Acoustic Emission Monitoring of Early Hydration Processes In Cementitious Materials

Acoustic emission (AE) technology is widely used in the study of various damage characteristics of concrete due to its high sensitivity and real-time dynamics. In this study, to investigate the relationship between cement content, the presence of aggregates in cementitious materials, and early cracking during the hydration process, an AE parameter-waveform acquisition system is used to monitor the early hydration process of concrete in real time for 72 h. The AE characteristics are analyzed using AE parameter and waveform analysis methods. Differences in AE parameters help identify the main relevant reaction components at each stage of the hydration process or in the event of damage, providing a reference basis for quality control. The results indicate that the early hydration process of cementitious materials can be divided into five stages: pre-induction, induction, acceleration, deceleration, and stabilization. It is mainly the cement particles that undergo the hydration reaction, and the higher the cement content is, the longer the reaction time. The introduction of aggregates into the pores of cementitious materials causes wave attenuation and early cracking.