472 AGRICULTURAL ENGINEERING 



The Roof. The roof of the Iowa silo is constructed of 

 concrete, making this part as durable and lasting as the rest 

 of the silo. The cornice is made of blocks laid flat-wise, 

 and the center is made of two and one-half to three inches 

 of concrete placed upon a conical form. The conical shape 

 is very desirable for a concrete roof, as nearly all of the 

 reinforcement may be confined in the base of the cone. If 

 thoroughly reinforced at this point, there is little opportunity 

 for failure. A window must be provided in the roof for 

 filling the silo. 



QUESTIONS 



1. Where should the silo be located? 



2. What are the factors that determine its diameter and height? 



3. How does the capacity of a silo vary with its diameter? How 

 does the amount of material in the walls vary with the diameter? 



4. How much silage should be fed from the surface each day? 



5. What are the essentials of a good silo? 



6. Discuss the construction of the stave silo. 



7. Upon what does the durability of the stave silo depend? 



8. What are the merits of the plain-stave silo? 



9. How are silo staves spliced? 



10. Discuss the construction of the silo foundation. 



11. Can a silo pit be used to increase the capacity of a stave silo? 



12. Describe how a stave silo should be anchored and guyed. 



13. Describe two types of doorways for silos. 



14. Describe the construction of the Minneapolis or panel silo. 



15. What is necessary to make a satisfactory silo wall of concrete? 



16. How should the walls be reinforced? 



17 What kind of mixture should be used in preparing the concrete? 



18. What are the advantages and disadvantages of the cement- 

 block silo? 



19. Describe the monolithic concrete silo. 



20. Describe the hollow clay block or Iowa silo. 



21. What are the desirable features of clay blocks for silos?" 



22. How may the wall be made impervious? 



23. How can the clay-block silo be carefully reinforced? 



24. Describe the construction of the doorframe, the foundation, 

 the floor, and the roof of the Iowa silo. 



