Ion corrosion behavior of tunnel lining concrete in complex underground salt environment

In this study, the ion corrosion behavior of tunnel lining concrete in complex underground salt corrosion environment was investigated using a self-designed corrosion simulation test device in a complex underground environment. The results indicated the following: the corrosion of flowing water leads to the dissolution of lining concrete, and the load promotes the development of cracks in the tensile area of lining concrete and inhibits the development of defects in the compression area, resulting in the transmission speed of chloride and sulfate ions in lining concrete under different corrosion conditions given as follows: concrete in tensile zone under flowing corrosive solution and load > flowing corrosion solution acting alone > static corrosion solution > concrete in compression zone under flowing corrosive solution and load. When the flowing corrosion solution alone and flowing corrosion solution and load act on the concrete in the tensile zone, the pore volume fraction of gel decreases and the macropore volume fraction increases. Under the combined action of static corrosion solution and flowing groundwater and load, the pore volume fraction of gel in the pressurized area increases and the harmless pore volume fraction decreases.