Acoustic emission monitoring of CFRP reinforced concrete slabs

Debonding of externally bonded carbon fiber reinforced polymer (CFRP) materials used for repair of reinforced concrete elements is commonly observed and is often the critical limit state for such systems. This paper presents an acoustic emission (AE) study performed during laboratory tests of concrete slab specimens strengthened with CFRP strips. Several specimens having different CFRP details were monitored. An AE paradigm to monitor damage initiation, progression, and location in the test specimens is demonstrated. An algorithm to classify the cracks in concrete, the disbond of the CFRP strips from the soffit of the slab, and the eventual failure (debonding or concrete shear) is also presented. The proposed general approach can be applied to large scale CFRP–concrete systems.