Research on damage and stress monitoring analysis of cement-based materials based on integrated sensing element (ISE)

Embedded sensors can achieve long-term on-site monitoring due to their stable position and good integration with the host medium. At present, there are few studies on the stress monitoring performance of integrated sensing element (ISE) applied to cement-based materials, especially in the absence of aggregates. Whether the coda wave plays a monitoring role is also not reported. This paper first tests the signal characteristics of the integrated sensor surrounded by different media, then analyzes its monitoring function of cement material damage, and finally uses the integrated sensing element and the traditional external sensor to monitor and analyze the ordinary Portland cement test blocks with 0.4 and 0.5 water to cement ratios after 28 days of curing under standard conditions. The results show that due to the innovation of the structure, ISE can independently respond to load changes as an exciter and receiver. The step-by-step coda wave interferometry (CWI) technique can be used to characterize the change process of the load received by the cement sample, and establish the relationship between stress and relative velocity change ( ∆v / v ), indicating the feasibility of ISE for load change monitoring. In addition, the correlation coefficient measured during the loading process changes less than 0.1, while the correlation coefficient of the external traditional sensing unit changes more than 0.3, indicating that ISE can obtain more stable waveforms than traditional contact sensors during the monitoring process.