PSI - Issue 28

Ezio Cadoni et al. / Procedia Structural Integrity 28 (2020) 933–942

941

Author name / Structural Integrity Procedia 00 (2020) 000–000

9

Fig. 9. Comparison between representative dynamic shear versus shear-slip curves in function of the percentage of fibre reinforcement.

first fracture is induced by a shear failure. The new set-up permitted to successfully tested a UHPFRCs direct-shear specimen at substantially high strain rates up to 297 1 / s. The experimental tests highlighted an enhancement in shear strength capacity as the fibre percentage increases (Fig. 8). A shear strength increment of 61% was obtained for the 4% UHPFRC in comparison to the matrix, while 26%, 44% and 46% strength increments were obtained for the 1%, 2% and 3% UHPFRCs, respectively. It was found that also the post-peak strength is strongly governed by the fibre per centage leading to the conclusion that it also depend from the fibre orientations and distributions. Further experimental research will be addressed to the combined e ff ects of direct-shear and triaxiality.

Acknowledgements

The authors would like to express his sincere gratitude to Dr. A. Koch (Dynamic Phenomena srl) for fruitful discussions. This work has been supported by armasuisse - Science and Technology of the Swiss Federal Department of Defence, Civil Protection and Sport.

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