ENCLOSURE OF GUARDED ROOM FOR KEEPING OF VALUES Russian patent published in 1998 - IPC

FIELD: keeping of values of banking, museum and other similar institutions. SUBSTANCE: enclosure of guarded room, including ceiling, walls and floor, is made as a closed structure of concrete, dispersedly reinforced by steel fibres and has at least two reinforcing fabrics. The fabric cells are shifted relative to one another in both directions in the plane of the structure by a value equal to half the cell dimensions. The fibre length is within $$$, where $$$ - maximum dimension of grains of concrete coarse aggregate, S - reinforcing fabric cellular dimension. Ratio $$$ is determined from condition $$$, where $$$-fiber diameter, $$$ - volume (relative) content of fibres in concrete, K - coefficient, whose value for fibres with relative length $$$= 50-75-100 is taken to be equal to 4.24-4.85-5.35, respectively. The fibre diameter is taken from condition $$$ for aggregate fractions with grain coarseness $$$ within 15 to 20 mm, or from condition $$$ for aggregate fractions with grain coarseness $$$ less than 15 mm. Steel fibre length-to-diameter ratio may be taken at least 1.55 $$$ for shaped fibres, or at least $$$ for smooth fibres, where $$$-strength of fibres (their ultimate rupture strength), $$$ - concrete compression strength. EFFECT: improved technology of erection of enclosures, enhanced resistance to burglary. 2 cl, 6 dwg