## 1 Introduction  
The health status of modern concrete infrastructures requires considerable intrinsic cement-based sensors for real-time monitoring [1; 2; 3]. The electrical properties of these sensors are frequently employed as sensing signals reflecting the stress or strain under external static and or dynamic loadings of the cement concrete matrix which is incorporated with some microscale or nano scale additives, such as carbon fibers (CFs), carbon nanotubes (CNTs) [4; 5; 6; 7; 8; 9; 10], or lead zirconate titanate (PZT) powder [11; 12; 13; 14; 15; 16]. As [PERSON] et al. [11; 15], [PERSON] et al. [12], [PERSON] et al. [13], [PERSON] et al. [14], [PERSON] et al. [16], [PERSON] et al. [17], [PERSON] et al. [18; 19; 20], and [PERSON] et al. [21] reported, the 0-3 type piezoelectric cement-based composite (PCM) wafer has excellent piezoelectric self-sensing and self-driving responses, and a good compatibility with long-life concrete. Therefore, it is easy to realize the fine regulation of performance indicators through changing the fillers' contents [14]. These superior features render PCMs, after curing and waterproof encapsulation, as novel candidates of sensors/actuators embedded in concrete-based infrastructures for structural health monitoring (SHM) [15]. Nevertheless, the driving performance in the non-polarized direction of the 0-3 type PCM is not so strong and it cannot produce enough stress or displacement in a specific direction for engineering needs [19; 20]. Owing to interdigitated electrode (IE) technology, the polarization direction of the piezoelectric device with IEs is the same as the voltage-driving one, rendering a great improvement of the in-plane strain/stress-driving capacity, and obvious orthotropic features [22; 23; 24; 25; 26; 27; 28]. [PERSON] et al. [22] documented that the 1-3 type PCM with IEs possessed a high piezoelectric constant and superior orthotropic features with different receiving sensitivities for the stress waves from orthogonal directions. [PERSON] et al. [23; 24] studied the piezoelectric characteristics of a pure PZT wafer with IEs and its application criteria by simulating the method. [PERSON] et al. [25] found that the harmonic resonant frequency of a PZT sheet with IEs is small and the resonance is more likely to happen, but its electromechanical coupling coefficient is lower than that of the general PZT. [PERSON] et al. [26] reported that the narrow electrode finger spacing, thin interlayer, small fiber thickness, and high volume fraction of a piezoelectric ceramic fiber were all positive with the enhancement of the free strain performance of the piezoelectric fiber composite with IEs. [PERSON] et al. [27] reported that the electrospinning of polyvinylidene fluoride (PVDF) and a CNT piezoelectric nanofiber array on IEs fabricated a flexible sensing device, and found that PVDF/CNT crystallization as spherical composite structures can enhance the piezoelectric properties of PVDF fibers and effectively convert the mechanical energies of low-frequency ambient vibrations and impacts into electrical signals. [PERSON] et al. [28] studied the converse mode piezoelectric coefficient for PZT thin film with IEs, where the film with IEs showed a lower average piezoelectric stress than that with parallel-plate electrode, and effectively prevented cracking. However, to the best knowledge of the authors, there is no research work on the use of the IE technique in 0-3 type PCMs, and no exploration into the orthotropic and driving properties of the corresponding PCM. The 0-3 type PCM with IEs (IEPCM) indeed can be regulated with almost the same durability, Young's modulus and acoustic impedance as concrete structures, and it effectively makes up for the deficiencies and defects in the engineering application of the common piezoelectric element. Meanwhile, as mentioned above [19; 22], the finite element software ANSYS is a powerful tool for simulating and analyzing static and dynamic responses of diversified materials on multi-field coupling problems.