PROPORTIONS AND MIXTURES 129 



working large stones back from the forms and leveling the 

 surface so that no large stones are left uncovered (Fig. 141). 

 This mixture and method of placing is used in nearly all re- 

 inforced structures where the reinforcing is put in place be- 

 fore the concrete is poured. For large structures, special ap- 

 paratus is used for elevating the material. 



FIG. 141. Working stones away from surface. 



124. Handling Concrete. There are three common 

 ways of conveying the mixture: 



a) It may be shoveled off the board directly into the 



work. 



6) It may be shoveled into wheelbarrows and wheeled 

 to position and dumped. 



