Numerical modeling of steel fiber reinforced concrete spallation exposed to medium loading rate

Ammar Babiker 1, *, Aamir Dean 1, 2, Ebtihag Abu-Elgasim 1 and Taghried Abdel-Magid 1, 3

1 College of Engineering, School of Civil Engineering, Sudan University of Science and Technology, Khartoum, Sudan.
2 Elasticity and Strength of Materials Group, School of Engineering, University of Seville, Seville, Spain.
3 BRE Center for Innovative Construction Materials, Department of Architecture and Civil Engineering, Faculty of Engineering, University of Bath, Bath, UK.
 
Research Article
Global Journal of Engineering and Technology Advances, 2022, 12(02), 001–014
Article DOI: 10.30574/gjeta.2022.12.2.0130
Publication history: 
Received on 25 June 2022; revised on 29 July 2022; accepted on 31 July 2022
 
Abstract: 
Properties of unreinforced concrete and cement-based matrix are well understood. One of the issues with the cement-based matrix is its inherently brittle failure when exposed to loading. As such, steel fibers were proposed to enhance the ductility of cement-based and concrete materials. Ever since, Fiber-Reinforced Concrete (FRC) has become a commonly used building material in many construction activities such as bridges, airport pavements, shotcrete, and many others. According to previous research, the addition of steel fibers, typically from 20 to 50 kg/m3 into the conventional concrete, can significantly enhance many of the desired engineering properties of hardened concrete such as flexural strength, tensile strength, micro-cracks as well as splitting. This research presents a study aimed to numerically investigate the influence of steel fibers on the dynamic behavior of Plain Concrete (PC) exposed the tensile loading at medium strain-rate. The influence of steel fibers is investigated using different fiber volume fractions ranging from 0.0 to 4.5%. The Modified Split-Hopkinson-Bar (MSHB) apparatus is employed to investigate the dynamic tensile behavior of PC and Steel Fiber-Reinforced Concrete (SFRC). Validation of the finite element model and constitutive material behavior is carried out with the comparison of computed and measured experimental pull-back velocities of the specimen’s free end. The results showed that impact properties of steel fibers exhibit significant improvement in the toughness and the dynamic tensile strength of concrete and higher fiber volume fraction is more effective in enhancing the mechanical properties of SFRC composite.
 
Keywords: 
Fiber-reinforced Concrete; Steel fibers; Strain-rate; Spallation; Pull-back velocity; Split-Hopkinson-Bar
 
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