scholarly journals DESIGN MODELS OF THE BEARING CAPACITY OF THE SUPPORT SECTIONS OF BASALT-CONCRETE BEAM STRUCTURES

Author(s):  
I.A. Karpiuk ◽  
◽  
A.S. Tselikova ◽  
V.M. Karpiuk ◽  
A.A. Khudobych ◽  
...  

Abstract. In the past decade, structures with non-metallic composite reinforcement (FRP) find more and more widespread use in construction practice, especially in buildings and structures for special purposes. Due to its high strength, resistance to chemical and physical corrosion, dielectric and diamagnetic properties, low weight and low thermal conductivity, FRP is increasingly replacing steel reinforcement. However, the wider use of concrete structures with FRP is constrained by insufficient knowledge of the features of their work, insufficient regulatory support and little experience in operating these facilities. Practice has shown the promise and economic feasibility of using FRP in road, hydraulic engineering, transport construction, in the construction of bridge spans, treatment facilities, chemical and food industry facilities, and foundations in an aggressive soil environment. At the same time, the prospects for using basalt-plastic reinforcement (BFRP) are primarily due to the low cost of the main raw material, basalt fibers, due to the presence of significant reserves of basalt in the world. The basic principles of calculation of bending structures reinforced with FRP, in all foreign standards, as well as in the domestic Manual, are the same as for elements with steel reinforcement. The design models of the bearing capacity of the bearing sections of concrete beams reinforced with BFRP are considered. The bearing capacity of inclined sections of elements with large and medium shear spans should be determined by an inclined crack using variable coefficients , taking into account the real length of a dangerous inclined crack , a significant reduction in tensile stresses in transverse reinforcement to . The bearing capacity of the support sections with small shear spans must be determined as for short cantilevers along an inclined compressed strip between the concentrated force and the support using a variable coefficient . This approach provides satisfactory convergence between the calculated and experimental values of the bearing capacity of inclined sections (coefficient of variation BFRP.

2000 ◽  
Vol 15 (1) ◽  
pp. 2-8 ◽  
Author(s):  
N.C. Wagner ◽  
S. Ramaswamy ◽  
U. Tschirner

AbstractA pre-economic feasibility study was undertaken to determine the potential of cereal straw for industrial utilization in Minnesota. Specifically, utilizing straw for pulp and paper manufacture was of interest. The availability of cereal straw fiber supplies at various locations across the state of Minnesota, along with pre-processing issues such as transportation, harvesting, handling, and storage, are discussed and priced. The greatest economic advantage of straw for industrial use appears to be the low cost of the raw material compared to traditional raw materials. This also provides an excellent opportunity for additional income for farmers. The methodology and information provided here should be helpful in evaluating the feasibility of utilizing straw for other industrial purposes in other parts of the world. However, in some Third World countries, long-standing on-farm, traditional uses of cereal straws for fuel, fiber, and animal feed may limit their availability for industrial utilization.


Polymers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2524
Author(s):  
Ilaria Papa ◽  
Alessia Teresa Silvestri ◽  
Maria Rosaria Ricciardi ◽  
Valentina Lopresto ◽  
Antonino Squillace

Among the several additive manufacturing techniques, fused filament fabrication (FFF) is a 3D printing technique that is fast, handy, and low cost, used to produce complex-shaped parts easily and quickly. FFF adds material layer by layer, saving energy, costs, raw material costs, and waste. Nevertheless, the mechanical properties of the thermoplastic materials involved are low compared to traditional engineering materials. This paper deals with the manufacturing of composite material laminates obtained by the Markforged continuous filament fabrication (CFF) technique, using an innovative matrix infilled by carbon nanofibre (Onyx), a high-strength thermoplastic material with an excellent surface finish and high resistance to chemical agents. Three macro-categories of samples were manufactured using Onyx and continuous carbon fibre to evaluate the effect of the fibre on mechanical features of the novel composites and their influence on surface finishes. SEM (Scanning Electron Microscopy) analysis and acquisition of roughness profile by a confocal lens were conducted. Tensile and compression tests, thermogravimetric analysis and calorimetric analysis using a DSC (differential scanning calorimeter) were carried out on all specimen types to evaluate the influence of the process parameters and layup configurations on the quality and mechanical behaviour of the 3D-printed samples.


2020 ◽  
Vol 1011 ◽  
pp. 116-122
Author(s):  
Evgeny Gaishun ◽  
Khungiaonos Yavruyan ◽  
Vladimir Kotlyar ◽  
Elizaveta Lotoshnikova

The article shows the prospects of using large-sized ceramic stones for modern housing construction. A review of the raw materials and technologies for their production is given. It is emphasized that the most promising technology for the large-sized ceramic stones’ production is a hard extrusion technology with the possibility of laying raw products on firing buggies and accelerated drying and firing modes. The characteristic of waste piles processing screenings in East Donbass, which are considered to be the by-products of coal mining, as the main raw material for the large-sized ceramic stones’ production is given. Their ceramic properties and results of the raw materials’ selection are given, including: screenings - 60-65%; siliceous clay - 20-30% coal sludge - 10-15%, on the basis of which it is possible to obtain the products with low cost and high strength for the load-bearing wall structures. The features of the ceramic material microstructure based on the obtained raw material mixtures with optimal porosity are noted. It is shown that the waste piles’ involvement in the process of ceramic stones production will make it possible to obtain products with a density of less than 800 kg/m3, less thermal conductivity 0,20 m·°С)/W and the brand strength M150 and above, with a minimum cost. This will create a serious competition for gas silicate products and achieve a level of ceramic stones’ use in the total volume of wall products for the housing construction of 80%, like in Western Europe.


Author(s):  
Emiru Yidnekew Melesse ◽  
Tesfaye Kassaw Bedru ◽  
Beteley Tekola Meshesha

The need for pulp and paper currently in the whole world has become shooting up massively. The generation of the pulp, as well as paper from woody materials, has a challenge due to deforestation, huge chemical and energy consumptions. Now, an alternative source for paper is lignocelluloses wastes, because of low cost, low energy, and chemical consumption. Among them, the banana pseudostem was best for the input of pulp and paper production. This investigation was on the production and characterization of pulp from Banana Pseudo Stem for Paper Making via Soda Anthraquinone pulping process. The amount of cellulose (41.45%), ash (12.4%), hemicellulose (23.37%), extractive (12.72%), and lignin (10.46%) contents were obtained at the initial compositional evaluation of the pseudostem. It has excellent fiber length (1.75mm), fiber diameter (22.15μm), an acceptable Runkle ratio (0.55), and flexibility coefficient (159.64). The effect of temperature (130,140 and 150 °C), cooking time (45, 60, and 75 minutes), the concentration of soda (10, 12.5, and 15%), were examined. The maximum pulp yield and kappa number was 36.7% and 22.8 respectively obtained at 10% of soda concentration, at 150 °C, and 63 minutes of cooking time from oven-dried raw material. The produced paper from the banana pseudostem has a tensile index, tearing index, smoothness, and porosity were 78.75 Nm/g, 19.1 mN.m2/g, 500-530μm, and 50 sec/100ml air respectively. This study indicates that high strength mechanical property and good surface properties paper can be produced from banana pseudostem pulp with a more environmentally friendly pulping process.


2021 ◽  
Vol 872 ◽  
pp. 91-95
Author(s):  
Bachrun Sutrisno ◽  
Alif Muhammad ◽  
Zikriani Genta ◽  
Arif Hidayat

The problem associated with biodiesel production is economic feasibility. The biodiesel cost will reduce when the low cost feedstock was used. Kapok seed oil (KSO) is a promising candidate as raw material for biodiesel synthesis. In this research, the investigation of biodiesel synthesis from KSO was studied using Indonesia Natural Zeolite as heterogeneous catalysts. The catalyst was tested to synthesize biodiesel from KSO. The reaction temperatures, KSO to methanol mole ratio, and catalyst amount were varied to examine their effects on biodiesel synthesis. The highest biodiesel yield of 84% were obtained at 65°C of reaction temperature, 1:16 of KSO to methanol mole ratio, and 10% of catalyst amount.


2021 ◽  
Author(s):  
I.N. Starishko

Extensive experimental researches of the author of the article showed that in T-profile beams, despite the fact that with an increase in the length of the shear span, the bearing capacity along inclined sections significantly decreases, the effect of overhangs of compressed flanges on the bearing capacity of these beams, on the contrary, increases, and when, with an increase in the length of the shear span, the beam becomes equal in strength in normal and inclined sections, the effect of overhangs, as a rule, becomes the same in both the strength of normal and the strength of inclined sections, which is not taken into account in the regulatory documents of Russia, the USA and a number of other countries. At the same time, experiments have shown that the smaller the rib width in the cross section of bent reinforced concrete T-profile beams (standard beams of bridge structures on the territory of Russia), the greater the effect of the overhangs of compressed flanges on their bearing capacity along inclined sections. The values of the influences on the bearing capacity of bent reinforced concrete elements of such factors as: the forces of engagement of the rough surface of the banks when they are displaced in an inclined crack from the action of the load; the nagel effect in the longitudinal steel reinforcement at the intersection of it with an inclined crack; prestressing in longitudinal steel reinforcement, depending on the amount of transverse steel reinforcement and the width of the cross-section of the elements, etc. The technology for conducting experimental researches will have a positive effect for the development of a reliable theory for calculating bent reinforced concrete elements along inclined sections only when it includes the whole complex of a variety of the influence of the main factors on the operation of the researched elements with its in-depth analysis.


2013 ◽  
Vol 357-360 ◽  
pp. 612-616
Author(s):  
Run Xia Hao ◽  
Xiao Yan Guo ◽  
Mei Yan Hang

High-effect concrete of C60 was made up by local cement of po42.5 and polycarboxy late super plasticizer through activity of the slag powder and the fly ash. Orthogonal test researches show that C60 adding higher activity index can be made, and it was characteristics of low cost, materials convenience and fine durableness.


Author(s):  
Y. L. Chen ◽  
S. Fujlshiro

Metastable beta titanium alloys have been known to have numerous advantages such as cold formability, high strength, good fracture resistance, deep hardenability, and cost effectiveness. Very high strength is obtainable by precipitation of the hexagonal alpha phase in a bcc beta matrix in these alloys. Precipitation hardening in the metastable beta alloys may also result from the formation of transition phases such as omega phase. Ti-15-3 (Ti-15V- 3Cr-3Al-3Sn) has been developed recently by TIMET and USAF for low cost sheet metal applications. The purpose of the present study was to examine the aging characteristics in this alloy.The composition of the as-received material is: 14.7 V, 3.14 Cr, 3.05 Al, 2.26 Sn, and 0.145 Fe. The beta transus temperature as determined by optical metallographic method was about 770°C. Specimen coupons were prepared from a mill-annealed 1.2 mm thick sheet, and solution treated at 827°C for 2 hr in argon, then water quenched. Aging was also done in argon at temperatures ranging from 316 to 616°C for various times.


Alloy Digest ◽  
1966 ◽  
Vol 15 (7) ◽  

Abstract INCONEL alloy X-750 is an age-hardenable, nickel-chromium alloy used for its corrosion and oxidation resistance and high creep rupture strength at temperature up to 1500 F. It also has excellent properties at cryogenic temperatures. It was originally developed for use in gas turbines, but because of its low cost, high strength and weldability it has become the standards choice for a wide variety of applications. This datasheet provides information on composition, physical properties, elasticity, and tensile properties as well as creep and fatigue. It also includes information on forming, heat treating, machining, joining, and surface treatment. Filing Code: Ni-115. Producer or source: Huntington Alloy Products Division, An INCO Company.


2020 ◽  
Vol 4 (1) ◽  
pp. 41-48
Author(s):  
Teodoro Astorga Amatosa ◽  
Michael E. Loretero

Bamboo is a lightweight and high-strength raw materials that encouraged researchers to investigate and explore, especially in the field of biocomposite and declared as one of the green-technology on the environment as fully accountable as eco-products. This research was to assess the technical feasibility of making single-layer experimental Medium-Density Particleboard panels from the bamboo waste of a three-year-old (Dendrocalamus asper). Waste materials were performed to produce composite materials using epoxy resin (C21H25C105) from a natural treatment by soaking with an average of pH 7.6 level of sea-water. Three different types of MDP produced, i.e., bamboo waste strip MDP (SMDP), bamboo waste chips MDP (CMDP) and bamboo waste mixed strip-chips MDP (MMDP) by following the same process. The experimental panels tested for their physical-mechanical properties according to the procedures defined by ASTM D1037-12. Conclusively, even the present study shows properties of MDP with higher and comparable to other composite materials; further research must be given better attention as potential substitute to be used as hardwood materials, especially in the production, design, and construction usage.


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