Mobile anti-vehicle barrier made of high-performance fibre-reinforced concrete

2021 ◽  
pp. 136943322199772
Author(s):  
Petr Konrád ◽  
Michal Mára ◽  
Jindřich Fornůsek ◽  
Luboš Nouzovský ◽  
Jan Zatloukal ◽  
...  

The article presents a mobile anti-vehicle barrier created from a high-performance fibre-reinforced concrete, which resembles a historical design of the Czech Hedgehog barrier. The performance of this design when subjected to a moderate velocity vehicle impact was evaluated. A preliminary crash test provided basic data to perform an optimisation of the design using numerical simulations conducted in LS-DYNA. Several key observations were made regarding the crucial role of the barrier-surface interactions and overall barrier behaviour. Based on the simulations, improved geometry of the barrier was proposed and subjected to more full-scale crash tests with various barrier placements. The improved barrier design was able to stop an ordinary road vehicle weighing 1300 kg moving with a velocity of 48 km/h while retaining beneficial characteristics, most importantly low weight.

Author(s):  
Benjamin Erzar ◽  
Christophe Pontiroli ◽  
Eric Buzaud

To evaluate the vulnerability of ultra-high performance fibre-reinforced concrete (UHPFRC) infrastructure to rigid projectile penetration, over the last few years CEA-Gramat has led an experimental and numerical research programme in collaboration with French universities. During the penetration process, concrete is subjected to extreme conditions of pressure and strain rate. Plasticity mechanisms as well as dynamic tensile and/or shear damage are activated during the tunnelling phase and the cratering of the concrete target. Each mechanism has been investigated independently at the laboratory scale and the role of steel fibres especially has been analysed to understand their influence on the macroscopic behaviour. To extend the experimental results to the structural scale, penetration tests on UHPFRC slabs have been conducted by CEA-Gramat. The analysis of this dataset combined with material characterization experiments allows the role of steel fibres to be identified in the different plasticity and damage mechanisms occurring during penetration. In parallel, some improvements have been introduced into the concrete model developed by Pontiroli, Rouquand and Mazars (PRM model), especially to take into account the contribution made by the fibres in the tensile fracture process. After a primary phase of validation, the capabilities of the PRM model are illustrated by performing numerical simulations of projectile penetration into UHPFRC concrete structures. This article is part of the themed issue ‘Experimental testing and modelling of brittle materials at high strain rates’.


2018 ◽  
Vol 183 ◽  
pp. 02005
Author(s):  
Ezio Cadoni ◽  
Matteo Dotta ◽  
Daniele Forni

The paper presents the results obtained on cylindrical Ultra High Performance Fibre Reinforced Concrete specimens with diameter of 30mm and a height of 60mm under compression at high stress rate (1.7–2.3 TPa/s). Four different percentages of fibre reinforcement are considered (1, 2, 3, and 4% fibre content) and compared with the results of the matrix (UHPC). A slight reduction of the strength and fracture time with the introduction of fibres is observed. The experimental results are analysed and discussed with the intent to better understand the mechanical behaviour of UHPFRC materials in case of dynamic event under service loading conditions.


2008 ◽  
Vol 17 (11) ◽  
pp. 316-317
Author(s):  
Daniel de MATTEIS ◽  
Pierre MARCHAND ◽  
Aude PETEL ◽  
Thierry THIBAUX ◽  
Nicolas FABRY ◽  
...  

Materials ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 1372 ◽  
Author(s):  
Krzysztof Ostrowski ◽  
Łukasz Sadowski ◽  
Damian Stefaniuk ◽  
Daniel Wałach ◽  
Tomasz Gawenda ◽  
...  

When understanding the effect of the morphology of coarse aggregate on the properties of a fresh concrete mixture, the strength and deformability of self-compacting high-performance fibre-reinforced concrete (SCHPFRC) can be seen to be critical for its performance. In this research, regular and irregular grains were separated from granite coarse aggregate. The morphology of these grains was described while using digital image analysis. As a result, the aspect ratio, roundness and area ratio were determined in order to better understand this phenomenon. Then, the principal rheological, physical, and mechanical properties of SCHPFRC were determined. The obtained results indicated that the morphology of the grains of coarse aggregate has an impact on the strength and stiffness properties of SCHPFRC. Moreover, significant differences in the transverse strain of concretes were observed. The morphology of the coarse aggregate also has an impact on the rheological parameters of a fresh concrete mixture. To better understand this phenomenon, the hypothesized mechanism of the formation of SCHPFRC caused by different morphology of coarse aggregate was proposed at the end of the article.


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