Effect of Chemical Aggressive Media on the Flexural Properties of Cured-In-Place Pipes Supported by Microstructure Observation and Acoustic Emission.

Jakub Hodul,Luboš Pazdera,Richard Dvořák,Libor Topolář,Jana Majerová,Rostislav Drochytka

doi:10.3390/ma13143051

Abstract

The cured-in-place pipe (CIPP) method is currently the most frequently used approach for the renovation of piping without digging; this technology is suitable for pipes made from all types of material. The authors of this paper examined how chemical substances and increased temperature change samples of CIPP with vinyl-ester resin taken from a simulated installation. Changes were observed at several levels: visually via a digital optical microscope, through changes of short-term bending properties and by observation of the activity of the sample structure by means of acoustic emission (AE). Interdependencies among the observed parameters were examined, specifically, the cumulative number of hits (cnt)/deflection and flexural properties/mechanic wave velocity. The test results prove that after three weeks of immersion in a simulated aggressive environment that mirrors what may happen to CIPP in real conditions, short-term mechanical properties change. This is also proven by the results of the AE measurements. For clarity, the results include images from a digital optical microscope. In addition, this paper proves that CIPP samples have good resistance to the action of organic and inorganic acids and to increased temperatures. After three weeks of exposure to a temperature of 100 °C the CIPP flexural properties of the samples had even improved.

Highlights

Sewage pipelines are a crucial part of city infrastructure; once they are constructed, they are expected to remain in use for 20 years [1]
How Flexural Properties and acoustic emission (AE) Are Affected by an Aggressive Environment
This can be explained by the crystallization of the individual solutions in the open surface porous structure of the samples, which would improve the stiffness of the samples

Summary

Introduction

Sewage pipelines are a crucial part of city infrastructure; once they are constructed, they are expected to remain in use for 20 years [1]. Cured-in-place pipe (CIPP) is a method of renovating piping without digging that was invented in 1971. In 1975, a request for a patent for this technology was submitted; it was obtained in 1977 [2,3]. After the patent was released in 1994, this technology spread all over the world and was innovated [4]. A further unambiguous advantage is the applicability of this method in town centers and densely built-up areas. This is shown by the fact that the CIPP method is used for most renovation works that are done without digging [5,6]. In typical CIPP applications, a lining tube saturated with a styrene-based

Methods

Results

Conclusion