The effect of different fibres on the flexural behaviour of concrete exposed to normal and elevated temperatures

• Published in: Construction & building materials Vol. 129; pp. 266 - 277
• Main Authors: Choumanidis, D., Badogiannis, E., Nomikos, P., Sofianos, A.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 30.12.2016; Elsevier B.V
• Subjects: Analysis; Bending; Concrete; Cracking; FRC; High temperature; Mechanical properties; Polypropylene fibre; Reinforced concrete; Steel fibre; Temperature; Thermal properties; Greece; Bending; Steel fibre; High temperature; Polypropylene fibre; FRC
• ISSN: 0950-0618; 1879-0526
• DOI: 10.1016/j.conbuildmat.2016.10.089

•Steel fibres improved strength and ductility at both ambient and elevated temperature.•Hybridization can contribute to the increase of the ductility.•Hybrid FRC mixtures without steel fibres, faces great ductility loss after heating.•Energy absorption seems to suitably expresses the post-cracking behaviour of FRC. The paper focuses on studying experimentally the potential benefits (in terms of stiffness, strength, ductility) stemming from the use of different fibres on the flexural behaviour of concrete beam specimens. Different types of steel and polypropylene fibres were added into the concrete mix at volumetric contents of 0.5% and 1.0% either individually or in different combinations. Three-point bending tests were carried out to establish the behaviour exhibited by the fibre reinforced concrete specimens produced up to failure and determine the associated mechanical properties of the subject material. The residual mechanical properties of the same specimens were also established after exposing them to temperatures of 280°C. From the test data obtained it was observed that even though the use of hybrid fibres can result in the development of higher residual tensile strength and improved toughness, at elevated temperatures, the use of steel fibres appears to provide optimum post-cracking behaviour.