Acoustic emission monitoring for assessment of prestressed concrete beams

• Prestressed concrete beams were tested using CLT method proposed by ACI Committee 437.
• Acoustic emission (AE) technique was used for damage assessment during CLT.
• AE assessed damage in the specimens favorably and also detected existing damage.
• Crack maps plotted by AE were in a good agreement with visually observed cracks.

Acoustic emission (AE) was used to monitor eight prestressed concrete (PC) T-shaped beams that were tested per the ACI 437 cyclic load test (CLT) method. Limited research has examined the validity of this test method for PC structures. The study aims to explore the use of AE for damage evaluation as a supplement to conventional measurements used to assess the condition of a structure based on the CLT acceptance criteria. The beams had different initial conditions: five specimens were pre-cracked and corroded to different corrosion levels while the remaining unconditioned beams served as control specimens. AE enabled to monitor the accumulation of damage during the load tests and damage quantification charts based on AE data are presented. These charts allowed determining load test failure with better sensitivity than the existing ACI 437 evaluation criteria. The charts enabled the assessment of damage regardless of the specimens’ initial condition. In addition, it is shown that accurate damage source location and crack mapping can be achieved by using suitably filtered AE data.