Pitch-Catch Guided Waves-Based Concrete Strength Monitoring Using an Embedded Smart Sensor Module

摘要

During the construction of concrete structures, real-time monitoring for their strength development is very crucial to determine the structures' readiness for in-service. However, it is very hard to estimate the compressive strength of the concrete nondestructively and in real-time. To provide the solution for this limitation, this study proposes a guided wave-based concrete strength estimation system using an embedded smart sensor module system. Because the guided waves could not propagate clearly inside the concrete, an embedded smart sensor module system was developed by attaching two piezoelectric ceramic sensors on a thin steel plate that could provide a propagating path for the guided waves. Because the boundary condition of the steel plate is changed according to the variation of the concrete strength, the guided wave signal obtained from the piezoelectric sensors might be changed with a certain pattern affected by the boundary condition. Therefore, the strength of the concrete can be estimated by analyzing the pattern-variations of the guided wave signals. To confirm the feasibility of the proposed methodology, an experimental study using a concrete specimen with the aforementioned embedded smart sensor module system is carried out and the optimized strength estimation equation is derived throughout a regression analysis.