## 2 Experimental Program  
### Specimen Details  
Six exterior beam-column connection specimens were prepared to examine the effect of the anchorage deficiency of GFRP bars on the flexural and shear performances of the beam. Thus, all the beam-column connections were designed to fail along the beam element. The specimens were classified into two-series according to the governing failure mechanism of the beam element as follows: F-series governed by flexure and S-series by shear, as given in Table 1. Note that the governing failure mechanism was designed in accordance with the design procedure for flexural and shear capacities of the beam specified in the ACI 318-14 [5] and ACI 440.1R-15 [6] provisions. The design compressive strength (\(f_{cd}\)) of concrete was selected to be 35 MPa and 70 MPa for the F-series specimens and it was fixed to 70 MPa for the S-series specimens. The main variables investigated in each series were the type and strength of longitudinal reinforcement. The amount of GFRP bars was determined to have the same longitudinal reinforcement index as the companion beams with conventional steel bars. Two types of yield strength (\(f_{y}\)) of steel bars were used in longitudinal reinforcement of the beams according to \(f_{cd}\); a 400 MPa-grade (SD 400) steel bar for the beam with a \(f_{cd}\) of 35 MPa and a 600 MPa-grade (SD 600) steel bar for the beam with \(f_{cd}\) of 70 MPa. Thus, the specimen notation listed in Table 1 is composed of three parts. The first and second parts in the notation refer to the governing failure mechanism of the beam and design compressive strength of concrete, respectively. The third part indicates the type of the longitudinal reinforcement of the beam: C for the conventional steel bar and G for the GFRP bar. For example, specimen F-N-C indicates a beam-column connection governed by flexure with a \(f_{cd}\) of 35 MPa and conventional steel bar as a longitudinal reinforcement of the beam; and specimen S-H-G indicates a beam-column connection governed by shear with a \(f_{cd}\) of 70 MPa and GFRP bar as a longitudinal reinforcement of the beam. All specimens had the same geometrical dimensions and arrangement of reinforcing bars in columns, as shown in Figure 1. The section size and span of the square column were 500 mm and 1600 mm, respectively. Eight deformed steel bars with a diameter of 25 mm were arranged for the longitudinal reinforcement of the column. For the hoop of the column, steel bars with a diameter of 10 mm were arranged at a spacing of 50 mm in the connection and support zones, and 100 mm in the intermediate areas between the connection and support zones. The beam connected into the column had a width (\(b_{w}\)) of 412 mm and an overall depth (\(h\)) of 500 mm. The beam spans (\(L\)) in the F-series and S-series specimens were 2200 mm and 800 mm, respectively. The amount of the longitudinal reinforcement of the beams varied according to the test parameters. To derive the flexure failure of the beam in the F-series specimens, the following longitudinal reinforcement details were designed: Five steel bars (SD 400) with a diameter (\(\phi\)) of 13 mm for the specimen F-N-C; the combination SD 600 steel reinforcement of two bars with \(\phi\) of 16 mm and three bars with \(\phi\) of 19 mm for the specimen F-H-C; three GFRP bars with \(\phi\) of 12 mm for the specimen F-N-G; and eight GFRP bars with \(\phi\) of 12 mm for the specimen F-H-G. Thus, the longitudinal reinforcement ratios of the beam in these specimens were 0.003, 0.007, 0.002, and 0.005, respectively. For the longitudinal reinforcement of the beam in the S-series specimens, the SD 600 steel reinforcing bars (three bars with \(\phi\) of 16 mm and three bars with \(\phi\) of 19 mm) were used for the specimen S-H-C; and 10 GFRP bars with \(\phi\) of 12 mm were used for the specimen S-H-G. For the shear reinforcement, deformed steel bars with \(\phi\) of 10 mm were arranged at an interval of 200 mm and 300 mm for the F-series and S-series specimens, respectively.