**2. Methodology and Materials**

An overview of the adopted methodology in this work is shown in the flowchart in Figure 1. The first module corresponds to dataset construction's image acquisition and preparation process. The second module represents the implementation of the pre-trained VGG16 network using Transfer Learning to classify three types of defects in concrete bridges. Finally, interpretation techniques were deployed in the third module to generate pixel-level heatmaps to localize concrete damage.

**Figure 1.** Overview of the proposed method.
