Abstract:To study the variation features of infrared radiation(IR) and acoustic emission(AE) of concrete during the fracturing and water seepage process,a concrete block is pressurized with embodied water to uniaxially compressive stress. The changes of its IR radiation and AE are measured using an infrared thermal imager and a AE instrument. The experimental results show that IR radiation of the sample¢s surface regularly varies with the stress in different stages. The IR radiation shows an overall rise in early term,then partial high temperature in medium term,and partial low temperature in late term. The corresponding AE shows a little increase in the early term,then steadily increase in the medium term,and rapidly increase in the late term. It is revealed that the IR radiation experiences decreasing after early increase is the anomalous precursor of the fracturing and water seepage of concrete. The IR anomalous precursor happens earlier than stress and AE anomalous precursor. The thermal images of the sample also show that the low-temperature areas are surrounded by the high-temperature areas during the fracturing and water seepage process,which is the main feature of radiation temperature field. The mechanism of IR radiation variation in the loading process and the IR anomalous precursor of fracturing and water seepage are analyzed. The time difference between stress precursor,IR radiation precursor and AE precursor is also discussed. The experimental results are useful for the remote sensing monitoring and disaster forecasting on concrete dam and other concrete engineering.