Adapting piezoelectric ring actuator for early hydration monitoring in cementitious materials

There is a need for non‐destructive testing (NDT) methods to evaluate concrete properties in fresh and hardened states. The current study aims to utilize the piezoelectric ring actuator technique (P‐RAT), originally developed for soil applications, to assess the properties of cementitious materials. The research presents the adaptation of P‐RAT to monitor hydration kinetics of cement‐based materials at an early age. The technique measures shear wave velocity ( V S ) through the materials, offering insights into their behavior during the setting process. The methodology involves a new configuration for the sample holder and new ring dimensions adapted to obtain resonance frequency appropriate for evaluating the cementitious materials at an early age. The study includes an experimental evaluation of different cement paste and mortar mixtures—focusing on examining factors like repeatability, calibration, and ability to determine setting times using both P‐RAT in comparison to traditional methods like the Vicat needle test. The study demonstrates the feasibility of adapting the P‐RAT technique to measure V S along with its potential to provide valuable insights into the cement‐based materials' characteristics during their critical early stages of development.