50 PRACTICAL SILO CONSTRUCTION 



against the forms or "puddling." The wet mix will 

 thus pack more solidly than a semi-dry mix well 

 tamped, hardening with equal speed under favorable 

 conditions, and giving a smoother and more perfect 

 finish to the surface of walls. 



The composition usually employed for plastered 

 silos is the same as that used for stucco; and often 

 a small amount of plastering hair is added to the 

 mixture. Where lime is added to the mix the 

 usual proportions are 2:5:1, cement, sand, and lime. 

 Without the addition of lime the best proportion is 

 1:2J, using well-graded sand, although a proportion 

 of 1:3 has been employed with success. The use of 

 lime, either the hydrated lime as sold almost exclu- 

 sively to-day or the cream of lime prepared by the 

 plasterer as needed, is of advantage in the concrete, 

 as it gives it great plasticity and lightens the work 

 of spreading to a large extent. 



REINFORCEMENT OP SILOS 



The question of reinforcement is an important 

 one to the silo builder; and in planning and placing 

 the steel every precaution should be taken to pre- 

 vent a weak point in the work. 



At Fig. 12 is shown a type of reinforcement that 

 employs vertical |" rods around the wall of silo, 

 except upon each side of the door-openings, where 

 the rods are replaced by 2" angle irons or bars. 

 These are connected together between each door- 

 opening with a horizontal bar of the same material 



