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Experimental modal analysis of RC beams strengthened with SHCC subjected to shear under impact strain rates
Highlights RC beams without stirrups did not preserve their original natural frequencies and vibrational modes. Specimens with stirrups kept a residual dynamic response until impact speeds of 26.1 m/s. Specimens strengthened with SHCC excelled on enduring a residual dynamic response.
Abstract Strain Hardening Cement-based Composites (SHCC) holds great potential to be a remarkably effective material for shear strengthening of reinforced concrete beams in case of impact scenarios due to its great energy dissipation capability through the formation of multiple very fine cracks (∼100 μm of width). The effectiveness of this technique is investigated in the paper at hand through the observation of the changes in the dynamic properties in terms of natural frequencies, mode shapes, and damping ratios. Considering a non-destructive free vibration excitation of the specimens before the experiment (undamaged/intact state) to their condition after the destructive impact of an accelerated steel projectile. In this sense, two types of reinforcement configurations and two types of strengthening layers were investigated: reinforced concrete beams with and without stirrups were strengthened with SHCC made with polyvinyl alcohol (PVA) and ultra-high molecular weight polyethylene (UHMWPE) and tested under increasing levels of kinetic energy varying between 2.1 kJ and 6.4 kJ by using an accelerated impactor inside a drop tower facility. The parameter variation enabled conclusions with respect to the influence of the stirrup reinforcement and the SHCC strengthening contributions in the case of dynamic scenarios.
Experimental modal analysis of RC beams strengthened with SHCC subjected to shear under impact strain rates
Highlights RC beams without stirrups did not preserve their original natural frequencies and vibrational modes. Specimens with stirrups kept a residual dynamic response until impact speeds of 26.1 m/s. Specimens strengthened with SHCC excelled on enduring a residual dynamic response.
Abstract Strain Hardening Cement-based Composites (SHCC) holds great potential to be a remarkably effective material for shear strengthening of reinforced concrete beams in case of impact scenarios due to its great energy dissipation capability through the formation of multiple very fine cracks (∼100 μm of width). The effectiveness of this technique is investigated in the paper at hand through the observation of the changes in the dynamic properties in terms of natural frequencies, mode shapes, and damping ratios. Considering a non-destructive free vibration excitation of the specimens before the experiment (undamaged/intact state) to their condition after the destructive impact of an accelerated steel projectile. In this sense, two types of reinforcement configurations and two types of strengthening layers were investigated: reinforced concrete beams with and without stirrups were strengthened with SHCC made with polyvinyl alcohol (PVA) and ultra-high molecular weight polyethylene (UHMWPE) and tested under increasing levels of kinetic energy varying between 2.1 kJ and 6.4 kJ by using an accelerated impactor inside a drop tower facility. The parameter variation enabled conclusions with respect to the influence of the stirrup reinforcement and the SHCC strengthening contributions in the case of dynamic scenarios.
Experimental modal analysis of RC beams strengthened with SHCC subjected to shear under impact strain rates
Figueiredo, Tathiana Caram S.P. (author) / Gaspar, Cassio M.R. (author) / Hering, Marcus (author) / Curosu, Iurie (author) / Curbach, Manfred (author) / Mechtcherine, Viktor (author) / de Andrade Silva, Flávio (author)
Engineering Structures ; 264
2022-05-21
Article (Journal)
Electronic Resource
English
SHCC-strengthened RC panels under near-field explosions
| British Library Online Contents | 2018