Apparatus and method for reinforcing cast structures

Abstract

A rectangular reinforcing cage is provided for a cast concrete structure having longitudinal registration tubes at each corner of the cage. An outer reinforcing cage surrounds the registration tubes and a coaxial inner reinforcing cage is supported from the outer cage by a plurality of spacers. Each reinforcing cage has a pair of facing C-shaped mats having straight mats overlapping and connected to the bent ends of the 'C' to complete each reinforcing cage. Each end of the C-shaped mats have a smoothly curved transition bend joining a portion perpendicular to the main portion of the mat. Each mat has a layer of longitudinal wires connected to a layer of transverse wires. The longitudinal wires being more closely spaced near the end of each mat than in the remainder of the mat with no longitudinal wires in the transition bend of each C-shaped mat. The longitudinal wires are positioned inside each C-shaped mat and outside each straight mat when a reinforcing cage is assembled. Each reinforcing cage including each mat and each C-shaped mat is shaped to close tolerances for producing consistent cast reinforced concrete structures. A jig for manufacturing the reinforcing cages is disclosed as well as the method for assembling the reinforcing cages and cast concrete structures including the reinforcing cages.