scholarly journals A Novel Strengthening Method for Damaged Pipeline under High Temperature Using Inorganic Insulation Material and Carbon Fiber Reinforced Plastic Composite Material

Materials ◽  
2019 ◽  
Vol 12 (21) ◽  
pp. 3484 ◽  
Author(s):  
Li ◽  
Tsai ◽  
Yang

In this paper, a strengthening method for the damaged high-temperature steel pipeline using inorganic insulation material which was confined by carbon fiber reinforcement plastic (CFRP) composite materials was proposed. Two inorganic insulation materials were composed of magnesium phosphate cement (MPC) mixing with perlite and vermiculite powders, respectively. The influences of insulation material composites with various ratios of the perlite or vermiculite powder were discussed, in terms of compressive strength and thermal conductivity coefficients of inorganic insulation materials. The insulation materials confined by carbon fiber reinforced polymer jackets for enhancing the mechanical behavior were also investigated. From the experimental results, the main finding of the work was that the inorganic insulation materials added to the perlite powder represented greater insulation capability than added vermiculite ones under the condition of the same compressive strength. Different ratios of perlite inorganic insulation material cylinders with the dimension of ϕ 10 cm × 20 cm were confined by one layer and two layers of CFRP composite material. The compressive strength of the specimens increased by 258%–927% after using 1-layer CFRP composite material and increased by 480%–1541% after applying 2-layer CFRP composite material. A peak strength prediction model of insulation materials confined by CFRP was proposed, and it was found that the proposed model accurately predicted the peak strength of the inorganic insulation material cylinder. Finally, a verification test of the strengthening method for damaged high-temperature pipeline was performed to prove that the proposed strengthening method is feasible.

Materials ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 26 ◽  
Author(s):  
Yeou-Fong Li ◽  
Wai-Keong Sio ◽  
Ying-Kuan Tsai

In this paper, a compressive peak strength model for CFRP-confined thermal insulation materials under elevated temperature was proposed. The thermal insulation material was made by Portland cement with different portions of perlite. The compressive strengths of four different perlite ratios in weight, such as 0%, 10%, 20%, and 30% of thermal insulation materials, confined by one-layer, two-layer, and three-layer carbon fiber-reinforced polymer (CFRP) composite materials, were obtained. The test results indicated that the specimen’s compressive strength decreased with an increase in the amount of perlite replacement and increased with an increase in the number of CFRP wrapping layers. Based on the test results, a theoretical compressive peak strength model with some parameters was proposed. In the meantime, the compressive strengths of the above four different perlite ratios of thermal insulation materials under elevated temperature, such as ambient temperature, 100 °C, 150 °C, 200 °C, 250 °C, and 300 °C, were obtained. For compression tests of specimens with a fixed amount of perlite, the test results indicated that the specimen’s compressive strength decreased with an increase in temperature, highlighting a thermal softening phenomenon. Based on the test results, a compressive peak strength model with a thermal softening parameter was proposed to predict the peak strength under elevated temperature. Finally, a compressive peak strength model for thermal insulation material with CFRP confinement under different elevated temperature was derived, and it achieved acceptable results in comparison to the experimental results.


Author(s):  
S. I. Voinov ◽  
I. V. Zelenina ◽  
M. I. Valueva ◽  
I. N. Gulyaev

The article presents the results of studies of carbon fiber reinforced plastic VS-51/VTkU-2.200. The influence of the thickness of the specimens and the size of working gage on the compressive strength of carbon fiber reinforced plastic specimens was evaluated; tests were done in accordance with different standards. The results of compression strength tests at high temperature (300–320°С) are given: carbon fiber reinforced plastic VS-51/VTkU-2.200 shows high heat resistance and keeps compressive strength at high temperature tests. Carbon fiber reinforced plastic VS-51/VTkU-2.200 is of increasing interest for application in aircraft structural parts requiring high temperature resistance.


2021 ◽  
Vol 11 (7) ◽  
pp. 354
Author(s):  
Waleed Ahmed ◽  
Essam Zaneldin ◽  
Amged Al Hassan

With the rapid growth in the manufacturing industry and increased urbanization, higher amounts of composite material waste are being produced, causing severe threats to the environment. These environmental concerns, coupled with the fact that undergraduate students typically have minimal experience in research, have initiated the need at the UAE University to promote research among undergraduate students, leading to the development of a summer undergraduate research program. In this study, a recycling methodology is presented to test lab-fabricated Carbon-Fiber-Reinforced Polymer (CFRP) for potential applications in industrial composite waste. The work was conducted by two groups of undergraduate students at the UAE University. The methodology involved the chemical dissolution of the composite waste, followed by compression molding and adequate heat treatment for rapid curing of CFRP. Subsequently, the CFRP samples were divided into three groups based on their geometrical distinctions. The mechanical properties (i.e., modulus of elasticity and compressive strength) were determined through material testing, and the results were then compared with steel for prompt reference. The results revealed that the values of mechanical properties range from 2 to 4.3 GPa for the modulus of elasticity and from 203.7 to 301.5 MPa for the compressive strength. These values are considered competitive and optimal, and as such, carbon fiber waste can be used as an alternate material for various structural applications. The inconsistencies in the values are due to discrepancies in the procedure as a result of the lack of specialized equipment for handling CFRP waste material. The study concluded that the properties of CFRP composite prepreg scrap tend to be reusable instead of disposable. Despite the meager experimental discrepancies, test values and mechanical properties indicate that CFRP composite can be successfully used as a material for nonstructural applications.


2016 ◽  
Vol 697 ◽  
pp. 433-436
Author(s):  
Shi Chao Zhang ◽  
Yu Feng Chen ◽  
Wei Wu ◽  
Hao Ran Sun ◽  
Guang Hai Wang ◽  
...  

In this paper, fumed nano-silica as the main raw material, nano-silica insulation materials were prepared by the dry processing. Research on humidity-reinforcement of nano-Silica insulation materials has been carried out and analyzed. When hygroscopicity of samples reach to 23%, the compressive strength 1.65MPa is at twice the one without high humidity-reinforcement, while the thermal conductivities are almost the same. Then, the action mechanism of high humidity-reinforcement method was analyzed. In humidity-reinforcement method, as vapor enters, silica sol is formed in the gap between one aggregate particle and another, and various condensation polymerization occurred in the drying process, which lead to aggregates connection and compressive strength improvement.


2011 ◽  
Vol 462-463 ◽  
pp. 1-6 ◽  
Author(s):  
Tao Suo ◽  
Yu Long Li ◽  
Ming Shuang Liu

As Carbon-fiber-reinforced SiC-matrix (C/SiC) composites are widely used in high-temperature structural applications, its mechanical behavior at high temperature is important for the reliability of structures. In this paper, mechanical behavior of a kind of 2D C/SiC composite was investigated at temperatures ranging from room temperature (20C) to 600C under quasi-static and dynamic uniaxial compression. The results show the composite has excellent high temperature mechanical properties at the tested temperature range. Catastrophic brittle failure is not observed for the specimens tested at different strain rates. The compressive strength of the composite deceases only 10% at 600C if compared with that at room temperature. It is proposed that the decrease of compressive strength of the 2D C/SiC composite at high temperature is influenced mainly by release of thermal residual stresses in the reinforced carbon fiber and silicon carbon matrix and oxidation of the composite in high temperature atmosphere.


Author(s):  
Bai Shuxin ◽  
Tong Yonggang ◽  
Ye Yicong ◽  
Zhang Hong

Carbon fiber reinforced ultra high temperature ceramic matrix composite (C/UHTC) is one of the most promising structural materials capable of prolonged operation in oxidizing environment at ultra high temperatures above 2000 ?C. Reactive melt infiltration (RMI) is a viable processing choice for C/UHTC composite. Compared with chemical vapor infiltration (CVI) and polymer impregnation and pyrolysis (PIP), RMI does not suffer from the drawbacks of time-consuming and high cost. It is viewed as a promising means of achieving near-net shape manufacturing with quick processing time and at low cost. Recently, great efforts have been made on RMI process for C/UHTC composite. Carbon fiber reinforced ZrC, HfC and TiC composites have been successfully fabricated by RMI. The aim of the following chapter is to introduce the RMI process and summarize the progress in RMI process for C/UHTC composite. In addition, future research directions of RMI are also proposed.


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