Chemo-Mechanical AGIng of Cementitious materials (MAGIC)
Increase the confidence in Chemo-Mechanical simulations by reducing uncertainties in input data and understanding of key coupled
MAGIC aims to:
• quantify the chemo-mechanical multi-scale evolution of cementitious materials under the chemical degradation expected in repository environments. To identify the main reactive pathways at the repository scale during the re-saturation phase and at the saturated conditions.
• obtain a reference chemo-mechanical model of Portland and low-pH concrete exposed to relevant disposal environments, considering representative boundary conditions.
• estimate the extent of the impact of microbial activity on concrete properties (low-pH and Portland cement) in partially and fully saturated media.
Nowadays, most of the experimental data are limited to the short-term material evolution and the long-term mechanical integrity of the cementitious material remains largely unknown. Following knowledge gaps have been identified:
• What is the impact of various chemical degradation phenomena on the mechanical behavior of massive cementitious materials?
• What is the impact of microbially induced processes in the chemo-mechanical behavior of cementitious materials? Do these processes change the chemical evolution which is expected to occur without microbiological activity?
• How to model the long-term mechanical behavior of cementitious materials during hydraulic transients or fully saturated media with respect to the chemical evolution with and without microbial activity?
• How to achieve a comprehensive model based description of the multi-scale modelling process?
Major highlights (June - Nov 2022)
- The initial SOTA of MAGIC was delivered in November. 29 persons worked on the document to give a detailed overview of the current knowledge about cementitious materials in DGD.
- All experimental and modelling works are in progress. A part of studies are well advanced with interesting experimental results especially on low-pH cementitious materials exposed to Mg disturbances with quantitative measurement of chemical and mechanical changes.
- Significant changes of mechanical properties (deacreasing of Young modulus) were also measured on low-alkali cement (LAC) concrete close to the interface with Opalinus clay.
- Main part of results will be acquired during the second part of the year 4 and the first semester of year 5.
- The existing data (previously mentioned) will be useful to test the modelling under development.