A Multiscale Multiphysics Platform to Investigate Cement Based Materials

Abstract

As the owner of an extensive fleet of power plants, EDF is committed to the safe and sustainable long-term operation of massive civil engineering facilities. This involves inspection and auscultation of the current state of the structure, and structural computations to anticipate durability and to test mitigation strategies. Both require relevant material properties for the concretes at stake, which often cannot be measured directly, for either practical or economical reasons. The design of next-generation plants involves concrete mixes not yet existing, but whose behavior is required by structural engineers, to ensure that each facility correctly fulfills its function. Investigating the properties and behavior of cement based materials is thus of paramount importance. In addition to classical lab experiments, EDF is currently developing a “virtual lab” dedicated to concretes. It is based on a multidisciplinary platform, built taking advantage of recent advances in cement based materials modeling. A multiscale and multiphysics approach is adopted: materials are morphologically described down to the scale where the physical processes can be uncoupled, and where elementary constituents whose properties are mix independent can be identified. Then, upscaling techniques are used to estimate properties and behaviors at the engineering scale. The platform, named Vi(CA)2T, includes toolboxes to upscale mechanical behavior (stiffness, creep) and transport properties (dielectric permittivity). It adheres to an open design: new physics are straightforward to add. After discussing the platform design and the challenges raised by such an approach, examples of applications at EDF are presented.