Influence of brine on hydration reaction of calcium sulfoaluminate and slag blended cement

Abstract

A study was conducted to develop an eco-friendly, low-carbon cement and to find new applications for waste brine discharged from seawater desalination plants. As the binder, a binary blended binder of calcium sulfoaluminate type K expanding agent (CSA) classified as ACI 223R-10 and slag was used. The CSA content was 0%, 10%, 20%, and 30% substituted. For mixed water, freshwater and brine were used. The brine promoted the hydration reaction of the CSA to promote the formation of ettringite and increased the pore content of 50 nm or less to form a dense matrix, thereby improving the mechanical performance. The 20% CSA sample exhibited the best strength for freshwater and brine samples. However, for the 30% CSA, a decrease in strength was measured, which is due to the excessive expansion effect. Mixing the CSA–slag-blended cement and brine suggests the possibility of its application as a new construction material. © 2023 The Authors