Abstract: A grid assembly, and method for use in manufacturing a grid reinforced concrete deck, including a plurality of longitudinally extending main beams in parallel spaced relation, each of the main beams having a plurality of longitudinally spaced slots therein and a central flange thereon, a plurality of cross bars adapted to be inserted through the aligned slots and rotated into an upright position, a form pan extending between two adjacent main beams and having a first and a second side portion adapted to rest on the central flange of the two adjacent main beams, respectively, wherein the form pan includes at least a first ridge extending upwardly thereon, the first ridge having a height which enables a lower edge of the cross bars to come into contact therewith when in the upright position, wherein the contact causes a downward force on the first ridge which mechanically locks the form pan between the cross bars and the flange on the adjacent main beams.