*2.1. Test Matrix*

The experimental program involved thirty-two square specimens tested mainly in two groups, as shown in Table 1. The two groups were separated depending upon the provision of the corner radius. The specimens in the first group were tested without any corner radius and identified with R0 in their notation, whereas a 26 mm corner radius was provided in the second group. Each group comprised eight different specimen types with two representative specimens for each type. The specimens in each group were differentiated by the concrete strength, i.e., low- or high-strength concrete specimens. Furthermore, in each group two specimens were considered as the control and tested without LC-GFRP wraps. Meanwhile, the remaining specimens were wrapped with two, four, and six layers of GFRP. The notation used to identify specimens involved four parts. The first part "SQ" was constant for all of the specimens identifying the cross-sectional shape as square, the second part was either "LS" or "HS" for low- or high-strength concrete strength, the third part identified the presence of the corner radius with R0 and R26 for no corner radius and a corner radius of 26 mm, respectively, and the last part identified the number of GFRP layers. For instance, the notation SQ-LS-R26-6GFRP referred to a square specimen constructed with low-strength concrete with its corner rounded to a 26 mm radius and strengthened with six layers of GFRP. Further details are provided in Table 1.
