Study of restoration epoxy composites with initial and water-cured fillers

2021 ◽  
Vol 87 (8) ◽  
pp. 34-41
Author(s):  
D. L. Starokadomsky ◽  
M. N. Reshetnyk

The goal of the study is to compare the properties of epoxy composites with initial and water-treated (hydrated) water-hardening binders (gypsum and cement). The effect of 50% filling of ED20 epoxy resin with initial and water-treated binders (cement and gypsum) on the strength of composites, their structure and physicomechanical properties is considered. An increase in such indicators as the elastic modulus value, fire- and heat resistance, as well as the resistance to organic solvents was observed. Optical and SEM microscopy revealed a difference in their structure compared to the original composites. However, there was no noticeable effect on the strength characteristics of conventional heat treatment (50 – 60°C). After heating at 250°C, the effect of thermal hardening (and thermoplasticization) was observed for filled composites: a significant increase in the compressive strength (and plasticity), microhardness, and abrasion resistance, compared to an unfilled polymer. The results obtained can be used to develop polyepoxide materials with new properties necessary for solving important production applications.

2019 ◽  
pp. 40-43
Author(s):  
D. L. Staroadomskyk

New data on the eff ect of a SiC and TiN fi llers on the practically important properties of epoxy polymer are presented. The possibilities for a signifi cant increase in microhardness – 1.5–2 times, bending modulus (1.4–1.7 times), compressive strength (for SiC), abrasion resistance and chemical resistance (in nitric acid and acetone/ethyl acetate) are established. At the same time, the thermal stability of the compositions and their strength properties is substantially increased. This is manifested in the eff ects of strengthening (compared with the unfi lled analogue) and plasticization of such composites after temperatures that destroy the ordinary polyepoxides (200–300°C. These eff ects are not covered in the literature and are named by the author as “eff ects of thermal strengthening and thermoplasticization of epoxy composites”.


Alloy Digest ◽  
1971 ◽  
Vol 20 (8) ◽  

Abstract ABRASALLOY No. 3 is a space-age composite alloy steel developed to provide a unique combination of strength, ductility and abrasion resistance for earth-moving, mineral processing and mining machinery. It is not available in any other plate manufactured by conventional rolling and heat treatment. This datasheet provides information on composition, hardness, elasticity, tensile properties, and shear strength as well as fracture toughness. It also includes information on forming, heat treating, machining, and joining. Filing Code: SA-267. Producer or source: Atlantic Steel Corporation.


Alloy Digest ◽  
1976 ◽  
Vol 25 (12) ◽  

Abstract DEWARD is an oil-hardening, non-deforming, manganese die steel that is characterized by uniformity, good machinability and satisfactory performance in service. Its composition permits a relatively low hardening temperature to give minimum distortion after heat treatment and little danger of cracking. It has good wear resistance and gives excellent results when used for all kinds of intricate tools. This datasheet provides information on composition, physical properties, hardness, elasticity, and compressive strength as well as fracture toughness. It also includes information on forming, heat treating, and machining. Filing Code: TS-310. Producer or source: AL Tech Specialty Steel Corporation.


2020 ◽  
Vol 62 (4) ◽  
pp. 362-367
Author(s):  
I. S. Sirotin ◽  
I. A. Sarychev ◽  
I. V. Terekhov ◽  
M. A. Khaskov ◽  
S. N. Filatov ◽  
...  

Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2303
Author(s):  
Congyu Zhong ◽  
Liwen Cao ◽  
Jishi Geng ◽  
Zhihao Jiang ◽  
Shuai Zhang

Because of its weak cementation and abundant pores and cracks, it is difficult to obtain suitable samples of tectonic coal to test its mechanical properties. Therefore, the research and development of coalbed methane drilling and mining technology are restricted. In this study, tectonic coal samples are remodeled with different particle sizes to test the mechanical parameters and loading resistivity. The research results show that the particle size and gradation of tectonic coal significantly impact its uniaxial compressive strength and elastic modulus and affect changes in resistivity. As the converted particle size increases, the uniaxial compressive strength and elastic modulus decrease first and then tend to remain unchanged. The strength of the single-particle gradation coal sample decreases from 0.867 to 0.433 MPa and the elastic modulus decreases from 59.28 to 41.63 MPa with increasing particle size. The change in resistivity of the coal sample increases with increasing particle size, and the degree of resistivity variation decreases during the coal sample failure stage. In composite-particle gradation, the proportion of fine particles in the tectonic coal sample increases from 33% to 80%. Its strength and elastic modulus increase from 0.996 to 1.31 MPa and 83.96 to 125.4 MPa, respectively, and the resistivity change degree decreases. The proportion of medium particles or coarse particles increases, and the sample strength, elastic modulus, and resistivity changes all decrease.


Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1845
Author(s):  
Narcis Anghel ◽  
Valentina Maria Dinu ◽  
Liliana Verestiuc ◽  
Irene Alexandra Spiridon

Designing composites based on natural polymers has attracted attention for more than a decade due to the possibility to manufacture medical devices which are biocompatible with the human body. Herein, we present some biomaterials made up of collagen, polyurethane, and cellulose doped with lignin and lignin-metal complex, which served as transcutaneous drug delivery systems. Compared with base material, the compressive strength and the elastic modulus of biocomposites comprising lignin or lignin-metal complex were significantly enhanced; thus, the compressive strength increased from 61.37 to 186.5 kPa, while the elastic modulus increased from 0.828 to 1.928 MPa. The release of ketokonazole from the polymer matrix follows a Korsmeyer–Peppas type kinetics with a Fickian diffusion. All materials tested were shown to be active against pathogenic microorganisms. The mucoadhesiveness, bioadhesiveness, mechanical resistance, release kinetic, and antimicrobial activity make these biocomposites to be candidates as potential systems for controlled drug release.


2021 ◽  
Vol 13 (3) ◽  
pp. 1364
Author(s):  
Michele La Noce ◽  
Alessandro Lo Faro ◽  
Gaetano Sciuto

Clay has a low environmental impact and can develop into many different products. The research presents two different case studies. In the first, the clay is the binder of raw earth doughs in order to produce clay-bricks. We investigate the effects of natural fibrous reinforcements (rice straws and basalt fibers) in four different mixtures. From the comparison with a mix without reinforcements, it is possible to affirm that the 0.40% of basalt fibers reduce the shrinkage by about 25% and increase the compressive strength by about 30%. Future studies will focus on identifying the fibrous effects on tensile strength and elastic modulus, as well as the optimal percentage of fibers. In the second study, the clay, in form of brick powder (“cocciopesto”), gives high alkaline resistance and breathability performance, as well as rendering and color to the plaster. The latter does not have artificial additives. The plaster respects the cultural instance of the original building. The research underlines how the use of a local (and traditional) material such as clay can be a promoter of sustainability in the contemporary building sector. Future studies must investigate further possible uses of clay as well as a proper regulatory framework.


2021 ◽  
Vol 11 (7) ◽  
pp. 3032
Author(s):  
Tuan Anh Le ◽  
Sinh Hoang Le ◽  
Thuy Ninh Nguyen ◽  
Khoa Tan Nguyen

The use of fluid catalytic cracking (FCC) by-products as aluminosilicate precursors in geopolymer binders has attracted significant interest from researchers in recent years owing to their high alumina and silica contents. Introduced in this study is the use of geopolymer concrete comprising FCC residue combined with fly ash as the requisite source of aluminosilicate. Fly ash was replaced with various FCC residue contents ranging from 0–100% by mass of binder. Results from standard testing methods showed that geopolymer concrete rheological properties such as yield stress and plastic viscosity as well as mechanical properties including compressive strength, flexural strength, and elastic modulus were affected significantly by the FCC residue content. With alkali liquid to geopolymer solid ratios (AL:GS) of 0.4 and 0.5, a reduction in compressive and flexural strength was observed in the case of geopolymer concrete with increasing FCC residue content. On the contrary, geopolymer concrete with increasing FCC residue content exhibited improved strength with an AL:GS ratio of 0.65. Relationships enabling estimation of geopolymer elastic modulus based on compressive strength were investigated. Scanning electron microscope (SEM) images and X-ray diffraction (XRD) patterns revealed that the final product from the geopolymerization process consisting of FCC residue was similar to fly ash-based geopolymer concrete. These observations highlight the potential of FCC residue as an aluminosilicate source for geopolymer products.


2014 ◽  
Vol 976 ◽  
pp. 202-206 ◽  
Author(s):  
Javier Flores Badillo ◽  
Juan Hernández Ávila ◽  
Francisco Patiño Cardona ◽  
Norma Yacelit Trápala Pineda ◽  
José Abacú Ostos Santos

In this paper we present the production of alternative industrial materials from the mining waste in the form of tailings, this study was made with the tailings of Dos Carlos, establishing 4 sampling zones, dividing them into three strata in the bottom, middle and top. The sampling method used is quartering, to homogenize the material and anticipate the possible use of it as a building material, having for this purpose 12 ceramic mixtures for subsequent treatment. Chemical composition was determined as 70.43% SiO2, 7.032% Al2O3, 2.69% Fe2O3, 0.46% MnO2, 3.98% K2O, 3.34% CaO, 2.50% Na2O, 56 grams per tonne of Ag y 0.6 grams per tonne of Au. In the mineralogical characterization the tailings presents silica, albite, berlinite, orthoclase and potassium jarosite as the main mineral phases, among other mineral phases in lesser concentration such as gypsum, calcite, anorthoclase, pyrite, sphalerite and galena. The determinations of the tailing material granulometry in the range of 60% in a size less than 270 mesh (53 μm). Afterwards, the alternative industrial materials were produced by using the tailings and heavy clay in order to give the composite a good green strength and plasticity during development, but above all to give it a compressive strength similar or higher than that of products derived from conventional processes. Keywords: Tailings, green strength, compressive strength, plasticity, heavy clays, alternative industrial materials.


2014 ◽  
Vol 894 ◽  
pp. 45-49 ◽  
Author(s):  
Luisa Pani ◽  
Lorena Francesconi

In this paper an experimental program has been carried out in order to compare compressive strength fcand elastic static modulus Ecof recycled concrete with ultrasonic waves velocity Vp, to establish the possibility of employing nondestructive ultrasonic tests to qualify recycled concrete. 9 mix of concrete with different substitution percentage of recycled aggregates instead of natural ones and 27 cylindrical samples have been made. At first ultrasonic tests have been carried out on cylindrical samples, later elastic static modulus Ecand compressive strength fchave been experimentally evaluated. The dynamic elastic modulus Edhas been determined in function of ultrasonic wave velocity Vp; furthermore the correlations among Ed, Ec, fce Vphave been determined. It has been demonstrated that ultrasonic tests are suitable for evaluating different deformative and resisting concrete performances even when variations are small.


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