Non-destructive concrete strength evaluation using smart piezoelectric transducer—a comparative study

Abstract

Concrete strength monitoring, providing information related to the readiness of the structure for service, is important for the safety and resource planning in the construction industry. In this paper, a semi-analytical model of surface bonded piezoelectric (lead zirconate titanate) based wave propagation (WP) technique was developed for strength evaluation of mortar with different mix, throughout the curing process. Mechanical parameters of the mortar specimen were mathematically evaluated from the surface wave (R-wave) and pressure wave (P-wave) using elastic wave equations. These parameters were then empirically correlated to the strength. The model was found to be very robust as it could be generalized to account for different water to cement (W/C) ratio. The performance of the WP technique was then compared to the electromechanical impedance technique and other conventional techniques, such as the ultrasonic pulse velocity (UPV) test and the rebound hammer test. Results showed that the WP technique performed equally well as the conventional counterparts. The proposed technique is also advantageous over embedded WP technique and the UPV test, in terms of its capability to capture two types of waves for the evaluation of dynamic modulus of elasticity and Poisson's ratio. A separate study was finally conducted to verify the applicability of this technique on heterogeneous concrete specimen. With the inherent capability of the WP technique in enabling autonomous, real-time, online and remote monitoring, it could potentially replace its conventional counterparts, in providing a more effective technique for the monitoring of concrete strength.

Application of piezoelectric materials to monitor modulus and strength development of cementitious materials

“…It developed to more than 90% of its 28-day value in the first 7 days. The results are consistent with earlier studies (Lim et al 2016) using the wave propagation technique, suggesting the validity of the proposed technique.…”

“…are among the commonly used NDT techniques (Malhotra andCarino 2004, Bungey et al 2006). In spite of their popularity, these methods suffer from some common shortcomings such as labourintensive, time-consuming and difficult to apply in inaccessible regions of the structure (Lim et al 2016). In addition, the results of some NDT techniques, such as the rebound hammer test, may not be satisfactorily repeatable (Soh and Bhalla 2005).…”

“…Making use of piezoelectric materials, the electromechanical impedance (EMI) technique has been developed and studied 2.3 Key developments in impedance based structural monitoring extensively in the past over two decades (Annamdas and Radhika 2013) to serve as a potential alternative to the conventional NDT techniques. In addition, the EMI technique can also be used alongside the wave propagation (WP) technique, using the same PZT transducers to obtain more physical information (Song et al 2007, Lim et al 2016, Dumoulin and Deraemaeker 2017, Hong et al 2017, Lim et al 2017, Zhu et al 2017 for better characterization of the structural condition.…”

“…Kim et al (2015) proposed an approach to concrete curing monitoring, which make use of the correlation between the curing status and the gradient of the susceptance spectrum The approaches based on the principle of wave propagation, including travelling wave (derived from ultrasonic testing) and standing wave, have also been extensively used in conjunction with piezoelectric transducers for concrete monitoring (Gu et al 2006). These piezoelectric transducers can be installed in the form of simply embedding (Song et al 2007), "smart aggregates" (Song et al 2008b, Xu et al 2017 or surface bonding (Lim et al 2016). While the EMI technique employs one transducer as both actuator and sensor, the WP technique requires separate actuator and sensor in most cases, which may increase the cost for certain monitoring applications.…”

Grouting Quality Evaluation in Post-Tensioning Tendon Ducts Using Wavelet Packet Transform and Bayes Classifier

“…Zima et al [18] used piezoelectric ceramic patches to generate ultrasonic guided wave for identifying debonding between bars and grouting mortar in ground anchors. Lim et al [19,20] developed a semi-analytical model of surface bonded piezoelectric based wave propagation technique for concrete strength monitoring during the curing process. Malinowski et al [21] applied piezoelectric sensors in the electromechanical impedance-based method to detect weak adhesive bonds of carbon fiber reinforced polymer.…”