Figure 22. Tremies in place before pouring, 



(3) Pumping. Pumped concrete may be defined as concrete conveyed 

 by pressures through either rigid pipe or flexible hose and discharged 

 directly into the desired area (Fig. 23). Pumping may be used for most 

 concrete construction, but is especially useful where space or access of 

 construction equipment is limited. Most concrete transported to the 

 placement areas by pumping methods is pumped through a rigid pipe or a 

 combination of rigid pipe and heavy-duty flexible hose. Effective pumping 

 range will vary from 90 to 305 meters (300 to 1 000 feet) horizontally or 

 30 to 90 meters vertically. 



143 



