In situ measurement of the transport processes of corrosive species through a mortar layer by FTIR-MIR

Fourier Transform Infrared Spectroscopy with Multiple Internal Reflection mode (FTIR-MIR) has been applied for the first time to in situ follow the transport process of corrosive species through a mortar layer and their accumulation at the internal reflection element (IRE)/mortar interface. The kinetic processes of H2O and SO42− transport through the mortar specimens with different curing time were studied. The results indicated that H2O and SO42− presented different transport behavior through the mortar layer. Adding Na2SO4 into distilled water resulted in a slower transport rate of H2O. And the curing time of mortar had a significant effect on its permeability. The in situ FTIR-MIR measurement was proved to be able to provide reliable information on the interface and the transport process through mortar.