UNIVERSAL PORTLAND CEMENT CO. 
75 
builder in the strength of the blocks, or failure to realize the enor- 
Reinforcing j^^^g outward pressure of the silage. Horizontal reinforcing is 
of the most importance and must not be overlooked. Vertical reinforcing 
in block silos is not necessary. The table on page 77 shows the size of rod 
which should be placed between each row of block or in the groove in each 
row of block, if such a groove is provided. Reinforcing rods in block silos 
are not lapped in the ordinary fashion, but are anchored around a block or 
the ends are hooked together. 
For illustration, assume that you are to build a concrete block silo 
32 feet high, 16 feet in diameter, with blocks 8 inches in height. The 
right amount of horizontal reinforcing can be found by referring 
Example ^-^^ ^^^^^ p^^^ ^rj, rpj^^ height of silos, in courses of six 
blocks (or 4 feet), is given in the left-hand column. As the silo is to be 
32 feet high, run down to the figures 28-32. This represents the bottom 4 
feet of the silo. Run your finger across the page to the column headed 16, 
the desired diameter, and the fraction, indicates that a 3^-inch round 
rod is required between each two courses of blocks, between the 32-28 foot 
levels. Following up this column (16 feet), you will see that 3^-inch 
Continuous Door Opening for a Concrete Block Silo, showing the method of fastening reinforcing rods 
to the door frames and anchoring rods in the end blocks. 
