To provide a reinforced batter for establishing a clamping batter used in a left-in-place form construction method as that usable in a simultaneous left-in-place form construction method.

A U-shaped channel batter is formed either by folding back the upper and lower toothed portions of a U-shaped channel across the back of the channel, and forming the channel so that the folded portions are integrally bonded together, or by folding the toothed portions until the folded portions reach the center of the back, and forming the channel so that the folded portions are in intimate contact with each other. Circular holes are bored in the back, either continuously or at equal intervals.