Relating Damage Assessed by Using Intensity Signal Analysis of Acoustic Emission with Surface Strain in Concrete and Ultrasonic Pulse Velocity in Reinforced Concrete Beams under Monotonically Increasing Load

摘要

This article reports on the assessment of damage state of reinforced concrete (RC) beams using the intensity signal analysis (ISA) based on acoustic emission (AE) testing. The influence of shear reinforcement in RC beams on damage developed was studied. There are few AE based studies related to distinguishing the damage (accumulation of microcracks) due to tensile and shear cracking in RC beams. The aim is to relate the surface strain in concrete and the corresponding damage as the load is increased monotonously. The damage developed in RC beams was represented with five levels namely Level - A (indication that insignificant AE has been detected in the region), Level - B, Level - C, Level - D, and Level - E (major defects detected and use of RC structural member is not recommended). The surface strain in concrete reached its maximum value quickly in shear failure. The AE sensor (s) present in the location where severe damage occurred, recorded higher number of AE signals than the other sensors. At the same location, ultrasonic pulse velocity decreased considerably. The surface strain in concrete reached its maximum value at the same region. The results reported in this article may be an improvement related to the knowledge on ISA of AE to monitor damage in RC structures.