Development of Wireless Remote-controlled Testing Machine for Vertical Concrete Wall

A lot of concrete structures are deteriorating to dangerous levels throughout Japan. These concrete structures need to be inspected regularly to be sure that they are safe enough to be used. The inspection method of these concrete structures is typically the impact acoustic method. In the impact acoustic method the worker taps the concrete on the surface with hammer. So it is necessary to set up scaffolding to access vertical structures for inspection. However, setting up of high scaffolding is not economical in time and money. Moreover setting up scaffolding is difficult on very high concrete walls. So we developed a wireless remote-controlled testing machine for vertical concrete walls. This testing machine adheres to the concrete wall by two sets of suction cups, and climbs the concrete wall by the alternating motion of the two sets of suction cups. The power is supplied by lithium polymer batteries. The impact acoustic method is used in this testing machine. This testing machine has a hammer for the impact and a microphone for the acquisition of the impact sound. The weight and the dimension of the testing machine are about 13 kg and1.39 m by1.39m, respectively. This testing machine climbs the concrete wall at a speed of one meter a minute. The testing efficiency of this machine is about 10 min/m 2 .