# Assessment of a Substandard Reinforced Concrete Frame's Beam-Column Joint Using Shake Table Testing
## 3 Experimental Study
### Overview of the Test Specim  
The test model was meticulously created to align with the defined similitude criteria pertinent to a scaled representation of the prototype showcased in Figure 4. This selected prototype is an aseismically designed RC frame building located in Turkive, which was constructed during the 1980s. It serves as a representative case for a multitude of RC structures built prior to the introduction of modern seismic regulations in Turkive and was originally designed exclusively to withstand gravity loads. As detailed in Figure 4, this prototype is characterized by a rectangular floor plan comprising three bays, each measuring 4.35 m and 5 m in two mutually perpendicular orientations. Furthermore, the prototype's story height was determined to be 3 m. The experimental setup consisted of a single-bay and a single-story RC frame, which was separated from the prototype structure. The structure was created using a scaled model, specifically a one-third reduced scale of the original prototype, adhering to the similitude principles detailed in Table 3.  
The simulation employed columns characterized by a rectangular cross-section, measuring 100 mm in width and 150 mm in height, and the columns were positioned with a center-to-center spacing of 1350 mm. Each column incorporated four longitudinal reinforcement bars with a diameter of 8 mm, which is recognized as the smallest available size of a deformed bar in the local market. The vertical extension of the columns was established at 950 mm, extending from the foundation's top to the underside of the upper slab. Transverse reinforcement consisted of 8 mm bars, strategically spaced at 100 mm intervals from center to center. The configuration of the stirrups included 90-degree hooks, further illustrating the substandard detailing of the columns. Moreover, 8 mm diameter steel bars were systematically arranged at 100 mm intervals both longitudinally and transversely at the upper and lower surfaces of the slab. In terms of foundation reinforcement, the longitudinal bars were constructed from 16 mm diameter steel, while the stirrups were fabricated from 10 mm diameter bars positioned 150 mm apart. The top slab dimensionswere noted to be 1450 mm in length, 450 mm in width, and 50 mm in thickness. To bolster structural integrity, a foundation beam was created, measuring 1950 mm in length, 600 mm in width, and 400 mm in depth. This beam was successfully anchored to the shaking table using anchor bolts of 50 mm in diameter. A schematic representation of the specimen is illustrated in Figure 5.  
The test columns were subjected to axial loading by integrating steel blocks into the setup. As discussed earlier, a combined weight of 6 tons was applied to the frame, resulting in an individual axial load of 30 kN on each reinforced concrete column. This axial load represented 44% of each column's axial load capacity, not factoring in the contribution of longitudinal reinforcement to the overall capacity. Figure 6 depicts the configuration of the specimens, including the added mass, positioned on the shake table.  
Figure 4: (**a**) Floor plan illustrating dimensions and structural layout of the prototype reinforced RC building; (**b**) the exact position and dimensional details of the experimentally analyzed frame.  
Figure 5: Details of the specimen.