METHOD AND FRAMEWORK FOR MANUFACTURING PIPES FROM POLYMER-IMPREGNATED CONCRETE Russian patent published in 1997 - IPC

FIELD: construction practice. SUBSTANCE: inner lining of pipe to be manufactured is constituted by polymer-made sleeve insertable onto pipe-forming core. Prior to inserting sleeve onto core, partial cuts are practised in lower part of sleeve. In total 10-30 cuts having length equal to 0.05-0.1 sleeve diameter are practised. Cut-marked part of sleeve is bent off towards upper axial end of device intended to form bell mouth of future pipe, device being mounted on replaceable pallet. During dismantling of framework, outer forms are moved away along guiding projections of core, guiding projections being shifted relative to each other at one and same angle equal to 10-12 deg., height of each projection being equal to 0.001-0.05 core diameter. Core has polymer-made facing which can be provided with anchoring elements in form of transversely or longitudinally extending protrusions, spaced apart with pitch which predetermines grain size of filler used to prepare concrete mix. Finally, latter is subjected to heat treatment at temperature 35-80 C for 3-10 h. EFFECT: method makes it possible to produce good-quality pipes from polymer- impregnated concrete. 5 cl, 3 dwg