Would you advise the use of pneumatic jacks for slipforming?
Hydraulic jacks are the most satisfactory. They don't stick during cold weather. They are not big and awkward, so they don't get in the way of reinforcing steel. At higher capacities they can be spaced farther apart to provide more room. One hydraulic pump is used to actuate all jacks. Two standbys should be kept on hand and hooked up, to cover almost all possible emergencies. It is well to have hand-operated standby pumps available in addition. The above Problem Clinic data were taken from question-and-answer sessions at the Advanced Seminar on forming, jointly sponsored by the American Society of Concrete Construction and the Portland Cement Association, February 21-24,1972, Lincolnwood, Illinois.