ANALYSIS OF PHASE STRUCTURE OF THE CERAMIC BRICK OF OVER FIVE HUNDRED YEARS

Statement of the problem. Problems of durability of constructions and buildings and decreasing expenses for their major repairs are rather actual and determined by the scales of industrial, hous-ing and individual construction. The aim of the given research is using the Mossbauer spectrosco-py to establish electron microscopic and x-ray phase methods of the phase structure analysis of brick of over 500 years, as it is the phase structure that mainly defines the operational properties of products.Results. The research showed that in the brick of the Nizhniy Novgorod Kremlin, mullite instead of finest needles crystallizes as isometric grains, short and long prismatic crystals. Mossbauer spectra of absorption showed that in the studied ceramic brick, hematite was found on the surface, while magnetite was in the internal layer.Conclusions. Based on the research made, it is assumed that clay was used in the production of brick which contained not less than 15 % of Al2O3, 5 to 8 % of Fe2O3 8 to 10 % of СаО and 2 to 5 % of R2O. The research showed as well that either ceramic brick burnt at the temperature of no less than 1050 оС was used in the construction of the Nizhny Novgorod Kremlin, or alkaline and alkaline-earth additives were introduced into the masses.