Application of natural fiber reinforced composites to trenchless rehabilitation of underground pipes

Although various trenchless technologies for repairing worn-out underground pipes have been developed and tried, they have not been widely used due to their drawbacks such as high cost, inconvenience of operation, and long construction time. The new rehabilitation process with glass fabric preform based on the vacuum assisted resin transfer molding (VARTM) could reduce cost and construction time much, but the entrapped air during resin transfer process often produced interior defects in the repaired composite. Since the glass fabric preform was not suitable for drain pipes or water pipes because of the health hazard of small broken glass fibers when the underground pipe is worn out, in this work, natural fibers were used for the trenchless rehabilitation of underground pipes. The permeability and strength of natural fiber reinforced composites were measured. The developed process with the natural fiber composites was found to satisfy both the required structural strength for rehabilitation and shorter processing time without interior defects.