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PKACTICE 8 



Determination of the Effects of Lime on Plastic Soils. 



Two students may work together in this experiment. 



Weigh out 6,300-gram samples of the clay soil using them as follows: 

 To sample 



No. 1, check, add no lime. 



No. 2 add .5 gr. of air slacked lime. 



No. 3 add 1. gr. of air slacked lime. 



No. 4 add 5. gr. of air slacked lime. 



No. 5 add 10 gr. of air slacked lime. 



No. 6 add 10 gr. sand. 



Mix each sample thoroughly in a soil pan with the lime and add 

 just enough water to make plastic. 



Fill the semicircular moulds, first placing a damp thin cloth in it 

 to facilitate the removal of the clay. Make duplicates of each number, 

 being careful to compress each to the same degree. Place on a cloth 

 in a soil pan and dry in an oven for 5 hours at 100° C. 



Test the strength of each brick by supporting the ends so as to 

 allow just 3 inches between points of support. Hang weight pan in 

 middle of brick and determine the weight necessary to break each. 



Explain the effect of lime. 



Why does the sand not have as much effect as the lime on the 

 breaking strength? 



