Mechanical properties and fracture behavior of nonwoven fabric reinforced plastics for rehabilitation of sewage pipes

Abstract

Trenchless construction of repair works on sewage pipes has been developed. In such methods, fiber reinforced plastics (FRP), especially nonwoven fabric composites with polyester felt, have been used. In order to reduce pressure to force the reinforcements on the wall of a pipe, low weight FRP have been expected. In the present study, FRP using polypropylene (PP) felt and banana-polyester felt which have lower density comparing with conventional polyester poly(ethylene terephthalate) (PET) felt were developed for alternative reinforcement. Three-point bending and creep tests were conducted to evaluate the mechanical properties of the composites. In static bending, PET and banana composites showed brittleness, whereas PP composites failed in a stable manner. Especially, PP composites with thicker layers showed higher load-bearing capacity. Creep test results indicated that modulus retentions of PET and PP composites are comparable. It was found that the composites using thicker PP nonwoven fabric was a candidate material for the rehabilitation of sewers.