Polypropylene fibres in heated concrete. Part 1: Molecular structure and materials behaviour

Polypropylene fibres are employed in concrete to combat explosive spalling in fire, but the molecular structure and the materials properties are not well understood. The current paper presents the physical, chemical, thermal and mechanical characteristics of polypropylene fibres as functions of temperature in the solid, melt and vapour states in relation to the structure and properties of heated concrete. This forms the foundation for the better understanding of the processes underlying the behaviour of the polypropylene–concrete composite that beneficially influence the risk of spalling and also provides data necessary for thermo-hydro-mechanical numerical modelling.