CONCRETE 



143 



present, because such a mix will not form a good bond with 

 the steel, and the steel is thus free to pull out. Avoid the 



Fig. 137. Use of a mixing platform 



Fig. 138. Method of adding water 



use of too dry a mix because of the difficulty of proper tamp- 

 ing. The dryer the mix, the faster it sets, which may be 



