High temperature behaviour of polypropylene fibres reinforced mortars

Mohammed Ezziane (1, 2) , Tahar Kadri (1) , Laurent Molez (2) , Raoul Jauberthie (2) , Ali Belhacen (1)

1 LMPC - Laboratoire de Matériaux et Procédés de Construction
2 MT Rhéo

The aim of this paper is primarily experimental and is intended to analyse the behaviour of two cementitious materials, before and after heat treatment: one unreinforced (i.e. without fibres) and the other reinforced (with polypropylene fibres).At room temperature and after heating up to 500 °C, the bending strength is improved by the presences of fibres. The residual young modulus is slightly higher for the fibres reinforced samples.As the temperature increases, the strength gain due to fibres inclusion is reduced. Beyond 500 °C, the bending strength is lower for the fibre reinforced cementitious material compared to those without fibres. Fracture energy is also improved for the fibre mortars at room temperature. At 400 °C this improvement decreases gradually with the introduction of polypropylene fibres. Beyond this temperature and due to the introduction of polypropylene fibres, the fracture energy is reduced.Another test is developed: rapid heating due to exposure to a flame. The temperature in the front side reaches in few seconds 1000 °C. At this temperature and after one hour of exposure, the opposite side reached 140 °C. After cooling, the punching shear strength of the fibre mortar is definitely weaker than of the mortar without fibre.

Mots clés: Spalling; Punching shear test; Mechanical behaviour; Fracture energy; Fire test; Polypropylene fibre mortar

Domaines: Génie civil; Mécanique des matériaux [physics.class-ph]; Matériaux

Mohammed Ezziane, Tahar Kadri, Laurent Molez, Raoul Jauberthie, Ali Belhacen. High temperature behaviour of polypropylene fibres reinforced mortars. Fire Safety Journal, 2015, 71, pp.324-331. ⟨10.1016/j.firesaf.2014.11.022⟩. ⟨hal-01096150⟩