Self-sufficient Reactive Transport Modelling in Cement-Based Materials with Low-Carbon Footprint

Abstract

A self-sufficient multi-species and multi-mechanism reactive-transport modelling framework for concrete is presented. The modelling framework is “self-sufficient” as its input data only include the chemical composition of the cementitious materials (e.g., cement, supplementary cementitious materials, etc.) and mixture proportions of the analysed concrete (e.g., water-binder ratio, aggregate content). The approach allows the calculation of transport properties of concrete using the formation factor of concrete, which can be calculated using the recently developed pore partitioning approach for concrete. This approach extends the Powers-Brownyard model to include concrete incorporating supplementary cementitious material and combines it with thermodynamic calculations to obtain electrical properties of concrete. These thermodynamic calculations predict pore solution composition, pore solution resistivity, pore volumes, and reactions between the solid and ionic components of the cementitious matrix such as pozzolanic processes, hydration, and chloride binding. The framework allows the solution of reactive-transport equations with minimal input data that is easily accessible to assess key transport questions related to service life such as ionic movement, chloride ingress, and time to corrosion. The approach eliminates the costly need to determine the transport properties of concrete experimentally, which are, in most cases, inaccurate because they do not represent the actual transport mechanisms that are intended to be simulated. This modelling framework has the potential to be used in conjunction with performance specifications currently being developed in the United States.