A combined numerical and experimental study on the mechanical aging of high slag content High Performance Concrete

This paper presents a study that combines experiments and numerical modeling to investigate the mechanical aging of plain High-Performance Concretes (HPCs) containing high amounts of slag. The primary objective of this research is to introduce a novel methodology for validating models that utilize advanced and non-conventional materials. This approach goes beyond the traditional method of comparing experimental trends with numerical simulations, offering a new perspective in the field. This is particularly relevant given the increasing efforts of the cement and concrete industry to achieve zero-carbon objectives. These efforts result in the formulation and use of cementitious composites containing increasing amounts of a variety of supplementary cementitious materials, for which the existing performance prediction models need to be updated and validated. To achieve this goal, one of the HPC mixes used in the ReSHEALience project (H2020 project), containing 50% by volume of ground granulated blast furnace slag, was tested at different ages to understand how its strength and stiffness change over time. The experimental tests were then simulated using a discrete numerical model, Multiphysics-Lattice Discrete Particle Model (M-LDPM), which was updated to account for the distinct material aging and evolution of mechanical performance that occurs when using high slag content. The comparison between the experimental and numerical results is not just a means of assessing the model’s predictive capability. It is a crucial step in validating a combined experimental and modeling framework, which we believe is essential whenever cementitious composites with innovative/non-conventional constituents are used for structural purposes.