Chloride binding and transport characteristic of phosphoaluminate cement-based marine sand coating subjected to marine environment

摘要

Marine sand with more or less aggressive Cl has received considerable attention because of the depletion of river sand resources; however, it should be treated to avoid harmful effects on reinforced concrete. Phosphoaluminate cement (PAC)-based coating is a promising method to treat marine sand, and it can potentially solidify Cl . In the experiment, the characteristics of Cl binding and transport of PAC-based coating material were thoroughly investigated. The results indicated that the characteristic of prohibiting Cl transport by PAC was more effective than using Portland cement in terms of erosion depth and free surface Cl concentration. The PAC-based coating material can bind large amounts of Cl efficiently by chemical bonding and improve the electrochemical performance of steel bar. In concrete, Cl can be bonded by PAC-based marine sand coating. Further, PAC-based marine sand coating can prohibit the transport of Cl , and significantly improve the resistance to chloride penetration of concrete. (C) 2021 Elsevier Ltd. All rights reserved.