Issue 53

D. Wang et alii, Frattura ed Integrità Strutturale, 53 (2020) 236-251; DOI: 10.3221/IGF-ESIS.53.20 238 M ETHODOLOGY Specimen design hree specimens, denoted as S1-3, with the same size were designed according to the provisions of the relevant code [32]. The plate is 4.8 m in length ( l 1 ), 4 m in width ( l 2 ) and 0.2 m in thickness ( h ). The square column is 0.4 m in side length ( a ) and 1.6 m in height. Beneath the column, there is a foundation with the side length of 1.4 m and thickness of 0.3 m. The vertical view and photo of a specimen are given in Fig. 1(a) and Fig. 1(b), respectively. (a): Vertical view of the specimen. (b): Photo of the specimen. Figure 1: Vertical view and photo of the specimen. The specimens were made with commercial concrete and cured for 221 days. For each specimen, three 150×150×150 mm standard concrete cubes were taken and cured under the same conditions as the specimens. On the test day, the mean compressive strength f cu of the concrete cubes was measured as 54.3 MPa, i.e., by using a microcomputer-controlled electro- hydraulic servo universal testing machine [33]. HRB400 steel bars were selected and subjected to pull-out tests [34]. The standard values of the yield strength f yk and the ultimate strength f stk of the steel bars were measured through the tests. Then, the mean design strength f y of the steel bars was derived as 412 MPa [32]. The plate was reinforced by two layers of bidirectional steel bars, with a diameter of 12 mm, a spacing of 150 mm and a 20 mm-thick protective layer. The column was reinforced by eight 20 mm-diameter longitudinal steel bars, and 8 mm-diameter stirrups, with a spacing of 100 mm. The foundation was reinforced at the bottom by bidirectional steel bars, with a diameter of 16 mm and a spacing of 200 mm. The reinforcement of each specimen is illustrated in Figs. 2. (a): Planar reinforcement of the specimen. (b): Site pouring of the specimen (c): Reinforcements of the column and the foundation. Figure 2: Reinforcement information and photos of specimen T