Recycled high performance polyester fibers for cement designed from micromechanics theory

The objective of this paper is designing a “greener” reinforced material of recycled PET (R-PET) fibers with high performance for cement. To balance the ductility and compression of fiber-reinforced cement composites (FRC), the reinforced fiber should be prepared with high mechanical property and FRC was designed based on micromechanics. First, the preparing processes of R-PET fibers are composed of melt-spinning of recycled PET and post-treatment (drawing, indentation and cutting). The effect of drawing ratio on the mechanical properties of R-PET fiber was studied by three phases model. The results showed that the R-PET fibers prepared has high mechanical properties (strength 736 ± 16 MPa; modulus 7.12 ± 1.6 GPa). Then, R-PET fibers were added in cement to prepare FRC and the results indicated that FRC tailed by micromechanics theoretical basis has high toughness and good compressive strength. Compared with plain cement, the result indicated that the compressive and bending strength of FRC with R-PET-3.1 at 16 kg/m3 content have increased by 41.0% and 113.5%, respectively. This melt spun R-PET fibers prepared by recycled PET bottle chips have the potential application in reinforcing and toughness of the cement mortar composites.