On the Surface of Concrete Modified with Ferrous Sulfate

When ferrous sulfates are mixed with cement slurries in setting processes of cement paste and aggregates, iron-rich layers are produced on the surface of the concrete. X-ray fluorescence spectrometry, X-ray analysis, and electron probe microanalysis have been applied to the cross section of the surfaces.The data indicates that iron and sulpher are dispersed to the surface layers ranging from the top of surface to 500μm and that amorphus iron oxide layers of 50μm in thickness are formed near surfaces and calcium sulfates are formed in next to the iron oxide layer.