METHOD FOR MEASURING DEPTH OF CONCRETE CRACK

摘要

PURPOSE:To measure the depth of a crack with high accuracy, by injecting a chemical liquid having expansibility in the crack and measuring the minute destructing sound generated from the leading end of the crack by a plurality of sensors to analyze the arrival time difference between the sensors. CONSTITUTION:In order to bring the inner surface of a concrete crack 1 to alkaline environment, an A-liquid (alkaline ethyl alcohol) 9 is injected in the crack 1. Next, a B-liquid (a liquid mixture prepared by adding azobisisobutylonitrile being a ploymerzing agent and an aluminum powder being an expanding agent to a prepolymer liquid of methyl methacrylate) 10 is injected in the crack 1 under pressure. Then, the minute destructing sound generating from the leading end part of the crack 1 is detected by sensors 3 and the destructing sounds detected are amplified by preamplifiers 6 and analyzed by a two-dimensional position locating system 7 to calculate the vibration generation source of the destructing sound. Since the vibration generating source of the destructing sound coincides with the position of the leading end part of the crack 1, the depth of the crack 1 can be calculated. By this method, highly accurate measurement can be performed.