BRICK Russian patent published in 2009 - IPC C04B33/02 

FIELD: construction.

SUBSTANCE: brick contains through-cavities arranged between its countersurfaces with the free area of one of the cavities varying lengthwise. Such a cavity contains at least two lengthwise sections both characterised by the cavity free area first gradually decreasing to reach the minimum value as per the specific section and subsequently gradually increasing to reach the maximum value as per the specific section. The brick ultimate compressive strength "σ" is equal to a value defined under the following condition: 7.0 MPa<σ≤35.0 MPa. The brick is fabricated of clay and sand, their wt % being as follows: clay - 75-59; sand - 25-41 with the clay containing the following components, with concentration per 100 g of clay wt %: SiO₂ - 56.05-64.12; Al₂O₃ - 23.47-24.99; Fe₂O₃ - 2.47-3.56; impurities - the rest. The brick length, width and thickness vary within the range of 200-300 mm, 100-150 mm and 30-140 mm accordingly.

EFFECT: optimisation of the brick heat exchange with the environment during drying, burning and cooling; enhanced power of the mortar cohesion with the cavity surfaces and the brick; improvement of the brick sound insulation properties.