Influence of steel and/or polypropylene fibres on the behaviour of concrete at high temperature: Spalling, transfer and mechanical properties

• Published in: Construction & building materials Vol. 132; pp. 240 - 250
• Main Authors: Yermak, N., Pliya, P., Beaucour, A.-L., Simon, A., Noumowé, A.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.02.2017; Elsevier B.V; Elsevier
• Subjects: Analysis; Civil Engineering; Concrete; Concretes; Engineering Sciences; Fire spalling; High temperatures; Mechanical damage; Mechanical properties; Permeability; Polypropylene fibres; Pore size; Porosity; Steel fibres; Thermal properties; United States; Thermal properties; Pore size; Fire spalling; High temperatures; Polypropylene fibres; Mechanical damage; Concrete; Steel fibres; Permeability; High temperatures; Concrete; Polypropylene fibres; Steel fibres; Fire spalling; Pore size; Permeability; Thermal properties; Mechanical damage
• ISSN: 0950-0618; 1879-0526
• DOI: 10.1016/j.conbuildmat.2016.11.120

•Ten different concretes with polypropylene and/or steel fibres are exposed to ISO 834 fire.•Plain concrete (fc=70MPa) did not show spalling contrary to steel fibres (60kg/m3) concretes.•Polypropylene fibres prevent any macroscopic damage of steel fibre concretes during ISO fire.•SEM observation and MIP analysis show that steel fibres reduce the crack opening during heating.•At 900°C steel fibres have more favorable effect on the residual mechanical performances. In this study different mixtures of high strength concretes (70MPa) were prepared with different natures of aggregates, moisture content, length and dosage of polypropylene fibres (PPF) and steel fibres (SF) and subjected to the standard ISO 834 fire. Concretes with 60kg/m3 of SF show spalling while plain concrete (without fibres) and concrete with 0.75kg/m3 of PPF and 60kg/m3 of SF did not spall. Microstructure, thermal, hydric and mechanical properties of concretes were investigated. PPF increase the porosity and permeability of concretes. Steel fibres control crack development which reduce the stress relaxation phenomenon and the size of new pores.