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Illinois State Dairymen s Ass.ociation. 



are that when we learn to handle concrete to the best advantage 

 this will be the material for building silos. 



Concrete Silos. 



Silos built of concrete have been 30 feet deep, with the wall 

 not more than six inches thick at the base and tapering to four 

 inches at the top. Where gravel or crushed stone can be obtained 

 at a reasonable price it may be advisable to make the walls slightly 

 thicker, and in cold climates they should be built with a dead-air 

 space in the wall to prevent the silage from freezing. In any 

 event there should be enough heavy wire or iron rods imbedded 

 in the wall to withstand the strain of the silage; unless this is 

 done cracks are likely to appear. The amount of wire necessary 

 in each case will depend upon the size and depth of the silo. The 

 wall should be plastered on the inside with one part of Portland 

 cement to two of good sharp sand troweled to a smooth surface. 

 This will resist the action of the acid in the silage. 



Cut 28 shows an all-concrete silo 20 feet in diameter and 

 42 feet deep. The wall is 22 inches thick for the first 14 feet, 19 

 inches thick the next 14 feet, and 16 inches thick the upper 14 

 feet. This silo cost approximately $1200, and as it holds 334 

 tons, the cost per ton was $3.59. While the first cost of this silo 

 was high it may prove economical in the end, as it should stand 

 for more than a hundred years. 



It is essential that a concrete, stone, or brick silo have a good 

 foundation, otherwise it is likely to settle unevenly and cracks 

 will appear in the wall, giving the air a chance to enter. If the 

 silo is put at least three feet into the ground this assures a firm 

 footing and also adds to the depth of the structure. 



There are great possibilities in reinforced concrete and a cir- 

 cular structure is the best to be easily reinforced. Silos have 

 been built of concrete, but usually with solid walls and much 

 thicker than necessary. The method of construction heretofore 

 has in most cases been cumbersome, requiring a large amount of 

 lumber to construct the forms. With unskilled labor the question 

 of concrete silos is still a problem. Good grades of cement are 

 now manufactured in the state and are becoming much cheaper. 

 Machines have already been made with which reinforced con- 

 tinuous hollow walls are built with comparative ease, and when 

 we learn how to handle cement to the best advantage possible 

 this will, undoubtedly, be the silo of the future, especially in sec- 

 tions where sand and gravel or crushed stone are abundant. 



