OHTSU Masayasu Faculty of Eng., Professor, 工学部, 教授 (80109016)
WATANABE Hiroshi Faculty of Eng., Research Associate, 工学部, 助手 (60244109)
YAMAO Toshitaka Faculty of Eng., Professor, 工学部, 教授 (40109674)
SAKATA Yasunori Kyushu Tokai Univ., Faculty of Eng., Professor, 工学部, 教授 (60099083)
|Budget Amount *help
¥10,700,000 (Direct Cost : ¥10,700,000)
Fiscal Year 1996 : ¥1,000,000 (Direct Cost : ¥1,000,000)
Fiscal Year 1995 : ¥3,300,000 (Direct Cost : ¥3,300,000)
Fiscal Year 1994 : ¥6,400,000 (Direct Cost : ¥6,400,000)
Diagnostic procedure is investigated in order to develop the evaluation and inspection techniques. The techniques to be studied and to be practically applied are associated with crack, delamination, surface damage, corrosion of reinforcement, and structural integrity. For this purpose, acoustic emission (AE) method, ultrasonic testing (UT), infrared thermography, radar, and half-cell potential are newly developed and improved. The evaluation of structural integrity is also studied, including an expert system based on the data base of aging bridges.
Results obtained are summarized, as follow :
(1) The UT measurement was improved and a new technique based on the spectral information was developed to identify crack depths and surface deterioration.
(2) AE application to core tests of concrete is investigated. On the dasis of the rate process analysis of AE generating behaviors in the core sample and the damage mechanics, a quantitative evaluation of damage in the core sample is developed.
(3) A moment tensor analysis of AE waveforms was investigated and thus a practical procedure is developed to identify crack location, crack type, and crack orientation.
(4) To estimate corrosion of reinforcement, two step inspection is proposed. At the first step, location of reinforcement is determined by employing the radar technique. Then, at the second, corrosion potentials on the reinforcement are estimated from half-cell potentials on the surface, by the charge simulation method analytically.
(5) The infrared thermography was studied to estimate temperature distribution on concrete surface. Concerning the corrosion of reinforcement, an inverse solution based on the boundary element method (BEM) is newly developed.