The Influence of Barium Sulphate and Barium Carbonate on the Portland Cement

Shielding of different types of radiation should be studied these days when there is a great development in the field of nuclear science. Barium ions can shield different type of radiation, therefore, by incorporation of barium ions into the system of Portland clinker, a binder with shielding properties can be made. The work is focused on influence of barium ions on the formation of Portland clinker and its properties. As a source of barium, barium sulphate and barium carbonate were added to raw meal. Clinkers and cements with a different amount of barium were prepared and the effect of barium on the clinker and cement properties respectively was studied. By Rietveld analysis (using X-Ray diffraction) and microscopic point counting method, the ratio of clinker phases was studied. With increasing amount of barium, the alite: belite ratio was decreasing and the amount of free lime was increasing. Sulphate decelerates the decreasing ratio and causes grow of alite crystals to great dimensions. The presence of barium in different phases was observed by SEM with EDS. The highest amount of barium was found in belite and clinker melt. In clinker melt, conglomerations of barium were formed. Furthermore, a difference in formation temperature of clinker phases was observed and some elementary tests were done on prepared cements according to the European standards.