The Tensile Strength of Glass Yarn in Rubber and the Effects of Moisture. I

1971 ◽  
Vol 44 (4) ◽  
pp. 937-945
Author(s):  
R. A. Gregg

Abstract The strength of glass tire yarn depends on its environment so that testing in rubber is necessary to determine the strength of the yarn as used. The techniques described for building and testing glass yarn-rubber composites lead to tensile values of good precision. The techniques allow specification of a standard tensile in rubber for a glass yarn. Tensiles which would exist under non-standard conditions experienced in manufacturing or use can also be determined. Tire operating temperature is one use condition covered. The techniques discriminate sufficiently to show the effects of small differences in moisture level on hot tensile strength. The rubber stock used here did not harm the tensile strength of the glass yarn. The observed tensile strength increase of the glass yarn encased in rubber as compared to air can be attributed to the stress transfer ability of the rubber and to the test piece configuration. The strength of a glass yarn-rubber composite is inversely related to the level of moisture in the composite. High moisture levels in the glass yarn and rubber stock at building and cure can hurt tensile since moisture loss from the composite can be slow. Also, high moisture level at cure may degrade the resin-adhesive system of some yarns. For this particular glass yarn under high humidity, storage at advanced temperatures and/or curing into rubber permanently damages the yarn. These observations were made under absolute humidity levels not usually encountered. The question of the extent of the humidity degradation of this type of glass yarn under practical humidities will be examined. Since the tensile loss is probably due to some degradative action on the sizing or resin, it cannot be assumed that all glass yarns will behave similarly. It will be necessary to determine the susceptibility of each glass yarn to moisture.

2021 ◽  
Author(s):  
Max Olsen ◽  
Ragni Hatlebakk ◽  
Chris Holcroft ◽  
Arne Stavland ◽  
Nils Harald Giske ◽  
...  

Abstract Scope Controlled dissolution glasses form a permanent consolidating mineral matrix inside formations with either permeable or impermeable properties. The unique solution has a low injection viscosity and can be easily injected into a wide range of formations. The application method is simple and does not require multiple fluids or pre- and post-flushing. This paper focuses on the benefits of controlled dissolution glasses and potential applications in the oil and gas industry. Methods, Procedures, Process Controlled dissolution glasses have been researched extensively by Glass Technology Services (GTS) since 1999 for the biomedical industry, nuclear waste storage industry, and defense and aerospace industries. GTS together with operators have been performing research and development for the oil industry over the last 10 years. The research investigated different glass compositions to determine their injectability and change in formation properties post-treatment. Sandstone, chalk, and shale formations were used in the testing. Flow testing using a Hoek cell and a core flood apparatus was used to determine the post-treatment permeability. For post-treatment strength measurement, Brazilian tensile strength tests and modified cone penetration tests were used to determine tensile strength and shear strength respectively. The testing evaluated different mixing fluids, such as water and different brines, compatibility, corrosion testing, and concentrations. Results, Observations, Conclusions The testing identified different glass compositions and concentrations that are suitable for different applications and formations. Certain glass compositions increase tensile strength significantly while also maintaining the permeability in the formation. Other glass compositions have similar tensile strength increase, but result in an impermeable seal. The liquid glass solutions react with the formation to form a mineral precipitation inside the formation. The reaction with the formation occurs quickly at downhole conditions, within hours of placement. The glass can be mixed with water and variety of brines to form a stable solution across a range of densities. The testing and results to date have laid the foundation for use in a variety of consolidation and P&A applications in oil and gas wells. Testing is ongoing for a chalk and sandstone consolidation solution and for a sealing solution. Novel/Additive Information These novel glass solutions can solve many of the production and instability challenges that plague weak formations. The glasses can be injected into very low permeability formation to either seal or consolidate.


2021 ◽  
Author(s):  
Max Olsen ◽  
Ragni Hatlebakk ◽  
Chris Holcroft ◽  
Roar Egil Flatebø ◽  
Asif Hoq ◽  
...  

Abstract This paper reports the development and testing, of a Phosphate controlled dissolution glass composition used to strengthen the matrix of chalk whilst retaining the permeability of the rock, facilitating improved hydrocarbon recovery in unstable wells. Multiple versions of the glass solutions and different types of colloidal silica were extensively tested in the laboratory to determine injectability and reactivity with calcium carbonate rocks. The goal of the testing was to determine the best performing solution for use in a field trial in the Norwegian North Sea. The laboratory testing included filtration and core flood tests to determine the injectability of the solutions and post treatment permeability, and Brazilian strength tests to determine the tensile strength of the treated chalk cores. The filterability was tested through filter screen sizes ranging from 5 to 0.6 µm. Core flood testing was performed on 10 cm long chalk cores with 1.5 mD permeability. The glass solutions showed the best results in the filtration and core flood testing, achieving significantly greater invasion depth than any of the colloidal silica samples. The phosphate glass treated chalk cores maintained 70 to 100% of the original permeability while delivering a 3 to 5 fold tensile strength increase. The lab tests demonstrated the potential of a glass based treatment to strengthen chalk formations without impeding permeability.Based on the promising results from the lab tests, it was decided to trial the selected glass solution in a mature vertical proppant fractured well. The test confirmed that the glass solution could be pumped into the well, but the test failed pre-maturely after two months of varied production, and the trial will not be covered in this paper.However, due to the high value in being able to stabilize chalk in the field, the Operator is evaluating a new trial in a horizontal well, and learnings from the first trial will be used to inform further lab tests in the next phase. The glass solution used in this trial is being further developed to be used in other formation types, such as sand and non-calcium containing reservoirs.


2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Ke Man ◽  
Xiaoli Liu

From the standard test method suggested by ISRM and GB/T50266-2013, the uniaxial static tensile strength, dynamic tensile strength, and dynamic fracture toughness of the same basalt at different depths have been measured, respectively. It is observed that there may be an empirical relation between dynamic fracture toughness and dynamic tensile strength. The testing data show that both the dynamic fracture toughness and dynamic tensile strength increase with the loading rate and the dynamic tensile strength increases a little bit more quickly than the dynamic fracture toughness. With an increasing depth, the dynamic tensile strength has much more influence on the dynamic fracture toughness, as which it is much liable to bring out the unexpected catastrophes in the engineering projects, especially during the excavation at deep mining. From the rock failure mechanisms, it is pointed out that the essential reason of the rock failure is the microcrack unstable propagation. The crack processes growth, propagation, and coalescence are induced by tensile stress, not shear stress or compressive stress. The paper provides estimation of the dynamic fracture toughness from the dynamic tensile strength value, which can be measured more easily.


2021 ◽  
Vol 1019 ◽  
pp. 102-109
Author(s):  
Endow Mazumder ◽  
L.V. Prasad M.

The primary goal of this work is to report the results of the experimental outcome of Geopolymer concrete (GEO-C) which is prepared and cured at room temperature. GEO-C is prepared using a blend of ground granulated blast furnace slag (GGSG) and F Class Fly Ash, and the replacement is ranged from 0% to 100% of binder material, to find the optimum dosage of binder material. Sodium Hydroxide (NaOH) and Sodium Silicate (Na2SiO3) which are alkaline in nature, used primarily as an activating agent for the polymerization process of geopolymer. Experiments were conducted on samples by fixing the NaOH concentration as 14M for optimum strength and the alkaline activator ratio is fixed as one. Mechanical properties of GEO-C like compressive strength, rupture modulus (i.e. flexural strength), and split tensile strength were evaluated at the ages 7, 14, 28 days. From the results, it is observed that with the addition of GGSG in the blend the compressive, flexural, and tensile strength increase but there is a drastic reduction in the workability of the mixture.


Materials ◽  
2019 ◽  
Vol 12 (15) ◽  
pp. 2460 ◽  
Author(s):  
Jelena Horky ◽  
Abdul Ghaffar ◽  
Katharina Werbach ◽  
Bernhard Mingler ◽  
Stefan Pogatscher ◽  
...  

In this study, two biodegradable Mg-Zn-Ca alloys with alloy content of less than 1 wt % were strengthened via high pressure torsion (HPT). A subsequent heat treatment at temperatures of around 0.45 Tm led to an additional, sometimes even larger increase in both hardness and tensile strength. A hardness of more than 110 HV and tensile strength of more than 300 MPa were achieved in Mg-0.2Zn-0.5Ca by this procedure. Microstructural analyses were conducted by scanning and transmission electron microscopy (SEM and TEM, respectively) and atom probe tomography (APT) to reveal the origin of this strength increase. They indicated a grain size in the sub-micron range, Ca-rich precipitates, and segregation of the alloying elements at the grain boundaries after HPT-processing. While the grain size and segregation remained mostly unchanged during the heat treatment, the size and density of the precipitates increased slightly. However, estimates with an Orowan-type equation showed that precipitation hardening cannot account for the strength increase observed. Instead, the high concentration of vacancies after HPT-processing is thought to lead to the formation of vacancy agglomerates and dislocation loops in the basal plane, where they represent particularly strong obstacles to dislocation movement, thus, accounting for the considerable strength increase observed. This idea is substantiated by theoretical considerations and quenching experiments, which also show an increase in hardness when the same heat treatment is applied.


2020 ◽  
Vol 978 ◽  
pp. 277-283
Author(s):  
Kishore Kumar Mahato ◽  
Krishna Chaitanya Nuli ◽  
Krishna Dutta ◽  
Rajesh Kumar Prusty ◽  
Bankim Chandra Ray

Fiber reinforced polymeric (FRP) composite materials are currently used in numerous structural and materials related applications. But, during their in-service period these composites were exposed to different changing environmental conditions. Present investigation is planned to explore the effect of thermal shock exposure on the mechanical properties of nanoTiO2 enhanced glass fiber reinforced polymeric (GFRP) composites. The samples were conditioned at +70°C temperature for 36 h followed by further conditioning at – 60°C temperature for the similar interval of time. In order to estimate the thermal shock influence on the mechanical properties, tensile tests of the conditioned samples were carried out at 1 mm/min loading rate. The polymer phase i.e. epoxy was modified with different nanoTiO2 content (i.e. 0.1, 0.3 and 0.5 wt. %). The tensile strength of 0.1 wt.% nanoTiO2 GFRP filled composites exhibited higher ultimate tensile strength (UTS) among all other composites. The possible reason may be attributed to the good dispersion of nanoparticles in polymer matrix corresponds to proper stress transfer during thermal shock conditioning. In order to access the variations in the viscoelastic behavior and glass transition temperature due to the addition of nanoTiO2 in GFRP composite and also due to the thermal shock conditioning, dynamic mechanical thermal analysis (DMTA) measurements were carried out. Different modes of failures and strengthening morphology in the composites were analyzed under scanning electron microscope (SEM).


1963 ◽  
Vol 9 (4) ◽  
pp. 555-561 ◽  
Author(s):  
Zofia Maciejowska ◽  
E. B. Williams

The fungus flora developing in cellulose-amended and non-amended soils of neutral pH at moisture levels of 60, 70, and 80% water-holding capacity (WHC) was investigated. A distinct, successive development of three species, Staphylotrichum coccosporum, Coccospora agricola, and Sependonium sp., was observed in soil held at 60% WHC. More species developed in soil held at 70% WHC, and they could effectively coexist during cellulose decomposition. S. coccosporum developed in smaller numbers at 80% WHC than at 60 and 70% WHC. Sepedonium sp. was associated with cellulose decomposition only at 80% WHC. Species of Trichoderma, Monilia, and Fusarium developed better at high moisture levels. It was concluded that available inoculum and the moisture of soils of similar pH values are major factors in determining composition of the microflora of cellulose-amended soil.


2006 ◽  
Vol 324-325 ◽  
pp. 671-674
Author(s):  
Wang Xiang ◽  
Xiao Hua Xue

TiCp/ZA-12 composites have been fabricated by XDTM method and stirring-casting techniques. The tests for mechanical properties reveal that the tensile strength and strength increase with increasing fraction of TiC particles. When the fraction of TiC particles increase up to 10%, the tensile strength and yield strength are 390MPa and 340MPa, respectively and they increase by 11% and 17% than that of matrix respectively. From the analysis of fractography we can see that mixed fracture of cleavage fracture and dimple fracture exists in the TiCp/ZA-12 composites, and fractured particles are not found. Finally the fracture model of composites has been established based on the experimental results.


2016 ◽  
Vol 2016 ◽  
pp. 1-15 ◽  
Author(s):  
P. Noorunnisa Khanam ◽  
MA AlMaadeed ◽  
Sumaaya AlMaadeed ◽  
Suchithra Kunhoth ◽  
M. Ouederni ◽  
...  

The focus of this work is to develop the knowledge of prediction of the physical and chemical properties of processed linear low density polyethylene (LLDPE)/graphene nanoplatelets composites. Composites made from LLDPE reinforced with 1, 2, 4, 6, 8, and 10 wt% grade C graphene nanoplatelets (C-GNP) were processed in a twin screw extruder with three different screw speeds and feeder speeds (50, 100, and 150 rpm). These applied conditions are used to optimize the following properties: thermal conductivity, crystallization temperature, degradation temperature, and tensile strength while prediction of these properties was done through artificial neural network (ANN). The three first properties increased with increase in both screw speed and C-GNP content. The tensile strength reached a maximum value at 4 wt% C-GNP and a speed of 150 rpm as this represented the optimum condition for the stress transfer through the amorphous chains of the matrix to the C-GNP. ANN can be confidently used as a tool to predict the above material properties before investing in development programs and actual manufacturing, thus significantly saving money, time, and effort.


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