IJ.O 



ENGINEERING ON THE FARM 



Quantities of Material for i Cubic Yard 

 of Cement Mortar 



Proportions by Volumes 



Cement 



Neat cement 



Sand 



IH 



l 

 l 

 2 



3 



5 



Quantities of Material 



Cement 

 Sacks 



30.0 

 19.4 



15-4 

 12.8 

 IO.8 



9-4 

 6.1 



Sand 

 Cu. Yd. 



O.OO 

 .70 

 .82 

 .90 

 .96 

 I OO 

 I.08 



Lime. In the mixing of cement mortar, 5 to 10 per cent 

 of thoroughly slacked lime may be added without injury. 

 The addition of the lime makes the mortar more impervious 

 to water and smoother to handle. 



MIXING 



Measuring. Some method of measuring exact volumes 

 should be provided. Since the cement is in sacks, it is 

 customary to have the measuring box of such size that it 

 is proportionate to the sack of cement, a given number of 

 boxes of coarse and fine aggregate being used for each sack 

 of cement. By this method the measuring of cement is 

 avoided. 



Hand mixing. Hand mixing is the only method avail- 

 able for individual work. A mixing platform such as 



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Fig. 135. Two styles of mixing boxes 



shown in Figure 136 is useful. The method of procedure 

 to mix a one-bag batch of 1:2:4 mixture is as follows : 



