A Proposed Standard for Evaluating Structural Integrity of Reinforced Concrete Beams by Acoustic Emission

Abstract

A series of studies has been performed to evaluate the structural integrity of reinforced concrete (RC) beams by acoustic emission (AE). Cyclic loadings were applied to RC beams with a single reinforcing bar, large repaired beams, beams deteriorated due to corrosion of reinforcement, and two beams with different damage levels in an aging dock. The test results demonstrated that the Kaiser effect starts to break down when shear cracking starts to play a primary role. It has been also shown that high AE activity is observed during unloadings after serious damage (slips between the concrete and the reinforcement or those between the original concrete and the repaired part) has occurred. A standard for evaluating structural integrity of RC beams by AE is proposed, based on these results.

Kaiser effect observation in reinforced concrete structures and its use for damage assessment

“…AE monitoring experiments were performed successfully under incremental cyclic loading of RC beams with different percentage of reinforcement using AE energy parameter. By defining two ratios, namely, calm ratio and load ratio based on AE energy and Kaiser effect, the state of damage in RC beams was investigated [19,20]. A damage assessment chart was made using load ratio, calm ratio parameters and linking them to the crack mouth opening displacement (CMOD) [20].…”

Acoustic Emission for Civil Structures

“…For acoustic emission evaluation, several investigators have reported correlation of AE parameters to damage levels of reinforced concrete structures. One of the most widely implemented damage assessment methods is the correlation of calm ratio and load ratio (also referred to as Felicity ratio) (Yuyama et al, 1999;JSNDI, 2000). Another approach makes use of severity versus historic index, known as 'Intensity Analysis', as a measure of deterioration for concrete bridges .…”

Acoustic Emission Method for Locating and Identifying Active Destructive Processes in Operating Facilities

“…The method involves performing comparative analysis of the acoustic emission signals recorded during the tests and those collected in the database of reference signals corresponding to particular destructive processes. The results are used to identify and locate active destructive processes in reinforced concrete structures (IADP-Identification of Active Damage Processes), in prestressed concrete structure (RPD-Recognition of Destructive Processes), and in steel structures, thereby allowing the global monitoring across the whole member and recording only active deterioration processes developing under actual loading conditions [7][8][9][10][11][12][13][14][15][16][17]. The AE method is being increasingly developed for use in the construction of gas pipelines.…”