Durability of concrete subjected to dry-wet cycles in various types of salt lake brines

Abstract

In view of the serious erosion of concrete in salt lake regions, the properties (the corrosion resistance coefficient, relative dynamic elastic modulus, and spalling amount) of concrete, including ordinary Portland concrete (OPC) and high-performance concrete (HPC), subjected to dry-wet cycles in a variety of salt lake brines, were investigated. Moreover, the microstructures of the concrete were analyzed by X-ray diffraction and scanning electron microscopy in detail. The results showed that the performance of HPC was notably better than that of OPC in salt lake brines. The corrosion degree of OPC was the largest in the Qinghai salt lake brine, and the corrosion degree of HPC was the largest in the Sinkiang saline lake brine, while the corrosion degree of both OPC and HPC was the smallest in the Inner Mongolia salt lake brine. Additionally, no matter what salt lake brines were used, the deterioration trend of concrete subjected to dry-wet cycles in salt lake brines progressed from the surface to the interior. Furthermore, the active admixture had a positive influence on crack repair and performance improvement of HPC, and HPC with active admixtures could be able to withstand the harsh environment of salt lake regions.