構造体コンクリートの破壊挙動モニタリングによる損傷度評価

抄録

The durability of concrete structures decreases easily due to such physical or chemical environmental effects as freezing-thawing process, chemical attack, fatigue or carbonation. The degree of damage in concrete is, in most cases, evaluated by a compression test and a rebound hammer test. For effective maintenance of concrete structures, it is necessary to evaluate not only the strength of concrete but also the damage degree. Quantitative damage evaluation system of concrete is proposed by applying acoustic emission (AE) method and damage mechanics. The procedure is named DeCAT, which is an abbreviation of “Damage Estimation of Concrete by Acoustic Emission Technique”. In this study, the relative damage evaluation of concrete by DeCAT in core tests. Core-samples were collected from a reinforced concrete water channel that had been used for 23 to 73 years. Mechanical properties of compressive strengths and Young's moduli were measured during the compression test, and dynamic Young's moduli were calculated from a longitudinal wave velocity. By estimating the concrete damage, it can be quantitatively evaluated from AE generating behavior under compression test and Calm ratio under cyclic loading test.