CEMENT AND CONCRETE FENCE POSTS. 13 



would be able to make at least twice as many posts as two men 

 working by hand and the cost for making would be very much less. 



The Effect of Alkali on Cement and Concrete Posts. It has 

 been found that some soils contain an excessive amount 

 of alkali, which has a tendency to destroy concrete work. 

 \Yhile no experimental work has been done to test the effect 

 of such soils upon cement or concrete posts, it has been ^conclusively 

 proven that cement drain and sewer tiles which come in contact 

 with water which has percolated through these alkali soils are soon 

 destroyed. 



While it might be possible that the action on cement or con- 

 crete posts would be slower than in case of the tiles, it is probable 

 that the post would eventually be destroyed. 



For further information in regard to the effect of alkali on 

 cement construction see Bulletin No. 69, of the Montana Agricul- 

 tural Experiment Station, and Bulletin No. 132, Agricultural Ex- 

 periment Station of the Colorado Agricultural College. 



TABLE NO. 2. Poured and Tamped Posts.* 



Size, 5x5 inches from base to ground line, tapering to 3x3 inches at 

 top. Length, 6 feet 6 inches. Cured weight, 115 to 120 pounds. Mixture, 

 1 part cement and<J5>parts sand, by measure. Cost for cement per post, 

 cents; sand, ,5^- cents. For cost of reinforcement, see table. 



Sta. 



* This table is a summary of Tables 3 and 4, Bulletin 148, Colo. Exp. 



