scholarly journals PHYSICAL AND MECHANICAL PROPERTIES OF SPECIALIZED CEMENT MIXTURES FOR INTEGRATED ISOLATION OF MINE WORKINGS

Author(s):  
Eugene I. Nurgaliev ◽  
◽  
Alexander E. Mayorov ◽  
2021 ◽  
Vol 315 ◽  
pp. 02018
Author(s):  
Yuriy Masaev ◽  
Vladislav Masaev ◽  
Yuriy Drozdenko

When developing coal and ore deposits by underground method, it is necessary to carry out a large volume of preparatory mine workings using drilling and blasting operations. Minerals are found in rocks under various conditions and their physical and mechanical properties change in a wide range. Under such conditions, it is necessary to use drilling machines this different to the principle of action and structural features. The article considers geometric parameters of roc cutters, peculiarities of drilling modes, affecting energy intensity and drilling productivity in rocks with different strength coefficient.


Author(s):  
I Sheka ◽  
Ye Tsivka

Purpose. To analyze composite materials and prospects of their use as fastening materials for mining of coal mines.Perform a comparative analysis of the physical and mechanical properties of the innovative material carbon fiber and metallic materials, as well as compare their features. To determine the possibility of using carbon fiber as a fastening material for mining of coal mines. Research methodology. The generalization of physical and mechanical properties of carbon fiber on the basis of its analysis is performed. The features of mechanical properties of carbon fiber, steel and aluminum are compared, which showed that this composite material has the best physical and mechanical properties and it is expedient to use it in the fastening elements of mine workings. Research results. The areas of use of composite materials in industry are analyzed and generalized, and it is concluded that it is better to use carbon fiber as a fastening material for coal mine workings. A comparative analysis of the physical and mechanical properties of carbon fiber and steel is performed, which shows that this composite material has identical (and sometimes even better) properties as metallic materials. The advantages and disadvantages of carbon fiber as a fastening material for mining of coal mines are estimated. It is specified that the restraining factor, today, is the cost of carbon fiber, and later their price will decrease and demand will increase. It is concluded that when using this composite material in the fasteners of mine workings, it is possible to increase the pace of their implementation, reduce the complexity of the work performed and improve working conditions while facilitating the design. Scientific novelty. It is established that carbon fiber as a composite material can be used in the fastening elements of the preparatory workings of coal mines. Practical value. According to the results of the analysis, it is established that carbon plastics can be used in the fastening elements of mine workings, which will promote the development of underground coal mining.


2012 ◽  
Vol 4 (1) ◽  
pp. 1
Author(s):  
Djoko Purwanto

Timber Acacia mangium (Acacia mangium, Willd) for Furniture. The study aims to determine the mechanical and physical properties and the decorative value (color and fiber) wood of acacia mangium with using finishing materials. This type of finishing material used is ultran lasur natural dof ,ultran lasur classic teak, aqua politur clear dof, aqua politur akasia dan aqua politur cherry. After finishing the wood is stored for 3 months. Test parameters were observed, namely, physical and mechanical properties of wood, adhesion of finishing materials, color and appearance of the fiber, and timber dimensions expansion. The results showed that the mechanical physical properties of acacia wood qualified SNI. 01-0608-89 about the physical and mechanical properties of wood for furniture, air dry the moisture content from 13.78 to 14.89%, flexural strength from 509.25 to 680.50 kg/cm2, and compressive strength parallel to fiber 342.1 - 412.9 kg/cm2. Finishing the treatment process using five types of finishing materials can increase the decorative value (color and fiber) wood. Before finishing the process of acacia mangium wood has the appearance of colors and fibers and less attractive (scale scores 2-3), after finishing acacia wood fibers have the appearance of colors and interesting and very interesting (scale 4-5).Keywords: mangium wood, mechanical properties, decorative value, finishing, furniture.


2016 ◽  
Vol 13 (2) ◽  
pp. 67
Author(s):  
Engku Liyana Zafirah Engku Mohd Suhaimi ◽  
Jamil Salleh ◽  
Suzaini Abd Ghani ◽  
Mohamad Faizul Yahya ◽  
Mohd Rozi Ahmad

An investigation on the properties of Tenun Pahang fabric performances using alternative yarns was conducted. The studies were made in order to evaluate whether the Tenun Pahang fabric could be produced economically and at the same time maintain the fabric quality. Traditional Tenun Pahang fabric uses silk for both warp and weft. For this project, two alternative yarns were used which were bamboo and modal, which were a little lower in cost compared to silk. These yarns were woven with two variations, one with the yarns as weft only while maintaining the silk warp and the other with both warp and weft using the alternative yarns. Four (4) physical testings and three (3) mechanical testings conducted on the fabric samples. The fabric samples were evaluated including weight, thickness, thread density, crease recovery angle, stiffness and drapability. The results show that modal/silk and bamboo silk fabrics are comparable in terms of stiffness and drapability, hence they have the potential to replace 100% silk Tenun Pahang.


2014 ◽  
Vol 62 (1) ◽  
pp. 129-137
Author(s):  
A. Sawicki ◽  
J. Mierczyński

Abstract A basic set of experiments for the determination of mechanical properties of sands is described. This includes the determination of basic physical and mechanical properties, as conventionally applied in soil mechanics, as well as some additional experiments, which provide further information on mechanical properties of granular soils. These additional experiments allow for determination of steady state and instability lines, stress-strain relations for isotropic loading and pure shearing, and simple cyclic shearing tests. Unconventional oedometric experiments are also presented. Necessary laboratory equipment is described, which includes a triaxial apparatus equipped with local strain gauges, an oedometer capable of measuring lateral stresses and a simple cyclic shearing apparatus. The above experiments provide additional information on soil’s properties, which is useful in studying the following phenomena: pre-failure deformations of sand including cyclic loading compaction, pore-pressure generation and liquefaction, both static and caused by cyclic loadings, the effect of sand initial anisotropy and various instabilities. An important feature of the experiments described is that they make it possible to determine the initial state of sand, defined as either contractive or dilative. Experimental results for the “Gdynia” model sand are shown.


Author(s):  
Thais Helena Sydenstricker Flores-Sahagun ◽  
Kelly Priscila Agapito ◽  
ROSA MARIA JIMENEZ AMEZCUA ◽  
Felipe Jedyn

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