Graduation Semester and Year

2023

Language

English

Document Type

Dissertation

Degree Name

Doctor of Philosophy in Civil Engineering

Department

Civil Engineering

First Advisor

Mohammad Dr. Najafi

Second Advisor

Karthikeyan Loganathan

Abstract

Pressure pipes are an important component of pipe infrastructure for water mains, distribution lines, fuel and gas piping, process piping, building services piping, and many more. Various material types are available to be used in the pressure pipes, in which metal pipes are ubiquitous for high pressure applications, plastic pipes are also commonly used, and sometimes concrete pressure pipes are used in large diameter pipes for its economic factors. Most of these pipes currently in service are 50 to 60 years old, and some are 100 years old. Furthermost pipelines have exceeded their design life and are continuously deteriorating to the catastrophic situations; thus, there is an urgent need to develop a method or technology to restore the existing underground pipeline and infrastructure. Spray applied pipe lining (SAPL) is a trenchless pipe renewal technology that can combat the issue of pipe aging and failure. SAPL is applied inside a pipe for either corrosion prevention or load-bearing capacity enhancement of the existing pipe by creating a new stand-alone pipe within the host pipe. Adding to the structural capabilities of SAPL, in some cases, its application also improves the hydraulic flow capacity of the pipelines by providing a smooth internal surface profile, even considering the application decreases the internal diameter. This dissertation presents the detailed testing and evaluation of structural and hydraulic properties of the polymeric liner material in pressure pipes. The testing plan includes full-scale laboratory tests of short-term hole-spanning, vacuum pressure, pressure integrity, and hydraulic flow. The short-term hole spanning test results on 30-inch pipe diameter samples determined the hole-spanning capacity of the SAPL when designed as semi-structural. The lining system was tested for a pressure resistance of up to 500 psi. The vacuum pressure test determined the vacuum load resistance of the lining system. The pressure integrity test on 8-inch pipe diameter samples determined the pressure resistance of the liner at extreme temperature conditions when designed as fully structural, i.e., with no support from the host pipe. Lastly, the hydraulic flow test was critical to determine the effect of liner installation on improving the flow characteristics of a 6-inch lined pipe sample, though the liner decreases the internal diameter. The head loss of the lined pipe was compared with a moderately corroded pipe in a turbulent flow regime, and the results showed a reduction in the head loss of the lined pipe when compared with a moderately corroded pipe. Furthermore, the experimental results provided the design methodologies and validated the design equations for applying SAPL in pressure pipes. The recommendations for future research studies are provided to test the lining system when designed as semi-structural and fully structural at different pipe diameters, with different thicknesses, and at varied temperatures. These test results will help evaluate the material's performance under different conditions of host pipes, environment, and loading.

Keywords

Spray applied pipe lining, Pressure pipes, Pipe, rehabilitation, Pipe renewal, Hole-spanning testing, Burst pressure, Hydraulic flow test

Disciplines

Civil and Environmental Engineering | Civil Engineering | Engineering

Comments

Degree granted by The University of Texas at Arlington

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Available for download on Tuesday, December 31, 2024

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