PSI - Issue 44

Elisabetta Maria Ruggeri et al. / Procedia Structural Integrity 44 (2023) 464–471 E. Ruggeri, G. D’Arenzo, D. Li Cavoli, R. Cottonaro, M. Fossetti/Structural Integrity Procedia 00 (2022) 000–000

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2. Materials The experimental tests presented in this study were performed at L.E.D.A. Research Centre of University of Enna “Kore” (Fossetti and Minafò 2017). Two CLT wall assembly configurations were considered to investigate the lateral performance of CLT shear walls connected to perpendicular CLT wall elements: single Shear Wall (SW) configuration, see Figure 2 (a), which considers a single CLT shear wall subjected to lateral load and Shear Wall connected to a Perpendicular Wall (SW+PW) configuration, see Figure 2 (b), which considers the same CLT shear wall subjected to lateral load connected to a perpendicular wall placed on the shear wall extremity. All shear wall specimens were made of monolithic wall panels with dimensions 1250×2500 mm. The CLT panels of the perpendicular walls were of the same type of the panels used for the shear walls, with dimensions 500×2500 mm.

Fig. 2. (a) Single Shear Wall configuration (SW); (b) Shear Wall connected to a Perpendicular Wall configuration (SW+PW).

CLT panels used for the tests were 100 mm thick, made with 5 crossed layers with thicknesses equal to 20 -20- 20 20- 20 mm (in bold the thickness of the layers arranged in vertical direction). Each layer was characterized by modulus of elasticity E mean equal to 12.000 MPa and shear modulus G mean equal to 690 MPa. They were made of European spruce and manufactured at Binderholz GmbH in Austria (ETA - European TechnicalAssessment 2017). The wall panels were anchored to a steel foundation with hold-downs and angle brackets. Hold-downs type WHT340 (ETA - European Technical Assessment 2015), manufactured by Rothoblaas were used to anchor the shear wall against rocking displacements. The connector was fastened in the vertical flange by means of twelve annular ringed nails 4×60 mm and anchored to the steel base beam through an M16 bolt. Angle brackets type WBR90110 (ETA-European Technical Assessment 2011) manufactured by Rothoblaas were used to anchor the shear wall against horizontal-sliding displacements. The angle brackets were fastened in the vertical flange by means of thirteen annular ringed nails 4×60 mm and anchored to the steel base beam by means of two M12 bolts. Self-tapping screws HBS 10×200 mm manufactured by Rothoblaas (ETA - EuropeanTechnicalAssessment 2022) were used in the vertical joint to connect perpendicular and shear walls. 3. Methods In total four experimental tests were carried out including one monotonic and one cyclic test for each configuration. Photo of the test set-up for both configurations is shown in Figure 3. The lateral load was applied by means of a 300 kN hydraulic actuator connected to a rigid steel beam IPE 160 type. This steel beam, which transferred the lateral load of the actuator, was connected to the top of the wall with self-tapping screws 10×200 mm. A HEB 220 steel beam was used to simulate the foundation. The CLT walls were anchored to this beam with the hold-downs and angle brackets, described in the previous section. Measurement instrumentation was attached to the wall panels at several locations as shown in Figure 3. Linear Variable Displacement Transducers (LVDTs) were used to measure vertical and horizontal displacements in different locations of the specimens. One LVDT was vertically located at each corner of the shear wall in correspondence of the hold-downs to measure the uplift of the shear wall. One LVDT was connected to the foundation steel beam and used to measure the sliding displacement at base of the shear wall, while another LVDT was used to control the horizontal displacement of the foundation steel beam (HEB 220). The horizontal displacement on the top of the wall was measured using an LVDT placed on an external steel structure. Finally, an