Restoration of plinthoi and bricks in mediaeval Novgorod
The paper presents the results of analysis of the composition of the black mass noted on the surface and filling fissures and cavities of plinthoi and bricks in mediaeval Novgorod. The investigations were conducted using an opticoelectronic polipolarization system designed at the IHMC RAS. As a result it was established that the black substance consists of clay and finely ground shells with molluscs. The mass thus obtained was fired at the temperature of 600-750 °C and served for restoration of plinthoi and bricks with the purpose of their further use in construction.