Analysis of mechanical properties and damage of polymer fiber reinforced concrete in post-fire conditions based on acoustic emission technology

This article discussed the post-fire damage to concrete materials by analysing the mechanical parameters and damage mechanisms of concrete reinforced with polypropylene (PP) fibres.The tested material is offered as a construction product and is approved for sale.The effect of different fire temperatures on the material performance was analysed in laboratory tests using the acoustic emission (AE) method.The analyses showed that the samples stored under ambient conditions exhibited ductile flexural fracture, whereas those exposed to fire temperatures exhibited brittle fracture.The number of AE cracks is strongly correlated with loading conditions.The b value effectively indicates the nature of the damage, serving as an early warning indicator.AF-RA images suggest that fire temperatures accelerate and intensify shear cracking.The AE method has potential as a diagnostic technology for post-fire conditions in PP fibre-reinforced concrete.