Diffusion And Critical Chloride Threshold In Reinforced Fly Ash Concrete

Diffusion And Critical Chloride Threshold In Reinforced Fly Ash Concrete (ASM S3 Contest - Juan Bosch Giner - Graduate) Fly ash concrete is gathering huge attention in the last decade as an alternative to ordinary Portland concrete, due to its lower greenhouse emissions (reduction of 80%). Understanding the corrosion mechanisms associated with the fly ash use, a new standard can be created in order to assess corrosion risk. Localized corrosion of the reinforced concrete caused by chloride attack occurs in two different stages, initiation and propagation. The first stage consists of the penetration of the chloride ions till reaching the reinforcement surface and thus, breaking its passive layer. This passivity breakdown is promoted by the accumulation of chlorides above a critical concentration threshold. In this work, different fly ash reinforced concrete mixes were studied in order to determine the critical chloride threshold. The chloride corrosion threshold was determined by monitoring the corrosion potential (Ecorr) and corrosion current density (icorr) values as well as analyzing the chloride content in the interface. In order to determine the chloride diffusion coefficient, cylindrical samples were cured under the same conditions and then tested according to both ASTM standards, C1152 and C1556. Presented by Juan Bosch Giner, a graduate student from The University of Akron and 2020 participant of the ASM Student Speaking Symposium (S3). To learn more about the ASM S3 Contest, please visit www.asminternational.org/virtual-presentation-contest