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| 2. |
- Kharazmi, Parastou, 1977-
(författare)
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An environmental method for renovation of sewer systems in building structures
- 2017
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Degradation of building materials particularly pipelines causes environmental damage during the renovation or replacement, disturbance for people living in the buildings, is time-consuming and last but not least is very costly. Rehabilitation by composite materials is a solution for renovation of degraded pipeline in residential buildings and any other structures which is less costly, faster and causes less damage to the environment. This study provides a brief state of the technology, methods, and materials which are being used in Nordic and some other European countries and an investigation on the performance of the relined pipes after they have been in working condition. The investigation was carried by different analyses in laboratory as well as numerous field inspections.
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| 3. |
- Kharazmi, Parastou, 1977-
(författare)
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Durability Evaluation of Reinforced Glass-Flake Polyester Material Used in Rehabilitation of Sewer Lines in Buildings-Dataset
- 2019
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Annan publikationabstract
- This dataset includes original data to support parts of research findings stated in the article: ”Durability evaluation of reinforced glass-flake polyester material used in rehabilitation of sewer lines in buildings”. Currently, different materials and methods are in use in alternative rehabilitations technologies for sewer renewal. This work was conducted to study one of these materials, which is a glass -flake reinforced polyester polymeric system, during artificial aging to provide a better understanding of the material’s performance under operating conditions when it is regularly exposed to degrading factors such as high temperature and water. Changes in the material during aging were monitored by conducting different tests, including thermal and mechanical analysis, water absorption and microscopy.
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| 4. |
- Kharazmi, Parastou, 1977-
(författare)
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Durability study of reinforced polyester composite used as pipe lining under artificial aging conditions
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Tidskriftsartikel (refereegranskat)abstract
- The aging of sewer infrastructure is an ongoing problem. As a result, different materials and methods are being used in alternative sewer rehabilitation approaches. This work was conducted to study one pipe lining, namely the reinforced polyester composite, under artificial aging; this was done to provide a better understanding of the material’s performance under operating conditions, where it is regularly exposed to degrading factors such as heat and water. Aging of the material was monitored by means of several tests, including thermal and mechanical analyses, water absorption and microscopy. The results showed that the combination of aging in water and at high temperatures resulted in greater effects on the material compared to aging at high temperatures in dry conditions. Although the measured properties were affected significantly when immersed in water at high temperatures, the material showed acceptable properties at lower exposure temperatures close to the expected temperature inside sewer systems.
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| 5. |
- Kharazmi, Parastou, 1977-, et al.
(författare)
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Durability study of reinforced polyester composite used as pipe lining under artificial aging conditions
- 2019
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Ingår i: Cogent Engineering. - : Taylor & Francis. - 2331-1916. ; 6:1
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Tidskriftsartikel (refereegranskat)abstract
- The aging of sewer infrastructure is an ongoing problem. As a result, different materials and methods are being used in alternative sewer rehabilitation approaches. This work was conducted to study one pipe lining, namely the reinforced polyester composite, under artificial aging; this was done to provide a better understanding of the material’s performance under operating conditions, where it is regularly exposed to degrading factors such as heat and water. Aging of the material was monitored by means of several tests, including thermal and mechanical analyses, water absorption and microscopy. The results showed that the combination of aging in water and at high temperatures resulted in greater effects on the material compared to aging at high temperatures in dry conditions. Although the measured properties were affected significantly when immersed in water at high temperatures, the material showed acceptable properties at lower exposure temperatures close to the expected temperature inside sewer systems.
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| 6. |
- Kharazmi, Parastou, 1977-
(författare)
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Effect of heat and water aging on the durability of rubber-epoxy lining used for rehabilitation of sewer infrastructure
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Tidskriftsartikel (refereegranskat)abstract
- One rehabilitation method used mainly for wastewater sewers in residential buildings involves applying a rubber-epoxy composite to the inner surface of the aged pipeline. In order to understand the material’s performance and stability in operation, during which it is constantly exposed to deteriorative factors, the properties of the material were studied in the laboratory under artificial water and air aging conditions. Changes in the material were monitored by means of tests such as thermal analyses, mechanical testing and water absorption assessment.
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| 7. |
- Kharazmi, Parastou, 1977-
(författare)
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Emerging Pipe-Lining Technologies in Sweden: Environmental and Quality Aspects
- 2020
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Konferensbidrag (refereegranskat)abstract
- Due to the immense need for repair created by aging and deteriorating sewer infrastructures, a range of innovative rehabilitation technologies have been emerging in this field, both within Sweden and worldwide. This paper includes results of a study, dedicated to evaluation and assessment of the rehabilitation technologies and materials, which are commonly used for renewal of sewer systems in Sweden.
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| 8. |
- Kharazmi, Parastou, 1977-
(författare)
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Evaluation of Innovative Rehabilitation Technologies Utilising Polymer Composites for Aging Sewer Systems
- 2019
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Water and wastewater sewer system maintenance is among the costliest aspects of infrastructure investment. The replacement of deteriorated lines is a difficult and expensive process that causes community disturbance and is generally not conducted fast enough to meet demand. To keep up with the rate of deterioration, the use of alternative rehabilitation technologies using polymer linings has increased significantly in recent years, both within Sweden and worldwide. Compared to the traditional pipe replacement method, these technologies are cost-effective, create less community disturbance, and offer a quick return to the service for the line. The main function of polymeric lining is to stabilise the condition of the pipeline, eliminate deterioration, and thereby extend the pipeline’s service life. Although rehabilitation technologies employing polymeric systems have been in use for over 30 years, there have been few technical assessments of either these technologies or the materials involved. Data gathered through the evaluation of these innovative technologies can make their benefits and limitations more widely understood, and can also be used to increase the effectiveness of the rehabilitation process in future.The main objective of this work was to contribute to an improved understanding of the most commonly used materials and methods employed in rehabilitation of wastewater and other applicable sewer lines in residential buildings in Sweden. The primary objective was not to prove that the emerging rehabilitation technologies work, but rather to increase knowledge of their weaknesses and strengths, identify any issues, and provide a technical assessment to support realistic expectations of pipeline rehabilitation. Gathering technical information in this way will help with the planning of future investigations; moreover, collecting extensive data will help to increase the effectiveness of the renewal works, aid progress in the field, and improve predictions regarding longevity and service life. As pipeline rehabilitation is still considered novel, and owing to the general lack of available data on the subject, a multi-approach study was carried out: this included evaluation of the polymeric materials’ performance in the presence of deteriorative factors, assessing the in-service state of the materials and lined sewers previously installed, monitoring the level of quality control implemented during previous rehabilitation works, and evaluating the environmental impacts of using pipe-lining technologies compared to pipe replacement. The techniques discussed included rehabilitation with epoxy and polyester resin-based lining materials, applied with brush-on and spray-on techniques, and cured-in-place pipe lining (installed by sending a resin-impregnated flexible tube inside the host pipe). Degradation of the resin-based lining materials was investigated via artificial aging involving immersion in water at elevated temperatures. The changes in materials that occurred during accelerated laboratory aging were tracked by means of various tests, including thermal and mechanical analyses, water absorption measurements and microscopy. The analysis focused on reinforced polyester-based and toughened epoxy-based lining materials in order to gain a better understanding of their performance as pipe lining. Moreover, the previously installed lined pipes and lining materials were also studied during laboratory examinations to evaluate the in-service performance of the materials and techniques under operating conditions over time, as well as to identify common defects. The state of the materials and the lined pipe were studied by means of different investigative methods, including visual inspection, microscopy, Fourier transform infrared spectroscopy, thickness measurement, thermal and mechanical analyses. This PhD work also includes an investigation to determine the level of quality control carried during some previous rehabilitation works. Data on the quality evaluation of previous rehabilitation works were gathered during visits to the work sites, as well as by analysing lined pipes that had already been installed. Finally, a comparative life-cycle assessment was undertaken to compare the environmental impacts of pipe replacement with those of alternative innovative rehabilitations, such as CIPP and coatings with polyester and epoxy polymeric systems. Data obtained from an LCA tool were used to facilitate comparison from an environmental perspective.Results from artificial aging in the lab indicated that the properties of polymeric lining materials changed significantly when high temperatures were combined with water exposure. However, the aging testing conducted for this study also found that the materials performed relatively well at temperatures close to the average temperatures inside sewerage systems. The results revealed that the polyester-based lining material was less sensitive when compared with epoxy-based lining materials during stimulated aging. Moreover, results from the in-service field demonstration (involving examination of 12 samples with up to 10 years of service, including reinforced polyester and modified epoxy linings or cured-in-place pipe (CIPP) lining) showed minimal evidence that the materials underwent significant deterioration after installation; instead, a majority of the common defects were found to be related to poor-quality installation practices. Because very few field samples were available to study, conclusions regarding overall performance could not be drawn. However, there is no evidence that these materials will not perform as expected during their service life when properly installed.Evaluating quality control of previous rehabilitation work revealed a gap between theory and practice where the level of quality control and documentation was concerned; furthermore, it also emerged that quality control and documentation is crucial to both the prevention of common issues and the overall effectiveness of the rehabilitation. Accordingly, a series of recommendations regarding the development of comprehensive quality control and quality assurance procedures (QC/QA) are provided in this work. These recommendations highlight the aspects that are most important to consider at each of several key stages (before installation, during installation, and after rehabilitation work is completed).Results from comparative life-cycle assessment (LCA) showed that alternative technologies, including cured-in-place (flexible sleeve) and coating techniques, have some advantages over pipe replacement from an environmental perspective. However, the choice to use one rehabilitation technology over another is a multi-stage decision-making process that should not be based solely on a single factor.This PhD work promotes an improved understanding of the limitations and benefits of polymeric lining through the testing performed and analyses conducted. This work highlights the need for improved quality control, and further suggests that developing a detailed and comprehensive quality control plan for each technology would provide higher and more consistent quality overall. The study also demonstrates that the long-term strength of any rehabilitation work depends on various factors, and that selecting one method over another must be a process based on extensive knowledge and understanding of each rehabilitation technology. No evidence was found to indicate that the materials could not perform well under working conditions if selected and installed appropriately. However, a larger number of field samples with longer in-service time and a more detailed technical history, along with a more extended experimental plan for laboratory investigations based on the results of this PhD work, will allow for the gathering of the data required to answer questions regarding life expectancy with a higher degree of certainty.
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| 9. |
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| 10. |
- Kharazmi, Parastou, 1977-
(författare)
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Experimental assessment of the state of the lining materials used in the rehabilitation of sewers in residential buildings
- 2019
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Ingår i: Case Studies in Construction Materials. - : Elsevier. - 2214-5095. ; 11
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Tidskriftsartikel (refereegranskat)abstract
- The global needs associated with aging sewers in infrastructures are immense; moreover, traditional renewal by replacement is very costly and not fast enough to meet the renewal needs. To keep up with the rate of deterioration, different rehabilitation technologies, such as the use of polymeric lining, have seen increasing use worldwide. Pipe lining is a solution to stabilize the deterioration of the host pipes in order to extend the service life of the piping system. However, the properties of polymeric materials may degrade over time; therefore, the long-term performance of these lined pipes is a frequently raised concern in the field. The aim of this study was to investigate the state of sewers that had been previously renewed, in order to gather information that facilitates an understanding of the changes in properties of the lining materials after installation. Moreover, to identify the general issues related to pipeline rehabilitation with polymeric systems. The samples investigated in this work had three different types of linings, service times ranging from one week to ten years, were installed by five separate installation companies and had been removed from residential buildings located in different parts of Sweden. The state of the polymeric lining and the relined samples were studied by means of tests including microscopy and visual inspection, as well as thermal analysis such as dynamic mechanical analysis (DMA) and differential scanning calorimetry (DSC), mechanical testing, such as tensile and flexural testing, and thickness measurements.
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