Acoustic-Emission Kaiser Effect in Fly-Ash Cement Mortar under Compression

Acoustic-emission (AE) technology is considered a potential new testing method to monitor the integrity of concrete materials. This study is devoted to the investigation of the AE Kaiser effect in fly-ash cement mortar (FACM) under uniaxial compression. The major experimental parameters include the amount of cement replaced by fly ash, curing time, compressive strain and stress, loading pattern, and loading rate. The test results showed that the AE Kaiser effect existed in FACM specimens up to 80% of its ultimate strength. Good correlation between the variation of the AE signals and the compressive strains was observed. In addition, the results indicated that the AE Kaiser effect existed in FACM specimen during different curing periods of three, seven, 14, and 28 days. These observations suggested that the AE Kaiser effect has good potential to be used as a new tool to monitor the loading history of concrete materials.