Effects of polypropylene fiber on plastic shrinkage crack and mechanical properties of concrete

This paper reports on the mechanical properties and plastic shrinkage crack of concrete containing modified polypropylene fiber-a kind of new porous polypropylene fiber. Results of crack properties tests show that after adding modified polypropylene fiber, crack area, maximum crack width and average crack width of concrete decreased markedly. Results of mechanical properties show that flexural and splitting tensile strength of concrete with 1.0 parts per thousand modified polypropylene fiber volume fraction at 28 days increased 24% and 28% respectively compared to the reference concrete; Reticulate polypropylene fiber has less effects than modified polypropylene fiber on flexural and splitting tensile strength. Compressive strength of fiber reinforced concrete changed slightly, but flexural strength and splitting tensile strength increased, and the ratio of splitting tensile strength to compressive strength decreased.