Image Number 6 for United States Patent #6533970.
A method for making aerated concrete blocks includes dispensing materials for making aerated concrete into a mold and allowing the materials to rise and stiffen into a body. The body may be divided into an array of blocks which are then cured. At least one passageway may be formed in each block, such as by drilling. The drilling may include drilling a plurality of spaced apart passageways through each block, and each passageway may have a circular cylindrical shape. The passageways permit easier grasping by the mason, reduce the weight without significantly compromising strength, and facilitate positioning of blocks during construction of a wall to facilitate the placement of vertical reinforcing members in aligned passageways. The positioning of the passageways in each of the blocks may assist alignment of adjacent passageways, especially at wall corners. The drilling may include providing a plurality of drills and causing relative movement between the drills and at least one group of blocks to simultaneously drill the one or more passageways in each block of the group. The step of causing relatively movement may include grasping and moving the group of blocks along a predetermined path while the plurality of drills remain stationary.