Experimental research on compressive properties of recycling polypropylene (PP) fiber recycled coarse aggregate concrete

Abstract

Recycling polypropylene (PP) fiber recycled coarse aggregate concrete refers to the incorporation of PP as a synthetic fiber into concrete, thereby improving the physical properties of concrete. As a synthetic fiber, PP fiber has been widely used in field concrete in recent years because of its high cost performance, no water absorption, light weight and excellent corrosion resistance.The effects of waste PP fiber volume fraction, length-diameter ratio and substitution ratio of recycled aggregate(RA) on the axial compressive properties of waste PP fiber recycled aggregate concrete(RAC) were studied. The compressive stress-strain curve, axial compressive strength, static elastic modulus, peak compressive strain and equivalent compressive toughness index were obtained by axial compressive test. The research reveals that compressive strength rises initially and then diminishes with the augmentation of fiber volume and aspect ratio, and diminishes with the augmentation of RA substitution rate. The measured stress-strain curve proposes a modified stress-strain constitution model for waste PP fiber recycled aggregate concrete, wherein static elastic modulus decreases with the growth of fiber volume fraction, length-diameter ratio, and RA substitution ratio, while equivalent compressive toughness index initially increases, then declines with the rise of fiber volume fraction and aspect rate.