Acoustic Emission of Examination of High Strength Prestressed Concrete Girders

High strength prestressed concrete girders were monitored with acoustic emission equipment, during load tests, to determine the possibility of crack prediction and location prior to their appearance at the surface. Three basic events and zones were monitored: shear-induced cracking in the web, flexural cracking at the region of maximum moment, and strand slippage at the anchorage zone. The research was directed to basic parametric analysis, source location, moment tensor analysis using a 6 channel digital AE instrument, and development of criteria for AE use on concrete bridge girders. The test results show a significant increase in cumulative energy shortly before shear and flexural cracking was observed on the surface. A good agreement between located and classified sources with actual crack pattern was observed.