PSI - Issue 42

Martina Drdlová et al. / Procedia Structural Integrity 42 (2022) 1382–1390 Martina Drdlova/ Structural Integrity Procedia 00 (2022) 000 – 000

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. Fig. 6 Real crash test of the barrier – before (left) and after (right) the test

4. Conclusions The presented study evaluates and compares the effectiveness of different reinforcement options in increasing the impact toughness of cement-based elements in order to find the best performance/cost ratio and optimal material composition suitable for using in vehicle restraint system. The following conclusions can be drawn: -Mesh and ribbed reinforcing steel increases the impact toughness more effectively than the steel fibre reinforcement and additional polymer layer. -Steel m esh reinforcement, although introducing higher mass of steel into the element, provides a lower effect in terms of increasing the toughness and resistance to impact loading compared to the rebar reinforcement. This is probably related to a certain stress concentration along the transverse reinforcement during the impact - the transverse reinforcement may act as an impactor on the longitudinal bars and initiate their rupture. -Comparing the specimens without bar reinforcement, t he highest impact toughness was achieved in the case of UHPFRC specimens with fine grained matrix. The value of the impact toughness was twice the respective value of HPFRC specimens. Strong concrete matrix is beneficial for improving the impact resistance of the concrete. The pullout of steel fibres from the high strength matrix can absorb a large amount of energy generated by the impact process. -Polyurea coating is highly effective in increasing the impact toughness of thin-walled elements and reduction of fragmentation and spalling. -The results also indicate that similar resistance capacity can be achieved using different reinforcement combinations, which is crucial for designing the material composition with the optimal performance/cost ratio. The presented research is a part of the project dealing with the development of the restraint system for stopping trucks. Within the next steps, the barrier systems for stopping N3 category trucks (weight 30 t) will be developed. Acknowledgements The authors wish to express their gratitude and sincere appreciation to the authority of the Ministry of the Interior of Czech Republic, project No. VI20192022129, for financial support. References Alyousef, R., Alabduljabbar, H., Mohammadhosseini H., Mohamed, A.M., Siddika, A., Alrshoudi, F., et al., 2020. Utilization of sheep wool as potential fibrous materials in the production of concrete composites, Journal of Building Engineering., 30, Article 101216. Al-Khafaji, F. Meyers, J.J., Alghazali, H.H., 2021. Evaluation of bond performance of glass fiber rebars embedded in sustainable concrete, Journal of Cleaner Production., 282, Article 124516. Bibora, P., Drdlová, M., Sviták, O., 2019. The impact of various types of steel fibres on the strength parameters and blast resistance of high - performance concrete, FIBRE CONCRETE 2019, 596. Drdlová, M., Popovič, M., Koutný, O., 2018. Blast resistance of hybrid fibre reinforced concrete containing polyvinyl alcohol, polypropylene and steel fibres with various shape parameters, European Physical Journal: Special Topics.