Short- and Long-Term Structural Characterization of Cured-in-Place Pipe Liner with Reinforced Glass Fiber Material

Abstract

Cured-in-place pipe (CIPP), as a kind of trenchless sewer rehabilitation technology, is a method to repair sewer pipe using unsaturated polyester resin. This study develops a CIPP liner using hot water or steam curing as well as glass fiber, in contrast to traditional methods, which use nonwoven fabric. Composite material samples were fabricated by combining liner materials using various methods, and the structural characteristics of the liners were compared and analyzed through short- and long-term flexural strength tests. A long-term test was conducted for 10,000 h, and the results revealed 13.3 times higher flexural strength and 8 times higher flexural modulus than the American Society for Testing Materials minimum criteria for CIPP short-term properties. The maximum creep retention factor was 0.64, thereby reducing the design thickness of the CIPP by up to 54%. The structural characteristics also improved when glass fibers were mixed with traditional CIPP liner, making it possible to reduce the thickness by 30%. Glass fibers result in high structural strength when combined with unsaturated polyester resin. Structural strength increased, even when glass fibers were mixed with traditional CIPP liner. The main contribution of this research is the development of a high strength CIPP liner and improvement of the structural properties of CIPP lining without using the specially formulated resin or lining materials.

Influence of Physical and Chemical Stress on the Properties of CIPP Pipes Based on Vinyl Ester

“…As the impregnation amount of the resin inside the liner must be maintained before and after curing, and handling must be easy, it is important for the resin to have an appropriate viscosity. The polymer resin for CIPP application needs to comply with the minimum requirement for the chemical resistance properties in standard domestic wastewater [8].…”

Properties and Structure of UV Light Cured CIPP Composites

“…The most significant disadvantages include dimensional restrictions and limits caused by the production liner and, of course, the cost of installation, which is higher when using UV radiation than curing with hot steam or hot water. The higher price is caused both by the material itself but also by the equipment needed for installation to the host pipeline and for the curing [4,5]. Glass reinforced liner for CIPP pipes was developed primarily for UV light cured liners because UV has limited wave penetration -the UV light penetrates approximately 10 mm in thickness of the liner [6].…”