Effect of accelerated carbonation on electrical resistivity and microstructure of clinker-slag-limestone cement based concretes

Low-clinker concretes offer potential for reducing CO 2 emissions of concrete and construction industries. However, it is important to consider the increased risk of corrosion resulting from carbonation. This article aims to assess the effect of accelerated carbonation on the electrical resistivity of concrete, which is closely related to the risk of corrosion propagation. An experimental study was conducted on six concretes based on binary binders (Clinker—Limestone and Clinker—Slag) and ternary binders (Clinker—Slag—Limestone) to characterize their resistivity and porosity in both non-carbonated and carbonated states. This study is complemented by microstructural characterization of cement pastes with the same water-to-cement ratio and containing the same binders, in both non-carbonated and carbonated states, using techniques such as TGA and XRD. The results show that carbonation significantly affects the electrical resistivity of concrete, with variations up to + 305%/− 70%, depending on the binder composition, especially the Limestone-to-Slag ratio. The changes observed can be partially attributed to the evolution of the pore structure due to carbonation. Further investigation into the evolution of the pore solution caused by carbonation is necessary to fully comprehend the observed changes.