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Number of results: 86
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Abstract

Hydraulic fracturing of rocks boosts the production rate by increasing the fracture-face surface area through the use of a pressurized liquid. Complex stress distribution and magnitude are the main factors that hinder the use of information gathered from in situ hydraulic fracturing in other locations. Laboratory tests are a good method for precisely determining the characteristics of these processes. One of the most important parameters is breakdown pressure, defined as the wellbore pressure necessary to induce a hydraulic fracture. Therefore, the main purpose of this investigation is to verify fracture resistance of rock samples fractured with the assistance of the most popular industry fluids. The experiments were carried out using a stand designed specifically for laboratory hydraulic fracturing. Repeatable results with a relative error within the range of 6-11% prove that the experimental methodology was correct. Moreover, the obtained results show that fracturing pressure depends significantly on fluid type. In the case of a water test, the fracturing pressure was 7.1±0.4 MPa. A similar result was achieved for slickwater, 7.5±0.7 MPa; however, a much lower value (4.7±0.5 MPa) was registered in the case of carbon dioxide.

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Authors and Affiliations

S. Stanisławek
P. Kędzierski
D. Miedzińska
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Abstract

This paper addresses the tensile and flexural strength of HPC (high performance concrete). The aim of the paper is to analyse the efficiency of models proposed in different codes. In particular, three design procedures from: the ACI 318 [1], Eurocode 2 [2] and the Model Code 2010 [3] are considered. The associations between design tensile strength of concrete obtained from these three codes and compressive strength are compared with experimental results of tensile strength and flexural strength by statistical tools. Experimental results of tensile strength were obtained in the splitting test. Based on this comparison, conclusions are drawn according to the fit between the design methods and the test data. The comparison shows that tensile strength and flexural strength of HPC depend on more influential factors and not only compressive strength.

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Authors and Affiliations

M. Kępniak
P. Woyciechowski
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Abstract

To improve mechanical properties and increasing useful life of metal pieces, different methods of welding are used for repairing surface

crack of metal pieces. In this research, performance of flame welding method by spraying pure iron powder evaluated for repairing surface

grooves of structural steel. First, four specimens including one control specimen and other three specimens grooved specimens in depth of

1mm and in length of 12.5mm and groove width in the sizes of 0.5, 0.75 and 1mm.were prepared then, powder melted using oxyacetylene

reducing flame and spraying iron powder in the flame path and attached to the inner surface of the groove and finally, the specimen

repaired. Results showed that after repairing surface groove, tensile strength of the repaired specimens were reached to the tensile strength

of control specimen with the margin of 2.5%.

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Authors and Affiliations

P. Keyhany
S.E. Vahdat
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Abstract

Aluminum and its alloys are one of the most favored metal-based materials for engineering applications that require lightweight materials. On the other hand, composites are getting more preferable for different kinds of applications recently. Boron nitride nanotubes (BNNTs) are one of the excellent reinforcement materials for aluminum and its alloys. To enhance mechanical properties of aluminum, BNNTs can be added with different processes. BNNT reinforced aluminum matrix composites also demonstrate extraordinary radiation shielding properties. This study consists of BNNT reinforced aluminum matrix composite production performed by casting method. Since wetting of BNNT in liquid aluminum is an obstacle for casting, various casting techniques were performed to distribute homogeneously in liquid aluminum. Different methods were investigated in an aim to incorporate BNNT into liquid method as reinforcement. It was found that UTS was increased by 20% and elongation at fracture was increased by 170% when BNNT was preheated at 800°C for 30 minutes.
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Authors and Affiliations

B. Nemutlu
1
ORCID: ORCID
O. Kahraman
1
ORCID: ORCID
K. B. Demirel
1
ORCID: ORCID
I. Erkul
1
ORCID: ORCID
M. Cicek
1
ORCID: ORCID
H. Sahin
1
ORCID: ORCID
K.C. Dizdar
1
ORCID: ORCID
D. Dispinar
1
ORCID: ORCID

  1. Istanbul Technical University, Turkey
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Abstract

Bioactive glass (BG) can be utilized as a replacement and regeneration material for orthopaedic and orthodontic. However, a load-bearing structure requires good mechanical properties to withstand high stress, in addition to good bioactivity properties. In this research, BG and cordierite (BG-cord) composite was fabricated to improve BG’s mechanical properties. The mechanical strength of the BG-cord was investigated. Both BG and cordierite were synthesized separately using the glass melting method. The synthesized BG and cordierite powders were used to fabricate BG-cord using a composition variation from 10 to 50 wt.%. The composite with 30 wt.% cordierite demonstrated the highest diametral tensile strength (DTS), 14.01 MPa.
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Authors and Affiliations

Ahmad Fakhruddin Mohd Mokhtar Kamil
1
ORCID: ORCID
Hamisah Ismail
1
ORCID: ORCID
Mohamad Hasmaliza
1
ORCID: ORCID

  1. Universiti Sains Malaysia, School of Materials and Mineral Resources Engineering,Biomaterial Research Niche Group, 14300 Nibong Tebal, Penang, Malaysia
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Abstract

Light-weight Self-Compacting Concrete (LWSCC) might be the answer to the increasing construction requirements of slenderer and more heavily reinforced structural elements. However there are limited studies to prove its ability in real construction projects. In conjunction with the traditional methods, artificial intelligent based modeling methods have been applied to simulate the non-linear and complex behavior of concrete in the recent years. Twenty one laboratory experimental investigations on the mechanical properties of LWSCC; published in recent 12 years have been analyzed in this study. The collected information is used to investigate the relationship between compressive strength, elasticity modulus and splitting tensile strength in LWSCC. Analytically proposed model in ANFIS is verified by multi factor linear regression analysis. Comparing the estimated results, ANFIS analysis gives more compatible results and is preferred to estimate the properties of LWSCC.

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Authors and Affiliations

B. Vakhshouri
S. Nejadi
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Abstract

Mechanical and technological properties of castings made from 3xx.x alloys depend mainly on properly performed process of melting and

casting, structure of a casting and mould, as well as possible heat treatment. Precipitation processes occurring during the heat treatment of

the silumins containing additives of Cu and/or Mg have effect on improvement of mechanical properties of the material, while choice of

parameters of solutioning and ageing treatments belongs to objectives of research work performed by a number of authors. Shortened heat

treatment, which is presented in the paper assures suitable mechanical properties (Rm), and simultaneously doesn’t cause any increase of

production costs of a given component due to long lasting operations of the solutioning and ageing. Results of the research concern effects

of the solutioning and ageing parameters on the Rm tensile strength presented in form of the second degree polynomial and illustrated in

spatial diagrams. Performed shortened heat treatment results in considerable increase of the Rm tensile strength of the 320.0 alloy as early

as after 1 hour of the solutioning and 2 hours of the ageing performed in suitable.

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Authors and Affiliations

J. Pezda
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Abstract

Metal pieces wear out due to variable loading, because cracks formed on their surface of them. In order to increase useful life of metal

pieces with the help of different methods of welding, surface cracks are repaired. In this research, performance of the diffusion welding of

pure iron powder through magnetic induction evaluated for repairing structural steel surface cracks. First, four specimens prepared

including one control specimen and other three specimens grooved specimens in length of 6.25mm and in depth of 1mm and groove

width in the sizes of 0.5, 0.75 and 1mm. Then by a coil, the induced current created in the piece surface. After crossing the current, the

powder melted and the groove repaired due to diffusion welding. To prevent oxidation, the atmosphere inside the coil filled with argon

gas. The results show that after repairing surface groove, tensile strength of the repaired specimens reached to the tensile strength of

control specimen with the margin of 7.5%.

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Authors and Affiliations

Y. Rahimy
S.E. Vahdat
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Abstract

An understanding of the fundamental correlation between grain size and material damping is crucial for the successful development of structural components offering high strength and good mechanical energy absorption. With this regard, we fabricated aluminum sheets with grain sizes ranging from tens of microns down to 60 nm and investigated their tensile properties and mechanical damping behavior. An obvious transition of the damping mechanism was observed at nanoscale grain sizes, and the underlying causes by grain boundaries were interpreted.

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Authors and Affiliations

Haneul Jang
Kwangmin Choi
Jaehyuck Shin
Donghyun Bae
Hyunjoo Choi
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Abstract

The aim of this study was to estimate the measurement uncertainty for a material produced by additive manufacturing. The material investigated was FullCure 720 photocured resin, which was applied to fabricate tensile specimens with a Connex 350 3D printer based on PolyJet technology. The tensile strength of the specimens established through static tensile testing was used to determine the measurement uncertainty. There is a need for extensive research into the performance of model materials obtained via 3D printing as they have not been studied sufficiently like metal alloys or plastics, the most common structural materials. In this analysis, the measurement uncertainty was estimated using a larger number of samples than usual, i.e., thirty instead of typical ten. The results can be very useful to engineers who design models and finished products using this material. The investigations also show how wide the scatter of results is.

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Authors and Affiliations

Stanisław Adamczak
Jerzy Bochnia
Bożena Kaczmarska
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Abstract

In this study, high performance magnesium-yttria nanocomposite’s room temperature, strength and ductility were significantly enhanced by the dispersion of nano-sized nickel particles using powder blending and a microwave sintering process. The strengthening effect of the dispersed nano-sized nickel particles was consistent up to 100°C and then it gradually diminished with further increases in the test temperature. The ductility of the magnesium-yttria nanocomposite remained unaffected by the dispersed nano-sized nickel particles up to 100°C. Impressively, it was enhanced at 150°C and above, leading to the possibility of the near net shape fabrication of the nanocomposite at a significantly low temperature.

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Authors and Affiliations

Fida S. Hassan
Khin Sandar Tun
F. Patel
Nasser Al-Aqeeli
M. Gupta
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Abstract

Recycling construction and demolition waste not only reduces project costs; and saves natural resources, but also solves the environmental threat caused by construction waste disposal. In this paper, C25 waste road concrete is used as an experimental material, the uniaxial compression strength and tensile splitting strength of C25 RAC whose coarse aggregate replacement rate is 0%, 25%, 50%, 75%, and 100% are tested under the condition that the water-to-cement ratio is 0.47, 0.55 and 0.61. The results show: (1) the uniaxial compression strength and tensile splitting strength decrease with the increase of RAC; (2) for concrete with the same water-to-cement ratio, when the coarse aggregate replacement rate changes from 0% to 50%, the uniaxial compression strength and tensile splitting strength of RAC changes slightly. When the coarse aggregate replacement rate changes from 50% to 100%, the uniaxial compression strength and tensile splitting strength of RAC decreases rapidly

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Authors and Affiliations

X.H. Deng
Z.L. Lu
P. Li
T. Xu
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Abstract

In this study, the effect of calcium treatment on the mechanical properties and fatigue behavior of low carbon steel material is investigated. By applying calcium treatment after aluminum deoxidation for steel cleanliness, the aim is to transform the inclusions into harmless structures and produce cleaner liquid steel. As a result of the study, calcium treated material’s tensile strength slightly increases while fatigue life decreases. SEM studies were conducted to evaluate the results and it was observed that while elongated inclusions were observed as well as spherical shapes in the untreated sample, the inclusions generally had a spherical shape in the calcium treated sample. After the steel cleanliness process, the mechanical properties of the samples were improved. The tensile strength of the calcium treated sample increased slightly. However, a significant decrease in fatigue strength was observed depending on brittle inclusions that occur as a result of the calcium treatment process.
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Authors and Affiliations

Barış Karabayrak
1
ORCID: ORCID
Sinem Baskut
2
ORCID: ORCID
Dilek Turan
1
ORCID: ORCID

  1. Eskisehir Technical University, Faculty of Aeronautics and Astronautics, Department of Airframe and Power Plant Maintenance, Eskisehir, Turkey
  2. Eskisehir Technical University, Faculty of Engineering, Department of Materials Science and Engineering, Eskisehir, Turkey
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Abstract

Heat treatment processes, due to qualitative requirements for the cast machinery components and restrictions on energy consumption resulting on the one hand from environmental concerns, and on the other hand from a requirements coming from minimization of manufacturing costs, are resulting in searching after a technologies enabling obtainment of satisfactory results, in form of improved mechanical properties mainly, while minimizing (limiting) parameters of successive operations of the heat treatment. Heat treatment of the T6 type presented in this paper consists in operations of heating of investigated alloys to suitably selected temperature (range of this temperature was evaluated on the base of the ATD method), holding at such temperature for a short time, and next rapid cooling in water (20 oC) followed by artificial ageing, could be such technology in term s of above mentioned understanding of this issue. Performed T6 heat treatment with limited parameters of solutioning operation resulted in visible increase in tensile strength Rm of AlSi7Mg, AlSi7Cu3Mg and AlSi9Cu3(Fe) alloys.

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Authors and Affiliations

J. Pezda
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Abstract

Natural fibres have recently gained attention as an alternative sustainable material for civil engineering applications due to natural fibres’ exceptional performance, including high strength, and their environmental-friendliness and cost-effectiveness. However, there are disadvantages to using natural fibres in extreme environments. Therefore, this paper reviewed the effect of moisture content and temperature on the tensile strength of potential natural fibres for engineering purposes. Furthermore, this paper also critically reviewed the influence of alkaline treatment on natural fibres’ tensile strength. This is significant because alkaline treatment enhances surface friction and the fraction of the revealed cellulose on the fibres’ surface, resulting in better mechanical interlocking. In conclusion, natural fibres demonstrate their potential for geotechnical applications due to the materials’ strong tensile properties after being subjected to treatment processes.
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Authors and Affiliations

Nur Faezah Yahya
1
ORCID: ORCID
T.N.H.T Ismail
1
ORCID: ORCID
Fatimah Mohamed Yusop
1
ORCID: ORCID
Norul Ahsanah Aulia Mohamad Mahani
1
ORCID: ORCID
Alia Farhana Malik
1
ORCID: ORCID
L.A. Sofri
2
ORCID: ORCID
Joanna Gondro
3
ORCID: ORCID

  1. Universiti Tun Hussein Onn Malaysia, Faculty of Engineering Technology, 84600 Panchor, Johor, Malaysia
  2. Universiti Malaysia Perlis (UniMAP), Centre of Excellence Geopolymer & Green Technology (CEGeoGTech), 01000 Perlis, Malaysia
  3. Częstochowa University of Technology, Faculty of Production Engineering and Materials Technology, Department of Physics, 19 Armii Krajowej Av., 42-200 Częstochowa, Poland
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Abstract

Activated tungsten inert gas (ATIG) welding has a good depth of penetration (DOP) as compared to the conventional tungsten inert gas (TIG) welding. This paper is mainly focused on ATIG characterization and mechanical behavior of aluminum alloy (AA) 6063-T6 using SiO2 flux. The characterization of the base material (BM), fusion zone (FZ), heat affected zone (HAZ) and, partially melted zone is carried out using the suitable characterization methods. The weld quality is characterized using ultrasonic-assisted non-destructive evaluation. A-scan result confirms that the ATIG welded samples have more DOP and less bead width as compared to conventional TIG. The recorded tensile strength of ATIG with SiO2 is better than the conventional TIG welding. The failure mode is ductile for ATIG welding with larger fracture edges and is brittle in the case of conventional TIG welding.

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Bibliography

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  2.  S.T. Amancio-Filho, S. Sheikhi, J.F. dos Santos, and C. Bolfarini, “Preliminary study on the microstructure and mechanical properties of dissimilar friction stir welds in aircraft aluminium alloys 2024-T351 and 6056-T4”, J. Mater. Process. Technol. 206. 132–142 (2008), doi: 10.1016/j.jmatprotec.2007.12.008.
  3.  P. Mukhopadhyay, “Alloy Designation, Processing, and Use of AA6XXX Series Aluminium Alloys”, ISRN Metall. 2012, 165082 (2012), doi: 10.5402/2012/165082.
  4.  B. Choudhury and M. Chandrasekaran, “Investigation on welding characteristics of aerospace materials – A review”, Mater. Today Proc. 4, 7519–7526 (2017), doi: 10.1016/j.matpr.2017.07.083.
  5.  R.R. Ambriz and V. Mayagoitia, “Welding of Aluminum Alloys”, in Welding, Brazing and Soldering, pp. 722–739, ASM International, 2018. doi: 10.31399/asm.hb.v06.a0001436.
  6. [6]  P.J. Modenesi, “The chemistry of TIG weld bead formation”, Weld. Int. 29, 771–782 (2015), doi: 10.1080/09507116.2014.932990.
  7.  A.K. Singh, V. Dey, and R.N. Rai, “Techniques to improveweld penetration in TIG welding (A review)”, Mater. Today Proc. 4, 1252–1259 (2017), doi: 10.1016/j.matpr.2017.01.145.
  8.  R.S. Vidyarthy and D.K. Dwivedi, “Activating flux tungsten inert gas welding for enhanced weld penetration”, J. Manuf. Process. 22, 211–228 (2016), doi: 10.1016/j.jmapro.2016.03.012.
  9.  R.S. Vidyarthy and D.K. Dwivedi, “Microstructural and mechanical properties assessment of the P91 A-TIG weld joints”, J. Manuf. Process. 31, 523–535 (2018), doi: 10.1016/j.jmapro.2017.12.012.
  10.  K.D. Ramkumar, V. Varma, M. Prasad, N.D. Rajan, and N.S. Shanmugam, “Effect of activated flux on penetration depth, microstructure and mechanical properties of Ti-6Al-4V TIG welds”, J. Mater. Process. Technol. 261, 233–241 (2018), doi: 10.1016/j.jmatprotec.2018.06.024.
  11.  H. Kumar and N.K. Singh, “Performance of activated TIG welding in 304 austenitic stainless steel welds”, Mater. Today Proc. 4, 9914–9918 (2017), doi: 10.1016/j.matpr.2017.06.293.
  12.  R.S. Vidyarthy, A. Kulkarni, and D.K. Dwivedi, “Study of microstructure and mechanical property relationships of A-TIG welded P91–316L dissimilar steel joint”, Mater. Sci. Eng. A. 695, 249–257 (2017), doi: 10.1016/j.msea.2017.04.038.
  13.  E.R. Imam Fauzi, M.S. Che Jamil, Z. Samad, and P. Muangjunburee, “Microstructure analysis and mechanical characteristics of tungsten inert gas and metal inert gas welded AA6082-T6 tubular joint: A comparative study”, Trans. Nonferrous Met. Soc. China (English Ed.) 27, 17–24 (2017), doi: 10.1016/S1003-6326(17)60003-7.
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Authors and Affiliations

Rajiv Kumar
1
S.C. Vettivel
2
Harmesh Kumar Kansal
1

  1. Department of Mechanical Engineering, UIET, Panjab University, Chandigarh, India
  2. Department of Mechanical Engineering, Chandigarh College of Engineering and Technology (Degree Wing), Chandigarh, India
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Abstract

This paper investigates the thermal and mechanical properties of a composite made from a combination of 2063-epoxy resin and three different braided carbon-fiber fabric reinforcements. These fibres consist of HTS carbon, HTS carbon braided with nickel coated carbon and HTS carbon braided with nickel coated copper, respectively. The composites were manufactured through resin transfer molding (RTM) route. The thermal diffusivity of carbon fibers composites was measured at different temperature by using a flash method. The transverse and planar thermal conductivities were determined by measuring the specific heat, density and thermal diffusivities, respectively. The current research highlights the influence of adding nickel coated carbon and nickel-plated copper wires on the braided composites. The evaluation shows that the HTS carbon braided manufactured with nickel-plated copper wires presents higher in-plane thermal conductivity (in direction parallel of the fibres) when comparing to HTS carbon and HTS carbon braided manufactured with nickel coated carbon. The thermal conductivity benefits of those composite were achieved at the expenses of lower mechanical properties of braided composites investigated.
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Authors and Affiliations

Jamal Arbaoui
1 2
ORCID: ORCID
Jérémie Aucher
1
ORCID: ORCID
Moussa Gomina
1
ORCID: ORCID
Joel Breard
1
ORCID: ORCID

  1. Laboratoire CRISMAT, UMR 6508 CNRS/ENSICAEN, 6 Bd Maréchal Juin, 14050 Caen Cedex 4, France
  2. University of Cadi Ayyad, National School of Applied Sciences, Laboratory of Materials, Processes, Environment and Quality, B.P. 63, 46000, Safi, Morocco
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Abstract

In this study, the effect of the coiling temperature on the tensile properties of API X70 linepipe steel plates is investigated in terms of the microstructure and related anisotropy. Two coiling temperatures are selected to control the microstructure and tensile properties. The API X70 linepipe steels consist mostly of ferritic microstructures such as polygonal ferrite, acicular ferrite, granular bainite, and pearlite irrespective of the coiling temperature. In order to evaluate the anisotropy in the tensile properties, tensile tests in various directions, in this case 0° (rolling direction), 30°, 45° (diagonal direction), 60°, and 90° (transverse direction) are conducted. As the higher coiling temperature, the larger amount of pearlite is formed, resulting in higher strength and better deformability. The steel has higher ductility and lower strength in the rolling direction than in the transverse direction due to the development of γ-fiber, particularly the {111}<112> texture.
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Authors and Affiliations

Dong-Kyu Oh
1
ORCID: ORCID
Seung-Hyeok Shin
1
ORCID: ORCID
Sang-Min Lee
2
ORCID: ORCID
Byoungchul Hwang
1
ORCID: ORCID

  1. Seoul National University of Science and Technology, Department of Materials Science and Engineering, Seoul, 01811, Republic of Korea
  2. Hyundai Steel Company, Dangjin-Si, Chungnam, 31719, Republic of Korea
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Abstract

In the past few years, overhead copper transmission lines have been replaced by lightweight aluminum transmission lines to minimize the cost and prevent the sagging of heavier copper transmission lines. High strength aluminum alloys are used as the core of the overhead transmission lines because of the low strength of the conductor line. However, alloying copper with aluminum causes a reduction in electrical conductivity due to the solid solution of each component. Therefore, in this study, the authors attempt to study the effect of various Al/Cu ratios (9:1, 7:3, 5:5) to obtain a high strength Al-Cu alloy without a significant loss in its conductivity through powder metallurgy. Low-temperature extrusion of Al/Cu powder was done at 350ºC to minimize the alloying reactions. The as-extruded microstructure was analyzed and various phases (Cu9Al4, CuAl2) were determined. The tensile strength and electrical conductivity of different mixing ratios of Al and Cu powders were studied. The results suggest that the tensile strength of samples is improved considerably while the conductivity falls slightly but lies within the limits of applications.

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Authors and Affiliations

Deokhyun Han
ORCID: ORCID
Geon-Hong Kim
Jaesung Kim
Byungmin Ahn
ORCID: ORCID
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Abstract

One of the biggest challenges facing a designer of paper structures is its low resistance to moisture and water. Paper is a hydrophilic material that absorbs moisture from the outside. This causes the hydrogen bonds between the cellulose molecules to loosen and as a result a rapid decrease in strength parameters. In order to be able to use paper as a construction material, there is a need to select and evaluate the effectiveness of the appropriate impregnant, as well as to know its impact on the mechanical properties of the impregnated paper. The paper analyzes the effect of the use of various impregnations, including wood oil, yacht lacquer, and fire-retardant agent impregnation, on the tensile strength of several types of cellulose-derived materials, e.g. corrugated board, solid board, paper cores, and honeycomb board. The effectiveness of the impregnation was also assessed using the method of measuring the contact angle of the reference and impregnated surfaces.
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Authors and Affiliations

Paweł Niewiadomski
1
ORCID: ORCID
Anna Karolak
1
Marta Oleksiak
1
Agnieszka Chowaniec-Michalak
1

  1. Wrocław University of Science and Technology, Wybrze˙ze Wyspia´nskiego 27, 50-370 Wrocław, Poland
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Abstract

One of the main causes of road pavement distress are low temperatures, and hence the need to thoroughly study the low temperature performance of all bituminous materials used in road construction. The purpose of this studywas to determine the performance of alternative and conventional bituminous mixtures in the temperature range between –25˚C and –10˚C using for this purpose the Tensile Creep Test (TCT). The low-temperature performance data were evaluated using the Burgers model, a tool that is widely used for evaluation of bituminous mixtures. This research focuses on bridge paving mixtures. These included both conventional (mastic asphalt) and alternative (SMAMA) materials. It was established, based on the test results and their analysis, that low temperature performance of a bituminous mixture is influenced, in the first place, by the characteristics of the asphalt binder it contains. Furthermore, SMA-MA mixtures showed better low temperature performance than conventional, mastic asphalt type mixtures.
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Authors and Affiliations

Bartosz Budziński
1
ORCID: ORCID
Paweł Mieczkowski
1
ORCID: ORCID

  1. West Pomeranian University of Technology, Faculty of Civil and Environmental Engineering, Al. Piastów17, 70-310 Szczecin, Poland
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Abstract

The scope of the paper is to determine the mechanical properties of the Precontraint 1302 polyester coated fabric under uniaxial and biaxial tensile tests. The results are compared for Precontraint 1302 fabric and other types of coated fabrics. The author applied an orthotropic model and a dense net model to reflect the polyester coated fabric performance under uniaxial and biaxial tensile tests. Material parameters are specified for both constitutive models. In order to observe the variation of immediate mechanical properties, the biaxial cyclic tests are performed for different load ratios. During uniaxial and 1:1 biaxial tensile tests it is barely observable to recognize warp or weft directions on the stress-strain curves. Load history acts strongly on the mechanical properties of the Precontraint 1302 polyester fabrics. The cyclic loads cause variation of immediate longitudinal stiffness with a comparison of values determined for unloaded coated fabrics. The paper can provide scientists, engineers, and designers an experimental and theoretical basis in the field of polyester coated fabrics.

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Authors and Affiliations

Andrzej Ambroziak
ORCID: ORCID
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Abstract

Plastic obtained from the discarded computers, televisions, refrigerators, and other electronic devices is termed as e-plastic waste. E-plastic waste is non-biodegradable waste. This paper focuses to investigate the replacement of fine aggregate with plastic aggregate obtained from e-plastic. The paper presents a detailed comparison of concrete properties (i.e.: compressive strength, tensile strength, flexural strength, density and workability) for normal concrete and concrete containing e-plastic fine aggregates. The testing was conducted according to the ASTM standards. 28-day Compressive, Flexural and Split tensile strengths were determined. In addition to the effect of e-plastic fine aggregate, silica fume is added as an admixture to find the effect on strengths. Authors have performed a compressive, flexural and tensile test of concrete mix with various percentages of e-plastic aggregates (i.e., 0, 5, 10, 15 and 20%) and silica fume (i.e.: 0, 5 and 10%) and concrete densities are also considered. It has been concluded that an increase in the e-plastic fine aggregate results in reduction in densities, compressive, flexural and tensile strength values. However, when we add silica fume to the concrete mixture it leads to strength values similar to the control mixture. The optimum obtained concrete blend contained 5% e-plastic fine aggregates and 10% silica fume. The addition of silica fume in concrete mixtures increases the 28-day compressive, flexural and tensile strengths. Moreover, the density of concrete decreases with the increase in the e-plastic aggregates.

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Authors and Affiliations

Adil Farooq
Muneeb Abid Malik
Tauqeer Tariq
Mamoon Riaz
Waqas Haroon
Awais Malik
Mujeeb Ur Rehman
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Abstract

This paper focused on the effect of pure torsion deformation and various torsion pitches on the mechanical properties of the commercial pure Al wires which has not been examined so far. The initial wires with diameter of 4 mm have been torsion deformed to different pitch length (PL). In order to investigate the effect of gradient microstructure caused by torsion deformation, three different pitch length of 15 mm, 20 mm and 30 mm are considered. The results revealed that the level of grain refinement is correlated with the amount of induced plastic shear strain by torsion deformation. For the wire with pitch length of 15 mm, the grain sizes decreased to about 106 μm and 47 μm in the wire center and edge from the initial size of about 150 μm of the annealed wire. The micro-hardness measurement results show a gradient distribution of hardness from the wire center to the wire surface that confirmed the increasing trend of plastic shear strain obtained by FE simulations. The hardness of annealed sample (35 HV) is increased up to 73 HV at the wire surface for the smallest pitch length. The yield and ultimate tensile strength of the torsion deformed wires are also increased up to about 85 MPa and 152 MPa from the initial values of 38 MPa and 103 MPa of the annealed one respectively while the maximum elongation reduced significantly.
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Authors and Affiliations

M. Sedighi
A. Vaezi
M. Pourbashiri

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