Field of technology: Industrial Machinery and Processes
Patent granted on: Tue, 25 Mar 1997
The invention presents a non-metallic laminated composite reinforcing rod for use in reinforced or prestressed concrete. The rod is made by creating a sheet of core material comprising a number of layers of "pre-preg" material. Ribs are formed on top of the core from additional layers of pre-preg material laid with the fibers transverse to those in the core. The ribs are then covered by additional layers of pre-preg laid with fibers parallel to the core fibers. The material is heated to fuse the layers. Finally, the sheets of laminated reinforcement are cut parallel to the core fibers to the width desired. The resulting reinforcing rod is superior to steel in corrosion resistance, flexibility, durability, and strength. The reinforcing rod may be used as a prestressing tendon in prestressed concrete after encasing the ends of the rod in an attachment formed of a sleeve filled with groutingmaterial such as mortar or epoxy. The glass-fiber embodiment is non-conductive. If carbon prepreg made of high modulus fibers is used, then the Young modulus of the LCRs is approximately equal to that of steel.