INDIRECT REINFORCEMENT Russian patent published in 2000 - IPC

FIELD: construction industry, concrete and ferroconcrete structures of column type. SUBSTANCE: indirect reinforcement is made of several separate closed shells anchored on forms as member is treated with concrete and forms rise. Shells are produced from plastic material, for example, polystyrene. Profile of outline of shells matches profile of outline of cross-section of ferroconcrete member. Outer dimensions of shells are equal to outer dimensions of ferroconcrete or concrete member. Radial holes are made in wall of shell to bond shell to concrete member. Thickness of wall of shell is found by formula t ≥ R_b•E_k-R_kE_b/R_k(E_k-E_b) and diameter of holes by formula d=0.9 x t x , where R_b is prism strength of concrete; R_k is strength of plastic material; E_k is modulus of elasticity of plastic material; E_b is modulus of elasticity of concrete; D is diameter of cross-section of concrete member with indirect reinforcement; t is thickness of wall of shell. EFFECT: enhanced strength of structure. 4 cl, 4 dwg