Beschreibung
This dissertation addresses the overarching question of how fiber orientation and targeted material placement can be actively controlled and exploited to enhance the performance and efficiency of SFRC. To this end, a mechanized casting device was developed to deliberately steer fiber alignment. Preliminary trials demonstrated its feasibility and robustness, enabling the production of specimens with a wide and reproducible range of favorable and unfavorable orientations. Building on this, systematic tests established the quantitative correlation between fiber orientation and residual flexural tensile strength, showing that favorable alignment can more than double the post-cracking capacity compared to unfavorable orientation. A comparison of measurement methods identified electromagnetic induction as a practical and reliable tool for large-scale quality control, while image analysis and X-ray computed tomography provided a detailed validation. The methodology was then transferred to structural scale through the production and testing of large SFRC plates subjected to a double splitting loading scenario. Optimized configurations with curved layers of high-performance SFRC, with fibers steered along isostatic tensile stress trajectories, achieved superior crack control compared to conventional reinforcement strategies. The successful application of fresh-on-fresh layered concretes confirmed that stable interfaces can be achieved without any internal divider. Additional validation came from beams and cubes extracted from the plates, which showed orientation and performance levels consistent with the benchmarks established at material scale.
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