Field Tests of Cementitious Composites Suitable for Protective Structures and Critical Infrastructure

2016 ◽  
Vol 722 ◽  
pp. 3-11 ◽  
Author(s):  
Jiří Štoller ◽  
Petr Dvořák
Keyword(s):  
Reinforced Concrete ◽  
High Performance ◽  
Critical Infrastructure ◽  
Field Tests ◽  
Plain Concrete ◽  
Cementitious Composites ◽  
Fibre Reinforced Concrete ◽  
Steel Fibre Reinforced Concrete ◽  
Ballistic Resistance ◽  
Protective Structures

The paper deals with field tests of cementitious composites suitable for protective structures and critical infrastructure. The tests of ballistic resistance against contact and distant explosions are performed according to the NATO standards. The results of tests of plain concrete, steel fibre reinforced concrete and high performance fibre reinforced concrete are analysed.

Application of Cement Based Materials for Critical Infrastructure Protection

2015 ◽  
Vol 796 ◽  
pp. 99-110
Author(s):  
Jiří Štoller ◽  
Petr Dvořák
Keyword(s):  
Reinforced Concrete ◽  
High Performance ◽  
Critical Infrastructure ◽  
Field Tests ◽  
Plain Concrete ◽  
Lessons Learned ◽  
Fibre Reinforced Concrete ◽  
Critical Infrastructure Protection ◽  
Infrastructure Protection ◽  
Cement Based Materials

The article describes the characteristics of a selected cement based materials and the possibilities of their use for critical infrastructure protection. The material properties were studied during field tests on slabs made from different materials – plain concrete, fibre reinforced concrete and high performance fibre reinforced concrete. In the article there are also presented lessons-learned of the research team of the military structures laboratory, which is run by the Department of Engineer Technologies at the University of Defence.

Numerical study of ultra-high-performance steel fibre–reinforced concrete columns under monotonic push loading

2017 ◽  
Vol 21 (8) ◽  
pp. 1234-1248 ◽  
Author(s):  
Shenchun Xu ◽  
Chengqing Wu ◽  
Zhongxian Liu ◽  
Jun Li
Keyword(s):  
Reinforced Concrete ◽  
Axial Compression ◽  
High Performance ◽  
Steel Fibre ◽  
Concrete Columns ◽  
Fibre Reinforced Concrete ◽  
Structural Behaviour ◽  
Reinforced Concrete Columns ◽  
Steel Fibre Reinforced Concrete ◽  
High Performance Steel

A finite element model is developed to investigate the behaviour of ultra-high-performance steel fibre–reinforced concrete columns under combined axial compression and horizontal monotonic push loading. The effects of steel fibre content, axial compression ratio, reinforcement ratio (or rebar ratio), stirrup ratio and shear span ratio on the structural behaviour of ultra-high-performance steel fibre–reinforced concrete columns are investigated in detail. The numerical model shows good agreement in bond–slip behaviour of specimens based on CEB model results and numerical results, and such behaviour should be taken into consideration in engineering practice. The results indicate that the developed finite element model could predict the structural behaviour and failure mode of ultra-high-performance steel fibre–reinforced concrete columns effectively. It is found that the reinforcement ratio, axial compression ratio, shear span ratio and volume fraction of steel fibre have a great influence on both the structural behaviour and failure modes of specimens.

Experimental Tests of Steel Fibre Reinforced Concrete Beams under Drop-Weight Impacts

2014 ◽  
Vol 626 ◽  
pp. 311-316 ◽  
Author(s):  
Yi Fei Hao ◽  
Hong Hao ◽  
Gang Chen
Keyword(s):  
Reinforced Concrete ◽  
Steel Fibre ◽  
Concrete Beams ◽  
Plain Concrete ◽  
Fibre Reinforced Concrete ◽  
Steel Fibres ◽  
Steel Fibre Reinforced Concrete ◽  
Impact Tests ◽  
Drop Weight ◽  
The Impact

Concrete is a brittle material, especially under tension. Intensive researches have been reported to add various types of fibres into concrete mix to increase its ductility. Recently, the authors proposed a new type of steel fibre with spiral shape to reinforce concrete material. Laboratory tests on concrete cylinder specimens demonstrated that compared to other fibre types such as the hooked-end, deformed and corrugated fibres the new fibres have larger displacement capacity and provide better bonding with the concrete. This study performs drop-weight impact tests to investigate the behaviour of concrete beams reinforced by different types of steel fibres. The quasi-static compressive and split tensile tests were also conducted to obtain the static properties of plain concrete and steel fibre reinforced concrete (FRC) materials. The quasi-static tests were carried out using hydraulic testing machine and the impact tests were conducted using an instrumented drop-weight testing system. Plain concrete and concrete reinforced by the commonly used hooked-end steel fibres and the proposed spiral-shaped steel fibres were tested in this study. The volume dosage of 1% fibre was used to prepare all FRC specimens. Repeated drop-weight impacts were applied to the beam specimens until total collapse. A 15.2 kg hard steel was used as the drop-weight impactor. A drop height of 0.5 m was considered in performing the impact tests. The force-displacement relations and the energy absorption capabilities of plain concrete and FRC beams were obtained, compared and discussed. The advantage and effectiveness of the newly proposed spiral-shaped steel fibres in increasing the performance of FRC beam elements under impact loads were examined.

scholarly journals USING TEXTILE ARAMID FABRICS TO INCREASE THE BALLISTIC RESISTANCE OF ULTRA-HIGH-PERFORMANCE STEEL-FIBRE REINFORCED CONCRETE

2020 ◽  
Vol 60 (6) ◽  
Author(s):  
Michal Mára ◽  
Radoslav Sovják ◽  
Jindřich Fornůsek
Keyword(s):  
Reinforced Concrete ◽  
High Performance ◽  
Steel Fibre ◽  
Rear Side ◽  
Fibre Reinforced Concrete ◽  
Ballistic Performance ◽  
Steel Fibre Reinforced Concrete ◽  
Textile Fabrics ◽  
High Performance Steel ◽  
Aramid Fabrics

Thin plates made of Ultra-High-Performance Steel-Fibre-Reinforced Concrete (UHPSFRC) with textile Aramid fabrics were subjected to a projectile impact and its post-test damage was discussed. The damage degrees were the type of the response and crater surface, which was determined by using a 3D scanner. The most common type of ammunition, which is a 7.62 × 39mm calibre with a full-metal jacket and a mild-steel core, was used for all specimens. It was verified experimentally that the UHP-SFRC with textile Aramid fabrics has a better ballistic performance in comparison with its counterpart made of the UHP-SFRC without any textile reinforcement. Also, it was verified that specimens with the point or segment interconnection threads between the front side textile fabrics and rear side textile fabrics have a higher resistance due to the better integrity of the monolithic UHP-SFRC mixture.

Experimental study of the tensile and flexural mechanical properties of directionally distributed steel fibre-reinforced concrete

2018 ◽  
Vol 233 (9) ◽  
pp. 1721-1732 ◽  
Author(s):  
Fangyuan Li ◽  
Yunxuan Cui ◽  
Chengyuan Cao ◽  
Peifeng Wu
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Reinforced Concrete ◽  
Steel Fibre ◽  
Plain Concrete ◽  
Design Parameters ◽  
Fibre Reinforced Concrete ◽  
Split Tensile Strength ◽  
Fibre Direction ◽  
Steel Fibre Reinforced Concrete

Directionally distributed steel fibre-reinforced concrete has been proposed as a novel concrete because of its high tensile strength and crack resistance in specific directions. Based on the existing studies of the effect of the fibre direction on the mechanical properties of fibre-reinforced concrete, the authors in this paper performed further studies of the mechanical properties of directionally distributed steel fibre-reinforced concrete by conducting split tensile and bending tests. The split tensile strength of the directionally distributed fibre-reinforced concrete clearly exhibited anisotropy. The split tensile strength perpendicular to the fibre direction was much higher than that parallel to the fibre direction. The split tensile strength perpendicular to the fibre direction was almost twice the tensile strength of plain concrete. The flexural performance of directionally distributed fibre-reinforced concrete in the fibre direction significantly improved compared to that of randomly distributed fibre-reinforced concrete. Specifically, the flexural strength increased by as much as 97%. Gravity resulted in a deviation in the tensile properties of concrete prepared by manually and directionally placing fibres in a layered casting process. The test results can be utilised in subsequent concrete designs. The conclusions reached in this paper provide comprehensive mechanical design parameters for the application of directionally distributed fibre-reinforced concrete.

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