Long-term durability of large-diameter polyester composite pipes

Introduction. The paper deals with relaxation and creep coefficients, long-term ultimate bending deformation under long-term exposure to moisture and chemically active environment (10,000 hours) of sewer pipes.Materials and methods. 400, 1,200 and 1,400 mm diameter sewer pipes made of glass-reinforc...

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Main Authors: M. G. Kovalev, V. A. Kakusha, O. A. Kornev, D. A. Melnikov, M. V. Fedorov, D. V. Zaitsev, P. D. Kapyrin
Format: Article
Language:English
Published: Moscow State University of Civil Engineering (MGSU) 2023-12-01
Series:Stroitel’stvo: Nauka i Obrazovanie
Subjects:
Online Access:https://www.nso-journal.ru/jour/article/view/132
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author M. G. Kovalev
V. A. Kakusha
O. A. Kornev
D. A. Melnikov
M. V. Fedorov
D. V. Zaitsev
P. D. Kapyrin
author_facet M. G. Kovalev
V. A. Kakusha
O. A. Kornev
D. A. Melnikov
M. V. Fedorov
D. V. Zaitsev
P. D. Kapyrin
author_sort M. G. Kovalev
collection DOAJ
description Introduction. The paper deals with relaxation and creep coefficients, long-term ultimate bending deformation under long-term exposure to moisture and chemically active environment (10,000 hours) of sewer pipes.Materials and methods. 400, 1,200 and 1,400 mm diameter sewer pipes made of glass-reinforced polyester. A compressive load was applied to the specimen at a constant rate until a specific annular strain of (3.0 ± 0.5) % was achieved in (60 ± 10) s. The obtained specific annular strain was kept constant for 2 minutes, after this time the compressive load and annular strain were determined and recorded. The essence of the method is to load a test specimen, placed horizontally and immersed in water, at a given temperature, with a diametrically compressive load for a time during which the annular strain remains constant. The load is measured at specified intervals until 10,000 h is reached. According to the test results, the long-term specific annular stiffness and relaxation coefficient under the influence of moisture are determined in accordance with the methodology of GOST R 57008–2016. Two specimens shall be used for testing, unless otherwise specified in the normative document. Long-term specific ring stiffness and relaxation coefficient are the arithmetic mean obtained for two specimens.Results. It was found that the performance characteristics (long-term ultimate bending deformation, relaxation and creep coefficients when exposed to moisture) of the investigated sewer pipes are determined by the specific ring stiffness and their diameter. For polyester pipes with initial ring stiffness of 5,000 N/m2 increasing their diameter from 400 to 1,400 mm leads to linear increase of relaxation coefficient (from 0.79 to 0.96) and decrease of long-term ultimate bending strain (from 0.84 to 0.75 %) when exposed to moisture during 10,000 hours.Conclusions. The durability of the investigated sewer pipes made of glass-reinforced polyester exceeds 50 years.
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spelling doaj.art-f87a3ecd3e88442da633b43ec68de6f42024-02-07T11:27:49ZengMoscow State University of Civil Engineering (MGSU)Stroitel’stvo: Nauka i Obrazovanie2305-55022023-12-0113461810.22227/2305-5502.2023.4.1116Long-term durability of large-diameter polyester composite pipesM. G. Kovalev0V. A. Kakusha1O. A. Kornev2D. A. Melnikov3M. V. Fedorov4D. V. Zaitsev5P. D. Kapyrin6Moscow State University of Civil Engineering (National Research University) (MGSU)Moscow State University of Civil Engineering (National Research University) (MGSU)Moscow State University of Civil Engineering (National Research University) (MGSU)New Pipe TechnologiesMoscow State University of Civil Engineering (National Research University) (MGSU)Moscow State University of Civil Engineering (National Research University) (MGSU)Moscow State University of Civil Engineering (National Research University) (MGSU)Introduction. The paper deals with relaxation and creep coefficients, long-term ultimate bending deformation under long-term exposure to moisture and chemically active environment (10,000 hours) of sewer pipes.Materials and methods. 400, 1,200 and 1,400 mm diameter sewer pipes made of glass-reinforced polyester. A compressive load was applied to the specimen at a constant rate until a specific annular strain of (3.0 ± 0.5) % was achieved in (60 ± 10) s. The obtained specific annular strain was kept constant for 2 minutes, after this time the compressive load and annular strain were determined and recorded. The essence of the method is to load a test specimen, placed horizontally and immersed in water, at a given temperature, with a diametrically compressive load for a time during which the annular strain remains constant. The load is measured at specified intervals until 10,000 h is reached. According to the test results, the long-term specific annular stiffness and relaxation coefficient under the influence of moisture are determined in accordance with the methodology of GOST R 57008–2016. Two specimens shall be used for testing, unless otherwise specified in the normative document. Long-term specific ring stiffness and relaxation coefficient are the arithmetic mean obtained for two specimens.Results. It was found that the performance characteristics (long-term ultimate bending deformation, relaxation and creep coefficients when exposed to moisture) of the investigated sewer pipes are determined by the specific ring stiffness and their diameter. For polyester pipes with initial ring stiffness of 5,000 N/m2 increasing their diameter from 400 to 1,400 mm leads to linear increase of relaxation coefficient (from 0.79 to 0.96) and decrease of long-term ultimate bending strain (from 0.84 to 0.75 %) when exposed to moisture during 10,000 hours.Conclusions. The durability of the investigated sewer pipes made of glass-reinforced polyester exceeds 50 years.https://www.nso-journal.ru/jour/article/view/132sewer pipesring stiffnesscreep and relaxation coefficientsglass-reinforced polyester
spellingShingle M. G. Kovalev
V. A. Kakusha
O. A. Kornev
D. A. Melnikov
M. V. Fedorov
D. V. Zaitsev
P. D. Kapyrin
Long-term durability of large-diameter polyester composite pipes
Stroitel’stvo: Nauka i Obrazovanie
sewer pipes
ring stiffness
creep and relaxation coefficients
glass-reinforced polyester
title Long-term durability of large-diameter polyester composite pipes
title_full Long-term durability of large-diameter polyester composite pipes
title_fullStr Long-term durability of large-diameter polyester composite pipes
title_full_unstemmed Long-term durability of large-diameter polyester composite pipes
title_short Long-term durability of large-diameter polyester composite pipes
title_sort long term durability of large diameter polyester composite pipes
topic sewer pipes
ring stiffness
creep and relaxation coefficients
glass-reinforced polyester
url https://www.nso-journal.ru/jour/article/view/132
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AT vakakusha longtermdurabilityoflargediameterpolyestercompositepipes
AT oakornev longtermdurabilityoflargediameterpolyestercompositepipes
AT damelnikov longtermdurabilityoflargediameterpolyestercompositepipes
AT mvfedorov longtermdurabilityoflargediameterpolyestercompositepipes
AT dvzaitsev longtermdurabilityoflargediameterpolyestercompositepipes
AT pdkapyrin longtermdurabilityoflargediameterpolyestercompositepipes