This project proposes the development of Modified Engineered Cementitious Composites (MECC), optimized for structural repair applications. The objective is to identify and validate innovative mix designs that retain key advantages, namely high ductility, sufficient tensile strength, crack control, workability, and high durability in the cracked state in terms of chloride permeability, while significantly reducing environmental impact and cost. The research will employ a multi-scale methodology linking composite behavior with material micromechanics. This integrative approach goes beyond conventional studies by defining performance through a global index that balances mechanical properties, crack management, and carbon emissions. Key innovations include the incorporation of environmentally friendly binders in varying proportions and the use of cost-effective fibers of different types and sizes. Rather than prescribing a single material solution, the goal is to identify combinations that lead to overall satisfactory behavior suitable for field deployment.
As part of TRR277, this project aims at providing a modelling and simulation approach across the scales starting from consistent material models for bulk deposited additively manufactured concrete and its interlayers towards a reduced substitute model for fast simulations of complex geometries on the part-scale.
The proposed project aims at advancing the modeling of reactive transport phenomena in partially saturated porous materials by combining numerical models and in-situ X-Ray Computed Tomography (XRCT) experiments. Reactive transport through porous media affects a wide range of relevant engineering materials, such as battery components, soil or rock. Whilst it is the applicants’ primary objective to push the boundaries of advanced numerical and experimental characterization of such complex materials in general, cementitious materials serve as an example class of reactive porous materials in this project. To investigate the diverse electro-chemo-mechanical interactions in cement mortar, in-situ 3D imaging and continuum mechanical modeling and simulation methods are to be combined and further developed. More specifically, the purpose is: 1. Extending the in-situ XRCT 3D imaging setup existing in the PI:s’ lab. 2. Enhancing the multiphysics modeling framework to incorporate electro-chemo-mechanical interactions. 3. Developing necessary computational algorithms within the finite element framework and integrating them into the open-source FE package Ferrite.jl. By this, the following scenarios shall be investigated: 1. Capillary suction with chemo-mechanical interactions in unfractured mortar. 2. Capillary suction with chemo-mechanical interactions in fractured mortar. 3. Electrically accelerated ion migration in fractured mortar. 4. Corrosion-induced fracture (2nd funding period). By closely interlinking time-resolved in-situ experiments for 3D imaging with continuum mechanical modeling and simulation approaches, the project makes an important contribution to deepening our understanding of the diverse multiphysical processes in this technologically highly relevant class of materials.