94 



SILOS OTHER THAN WOOD. 



same type Is built by replacing' the studding with % inch 

 vertical rods to which every rib of the metal is firmly wired. In 

 this way only one wall of the ribbed-steel is used and it is plas- 

 tered on both sides to a total thickness of about 2% inches. 



Cement Block Silos. 



The cement block silo is sometimes preferable to other types. 

 It will be found cheaper and easier to erect than the monolithic 

 concrete silo and although perhaps not so strong as the solid 

 wall, it is probably as good as any silo when properly con- 

 structed. The architectural effect is very pleasing, especially 

 where the rough exterior is used. The blocks should be well 

 made and plenty of reinforcement used. The reinforcement con- 

 sists of steel bands or rods laid in the wall between the courses as 

 in brick or stone construction. They should be entirely covered 

 by mortar to protect them from rust. 



Cement blocks are easily made at home or may be secured 

 at numerous factories. in Many cases the manufacturers will 

 move out their forms, mixers and other utensils and make the 

 blocks at the building site at less expense than for the monolith. 

 This is because the work can be done with greater facility on 

 the ground level than up in the air on scaffolding. "With a little 

 practice any mason can learn how to lay the blocks and follow 



specifications. 



The Nebraska Agricultural Experiment 

 Station Bulletin No. 138, has the follow- 

 ing regarding cement block silos: "There 

 are three general types of blocks which 

 can be used for silo construction, the solid 

 ^2;^x -^ block, the hollow block and the two-piece 



(^''Yy^^^^ block. These blocks may have rough or 



smooth outsides and may be either curved 

 or straight. The straight blocks, of 

 course, will need to be plastered on the 

 inside to produce a smooth surface to the 

 silo. 



"When cement blocks are made very 



fast, it is essential that the mixture of 



which the body of the block is made be 



Fig 35.— Type of con- l"''^^ '^'■y- Concrete when used in this 



Crete block which 'Z^'^ '® 1""^ porous. If the face of the 



can be used in silo "^^P^^® °^" ^'^her be of a much richer 



construction. mixture than the body of the block or 



be made of very wet concrete and trow- ■ 



eled, a much better block for silo construction can be made. It is 





