construction industry, for example in the context of Building Information Modeling, computer‐aided 3D modelling methods are increasingly being used in the planning of structures. These allow engineers to design components in free form. In reinforced concrete, prestressed concrete and composite construction, the design of such components is currently still associated with great effort. In the context of the development of a practical method for the calculation of free‐form concrete components, this paper presents a CAD‐integrated method for the calculation of cross‐section values. Cross‐section values are required as an essential calculation basis when real, three‐dimensional structural components are treated using simplified calculation theories, such as the beam theory. In this paper, the mathematical and numerical fundamentals of a method for the calculation of cross‐section values of free‐form concrete, reinforced concrete, prestressed concrete and compound components are presented. The calculation method is based on flat geometric regions described by Non‐uniform rational B‐Spline tensor product surfaces, which can be extracted from solid models, for example. [ABSTRACT FROM AUTHOR]

Modelling of the CUBE's TWIST shell This paper gives an overview of the main procedures prepared during the phase of the project development within the field of numerical modelling and design. The roof shell elements represent itself twisted shape that together with complicated structurally demanded inner structure forms quite complicated configuration for the concrete volumes as well as for the used reinforcement. Therefore, custom developed numerical method was required to be prepared. For that, the software solutions Rhinoceros 3D and Grasshopper 3D were used as the main algorithmic environment. The paper additionally gives an insight of important aspects required for production of the formwork components, thermal insulation, biaxially oriented carbon reinforcing grids and other parts of the load‐bearing shells. Finally, the paper gives an idea how was established a collaboration with partners of the CUBE project in particular in the field of structural analysis. [ABSTRACT FROM AUTHOR]

Debris flow actions on concrete bridge superstructures Bridge structures in alpine areas are subject to various hazards. These also include debris flows. Debris flows events demonstrably also lead to the destruction of bridges. In order to design bridges for such hazards, information on the impact force of debris flow is necessary. For debris‐flow impacts against piers, extensive miniaturized as well as real size tests are available. So far, no such tests are known for bridge superstructures. In this paper miniaturized debris‐flow impact tests on concrete bridge cross‐sections are presented. Based on the test results, recommendations for the design of concrete bridges in exposed locations are proposed. [ABSTRACT FROM AUTHOR]

Traffic Monitoring on a Highway Bridge – Data collection on local traffic characteristics as a basis for site‐specific traffic load models Developing site‐specific traffic load models for individual bridge structures based on local traffic data represents a potentially effective tool for existing road bridges with remaining calculative deficits when assessed according to current codes (guideline for assessment of existing structures, "Nachrechnungsrichtlinie"). A robust data basis to represent the local traffic characteristics is essential for this purpose. This paper presents investigations carried out during a long‐term monitoring campaign to comprehensively describe the traffic load on a selected bridge structure along Federal Highway A 92 over a period of one year. For the campaign, a measurement unit consisting of a laser scanner and a webcam, and structural monitoring with the application of bridge weigh‐in‐motion (BWIM), are used. Suitable strategies and concepts for collecting, processing, and evaluating all available measurement data enable a comprehensive collection of all parameters relevant for traffic load modeling and thus provide a data basis for detailed and realistic modeling of local traffic characteristics. Initial evaluations of the monitoring data for selected parameters and the comparison with otherwise typical assumptions from the literature in case of missing parameter information show partly significant differences to the extreme traffic characteristics underlying the load models in codes. [ABSTRACT FROM AUTHOR]

Nonwoven bonded pre‐applied waterproofing membranes – bond development and properties Pre‐applied bonded membranes are used as an additional waterproofing measure on waterproof concrete structures and are installed before concrete placement. They achieve a bond to the fresh concrete and often use nonwovens, which must be filled with cement paste during concrete placement. However, little is known about the separation of cement paste from fresh concrete, its properties in the nonwoven, or beneficial nonwoven characteristics. The following paper analyzes the bond of nonwovens in three parts: first, the deformation behavior of the nonwovens during concrete placement is determined using microsections. During concrete placement, the nonwovens are compressed and progressively recover during cement paste filling. As the fresh concrete is placed, filtration processes start. Excess water and a limited amount of fine solids separate into the nonwoven. A filter cake forms on top of the nonwoven and is responsible for a water‐rich cement paste within the nonwoven. Only with the onset of vibration compaction is the filter cake loosened, more solids penetrate the nonwoven, and the water‐solid ratio in the nonwoven is lowered. The bond subsequently develops proportionally to the tensile splitting strength of the concrete. Nonwovens influence the bond strength as they control the separable amount of excess water, which degrades the cement paste strength in the bonding layer. [ABSTRACT FROM AUTHOR]

Increase of technical lifetime of infrastructures based on semi‐probabilistic considerations One of the most important measures in the discussion on improved sustainability in construction is to extend the service life of our structures [1]. Therefore, intensive research is conducted with regard to changing environmental conditions as well as external load effects for structures and new materials and their impact on the production and operation of infrastructures. Already now, according to [2], changes in the kinematics of the degradation mechanisms can be observed. In particular, changing environmental conditions (exposures) can accelerate but also slow down the degradation of materials and structures. These understandings of the degradation processes, but also the improved knowledge of the geometry and effective mechanical building material properties, should be effectively transferred into engineering practice for the assessment of structural reliability and remaining service life [3]. This paper presents how the elements of reliability analysis can be combined with the elements of in‐depth testing and monitoring procedures to periodically evaluate the degradation processes due to changing environmental conditions and new building materials. Subsequently, the remaining service life can be continuously updated with the help of semi‐probabilistic partial safety considerations. [ABSTRACT FROM AUTHOR]

Experimental investigation on the effect of static system and load arrangement on the shear resistance of beams with low amounts of shear reinforcement In this paper, an experimental investigation on the shear behaviour of beams with low amounts of shear reinforcement and different static systems is presented. Four simply supported beams under concentrated loads, ten cantilevers and three simulated continuous beams under uniformly distributed loads were tested. The shear reinforcement ratio was varied between 0 (without shear reinforcement) and 2.0 times the minimum shear reinforcement according to EC2. The test results show a significant influence of the static system and the loading type on the crack pattern and ultimate load of the beams tested. While a reinforcement level below the minimum shear reinforcement has almost no influence on the shear resistance of simply supported beams under concentrated loads, a very low shear reinforcement leads to a significant increase in the shear capacity of beams under uniform distributed loads. The crack pattern, however, remains unchanged compared to beams without shear reinforcement where shear failure is characterized by a single critical shear crack. The test results were also compared with design and standard specifications. The comparisons show possible improvement potentials in the currently applied models. [ABSTRACT FROM AUTHOR]

New perspectives on the load bearing behavior of RC‐structures without shear reinforcement The shear behavior of structural members has been an integral part of research in concrete structures for more than 100 years. In recent years, various mechanical shear models have been developed that deliver important insights into the background of shear behavior and are able to provide physical explanations for shear failure in RC members without shear reinforcement. However, these models require further experimental validation. New measurement techniques (e.g. digital image correlation or fiber‐optic strain measurement) play a decisive role in this context, allowing deeper insights into the load‐bearing behavior of reinforced concrete components subjected to shear loads. Based on experimental investigations with modern measurement techniques, software has been developed that performs an automated crack detection based on the finite element method with detailed evaluation of the kinematics and the stresses transferred in the crack. In this paper an overview of different evaluation methods of experimental investigations with modern measurement techniques is given, on the basis of which an in‐depth evaluation of new model approaches can be carried out. [ABSTRACT FROM AUTHOR]

Influence of transverse tensile loads on the compressive strength of carbon reinforced concrete Initial findings on the load‐bearing behaviour of carbon reinforced concrete components under uniaxial compressive stress are available, however multi‐axial stress states are of particular relevance for an application in construction practice. It is known from steel reinforced concrete constructions that transverse tensile stresses lead to a reduction in the compressive strength, although there is still no international agreement on the actual reduction. In this paper we investigate the boundary conditions under which carbon reinforced disc shaped specimens can be tested under combined compressive and tensile loading. This includes the anchoring of the carbon yarns required for the tests in limited space conditions as well as the influence of the loading regime – proportional or sequential – and the manufacturing process – laminated or casted – on the test results. Finally, an outlook on the following investigations is given. [ABSTRACT FROM AUTHOR]

Double‐headed studs as shear and punching reinforcement – Current status and outlook Double‐headed studs have been established for decades as a very effective punching shear reinforcement because these reinforcement elements, which are optimized for shear and punching loads, combine a particularly high anchorage performance with a practicable installation on site. In this paper, an overview of current usability and applicability verifications for double‐headed studs in Germany is given. Afterwards, the currently valid design and construction rules for the use of double‐headed studs as shear reinforcement as well as punching reinforcement are summarized. Finally, the next Eurocode 2 generation 2023+is looked at, with excerpts presenting some significant innovations in the future integration of double‐headed studs into the shear and punching rules. [ABSTRACT FROM AUTHOR]

Influence of the arrangement of the punching shear and composite reinforcement made of L steel plates on the load‐bearing capacity The CLIXS punching shear and composite reinforcement system consists of L steel plates with one or two connected stirrups made of reinforcing steel. It is possible to increase the load‐bearing capacity by more than twice the load‐bearing capacity without punching shear reinforcement. The experimental investigations described in the paper were carried out on square slab cut‐outs with a length of 2.8 m and a thickness of 18 and 25 cm. The load‐bearing capacity as a function of the number of uniform arranged L steel plates was determined based on 17 experiments. For this purpose, test specimen with 6 L steel plates up to 36 L steel plates in the first three perimeters were investigated. In addition, 10 test specimen with different sized areas without L steel plates were tested. The areas without L steel plates were between 25 % and 75 % of the area within the first three perimeters. The use of stirrups with a diameter of 8 mm instead of 6 mm was investigated using two test specimens. [ABSTRACT FROM AUTHOR]

Manufacture and erection – TWIST The TWIST shell structure of the CUBE Result House was built from carbon concrete using the wet spraying method. The report from the executing company's perspective provides a detailed description of the technological realization based on the plans submitted for execution. The paper deals with special aspects of production, which result from technology, building materials used, building material properties and general conditions during construction. The experience gained should serve the further development of carbon concrete constructions and shows the need for development to be ready for practice with regard to construction. [ABSTRACT FROM AUTHOR]

Image‐based quality conctrol – part 1: consistency and paste content Today, only very simple empirical test methods are available for quality conctrol of fresh concrete on the construction site or in the production plant. Corrective actions in the case of quality deviations are based on a subjective visual inspection and thus on the experience of the inspector. The standard test method in Europe is the flow table test. The consistency of the concrete is derived from the diameter of the spread out fresh concrete. In order to overcome the deficiencies of this subjective fresh concrete testing, an image‐based method for determining (fresh) concrete properties was developed and validated. In addition to the diameter, extensive information can be derived from the surface properties of fresh conrete. In this paper, the image‐based determination of the consistency and the paste content is explained. The image‐based determination of granulometric properties (part 2) and the homogeneity of fresh concrete (part 3) will be presented in planned follow‐up articles. [ABSTRACT FROM AUTHOR]

Shape optimisation of eccentrically loaded columns – theory and experimental verification. In shape optimisation, the external shape of the structural component is adapted to the predominant force flow. In this way, large load increases can be achieved with the same material use, or high material savings can be achieved with the same load‐bearing capacity. In this paper, a shape optimisation for eccentrically loaded columns is presented, where the bending stress results from a frame effect of the load‐bearing system. This is the case, for example, in edge columns of typical reinforced concrete skeleton structures, as they are usually used in residential and commercial buildings. The shape optimisation method presented in the article can be applied to columns with an arbitrary ratio of a moment‐normal force loading, provided that a material failure occurs. Results for shape optimisation in the case of a stability failure have already been published separately for centrically pressed columns. The optimisation itself is carried out iteratively on a column segmented over the height under the criterion of achieving a uniform stress state in the component. With the help of an experimental check on 3.3 m high columns, the selected calculation and optimisation method could be verified. In addition to the failure loads, the concrete strains and the deformation behaviour were also analysed and evaluated at selected points of the specimen. [ABSTRACT FROM AUTHOR]

Punching shear in irregular flat slab systems – Recommendations for modeling and design The punching shear verification is often the decisive verification in design due to the concentrated load introduction. Moreover, uneven shear stress distributions often occur in the punching shear area as result of irregular flat slab systems or eccentric loads. In structural design it is often questionable, how a non‐uniform shear stress distribution can be considered with acceptable effort. The direct determination of the shear stress distribution along the control perimeters using FE methods is not explicitly excluded in the current Eurocode 2 but is also not described in more detail. This gives considerable freedom in design for the structural engineer, but also ambiguities for interpreting the results. In this paper, FE approaches for determining the factor β or for directly considering the non‐uniform shear stress distribution are presented and analyzed based on an application example. Finally, recommendations and modelling advice are given for the pragmatic and, as far as possible, realistic determination of factor β for consideration of unbalanced moments. [ABSTRACT FROM AUTHOR]

During the planned conventional deconstruction of the Salzbachtal bridges, which were highway bridges of BAB 66 in the district Biebrich of Wiesbaden, a roller bearing collapsed on June 18, 2021. The superstructure laid on a pier and pushed it sideward; furthermore, cracks arose in the superstructure. As the structural safety could not be guaranteed, the bridge itself as well as the street Mainzer Straße and the Taunus railway line to Wiesbaden main station were closed. To clear the resulting significant traffic disturbance a blast demolition was planned and executed in a short notice. Due to the confined space and several infrastructure worthy of protection in the direct neighbourhood, the blast concept envisaged to blast the southern bridge by vertical collapse and to lay down the northern bridge by tilting collapse on the southern bridge afterwards. The blast demolition of both bridges was carried out on November 6, 2021 by 204 kg explosives. All piers of the southern bridge buckled to the west as planned and the superstructure fell down exactly vertically. The northern bridge followed 3 seconds later and tilted to the south. In this paper, the history of the original conventional demolition concept, the accident as well as the blast demolition concept and execution is described. [ABSTRACT FROM AUTHOR]

Until now no mandatory guidelines for the structural planning of the deconstruction of existing concrete structures are introduced by the authorities, which assist the planning engineers in the evaluation of these existing or damage structures. Often complex structural states of deconstructions have to be calculated, which depend on the knowledge of the actual structural condition. Therefore the only source of information is given by the existing documents, which often don't represent the actual state. To reduce the risks and to increase the planning and tender security, diagnostic investigations offer a big potential. Because not all information, as e. g. the knowledge about the possibility of a subsequent anchorage of cut prestressed tendons can be evaluated in advance of a deconstruction, further experimental investigations are necessary. As yet no technical or contractual rules are defined. The paper gives an overview of practical experiences and possible potentials of these experimental investigations. [ABSTRACT FROM AUTHOR]

Blast demolition of Salzbachtalbrücken During the planned conventional deconstruction of the Salzbachtal bridges, which were highway bridges of BAB 66 in the district Biebrich of Wiesbaden, a roller bearing collapsed on June 18, 2021. The superstructure laid on a pier and pushed it sideward; furthermore, cracks arose in the superstructure. As the structural safety could not be guaranteed, the bridge itself as well as the street Mainzer Straße and the Taunus railway line to Wiesbaden main station were closed. To clear the resulting significant traffic disturbance a blast demolition was planned and executed in a short notice. Due to the confined space and several infrastructure worthy of protection in the direct neighbourhood, the blast concept envisaged to blast the southern bridge by vertical collapse and to lay down the northern bridge by tilting collapse on the southern bridge afterwards. The blast demolition of both bridges was carried out on November 6, 2021 by 204 kg explosives. All piers of the southern bridge buckled to the west as planned and the superstructure fell down exactly vertically. The northern bridge followed 3 seconds later and tilted to the south. In this paper, the history of the original conventional demolition concept, the accident as well as the blast demolition concept and execution is described. [ABSTRACT FROM AUTHOR]

Life Cycle Assessment in the Building Sector – Greenhouse Gas Emissions of Common Ceiling Systems In the past, life cycle assessments (LCAs) of buildings were only carried out in rare cases at the request of project initiators. Against the backdrop of social and political pressure to act more climate‐friendly and sustainably, LCAs and the available data are also becoming increasingly economically relevant. This paper therefore presents the essential principles of LCA in the building sector. In addition to a critical analysis of the scope of assessment, there is a brief presentation of available data bases, such as the national database ÖKOBAUDAT. Furthermore, the greenhouse gas balance of timber as a building material is discussed, which in some cases opens up considerable scope for assessment with the risk of false incentives. As horizontal building components, ceiling systems of multi‐storey buildings can cause almost 40 % of the structural emissions and are therefore highly relevant for a LCA. By varying the life cycle stages assessed and data sets used as possible factors influencing the results of a LCA, these building components are examined and compared in more detail in the following article. Despite some sensitive effects on the comparison of the ceiling systems, the LCA offers a decision‐making aid for the selection of ceiling systems in terms of reduced greenhouse gas emissions of a shell construction. [ABSTRACT FROM AUTHOR]

Internet of Construction: Potential of LoRaWAN quality assurance in the In‐situ concrete prozess Achieving high quality assurance standards when using in‐situ concrete requires a great amount of manual documentation. In particular, in‐situ concrete installation requires a great deal of attention, as the use of the right concrete in the intended building element must be ensured and errors mean additional time and costs. In other industries, it can be observed that IoT systems are already used profitably to support the execution processes and for documentation needs. However, despite the numerous digital solutions available, the use of Internet of Things (Iot) technologies for such monitoring tasks on the construction site are rarely observed. Yet the technologies have the potential to simplify quality assurance measures and make construction more attractive. This paper deals with the process step of concrete installation within the value chain of in‐situ concrete construction, which has so far been performed mainly manually, involves a high risk of error and is very time‐consuming to monitor. A Long Range Wide Area Network (LoRaWAN‐)‐based IoT system is designed to support humans in documenting the concrete installations. The system will then undergo a field test on a construction site. The results obtained are compared with the process‐related requirements, and with this it is shown that some important requirements are already satisfactorily fulfilled with the presented setup. [ABSTRACT FROM AUTHOR]

The structural condition as challenge for the deconstruction planning Until now no mandatory guidelines for the structural planning of the deconstruction of existing concrete structures are introduced by the authorities, which assist the planning engineers in the evaluation of these existing or damage structures. Often complex structural states of deconstructions have to be calculated, which depend on the knowledge of the actual structural condition. Therefore the only source of information is given by the existing documents, which often don't represent the actual state. To reduce the risks and to increase the planning and tender security, diagnostic investigations offer a big potential. Because not all information, as e. g. the knowledge about the possibility of a subsequent anchorage of cut prestressed tendons can be evaluated in advance of a deconstruction, further experimental investigations are necessary. As yet no technical or contractual rules are defined. The paper gives an overview of practical experiences and possible potentials of these experimental investigations. [ABSTRACT FROM AUTHOR]

KI/ML‐based Analysis and Interpretation of the IABSE‐Bridge Collapse Database Statistical analyses of bridge collapse data show that concrete bridges collapse significantly less frequently than bridges made of steel or wood. Since the main causes of bridge collapses worldwide are floods and associated fluvial processes, such as scouring, debris flows, etc. and impacts, it is reasonable to assume that the high dead load of concrete bridges leads to an overall more robust behavior in these events. This paper will examine whether the IABSE collapse database confirms this hypothesis and whether indications of further causes can be identified. For this purpose, the IABSE collapse database is examined using artificial intelligence and machine learning (AI/ML) methods. However, the AI/ML analysis does not confirm the previous thesis. The reasons for the rejection of the thesis, such as the representativeness of the data, are also discussed. An extension of the database for events with large numbers of collapses is recommended. [ABSTRACT FROM AUTHOR]

An UHPC for use in deep‐sea research The article deals with comprehensive material investigations carried out with an ultra‐high performance concrete (UHPC) intended for use in the deep sea. The tests performed include the determination of the stress‐strain behavior under uniaxial loading of the specimens, of the biaxial compressive strength of the UHPC under different stress ratios, of the tensile strength characteristics, and of the elastic modulus. Cubes, prisms and bone‐shaped test specimens were used for the investigations. From the determined material properties, conversion factors for the geometry‐dependent strengths of the concrete were calculated. In the paper, the determined biaxial compressive strength values are compared with data known from the literature. It is shown that an UHPC can have a similar increase in strength as a normal strength concrete. [ABSTRACT FROM AUTHOR]

Tensile load‐bearing behaviour of concrete components with impregnated textile reinforcement made of natural fibres Recently, the use of natural fibres as a reinforcement in composite building materials have witnessed a growing interest amongst researchers due to their ecological, economical and mechanical properties. In civil engineering, however, they have not been considered in extensive investigations or the development of design guidelines for concrete members with textile reinforcement made of synthetic fibres. In this paper, the uniaxial tensile load‐bearing behaviour of concrete members reinforced with flax fibre textiles (impregnated leno fabrics) is investigated. Therefore, test specimens were casted and tested, varying parameters of the textiles, e. g., the spacing of the weft threads. For a reference, both test specimens reinforced with non‐impregnated textiles and without any reinforcement were investigated. The suitability of this type of reinforcement for concrete members under uniaxial tension is shown by an increase in the ultimate load compared to members without or with less reinforcement. The curves of the stress‐strain diagrams can be divided into three stages typical for reinforced tensile test specimens (state I – uncracked, state IIa – process of cracking and state IIb – completed crack pattern). The differentiation of the areas is clearer with an increasing reinforcement cross‐section. Further, a finely distributed crack pattern with uniform crack widths was observed which supports the findings of the diagrams. [ABSTRACT FROM AUTHOR]

Environmental Performance of Ceiling Systems in Building Construction – Currently used Systems and Future Optimisation Potenzial The building industry counts to the most influencing sectors regarding raw material demand, energy use and solid waste generation (≥ 38 %). The development and use of construction methods and building materials with minimal environmental impact over the entire life cycle has therefore utmost relevance. In order to quantify the environmental impact of construction methods and materials, a fact‐based life cycle assessment must be carried out. Currently, these kinds of assessments are not state of practice with a lack of objective comparisons missing on the market. When looking at building construction, ceiling systems in particular have a great influence on the environmental footprint of the entire building. Therefore, this paper is dedicated to the environmental comparison of different ceiling systems in building construction based on EN 15804 and EN 15978. The system boundaries were defined with the life cycle phases of cradle‐to‐gate and cradle‐to‐grave. A total of nine different ceiling types within different structural systems were considered and evaluated. All systems were dimensioned as efficiently as possible according to common engineering practice for the given boundary conditions with the currently valid standards (ÖNORM, Eurocode). The results show that environmental competitive systems can be implemented using all considered materials. The key is to take the materials properties into account while simultaneously optimising the structure and load‐bearing systems. [ABSTRACT FROM AUTHOR]

Radiography in civil engineering – practical applications of RT in NDT‐CE Radiographic Testing (RT) has been a proven testing method in NDT for decades. This is because RT is the only method providing direct imaging of the inner structure of welds, castings, and workpieces. However, radiography is widely unknown in the field of non‐destructive testing in civil engineering (NDT‐CE) in Germany – although great progress has been made in the last decades, especially in the field of digital imaging and mobile applications. This allows for many practical testing tasks, e. g. on‐site quality assurance, damage assessment, and non‐invasive investigation of buildings under a preservation order. In general, RT allows for identification, size and depth determination of reinforcement, tendon ducts and other components. Investigation and evaluation of cracks and corroding steel should be possible as well and may be the aim of future research work. This paper outlines basics, possibilities and limitations of radiography in civil engineering and shows its potential basing on practical applications. [ABSTRACT FROM AUTHOR]

Ductility‐increasing reinforcement systems for fabricated column elements made of UHFB In order to build faster, lighter and more precisely with concrete, a new modular construction concept based on ultra‐high performance concrete (UHPC) was investigated, which has a highly advantageous ratio of axial compression load‐bearing capacity and dead weight [1]. In order to enable proper manufacturing of this column element, which is referred to as a winding‐reinforced UHFB hybrid tube, in an automated extrusion process, a novel reinforcement concept has to be developed without the usual steel reinforcement. In an extrusion process, a supporting inner steel tube is encased with UHPC and advanced together with the UHPC. Subsequently, a ductility‐enhancing confinement reinforcement is applied to the surface of the components from the outside in a process that can be automated. As UHPC fragments damage the CFRP reinforcement in case of failure, this paper investigates which protective layer/reinforcement system can be used to achieve ductile component behavior for beam structures subjected to axial compression. For this purpose, different textile reinforcement layers were applied to UHPC specimens and their influence on the load‐bearing behavior of the components was determined with special consideration of ductility and residual load‐bearing capacity after exceeding the maximum load. A combination of aramide fabric and carbon fiber textile showed favorable load‐bearing behavior with enhanced quasi‐ductility in experimental investigations. [ABSTRACT FROM AUTHOR]

Persönliches Rolf Eligehausen – 80 Jahre Manfred Keuser – 70 Jahre Zum 65. Geburtstag von Carl‐Alexander Graubner Nachrichten Bayerischer Denkmalpflegepreis 2022 verliehen Schülerwettbewerb Junior.ING startet 4. Symposium Ingenieurbaukunst – Bauen mit und im Bestand Call for papers Bestandsaufnahme zum nachhaltigen Bauen mit Beton Lieferengpässe und Preisanstiege bei Ausgangsstoffen [ABSTRACT FROM AUTHOR]

Explainable Domain‐Specific Artificial Intelligence for Bridge Engineering and Design The use of artificial intelligence (AI) is currently being discussed and evaluated across the board in research and practice in all industries. This paper first provides the necessary background knowledge on general AI and then elaborates the necessity of developing domain‐specific AI as well as explainable AI (XAI) for the calculation and design practice in civil engineering. The role of the civil engineering domain at the interface with AI in terms of data and modeling and design philosophy is discussed. The three examples of (i) computation of Kirchhoff slabs with physics‐informed neural networks, (ii) calibration of prior models for parametric bridge design from databases, and (iii) AI‐assisted conceptual design of bridges illustrate the application of domain‐specific machine and deep learning and XAI with special focus on concrete and bridge design. In particular, physics‐informed AI (piKI) represents an alternative to established numerical methods with special consideration of available simulation and experimental data and becomes explainable and comprehensible via the use of XAI. This paves the way for the use of piKI models in civil engineering as digital twins of a structure over its life cycles. [ABSTRACT FROM AUTHOR]

Automated Damage Classification on Concrete Bridges Using Convolutional Neural Networks Against the background of an ageing structure stock and the constant increase in heavy traffic, frequent structural inspections of high quality are indispensable. In accomplishing this task, the use of digital methods within the framework of digitized inspections (DIs) offers great potential for improvement in terms of cost‐effectiveness and quality. An essential component of DIs is the automated detection of damage with Convolutional Neural Networks (CNNs). As part of the research project "Model‐Based Digital Structural Inspection – MoBaP", CNNs are being trained at the University of the Bundeswehr Munich for the classification of defects occurring on concrete bridges. On this domain's currently largest open‐source dataset (CODEBRIM), the best CNN achieves an exact match ratio of 74 % and thus currently defines a strong baseline. In order to also train neural networks for object detection and semantic segmentation in this domain, a separate dataset is created. This enables not only the classification but also the localisation of damage on images. In this paper, the authors discuss the procedure of training neural networks for the classification of defects on concrete bridges and show a detailed analysis of test results. In addition, the development and current status of their own dataset is presented. [ABSTRACT FROM AUTHOR]

Climate Compatibility as a Criterion for the Design and Performance of Concrete illustrated by the Example of an ÖBB Small Animal Passage Concrete is the world's most widely used building material and is preferred for infrastructure construction inter alia due to its high performance, versatility and durability. Its production and use, however, generates significant amounts of greenhouse gas emissions (CO2eq). Consequently, any reduction of CO2eq of the building material contributes to achieving the societal goal of CO2 neutrality. In this paper, a small animal passage of an ÖBB railway line is used as an example to show how climate compatibility or CO2‐equivalents (kg CO2eq/m3) are directly integrated into the mix design. It is also explained how the essential performance characteristics of climate‐compatible concretes – in addition to the CO2‐equivalents, in particular their early strength and durability – can be considered and optimised in their entirety. For this purpose, performance‐based concepts are applied for the optimisation of binders with combined additives and for the verification of durability. Furthermore, experiences with the realization, testing and quality assurance of CO2eq‐reduced concrete in comparison to equivalent standard concrete will be reported. [ABSTRACT FROM AUTHOR]

De-icing of bridge decks, control of hardening or concrete strengthening through tempering are promising applications for active temperature induction into RC structures. The paper introduces fundamental approaches and devices: heating with infrared radiators, heating pads, heated water and Peltier elements, cooling liquids and dry ice, are discussed by means of nominal electric powers, attachment to the structure, interaction of device and structure, temperature control and potential losses. The characteristics of the approaches are analyzed and rated. A test series on insulated beams serves for reference. The alternative approaches are separately applied and combined to induce temperature gradients. Heating pads and infrared radiators are most suited for heating while Peltier elements and liquids are beneficial for cooling. From comparison recommendations for practical application are derived. [ABSTRACT FROM AUTHOR]

Abstract: Practical Application of an innovative concrete shell construction method: Construction of the deer pass AM2 by use of PFHC Concrete shells are aesthetic and economic supporting structures, if properly designed. They can absorb high loads and can span large areas with little material. Unfortunately, high costs for the complicated formwork avoid a wider use in practice. A new shell construction method called Pneumatic Forming of Hardened concrete (PFHC) was developed at the Institute for Structural Engineering at TU Wien. Within a tight development process numerous material tests, tensile tests, bending tests and two large scale experiments were performed. Now, the Austrian railways (ÖBB) used the construction method to build the deer pass AM2 as concrete shell bridge over the two‐rail track Koralmbahn in Carinthia in Austria. At first a test shell, which now serves as event canopy, was built with the plan dimensions 26.5 × 19.1 m and a height of 4.2 m. Directly after that the main supporting structure, the shell bridge, was built (plan dimensions 36.2 × 38.7 m, height 8.1 m). The first part of the paper which was published in the previous issue summarizes the development process of the new building method. Furthermore, the paper describes the building process of the two shell structures and chosen experiments for the construction process. Finally, the monitoring concept is explained. [ABSTRACT FROM AUTHOR]

Abstract: Current trends in concrete building technology – An outlook with short reviews „The Future is coming by installments. This makes it easier to be able to make it. But it comes. Therefore it's worth looking forward. What does the future hold for Construction?” – With these words the brochure the 100th anniversary of the German Society for Concrete and Construction Technology (DBV) “Outlook for the future” [1] is starting. The author has been Jürgen Schnell in 1998. This paper is dedicated to him on the occasion of his 65th birthday in February 2018 and in recognition of his wide‐ranging achievements for concrete construction as well as for the German Committee for Structural Concrete (DAfStb) and the DBV. In connection to the above words of Jürgen Schnell this paper deals also with an outlook, but oriented towards ta near‐term perspective – concerning several issues currently discussed among experts in concrete construction. [ABSTRACT FROM AUTHOR]

About the design concept for compressive fatigue loading of concrete - Structure of the fatigue design concept For building structures exposed to fatigue loading, especially for those made from high-strength concrete, the fatigue design is decisive for the structural design. Coincident, nowadays new experimental results exist which demonstrate that further developments of the fatigue design concept are expedient and necessary. The safety concept for fatigue design was assigned from the static design concept. From this approach, particularities and challenges arise for the further development of the design concept. In this paper the structure of fatigue design is described. Furthermore, the enclosed parameters are explained and their relevance in the context of safety considerations is discussed. Based on this, outstanding issues are identified for the further development of the design concept. In part 2 of this paper the safety concept of the fatigue verification is discussed and the potential of further developments is pointed out. [ABSTRACT FROM AUTHOR]

'Restless and unsettled' - Gustav Adolf Wayss, a pioneer of reinforced concrete (1851-1917) Gustav Adolf Wayss, editor of the well-known 'Monier Brochure' published in 1887 and founder of some of Germany's most renowned companies for reinforced concrete construction, has a very controversial reputation. Some contemporaries and researchers describe him as a successful engineer who laid the foundations for establishing reinforced concrete. Others characterise him as a poorly trained engineer who, due to his restless and unsettled character, was not successful in his business in the long run. So far, papers on Wayss mainly focus on the time when the Monier Brochure was published. On the occasion of the hundredth anniversary of his death, the present paper puts Wayss' entire life and work into focus in order to provide a new perspective. This case study further offers possibilities to examine how construction history is written. [ABSTRACT FROM AUTHOR]

Abstract: In‐situ tests at the bridge Hammelburg regarding the shear capacity of existing pre‐stressed bridges Part 2: Measuring concept, results of the in‐situ tests, comparison with different theoretical approaches Due to the relatively high average age of the existing bridges, a dramatic increase in traffic volume and axle loads and modified design standards, a realistic prediction of the shear capacity of existing pre‐stressed concrete bridges with little shear reinforcement has become an important topic in research. In 2017 the Chair of Concrete and Masonry Structures of the Technical University of Munich (TUM), supported by the Federal Ministry of Transport and Digital Infrastructure, was able to conduct unique field tests at the 1955 built Saalebrücke Hammelburg. According to systematic strength evaluations many concrete bridges, especially those which have been built prior to 1966, show severe (theoretical) deficits regarding the longitudinal shear capacity. Often the results of the strength evaluation cannot be verified at the real bridges though. The primary objective of the field test was therefore to determine the shear capacity of existing pre‐stressed bridges in order to contribute in closing the gap between calculations and experience for older concrete bridges. In the first part of this article the general assessment of the bridge and the original design concept as well as the conceptual approach, the execution of the in‐situ tests and the used measuring equipment were described. In the present paper the measuring concept and the results of the conducted tests are presented. Furthermore, the results of the in‐situ tests are discussed, and the measured maximum loads are compared to the results of different theoretical approaches and engineering models, respectively. [ABSTRACT FROM AUTHOR]

Abstract: Analysis of the intrusion of de‐icing salt into concrete pavements by a novel test method In recent years the German motorway network has seen an increase in the occurrence of damage in concrete pavements. This has been caused by the use of alkali‐sensitive aggregates. Given the exposure of the concrete pavement to water and the alkaline environment caused by the use of Portland cement during concrete mixing, this environment can lead to an alkali‐silica reaction (ASR) process. This ASR‐damage process in concrete pavements is further exacerbated by the external application of de‐icing salt in winter. Against this background, the evaluation of the intrusion of de‐icing salt becomes of great importance. Until now, the analysis of the intrusion of de‐icing salt was carried out in a wet‐chemistry process on finely ground segments of drilling cores. The disadvantages of this method are the relatively arduous testing process and the limited depth resolution. The alternative application of LIBS (laser‐induced breakdown spectroscopy) offers new possibilities in this context. In this paper, the procedure for the LIBS analysis of sodium and chloride distribution on vertical cut surfaces of drilling cores taken from representative ASR‐damaged concrete pavements is presented. Because the intrusion of de‐icing salt takes place primarily in the cement matrix, the distorting effect of the sodium content in the aggregates was eliminated by an exclusion criteria (namely, the calcium content). The comparable chloride mappings by micro X‐ray fluorescence spectroscopy and wet‐chemical analysis confirm the quality of the LIBS measurements. However, additional investigations are necessary for the quantitative analysis of sodium content in concrete pavements. [ABSTRACT FROM AUTHOR]

Abstract: In‐situ tests at the bridge Hammelburg regarding the shear capacity of existing pre‐stressed bridges – Part 1: General assessment, original shear design, conceptual approach and execution of the in‐situ tests Due to the relatively high average age of the existing bridges, a dramatic increase in traffic volume and axle loads and modified design standards, a realistic prediction of the shear capacity of existing pre‐stressed concrete bridges with little shear reinforcement has become an important topic in research. In 2017 the Chair of Concrete and Masonry Structures of Technische Universität München (TUM), supported by the Federal Ministry of Transport and Digital Infrastructure, was able to conduct unique field tests at the 1955 built Saalebrücke Hammelburg. According to systematic re‐analyses many concrete bridges, especially those which have been built prior to 1966, show severe (theoretical) deficits regarding the longitudinal shear capacity. Often the results of the strength evaluation cannot be verified at the real bridges though. The primary objective of the field test was therefore to determine the shear capacity of existing pre‐stressed bridges in order to contribute in closing the gap between calculations and experience for older concrete bridges. In the present paper the general assessment of the bridge and the original design concept as well as the conceptual approach and execution of the in‐situ tests are presented. In the following part 2 of this article the results of the conducted full‐scale tests will be discussed. [ABSTRACT FROM AUTHOR]

Abstract: Glass beams in analogy with Eurocode 2 – An analogy between pre‐compressed glass and concrete beams: Glass and concrete share some essential material characteristics: Their compressive strength exceeds their tensile strength considerably and both of them fail in a brittle manner. Therefore, it is reasonable to build beams from both materials based on the same principles and to transfer the knowledge from concrete design to the structural use of glass by an analogy study. First, a reference in a historical context between Franz Dischinger und the contemporary structural use of glass is made. A comparison of relevant material properties and structural details as well as a presentation of executed building projects follows afterwards. This demonstrates the applicability of structural details in glass design and shows the relevance to create a nomenclature for glass structures in analogy with the principles of reinforced and prestressed concrete design. Additionally, the paper introduces “Spannglass Beams” that entail a post‐tensioned steel cable to counteract initial cracks, uplift the member and ensure a sufficient post‐fracture bending capacity. Advanced problems such as the loss in tension force or a proof of feasibility of those structures is addressed. In conclusion, this makes the expertise from concrete design available to create novel and efficient load‐bearing glass structures. [ABSTRACT FROM AUTHOR]

Abstract: Fire design of reinforced and prestressed concrete columns – To practical use of Method A in DIN EN 1992‐1‐2 This paper provides practical guidance on the fire design of reinforced concrete columns using Eurocode 2 (DIN EN 1992‐1‐2) Method A by giving explanations, diagrams and extended tables for columns with fire exposure on more than one side and on only one side. For columns fire exposed on one side extended tabulated data are given, which were calculated with the Advanced calculation method. [ABSTRACT FROM AUTHOR]

Abstract: Digitalization of structural civil engineering Digital transformation will influence civil engineering as well as other areas of life and industry. For this reason, selected developments and drivers of digitalization will be presented after a contextual classification. In the following they will be examined with a specific view on civil engineering in order to analyze and evaluate some possible effects. Developments in the areas of Building Information Modeling (BIM) and Virtual Reality are taken up as well as the impact on the construction processes or the changing role of stakeholders. The paper gives an overview of the state of digitalization and further points out possible developments with corresponding opportunities and risks. Herby focus is put on structural civil engineering and solid constructions, e.g. concrete or masonry. [ABSTRACT FROM AUTHOR]

Im vorliegenden Beitrag wird über besondere Fragestellungen und Lösungen bei der Tragwerksplanung und der Rohbauausführung des neuen Henninger Turm in Frankfurt berichtet. Bei dem 140 m hohen Henninger Turm handelt es sich um ein schwingungsanfälliges Bauwerk, welches besondere Anforderungen an die Planung der aussteifenden Bauteile, die Gründung und die Modellierung des Tragwerks stellt. Zunächst wird dargestellt, wie der anspruchsvolle Entwurf der Architekten (MSW - Meixner Schlüter Wendt) bei einer maximalen Raumausnutzung möglichst wirtschaftlich tragwerksplanerisch umgesetzt und die Kombination der unterschiedlichen Gebäudearten von Turm und Sockel fugenlos realisiert wurde. Weiterhin werden besondere Lösungen bei der Bauausführung aufgezeigt, mit denen es gelang, den Rohbau des gesamten Henninger Turm in etwas mehr als 1 ½ Jahren fertig zu stellen. Structural design and construction of the new Henninger Turm The following paper covers special issues and solutions on the structural design and construction of the new Henninger Turm in Frankfurt. The 140 m tall high-rise building susceptible to structure oscillations demanded special efforts in the design of the bracing structural elements, the foundation and the structural modelling. The first part of the paper focuses on how the ambitious architetural design by MSW - Meixner Schlüter Wendt was adopted in a maximum space and cost-efficient structural design in which the contrary building types, high-rise building and base structure, were combined jointless. The second part shows special construction solutions due to which the complete shell construction could be completed in somewhat more than 1 ½ years. [ABSTRACT FROM AUTHOR]

This paper deals with the repair, strengthening, improvement and widening of the Nels River Bridge situated in the Mpumalanga province of South Africa. The paper outlines the design complexities and discusses the solutions and the construction techniques followed that resulted in a successful project. [ABSTRACT FROM AUTHOR]

Abstract: Reinforcement made of carbon fiber reinforced concrete In the research project C3 – Carbon Concrete Composite new reinforcement systems made of carbon for concrete construction are developed. In that case, mesh‐like and bar‐shaped reinforcements are examined. Until now, these carbon reinforcements predominantly contain a plastic matrix that combines thousands of carbon filaments into one cross section. Scientists of the HTW Dresden and the TU Dresden are currently pursuing an approach to replace this plastic matrix with a mineral matrix to further improve the properties of the carbon reinforcement. In this paper, the basic principle of this new type of reinforcement for concrete construction as well as associated tests are presented. This should give an impulse for further research in this field. [ABSTRACT FROM AUTHOR]

Abstract: Contribution concerning load bearing behaviour of CFRP confined RC columns with circular cross section Beside CFRP (Carbon Fiber Reinforced Polymer) strips, which are successfully utilized as an additional glued reinforcement in tension zones of existing reinforced concrete (RC) members, CFRP sheets gain more and more attention in terms of strengthening and retrofitting. Those sheets are capable to increase the bearing capacity of RC slaps and beams significantly. Furthermore, CFRP sheets can improve the capacity of RC columns, too. In doing so, the connection of concrete surface and CFRP sheet is enabled by an epoxy resin (CFRP confinement). Thereby, concrete's lateral expansion is efficiently restricted in cases of imposed axial compressive deformation; therefore, the elastic CFRP resisting response generates an ever increasing lateral compressive stress state on concrete, leading to structural upgrade of the member core to provide a remarkable higher concrete strength and sufficient deformability. Regarding CFRP confinement design in Germany, this paper presents a brief overview concerning the state‐of‐the‐art, and it introduces a design procedure utilized in German DAfStb‐Guideline „Strengthening of concrete structures with adhesive bonded reinforcement“. Furthermore, some recent research efforts and findings to improve the current model will be offered, too. [ABSTRACT FROM AUTHOR]

Abstract: Calculation of the deflection of reinforced concrete members – general procedures for slabs and beams This paper introduces the fundamental procedures to calculate the deflection in the cracked state taking into account creep and shrinkage. A range of different methods with various degrees of accuracy is presented for beams and one‐way slabs, based on the guidelines of EC2. For simple systems these methods can also be used for hand calculations, permitting a high degree of control over the procedure. Subsequently, the usually rather complex calculation of deflections caused by the shrinkage of the concrete is considered in more detail. For a selection of systems, diagrams containing coefficients for a more efficient estimation of shrinkage deflections can be derived. Furthermore, the cracked state deflection of concrete slabs is addressed more closely. It can be calculated with the help of suitable finite element programs or using simplified manual procedures. The basic principles can be transferred from the previously considered beam structures. However, other influence factors have to be addressed, such as the procedure to reduce the flexural stiffness and the redistribution of the internal forces caused by cracking. [ABSTRACT FROM AUTHOR]

Abstract: Fatigue strength of RC beams without transverse reinforcement under cyclic loads The shear design of RC members without transverse reinforcement (e.g. slabs, bridge decks, footings of wind energy plants) for fatigue loads is based on empirical approaches, which had been rarely validated by experiments. This paper presents theoretical, experimental and numerical studies, which aim to give a better understanding of the load transfer in RC members without web reinforcement under static as well as cyclic loads. Furthermore, the approach of Eurocode 2 will be examined. [ABSTRACT FROM AUTHOR]