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The bond behavior between reinforcement and concrete has a significant influence on the load‐bearing behavior and serviceability of the composite material. This paper focuses on the characterization of the bond behavior between fine‐grained concrete and mineral‐impregnated carbon‐fiber reinforcement. In this study, the influence of different bond lengths on local bond behavior was experimentally investigated. To predict the bond stress along the bond length, an analytical bond stress‐slip model was specified, and its model parameters were determined based on the experimental tests using an iterative approximation approach. Based on the defined bond stress‐slip model, a numerical bond model was developed and adjusted for the first time. A three‐dimensional (3D) finite element analysis (FEA) allows the simulation of the local bond stress along the bond length. Finally, the results of the 3D FEA were compared with the results of the experimental investigations to validate the developed numerical model. [ABSTRACT FROM AUTHOR]

This work was dedicated to the simulation of fiber composite structures consisting of carbon fibers and mineral impregnation. The aim of this study was to generate a micromodel that predicts the properties of a mineral-impregnated carbon fiber reinforcement. The numerical characterization was based on the discrete microscopic modeling of the individual phases using a representative volume element. In addition, the stochastic nature of the fiber strength, the anisotropic damage mechanisms of the brittle matrix, and the non-linear bonding behavior between the filaments and the matrix were considered in the material models. The material models were adjusted based on the literature sources and our own experimental investigations. This was followed by the validation of the representative volume element, quantifying the evolution of stiffness and damage under longitudinal tensile loading. The numerical results of material stiffness, as well as the tensile strength of the representative volume element, were compared with the results of the experimental investigations. To verify the robustness of the numerical model, significant model parameters were subjected to a sensitivity analysis. [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]

Industry Standard for carbon reinforced concrete ‐ with standardization into a resource‐efficient way of construction Making construction more sustainable – that is the challenge! So manage this, a fundamental transformation of construction industry is necessary. The material carbon reinforced concrete makes a substantial contribution in this regard. With the aim of creating the necessary foundations for a climate‐conscious construction method, in January 2022 the research project Industry Standard Carbon Reinforced Concrete (ISC) was launched, funded by the BMBF as part of the program RUBIN (Regional Entrepreneurial Alliances for Innovation). Missing standards and guidelines for using carbon reinforced concrete in new construction are being drawn up in this project. The ISC will increase the acceptance and the economic efficiency of carbon reinforced concrete. Entry barriers will be removed for planners, builders, manufacturers and contractors. In this paper, the project partners, the objectives of the ISC, selected research activities and results are presented and an outlook on further activities is given. [ABSTRACT FROM AUTHOR]