Two-component blend to produce clinker
With the transition in 1995 to the new standards of the thermal resistance of building envelopes the walls of residential buildings began to be constructed with new technologies using effective thermal insulation materials. Today most of the exterior walls of residential buildings are multilayer structures, in which a facial hollow brick is most widely used for outer facade. After a few years of operation of such buildings numerous shortcomings of the exterior facades have been identified - the presence of a long cracks a few floors long on the surface of the masonry, partial destruction of the outer surface of the brick face exposing brick voids, complete loss of masonry's fragments exposing insulating layer. One of the main causes of these defects - low maintenance properties of the facial brick associated with a thin brick voids' outer wall (16 mm) and low frost resistance. In this connection, the designers and builders are encouraged to use for the front of the masonry facades more durable and frost-resistant bricks with a thicker outer wall and smaller emptiness. A clinker facade brick has these properties but is almost not produced in Russia because of the lack of conditioned clays to produce it, absence of tried and true formulas and technology. In this regard, the authors of this article evaluated the possibility of producing clinker on the basis of a two-component mixture, in which the main component is fusible clay widespread throughout Russia and traditionally used in the conventional brick production and scarce fire clay as the additive. Laboratory tests proved the possibility of obtaining high-grade clinker with strength from 600 to 1000 on the basis of two-component mixtures containing fusible Kalininskaya clay as the main part and refractory Nizhny-Uvelskaya clay as an additive. It is proved that the bricks of «600», «800» and «1000» grades can be produced if the ratio of the specified clays (Kalininskaya to Nizhny-Uvelskaya) equals 90:10, 75:35 and 50:50 wt.%, respectively. Thus the authors solved the topical problem of high-strength and frost-resistant clinker, which provides long life for facades of modem residential buildings.