METHOD OF PRODUCING COMPOSITE CONCRETE - STEEL PIPES AND JOINTS AND PIPE AND JOINT OBTAINED BY MEANS OF SAID METHOD

摘要

1. Method of producing a composite concrete-steel pipe comprising the steps of taking a thin mild steel sleeve to SERVE AS THE INNER WALL OF THE PIPE, ATTACHING METAL REINFORCING MEANS TO THE OUTER FACE OF SAID SLEEVE, FORMING AN INJECTING MOULD ABOUT SAID SLEEVE BY PLACING MEANS ACTING AS A MOISTURE-PERMEABLE ENCLOSURE AROUND SAID SLEEVE, SAID ENCLOSURE CONSTITUTING THE OUTER WALL OF SAID MOULD AND SAID SLEEVE CONSTITUTING THE INNER WALL OF SAID MOULD, INJECTING COLLOIDAL CONCRETE INTO SAID MOULD, COMPRESSING THE CONCRETE BEFORE IT HAS SET BY CREATING AN INTERNAL HYDRAULIC PRESSURE IN SAID SLEEVE SO AS TO EXPAND SAID SLEEVE BEYOND THE ELASTIC LIMIT OF SAID MILD STEEL, RELEASING SAID HYDRAULIC PRESSURE IN SAID SLEEVE AFTER HARDENING OF THE CONCRETE, AND REMOVING THE RESULTING COMPOSITE CONCRETE-STEEL PIPE COMPRISING SAID CONCRETE, SAID REINFORCING MEANS AND SAID MILD STEEL SLEEVE EXPANDED AGAINST SAID CONCRETE.