Abstract:Strength properties and permeability of the self-compacting concrete, which are reinforced with polypropylene monofilament fiber of different volume fractions, were investigated through mechanical test, water permeability test and chloride permeability test (chloride penetrability based on charge passed). Then, the microstructure of the polypropylene fiber reinforced self-compacting concrete (PFRSCC) was observed through scanning electronic microscope. The impact of polypropylene fiber on strength properties and permeability was analyzed according to the material composition and fracture theory. The results show that: 1) PFRSCC, when the volume fraction of polypropylene monofilament fiber is less than 0.15%, has good impermeability, characterized with high impermeability mark (>S 35, based on Chinese Standard Test Method T 0568-2005); 2) When the volume fraction of polypropylene monofilament fiber is less than 0.10%, PFRSCC’s strength properties and water impermeability increase with the addition of polypropylene fiber, and electric flux increases slightly. Whilse when the volume fraction of polypropylene fiber is higher than 0.15%, electric flux increases dramatically; 3) Compared with ordinary self-compacting concrete, PFRSCC, 0.10% polypropylene fiber has 16.4% increase in flexural tensile strength, 13.4% increase in splitting strength and 57% decrease in permeation depth, and chloride ion penetrability is low, about 919 C at 56 d.