PURPOSE: To form a lining layer having uniformity and excellent quality by a few workers, by providing an accelerating agent synchronizing control device to automatically control the supplying quantity of the accelerating agent corresponding to the flow rate of concrete.

CONSTITUTION: A concrete flow rate detector 11 is provided on a wet pressure pump 1 for discharging concrete material, and an accelerating agent flow rate detector is provided on an accelerating agent supplying device 9. The respective detected values 11', 12' of the detectors are sent to a control circuit 13. The right value of accelerating agent flow rate is calculated by the calculator 16 in the control circuit 13 based on concrete flow rate 11'. Further, the accelerating agent flow rate 12' is compared with the right flow rate of accelerating agent by a comparator 17, and a driving signal corresponding to a deviation amount is sent to the driving part of a motor 95 via a driver 18. As a result, the accelerating agent in an amount tuned to the discharged amount of concrete is supplied from the accelerating agent supplying device 9.