Concrete Silos 33 



In this connection, it might be well to suggest that 

 frozen silage, which is often attributed to frost getting 

 through the walls, is frequently caused by insufficient 

 protection at the top. The fact that this freezing is 

 only around the wall does not disprove this statement. 

 The silage is of course colder next to the wall than it 

 is in the middle of a silo, and with the loss of heat 

 from above, the outside ring will naturally freeze first. 

 As each day's silage is removed, the freezing continues 

 on down, and the farmer believes that the silage is 

 frozen for its entire depth. Investigation, however, 

 would in many cases show that this is not so, but that 

 it is frozen only >a few inches below the surface. 



As to strength, concrete is also subject to the will 

 of the builder. By the addition of a sufficient amount 

 of steel, he can build it to withstand any desired 

 strain. 



One of the pre-eminent qualities of concrete is dur- 

 ability. When once built, and built right, it is prac- 

 tically indestructible. It is sufficiently heavy to main- 

 tain its position against winds or other elemental forces, 

 and it is not 'affected by age, except that as it grows 

 older, it grows stronger. 



The objection has often been raised against cement 

 that it is affected deleteriously by the acids in the 

 silage. This contention has never been proven and 

 there are numberless authoritative statements to the 

 contrary. It might be pointed out, however, that even 

 if there, should be a slight eating away of the con- 

 crete by these acids, such action can effectually be 

 counteracted -by some asphaltic or bituminous prepara- 

 tion once every three or four years. If such a coat- 

 ing as this is considered necessary, this is practically 

 the only item of maintenance cost which it will be 



