Sulfates Type and Effects in Portland Cement

Although the sulfates content of Portland cement is slight, there are many types and the corresponding complex functions of sulfates in Portland cement.It is thus important for Portland cement production and application to distinguish the types and functions of the sulfates.Based on the results of recent studies, sulfate sources of Portland cement in the production and some aspects concerned in future work were discussed.It is indicated that the content of the original sulfates in the clinker and blended materials increases considerably.The total content of SO₃ incement, which is limited usually by the existing standards and regulations, is controlled a a low level in the cement production.With the development of test technology, it is possible to analyze the roles of different sulfates in cement.It is suggested that the theoretical and applied investigations on sulfate classification and function in Portland cement for the cement application should be strengthened, thus improving the whole performance of cement and enhancing the utilization of the rich sulfatebearing industrial slags in Portland cement production.