CHAPTER XXIV 



CONCKETE 



Material necessary. — 



1. Cement, standard grade. 



2. Sand, all grains that pass through one-quarter inch. 



3. Gravel and crushed stone. Should be clean, having no soil, 

 clay or vegetable matter mixed with it. It grades from one- 

 quarter-inch screening to one and one-half-inch material. In 

 using crushed stone, eliminate the dust. 



4. Water. Do not use acid or alkali water. Should be clean. 

 Miscellaneous tools (U. S. Dept. of Agr.). — The following is 



a list of the tools and plant to be used in mixing, giving sizes, 

 quantities, etc. : 



The lumber for the concrete board for a two-bag batch, nine 

 feet by ten feet in size, is as follows : 



Nine pieces seven-eighths-inch by twelve inches by ten feet, 

 surfaced on one side and two edges. 



Five pieces two inches by four inches by nine feet, rough. 



Two pieces two inches by two inches by ten feet, rough. 



Two pieces two inches by two inches by nine feet, rough. 



The lumber for the concrete board for a four-bag batch, twelve 

 feet by ten feet in size, is as follows : 



Twelve pieces seven-eighths-inch by twelve inches by ten feet, 

 surfaced on one side and edges. 



Five pieces two inches by four inches by twelve feet, rough. 



Two pieces two inches by two inches by ten feet, rough. 



Two pieces two inches by two inches by twelve feet, rough. 



For the runs, planks two, two and one-half or three inches 

 thick and ten or twelve inches wide are needed. 



The measuring boxes for the sand and stone or gravel should 

 have the following dimensions : 



For a two-bag batch with the 1 : 2 : 4 mixture : 



Four pieces one inch by eleven and one-half inches by two feet 

 rough (for the end of the sand and stone boxes). 



Two pieces one inch by eleven and one-half inches by four feet, 

 rough (for the sides of the sand box). 



Two pieces one inch by eleven and one-half inches by six feet, 

 rough (for the sides of the stone box). 



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