Sydorov O. Quality management of the natural stone face surface using physical and chemical methods

Natural stone creates a certain flair of urban development, gives buildings special significance, helps to highlight the role of public buildings in urban ensembles, emphasizes their monumentality and durability. It is perfectly combined with new architectural forms, where its properties are evaluated in a new way. An important factor in choosing natural stone is the uniformity of facing products in color and hue. Sometimes, it is not possible to make one batch of natural stone uniform in color and shade. Because, even within a single block of natural stone, slabs have different shades of color. The color of natural stone of the same brand can change within a single quarry. It is known that with the depth of the quarry, the color of natural stone darkens, and the grains of minerals decrease in size. However, there is a problem with choosing natural stone for the restoration of buildings, since most natural stone deposits have ceased to exist or quarries have exhausted the reserves of this trademark of natural stone. The restoration takes into account anthropogenic activities that cause air pollution and is one of the main factors responsible for the destruction of archaeological and historical stone monuments. When corrosion occurs, natural stone changes its color. In this case, sections of the facade of buildings made of natural stone that are being restored must be given a similar color to the entire facade. Otherwise, the restored part of the facade will show up visually.