Damage Evolution Analysis of Mortar with Different w/c Ratio by Acoustic Emission Technique

In this paper, mortar specimens with different w/c ratio were tested under axial compression. The damage progress was monitored by acoustic emission (AE) technique and AE signals were collected. AE characteristics of mortar specimens with different w/c ratio are studied and the damage evolution process is analyzed by AE amplitude, peak frequency and AE N/E ratio (cumulative hits/cumulative energy). Under different w/c ratio, variation trend of the ratio of AE cumulative hits number to total AE cumulative hits number (AE cumulative hits number ratio) in each amplitude and frequency band is generally consistent, what's more, AE cumulative hits number ratio in each frequency band and amplitude band at different stress level are studied. Distribution variation trend of AE cumulative hits number ratio in each amplitude and frequency band changing with the stress is generally consistent. When AE cumulative hits number ratio significantly increases sharply, it indicates that the mortar specimen will be destroyed. The damage evolution progress of mortar specimens with different w/c ratio under axial compression is analyzed by AE cumulative hits number ratio in each frequency band and amplitude band at different stress level and AE N/E ratio.