The goal of this study was to develop viable tools that utilize ultrasonic smart piezoelectric material (lead zirconate titanate, PZT) to assess the condition of concrete bridges. Information about the condition of concrete bridges and the type and severity of damage is helpful to identify concrete bridges in critical condition and to allocate funds more effectively. However, existing non-destructive testing methods for inspecting concrete structures all suffer from limitations in accuracy, cost, maneuverability, in situ capability, and implementation, and most laboratory-based investigation methods lack practicality and applicability to in-field structural health monitoring.
The primary objective of the study was to determine the effectiveness of utilizing a surface-mounted PZT patch system to determine the wave modulus of elasticity (WMoE) of concrete. An embedded PZT cement module system, less practical because of the difficulties of accurately positioning the PZT cement modules during construction and in placing them in existing structures, was used for comparison purposes.
A combined experimental and numerical investigation was conducted on concrete beams and a concrete panel using both the smart surface-mounted PZT patch and the embedded PZT cement module systems. The ideal orientation of the PZT cement modules, effects of distance of the PZT pairs, and effects of concrete dimension were investigated.
The researchers found that the surface-mounted PZT system was as effective as or even better than the embedded PZT cement module system in determining the WMoE of concrete with a certain degree of confidence and in assessing concrete properties. The one limitation was that the surface-mounted PZT patch system represented the measurement of WMoE within only one wave length of depth, and it may be not truly reflect the WMoE of all the interior of the concrete. However, the PZT patch system has more advantages in terms of monitoring and assessing existing concrete structures than the embedded PZT cement module system because the PZT patches can be nondestructively surface-mounted to concrete structures. Therefore, it is a promising alternative nondestructive technique for determining the WMoE of concrete structures.
Authors:
Pizhong Qiao
Ayumi K. Manawadu
Zhidong Zhou
WSU Department of Civil and Environmental Engineering
Sponsor: PacTrans