Fracture of fibre-reinforced cementitious composites after exposure to elevated temperatures

The effects of aramid, glass, basalt and polypropylene (PP) fibres in a fibre-reinforced cementitious composite (FRCC) were examined. Specifically, this work investigated the effects of the fibres on the compressive strength, splitting tensile strength, flexural strength and fracture behaviour of the FRCC after exposure to normal and elevated temperatures. Relationships for the compressive, splitting tensile and flexural strengths of the FRCC were developed based on response surface methodology. The microstructures of samples at various temperatures were explored using scanning electron microscopy. The experimental results showed that the fracture energies of the mixtures were related to both temperature and fibre type. The most detrimental effects of high temperatures were on the fracture energy, which diminished by about 35% and 69% on average at 100 degrees C and 300 degrees C, respectively. The samples reinforced with PP fibres exhibited the maximum fracture energy at 20 degrees C. In other words, the energy absorption of the PP fibres was far more than that of the other fibre types investigated. Finally, it was found that use of fibres with higher melting points did not improve the fracture energy of the specimens after exposure to elevated temperatures.