156 Concrete Silos 



silo form a vertical reinforcement every foot. A strip 

 of netting composed of 7 longitudinal and 12 vertical 

 steel wires, imbedded in the block just beneath the 

 outer surface, is designed to prevent any liability of 

 cracking of the face of the block. To unite the blocks 

 and to overcome the outward pressure or thrust, a 

 2-ply twisted steel cable of No. 8 wire is laid outside 

 the dowel pins between each course of blocks, in 

 grooves provided in the edge of the blocks for that 

 purpose, and imbedded in the mortar in which they 

 are laid. The ends of these cables are looped about 

 a continuous gas pipe, which extends from the top to 

 the bottom of the structure, through the blocks each 

 side of the doorway, in place of dowel pins. This same 

 gas pipe also passes through holes in the ends of the 

 ladder rounds. 



Zagelmeyer System. This method of making silo 

 blocks is the invention of the Zagelmeyer Cast Stone 

 Block Company of Bay City, Mich., and is identical 

 with the system used by this company for making 

 building blocks, except that the silo blocks are made 

 to fit the curve of the silo instead of being straight. 

 The molds, which are of sheet steel, are assembled in 

 multiple form on roller bearing trucks, each truck car- 

 rying molds for thirty silo blocks. The truck is then 

 carried under the discharge end of the mixer and filled 

 with slush concrete. 



Each block carries two air spaces, and has a depres- 

 sion in the top for carrying a continuous circle of rein- 

 forcing around the silo. 



Molds are made in both rock face and plain. The 

 blocks can if desired be given a granite or other orna- 

 mental face, similar to the Zagelmeyer building blocks. 



