METHOD FOR PRE-STRESSING REINFORCED CONCRETE STRUCTURES Russian patent published in 2001 - IPC

FIELD: pre-stressing reinforcement by thermoelectric method with reinforcement tensioned on concrete. SUBSTANCE: method involves forming through channel during structure concreting, placing smooth metal pin carrying polymeric sleeve on pan supports. Reinforcement items are assembled and structures are concreted using traditional technology. Upon extraction of inventory pin through channel is formed in body of structure where reinforcement rod threaded on ends is inserted after concrete has hardened to desired strength. Washers and nuts are screwed on mentioned treaded part. Electric current is applied to projecting reinforcement ends for heating them. As soon as desired elongation is attained, nuts are screwed in to design reference marks. Reinforcement heating causes melting of thermoplastic polymer and the latter covers reinforcement. As nuts are cooling down they rest on structure ends through washes thereby limiting free deformation of reinforcement and building-up pre-stressing. EFFECT: reduced labor consumption; improved protection from corrosion. 2 dwg