Degradation of Glass Fiber Reinforced Polymer (GFRP) Material Exposed to Tropical Atmospheric Condition

2021 ◽  
Vol 879 ◽  
pp. 265-274
Author(s):  
Mousay Mohammed ◽  
Yew Ying Chai ◽  
Shu Ing Doh ◽  
Kar Sing Lim

Fibre reinforced polymers (FRPs) have emerged as popular materials for structural application in recent decades due to numerous of advantages. Despite the growing body of research on the use of glass fibre reinforced polymers (GFRP) composites in repairing and retrofitting the important structures such as oil and gas pipelines, the lack of comprehensive data on the long-term degradation mechanism for these materials is still impeding their widespread use in open-air structures repairs particularly in tropical climate locations such as Malaysia. Therefore, this paper presents an experimental investigation to determine the influence of tropical atmospheric condition on tensile properties of the GFRP. In this study, a set of GFRP samples were fabricated using epoxy resin as polymer matrix and woven E-glass fibres as reinforcing materials. These samples were exposed to tropical atmospheric condition in Malaysia for a period of four months. Tensile test was carried out for each sample before and after four-months period of exposure. The experimental tensile test results recorded a 15% reduction in tensile strength after 4 months of exposure as compared to its original strength. Further, the dominant failure mode of the exposed sample was characterized with longitudinal splitting of the fibres without completely breaking out. Overall, the tropical atmospheric condition has a noticeable impact on the GFRPs tensile strength degradations over the exposure duration.

2017 ◽  
Vol 747 ◽  
pp. 525-532 ◽  
Author(s):  
Lara Calabrese ◽  
Francesco Micelli ◽  
Marco Corradi ◽  
Maria Antonietta Aiello ◽  
Antonio Borri

Many areas of Europe, especially Italy, Greece, Slovenia and other Balkan States, are generally associated with earthquakes. In the last two decades Fiber Reinforced Polymers (FRP) have gained an increasing interest, mostly for upgrading, retrofitting and repair of masonry and timber structures belonging to the architectural heritage. Recent researches demonstrated that masonry constructions or single structural elements are likely to be effectively repaired or enhanced in their mechanical properties using FRPs. The objective of the research presented in this paper is to study the long-term behavior of composite grids, made of E-CR glass fibers and epoxy-vinylester resin, subjected to harsh environmental factors including fatigue loading and ageing in aqueous solution. The paper presents new original test results on the relationship between the durability and the governing material properties of GFRP (Glass Fiber Reinforced Polymers) grids in terms of tensile strength and axial strains, using specimens cut off from GFRP grids before and after ageing in aqueous solution. The tensile strength of a GFRP grid was measured after conditioning in alkaline bath made by deionized water and Ca(OH)2, 0.16% in weight, solution. The reduction in terms of tensile strength and Young’s modulus of elasticity compared to unconditioned specimens is illustrated and discussed. This degradation indicated that extended service in alkaline environment under fatigue loads may produce reductions in the GFRP mechanical properties which should be considered in design, where cyclic loads and aggressive conditions are prevented in service life.


2004 ◽  
Vol 449-452 ◽  
pp. 305-308
Author(s):  
Lei Wang ◽  
Toshiro Kobayashi ◽  
Chun Ming Liu

Tensile test at loading velocities up to 10 m·s-1(strain rate up to 3.2x102s-1) was carried out forr SiCp/AC4CH composite and AC4CH alloy. The microstructure of the composite before and after tensile deformation was carefully examined with both optical microscope and SEM. The experimental results demonstrated that the ultimate tensile strength (UTS) and yield strength (YS) increase with increasing loading velocity up to 10 m·s-1. Comparing with AC4CH alloy, the fracture elongation of the composite is sensitivity with the increasing strain rate. The YS of both the composite and AC4CH alloy shows more sensitive than that of the UTS with the increasing strain rate, especially in the range of strain rate higher than 102s-1.


Author(s):  
Gang Wu ◽  
Xin Wang ◽  
Zhishen Wu ◽  
Zhiqiang Dong ◽  
Qiong Xie

AbstractThis paper investigates the degradation of basalt fiber reinforced polymer (BFRP) bars used for concrete construction in an alkaline environment. The relationships between tensile strength, elastic modulus, shear strength and moisture absorption rate over time are analyzed using a tension test, short-beam test and moisture absorption weighting. The tensile strength degradation of BFRP bars was further compared with that of Glass FRP (GFRP) bars in the literature. The results indicated that BFRP bars exhibit relatively good resistance to alkaline corrosion, maintaining more than 60% of their original strength after 9 weeks at 55°C in an alkaline solution. The moisture absorption of BFRP bars conforms to Fick’s law, which shows that the degradation mechanism is controlled by matrix and related interface degradation. This finding is supported by comparison with the shear strength degradation trend. Compared to GFRP bars under similar alkaline conditions, BFRP bars exhibit a similar degradation rate during the initial phase, but maintain higher tensile strength and strength retention over time.


2021 ◽  
Vol 16 ◽  
pp. 155892502110034
Author(s):  
Xiongfang Luo ◽  
Pei Cheng ◽  
Wencong Wang ◽  
Jiajia Fu ◽  
Weidong Gao

This study establishes an eco-friendly anti-wrinkle treating process for cotton fabric. Sodium hydroxide-liquid ammonia pretreatment followed by 6% (w/w) PU100 adding citric acid pad-cure-dry finishing. In this process, citric acid (CA) was used as the fundamental crosslinking agent during finishing because it is a non-formaldehyde based, cost-effective and well wrinkle resistance agent. Environmental-friendly waterborne polyurethane (WPU) was used as an additive to add to the CA finishing solution. Six commercial WPUs were systematically investigated. Fabric properties like wrinkle resistance, tensile strength retention, whiteness, durable press, softness, and wettability were well investigated. Fourier transform infrared spectra and X-ray diffraction spectra were also measured and discussed before and after adding waterborne polyurethane. Tentative mechanism of the interaction among the WPU, CA, and modified cotton fabrics is provided. The effect of cotton fabric pretreatment on fabric performance was also investigated. After the eco-process’s treatment, the fabric wrinkle resistant angle was upgraded to 271 ± 7°, tensile strength retention was maintained at 66.77% ± 3.50% and CIE whiteness was elevated to 52.13 ± 3.21, which are much better than the traditional CA anti-wrinkle finishing based on mercerized cotton fabrics. This study provides useful information for textile researchers and engineers.


Author(s):  
Sara LIFSHITS

ABSTRACT Hydrocarbon migration mechanism into a reservoir is one of the most controversial in oil and gas geology. The research aimed to study the effect of supercritical carbon dioxide (СО2) on the permeability of sedimentary rocks (carbonates, argillite, oil shale), which was assessed by the yield of chloroform extracts and gas permeability (carbonate, argillite) before and after the treatment of rocks with supercritical СО2. An increase in the permeability of dense potentially oil-source rocks has been noted, which is explained by the dissolution of carbonates to bicarbonates due to the high chemical activity of supercritical СО2 and water dissolved in it. Similarly, in geological processes, the introduction of deep supercritical fluid into sedimentary rocks can increase the permeability and, possibly, the porosity of rocks, which will facilitate the primary migration of hydrocarbons and improve the reservoir properties of the rocks. The considered mechanism of hydrocarbon migration in the flow of deep supercritical fluid makes it possible to revise the time and duration of the formation of gas–oil deposits decreasingly, as well as to explain features in the formation of various sources of hydrocarbons and observed inflow of oil into operating and exhausted wells.


2007 ◽  
Vol 340-341 ◽  
pp. 525-530 ◽  
Author(s):  
Satoshi Kajino ◽  
Motoo Asakawa

The mechanical and electrical applications of fine wires (D = 0.1 mm) has become more widely spread. In general, it is well known that fine drawn wires have high tensile strength while maintaining ductility. It has been determined that a hardened layer of around 0.04 mm in depth, referred to as the “additional shear strain layer,” is generated beneath the surface layer of the wire, and this additional shear strain layer affected the tensile strength of the fine wire. As an origin of this phenomenon, it was ascertained that the microstructure of surface layer was finer than that of center layer. The purpose of this paper is to investigate the effect of die angle on the microstructure and the tensile strength of the additional shear strain layer. The tensile test was performed as the surface layer was thinned by electro-polishing, and the crystal orientation and the crystal grain were measured via EBSD. As a result, it was ascertained that die angle affected the tensile strength and crystal grain refinement of the additional shear stray layer.


Author(s):  
Hidenori Shitamoto ◽  
Nobuyuki Hisamune

There are several methods currently being used to install offshore oil and gas pipelines. The reel-lay process is fast and one of the most effective offshore pipeline installation methods for seamless, ERW, and UOE line pipes with outside diameters of 18 inches or less. In the case of the reel-laying method, line pipes are subjected to plastic deformation multiplication during reel-laying. It is thus important to understand the change of the mechanical properties of line pipes before and after reel-laying. Therefore, full-scale reeling (FSR) simulations and small-scale reeling (SSR) simulations are applied as evaluation tests for reel-laying. In this study, FSR simulations were performed to investigate the effect of cyclic deformation on the mechanical properties of weldable 13Cr seamless line pipes. Furthermore, SSR simulations were performed to compare the results obtained by FSR simulations.


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