scholarly journals The effect of the addition of granite powder to the primer on the pull-off strength of epoxy resin coatings

2021 ◽  
Author(s):  
Lukasz Kampa ◽  
Keyword(s):  
Epoxy Resin ◽  
Reference Sample ◽  
Control Sample ◽  
Automatic Device ◽  
Measurement Time ◽  
Resin Layer ◽  
Strength Tests ◽  
Granite Powder

This article describes the effect of adding waste granite powder to the epoxy resin layer on its pull-off strength. The substrate was C30 / 37 concrete. The priming resin was modified with 10%, 20%, 30%, 40%, 50%, and 60% of granite powder. For control purposes, a sample was also made without the addition of powder. For each material configuration, four strength tests were carried out with the use of an automatic device recording both the pull-off strength and the measurement time. The obtained results were compared with the control sample. The best result in the test was obtained with the addition of 20%, which gave an increase of 19% compared to the reference sample. An equally good result was obtained with the addition of 10% granite powder (increase by 11%). The addition of a larger amount of the additive resulted in a decrease or a slight increase in the pull-off strength compared to the reference sample. Additionally, the additive has been found to darken the coating, and the coating becomes completely opaque when added above 50%.

scholarly journals The Effect of the Addition of Polypropylene Fibers to Primer on the Pull-Off Strength of Epoxy Resin Coatings

Materials ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 4674
Author(s):  
Łukasz Kampa ◽  
Agnieszka Chowaniec ◽  
Aleksandra Królicka ◽  
Łukasz Sadowski
Keyword(s):  
Epoxy Resin ◽  
Cement Mortar ◽  
Reference Sample ◽  
Automatic Device ◽  
Polypropylene Fibers ◽  
Cement Slurry ◽  
Optimum Content ◽  
Resin Coating ◽  
Strength Tests ◽  
Epoxy Resin Coating

This article describes the effect of adding polypropylene fibers to primer on the pull-off strength of epoxy resin coatings. Investigated primers were laid on substrates made of cement mortar and cement slurry. The primer was made of epoxy resin modified with the addition of 0.5%, 1%, 1.5% and 2% of polypropylene fibers. One reference sample was made without the addition of fibers. Then, an epoxy resin coating was applied to each substrate. Four pull-off strength tests were performed for each material configuration. For this purpose, an automatic device for measuring the pull-off strength of the coatings was used. The results were compared with the results obtained for the reference sample. The optimum content of polypropylene fibers was found to be in the range of 0.5–1.0 wt. % of the mass of the resin. One percent of fibers was optimum for the epoxy resin laid on the cement slurry, while 0.5 wt. % of fibers was optimum for the mortar substrate. The addition of a higher amount of polypropylene fibers resulted in a lower pull-off strength of coatings than for the reference sample.

scholarly journals A Reference Sample: ISM of the Most Isolated Galaxies

2004 ◽  
Vol 217 ◽  
pp. 220-221
Author(s):  
L. Verdes-Montenegro ◽  
J. Sulentic ◽  
D. Espada ◽  
S. Leon ◽  
U. Lisenfeld ◽  
...  
Keyword(s):  
Star Formation ◽  
Interstellar Medium ◽  
Galaxy Evolution ◽  
Reference Sample ◽  
Control Sample ◽  
Evolution Of Galaxies ◽  
Isolated Galaxies ◽  
Internal Evolution

We are constructing the first complete unbiased control sample of the most isolated galaxies of the northern sky to serve as a template in the study of star formation and galaxy evolution in denser environments. Our goal is to compare and quantify the properties of different phases of the interstellar medium in this sample, as well as the level of star formation, both relevant parameters in the internal evolution of galaxies and strongly conditioned by the environment. To achieve this goal we are building a multiwavelength database for this sample to compare and quantify the properties of different phases of the ISM.

ASSESSMENT OF STRONTIUM, RUBIDIUM AND SCANDIUM STATUS IN SOILS AFFECTED BY SOLID WASTE DEPOSITS

2021 ◽  
Author(s):  
Luminita Pirvulescu ◽  
Despina-Maria Bordean ◽  
Loredana Copacean ◽  
Narcis Gheorghe Baghina
Keyword(s):  
Solid Waste ◽  
Soil Analysis ◽  
Reference Sample ◽  
Control Sample ◽  
Pollution Index ◽  
Random Pattern ◽  
Contamination Level ◽  
Accumulation Index ◽  
Waste Deposit ◽  
Waste Deposits

The aim of the study was to assess the level of contamination of soil with strontium, rubidium and scandium in the solid waste deposits. The study was performed on soil samples collected from Moldova Noua, southwest of Romania, an area with historical anthropogenic history. The soil analysis was performed using X-ray fluorescence (XRF). The samples were collected from five collection points using a random pattern from around the illegal waste deposit and all analyses were performed in triplicate. To assess the influence of wastes on the soils concentration levels of strontium (Sr), rubidium (Rb) and scandium (Sc), were calculated contamination factors (CF), and pollution index (PIL) by reporting the concentration of the investigated elements of the upper earth crust concentrations and geo-accumulation index (Igeo) calculated by reporting the elements concentration values to a control sample, used as reference. The reference sample was collected from an area close to the waste deposit but located in a protected green area. The results show that from the investigated elements, scandium is the element of concern, the soil presenting a moderate contamination level with this element.

scholarly journals Starch-Jute fiber hybrid biocomposite modified with Epoxy resin layer: Fabrication and Experimental Characterization

2018 ◽  
Author(s):  
Akarsh Verma ◽  
Kamal Joshi ◽  
Amit Gaur ◽  
V. K. Singh
Keyword(s):  
Tensile Strength ◽  
Water Absorption ◽  
Epoxy Resin ◽  
High Water ◽  
Epoxy Coating ◽  
Jute Fiber ◽  
Compression Moulding ◽  
Resin Layer ◽  
Major Disadvantage ◽  
Water Absorption Property

In this article, bio-composites derived from starch-glycerol biodegradable matrix reinforced with jute fibers have been fabricated using the wet hand lay-up and compression moulding techniques. Samples having different weight percentages of jute fiber in the starch matrix have been analysed. The fibers surface was chemically treated by alkaline sodium hydroxide for improving the interphase bonding between fiber and matrix. Tensile test for the composites were done and the sample with highest tensile strength was selected for further tests that included water absorption, scanning electron microscopy and thermal analysis. It has been concluded that the ultimate tensile strength was found to be maximum for the composition of 15% fiber by weight composite as 7.547 MPa without epoxy coating and 10.43 MPa with epoxy coating. The major disadvantage of bio-composite is its high water absorption property, which in this study has been inhibited by the epoxy resin layer. Herein, the results of various tests done disclose a noteworthy improvement in the overall properties of bio-composite, in comparison to the neat biodegradable starch matrix.

scholarly journals An Experimental Study on a Composite Bonding Structure for Steel Bridge Deck Pavements

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Xiaoguang Zheng ◽  
Qi Ren ◽  
Huan Xiong ◽  
Xiaoming Song
Keyword(s):  
Tensile Strength ◽  
Shear Strength ◽  
Epoxy Resin ◽  
Bonding Strength ◽  
Bridge Deck ◽  
Steel Bridge ◽  
Shear Tests ◽  
Bonding Structure ◽  
Asphalt Overlay ◽  
Strength Tests

As one of the major contributors to the early failures of steel bridge deck pavements, the bonding between steel and asphalt overlay has long been a troublesome issue. In this paper, a novel composite bonding structure was introduced consisting of epoxy resin micaceous iron oxide (EMIO) primer, solvent-free epoxy resin waterproof layer, and ethylene-vinyl acetate (EVA) hot melt pellets. A series of strength tests were performed to study its mechanical properties, including pull-off strength tests, dumbbell tensile tests, lap shear tests, direct tension tests, and 45°-inclined shear tests. The results suggested that the bonding structure exhibited fair bonding strength, tensile strength, and shear strength. Anisotropic behaviour was also observed at high temperatures. For epoxy resin waterproof layer, the loss of bonding strength, tensile strength, and shear strength at 60°C was 70%, 35%, and 39%, respectively. Subsequent pavement performance-oriented tests included five-point bending tests and accelerated wheel tracking tests. The impacts of bonding on fatigue resistance and rutting propagation were studied. It was found that the proposed bonding structure could provide a durable and well-bonded interface and was thus beneficial to prolong the fatigue lives of asphalt overlay. The choice of bonding materials was found irrelevant to the ultimate rutting depth of pavements. But the bonding combination of epoxy resin waterproof and EVA pellets could delay the early-stage rutting propagation.

An Epoxy Bonding Apparatus for Applications under Extreme Environment

MRS Advances ◽  
2016 ◽  
Vol 1 (21) ◽  
pp. 1525-1530
Author(s):  
Runkun Jiang ◽  
Lei Mei ◽  
Q. M. Zhang
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Epoxy Resin ◽  
Bonding Strength ◽  
Extreme Environment ◽  
Oil Drilling ◽  
Resin Layer ◽  
Trapped Air ◽  
Acoustic Transducers ◽  
Epoxy Bonding

ABSTRACTA number of electrical components and devices work in extreme environment such as high temperature, high pressure, strong vibration, corrosive chemicals, etc. A common practice to protect them is to shield them in materials that are mechanically and chemically resistant to these harsh conditions. In this scenario, epoxy bonding is preferred and it is crucial to have high bonding strength. One example is the acoustic transducers used in oil drilling. The temperature can reach 200 °C and the pressure can reach 140 MPa. The piezoelectric ceramic parts cannot withstand these conditions so different packaging materials are used such as polyether ether ketone (PEEK).Here an epoxy bonding apparatus is presented that has demonstrated ultrahigh bonding strength. Though epoxy resin is degassed before applying, which gets rid of air bubbles generated in the mixing process, there is trapped air when two surfaces are closed together. This trapped air has minuscule effect for applications in ambient environment, but under extreme environment, it compromises the bonding strength majorly. We devised a vacuum system that contains a motorized stage with the bonding parts attached. After the epoxy is applied and the system is pumped to 1% vacuum, a computer controls the motor to move the bonding parts into contact. Since the entire operation is in vacuum, it leaves no trapped air and results in increased bonding strength. This apparatus confirmed the importance of surface preparation, including removal of air by starting the cure in vacuum (5 mm Hg) and subsequently releasing the vacuum [1].Another technique to improve the bonding strength utilizes the finding that a uniform epoxy resin layer between 50 µm and 150 µm [2] results in the optimal bonding strength. Here we applied spacers such as optic fiber (125 µm in diameter) or glass fiber fabric (150 µm in thickness) in between the bonding surfaces. These spacers ensure that the epoxy resin layer is of uniform thickness. It also utilizes the principle of glass-epoxy compositing to increase mechanical strength by fiber reinforcement and load distribution [3, 4].The above bonding apparatus has been proven to increase the bonding strength by experiments. Acoustic transducers bonded with this technique passed the high pressure, high temperature tests resembling the oil drilling conditions.

scholarly journals Mechanical Properties of Selected Epoxy Adhesive and Adhesive Joints of Steel Sheets

2021 ◽  
Vol 2 (1) ◽  
pp. 108-126
Author(s):  
Anna Rudawska
Keyword(s):  
Mechanical Properties ◽  
Epoxy Resin ◽  
Experimental Tests ◽  
Epoxy Adhesive ◽  
Adhesive Joints ◽  
Stoichiometric Ratio ◽  
Curing Agent ◽  
Steel Sheets ◽  
Epoxy Adhesives ◽  
Strength Tests

The article presents the issues of the mechanical properties of epoxy adhesives and the adhesive joints strength of steel sheets which were made using the epoxy adhesives. The aim of the paper is to study the mechanical properties of epoxy adhesive of different epoxy resin/curing agent ratios (within and above the recommended stoichiometric ratio) and their effect on mechanical properties of adhesive joints of steel sheets. In experimental tests three types of epoxy adhesives, containing a low molecular weight epoxy resin based on bisphenol A and polyamide curing agent, were used. A single-lap adhesive joint type of stainless-steel sheets was also applied. Two types of strength test were used: the compressive strength tests (DIN EN 196-1) for epoxy adhesive samples and the shear strength tests (DIN EN 1465) for adhesive joints. Both the analysis of the strength results of the samples of epoxy adhesive and adhesive joints as well as the failure analysis was carried out. On the basis of the results of strength tests it can be stated that the greatest deformation occurred for the samples of epoxy adhesive containing the modified epoxy resin (epoxy number—0.40) and the polyamide curing agent, and the smallest for the samples of epoxy adhesive containing the basic epoxy resin (epoxy number—0.49–0.52) and the polyamide curing agent. The epoxy adhesives with a smaller amount of curing agent were characterized by higher strength. This applies to all analyzed epoxy resins. The same dependences were obtained for the strength of adhesive joints of steel sheets made of the analyzed epoxy adhesive.

scholarly journals Mechanical and physical properties of water hyacinth and cogon grass fiber reinforced epoxy resin composites

2021 ◽  
Vol 2145 (1) ◽  
pp. 012036
Author(s):  
P Kongkaew ◽  
P Praneekrit ◽  
T Rudchapo ◽  
K Khampui
Keyword(s):  
Physical Properties ◽  
Water Absorption ◽  
Epoxy Resin ◽  
Water Hyacinth ◽  
Fracture Behavior ◽  
Hybrid Composites ◽  
Fiber Reinforced ◽  
Surface Fracture ◽  
Strength Tests ◽  
Mechanical And Physical Properties

Abstract In this paper, the study investigates the mechanical and physical properties of water hyacinth and cogon grass fiber reinforced epoxy resin hybrid composites. Hand lay-up technique was used to fabricate the composites. Water absorption, microstructure, tensile properties, flexural properties, and impact strength tests for total fiber contents, 15 wt %, and different water hyacinth and cogon grass fiber ratios (10/0, 8/2, 6/4, 4/6, 2/8, and 0/10) were used to evaluate the investigation’s effects. The addition of water hyacinth and cogon grass fiber into epoxy improves tensile, flexural, and impact properties while decreasing water absorption, according to the findings. Using a scanning electron microscope (SEM), the microstructure of the composites was analyzed, and surface fracture behavior and the void between the fiber and matrix were observed.

Sign in / Sign up

Export Citation Format

Share Document