Contribution of cocktail of polypropylene and steel fibres in improving the behaviour of high strength concrete subjected to high temperature

The aim of the study is to improve the understanding of the influence of a polypropylene and steel fibres cocktail on the behaviour of high strength concretes subjected to high temperature. Concrete mixes were studied by adding polypropylene fibres, steel fibres and cocktail of fibres. The concrete specimens were subjected to various heating–cooling cycles. The initial and residual mechanical properties, the porosity and the mass loss of the studied concrete mixes were investigated. Different concretes compositions with various amounts of polypropylene and/or steel fibres were tested. Experimental results show the significant improvement of the residual mechanical properties of concretes containing the cocktail of fibres compared to concretes without fibres.