Experimental study shows that polypropylene fibres mitigate explosive spalling in high-temperature cement mortars, indicating improved fire safety for energy infrastructure.
Key Points
To evaluate the effects of monofilament and multifilament polypropylene fibres on the mechanical performance, microstructural properties, and thermo-chemical degradation of cement mortars exposed to temperatures up to 600 °C.
Subjected cement mortars incorporating monofilament and multifilament polypropylene fibres to thermal exposure ranging from 100 to 600 °C.
Evaluated elasticity on dog-bone specimens, flexural and compressive strength on 4 × 4 × 16 cm prisms, and cube strength on 10 × 10 × 10 cm specimens.
Characterized temperature-induced microstructural degradation and matrix changes using scanning electron microscopy (SEM).
Polypropylene fibres melted between 200 and 400 °C, creating interconnected pore channels that allowed boiling water vapour and dehydration moisture to escape.
Thermal loading induced progressive decomposition of calcium silicate hydrate (C–S–H) gels and matrix microstructural breakdown.
Fibre-derived pore networks effectively mitigated rapid internal steam pressure accumulation, lowering the risk of explosive spalling.