A reinforced concrete box culvert (RCBC) is a box culvert constructed of reinforced concrete. Because the sudden collapse of an RCBC could result in a serious accident, continuous management and maintenance work of the RCBC should be performed. In this paper, the RCBC chipping robot that is developed as an alternative to skilled construction workers for carrying out the concretechipping work, one of the RCBC maintenance process, is introduced, and the force-regulated impact control for improving quality of the chipping work is described. In order to implement the proposed algorithm, reaction forces when the robot strikes concrete with chipping tool are collected, and classification to identify the striking object and its hardness is carried out based on the obtained reaction forces. In addition, a variable motion control algorithm is realized by setting the dynamic characteristics of the robot with respect to the reaction force according to striking object and its stat. To verify the effectiveness of the proposed algorithm, chipping work with an RCBC chipping robot is conducted in a simulation environment consisting of reinforced concrete.