PSI - Issue 64

Carmine Lima et al. / Procedia Structural Integrity 64 (2024) 849–856 Lima et al. / Structural Integrity Procedia 00 (2019) 000 – 000

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arranged (Fig. 3b); (iii) the concrete was then casted (Fig. 3c) and (iv) cured at environmental condition for 28 days (Fig. 3d).

a

b d Fig. 3 Preparation and casting process for steel-concrete samples c

2.3. Push-out testing device and setup Push-out tests were performed by using an actuator with maximum load equal to 3000 kN. The specimens were instrumented with LVDTs and sensors in order to monitor all possible displacements: LVDTs (four for each side) and three wire displacement meters were disposed as also shown in Fig. 4.

Fig. 4 Push-out test instrumentation

The test was performed in accordance with the standard push-out protocol defined by EN1994-1-1 (2004). Therefore, in the first stage of the test, the load was applied in force-control up to the 40% of the expected failure load with a loading rate equal to 20 kN/min; in the second stage of testing 25 cycles between 5% and 40% of the expected failure load were executed with a loading rate equal to 20 kN/min; finally, load increments was imposed in displacement control (loading rate equal to 0.20 mm/min) considering that failure did not occur before than 15 minutes. During the whole execution of the push-out test, the longitudinal slip between concrete slab and the steel element was recorded continuously in each monitored point by the eight LVDTs (Fig. 4) and the test was ended when the load dropped to 20% below the maximum load. The expected failure load P dR was estimated as the minimum value between the failure of connectors P dR,a and the one of the concrete slab P dR,c according to EN1994-1-1 (2004). , =0,8 ∙ ∙ ( ∙ 2 ⁄4) (1) , = 0,29 ∙ ∙ 2 ∙ ( ∙ ) 0,5 (2)