PSI - Issue 64

7

Ravina Sriram et al. / Procedia Structural Integrity 64 (2024) 2051–2058 Author name / Structural Integrity Procedia 00 (2019) 000–000

2057

The installation procedure involves temporarily fixing the Fe-SMA strips to the slab using T-supports. At both ends, the strips were anchored using Hilti nails to the concrete substrate. Then, the strips were heated segment-wise with a blowtorch to activate and create the prestressing force. Once cooled, the Fe-SMA strips become load-bearing.

Figure 6: Layout of CFRP (green) and FeSMA (red) strips (left) and reinforcement detail of the post-installed “mushrooms”.

Figure 7: Installed Fe-SMA strips (left) and reinforment and formwork for "mushrooms"

5. Conclusions This work focused on two primary methods to enhance punching shear resistance: the prestressing of Fe-SMA bars over the support columns and the prestressing of Fe-SMA strips within the span. The efficacy and practical applications of these approaches were explored herein. When reinforcement above a support reaches yield strength and shear resistance is insufficient, the implementation of prestressed reinforcement above the support is advantageous. Within the first case study, the prestressing of Fe SMA bars over support columns has been shown to be particularly effective in increasing the punching shear resistance. This method induces an eccentrical compressive force in the concrete, which is useful for reducing the rotation of the slab.