Assessing the critical chloride threshold of conventional reinforcement embedded in alternate cementitious systems

Abstract

Alternate cementitious materials (ACMs), such as calcium aluminate cements (CAC) and calcium sulfoaluminate cements (CSA), contain lower embodied energy and carbon footprints when compared to traditional ordinary portland cement (OPC) systems. However, the sustainability of these ACM systems can be nullified by a lack of durability and/or resiliency. To develop an understanding of the durability and long-term performance of the ACMs, standardized test methods are required to assess their corrosion resistance. OCcrit, a new test method that was developed at Oregon State University, is a fast and reliable method to study the corrosion performance of cementitious systems. This method, however, has only been evaluated using OPC systems. In the first part of this study, testing was performed to potentially extend the applicability of this new test method to CAC and CSA systems, thereby increasing its robustness and value. In the second part of the study, the updated OCcrit method was used to assess the critical chloride threshold of steel reinforcement embedded in CAC and CSA systems. Results indicate that CSA specimens exhibit lower critical chloride threshold values than OPC and CAC specimens and the critical chloride threshold of the CAC seems to be dependent on the water-cementitious materials ratio.