Complex bridge structures assembled by utilising facetted planar elements made of carbon-reinforced ultra-high performance concrete - Graph-based modularisation and trajectory-sensitive production

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Bridge structures are currently mostly characterised by the fact that essential work is carried out on the construction site and the structure is designed/erected individually, either as a whole or from large-scale individual prefabricated members which are connected on site using conventional joining techniques. This results in long construction times, the quality depends largely on the weather conditions and the skills of the personnel used, and an adaptation, replacement of individual components or even temporary use and subsequent dismantling are not possible or only at great expense. Even when using prefabricated parts, no actual modular design with industrial flow production is possible due to the large individual weights, the low degree of repetition and the comparatively high manufacturing tolerances. The basic idea of the research project is to consistently further develop the modularisation principle by using facetted structural elements made of carbon-reinforced ultra-high performance concrete for bridge construction. The approach, comparable with the geometric division of structures into finite elements, is characterised by a systematic division of the overall system into basic partitions ("modules") which are easy to produce. The boundary conditions to be adhered to here result on the one hand from loads and the structural capacity (especially in module joints), on the other hand from the requirements of manufacture and assembly. The complex problem of optimisation can only be solved by a further development of computer-aided methods and the conception of efficient modules, their production and the associated (variable) joining technology. Therefore, suitable joining methods and individual modules made of ultra-high performance concrete adapted to internal stresses are developed and investigated theoretically and experimentally in the project. Short carbon fibres are used as reinforcement, which can be aligned to the stress paths by module production in 3D printing and thus enable a highly efficient load-bearing behaviour. In addition, the modularisation process is systematically analysed and further developed so that segmentation is largely automatic. On the one hand, the boundary conditions resulting from module production and assembly are to be taken into account, and on the other hand, the module arrangement is to be optimised with regard to static aspects. The semi-automated decomposition into modules is to take place by using a rule-based graph substitution system or a graph grammar, so that on the basis of the initial geometry and boundary conditions different arrangement possibilities of the variable basic modules are generated. Both the conceptual and structural-mechanical investigations as well as the investigations for semi-automated modularisation may provide valuable contributions to the overall goals of the SPP.