Mechanical properties of macrosyntheticrnfibre-reinforced concrete exposed tornsulfate attack

摘要

The performance and durability of concrete is always affected by atmospheric conditions, chemical ions and mechanicalrnloads, which reduce its bearing capacity, leading to the occurrence of accidents. Macrosynthetic fibre-reinforced (MFR)rnconcrete, as an alternative material, is used to improve the corrosion resistance of underground structures. In thisrnstudy, accelerated corrosion tests were designed to investigate the change in compressive strength, elastic modulusrnand fracture toughness of concrete soaked in sulfate environment. Microscopic monitoring techniques, includingrnscanning electron microscopy and energy-dispersive X-ray spectroscopy, were adopted to find changes in the structure.rnCompared to macrosynthetic fibre-reinforced concrete and ordinary concrete soaked in sulfate corrosion environment,rnthe results indicated that macrosynthetic fibre improved the structure compactness of concrete; the losses of elasticrnmoduli and compressive strength of the specimens soaked in sulfate were reduced. The maximum crack initiation loadrnof macrosynthetic fibre-reinforced concrete was enhanced. Through microstructure monitoring, it is found thatrnmacrosynthetic steel fibre contributes to a remarkable improvement in the fracture resistance of concrete.