Wyniki wyszukiwania - BazTech

1

Tensile Strength Testing of Samples made of ABS-M30 Polymer Using FDM Technology

Kiński Wojciech, Cader Maciej, Zboiński Grzegorz

Problemy Mechatroniki : uzbrojenie, lotnictwo, inżynieria bezpieczeństwa

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2023

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Vol. 14, Nr 1 (51)

135--143

EN

The article details the principle behind Fused Deposition Modelling (FDM) technology. Strength tests were carried out on a Stratasys FORTUS 400mc industrial 3D printer. Prints of the strength specimens were made in different orientations in the working chamber of the machine.

PL

W artykule szczegółowo przedstawiono zasadę działania technologii FDM (Fused Deposition Modeling). Zostały przeprowadzone badania wytrzymałościowe na przemysłowej drukarce 3D Stratasys FORTUS 400mc. Wydruki próbek wytrzymałościowych zostały wykonane w różnej orientacji w komorze roboczej urządzenia.

2

The influence of calcium carbonate and its modifications on the extrusion process and selected properties of polypropylene cast films

Kloziński Arkadiusz, Szczepańska Małgorzata, Jakubowska Paulina, Samujło Bronisław, Barczewski Mateusz, Lota Grzegorz

Polimery

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2022

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Vol. 67, nr 10

509--521

EN

The effect of unmodified and stearic acid-modified calcium carbonate (5, 10, 20 and 30 wt%) on selected properties (tensile strength, puncture resistance, haze and gloss) and processability of polypropylene films (MVR, extensional viscosity) was investigated. The composites were obtained in the twin-screw extrusion process with cold granulation, and the films in the single-screw extrusion process, using a flat die head (so-called cast films) and a chill roll type cooling and pull-back device. It has been shown that stearic acid is an effective modifier of polypropylene processing properties both under shear and tensile flow conditions (lower extensional viscosity of films containing modified calcium carbonate).

PL

Zbadano wpływ dodatku 5, 10, 20 oraz 30 % mas. niemodyfikowanego imodyfikowanego kwasem stearynowym węglanu wapnia na wybrane właściwości użytkowe (wytrzymałość na rozciąganie, odporność na przebicie, zamglenie, połysk) iprzetwórcze folii polipropylenowych (MVR, lepkość wzdłużna). Kompozyty otrzymano w procesie dwuślimakowego wytłaczania z granulacją na zimno, a folie w procesie jednoślimakowego wytłaczania, przy użyciu głowicy płaskiej (tzw. cast films) oraz urządzenia chłodząco - odciągającego typu chill roll. Wykazano, że kwas stearynowy jest efektywnym modyfikatorem właściwości przetwórczych folii polipropylenowych zarówno w warunkach przepływu ścinającego, jak i rozciągającego (mniejsza lepkość wzdłużna folii zawierających modyfikowany węglan wapnia).

3

Properties and characteristics of alkali treated Calotropis gigantea fiber-reinforced particle-filled epoxy composites

Jeyapragash R., Sathiyamurthy S., Srinivasan V., Prithivirajan R., Swaminathan G.

Composites Theory and Practice

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2022

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R. 22, nr 2

99--105

EN

The presence of particles and fibers as reinforcement in a polymer matrix greatly enhances the mechanical properties. Agricultural residues and natural fibers are commonly used nowadays due to the fact that they easily decompose even after a longer period and they are eco-friendly in nature. f Fiber that was extracted from stem of Calotropis gigantea was selected as reinforcement in the present investigation. Initially the fiber was treated with a sodium hydroxide solution and CG fiber-epoxy composites were prepared. The properties of alkaline treated CG fiber-reinforced epoxy composites were further improved by the addition of particles such as chitosan, red mud and rice husk. Properties such as the tensile strength, flexural strength, impact toughness, hardness, water absorption, thickness swelling behaviour, specific wear rate and coefficient of friction were evaluated and compared. The XRD pattern of the chemically treated CG fiber-reinforced parrticle-filled epoxy composites was presented in the present study.

4

Mechanical Property Comparison of Al11Si Wheels Grain Refined by Ti, Nb and MTS

Aydogan F., Dizdar Kerem Can, Sahin Hayati, Mentese E., Dispinar Derya

Archives of Foundry Engineering

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2022

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Vol. 22, iss. 4

14--18

EN

In this work, 25 wheels were cast with three different grain refiners: Al5Ti1B, Al3Nb1B and MTS 1582. Samples were machined from the wheels to check the mechanical properties. It was found that Nb grain refinement had the lowest grain size (260 mm) and highest tensile properties (yield strength of 119-124 MPa and ultimate tensile strength of 190-209 MPa). Al5Ti1B and MTS 1582 revealed quite similar results (110 MPa yield and 198 MPa ultimate tensile strength). The fading of the grain refining effect of Al5TiB1 master alloy was observed in both Nb and Ti added castings whereas during the investigated time interval, the fading was not observed when MTS 1582 was used.

5

Assessment of the application of CEM III with exposed aggregate as an alternative to CEM I for road pavements

Kurpińska Marzena, Wcisło Aldona

Archives of Civil Engineering

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2022

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Vol. 68, nr 2

461--481

EN

The article presents a results of study on the impact of replacing CEM I SR3/NA by CEM III/A LH/HSR/NA on the mechanical properties and durability of pavement concrete with exposed aggregate. Was used granite aggregate and washed sand. Water/cement (w / c) ratio in the tested concretes constituted 0.35 and 0.4 and part of the cement was replaced with a 5% addition of natural pozzolana - zeolite. Compressive strength tests were performed after 3, 7, 28 and 56 days, tests of tensile strength test by splitting method and flexural strength two-point loading tests. The characteristics of the air pores and the rate of water absorption by concrete surface of the samples cut out from the slabs with exposed aggregate were presented. The resistance of the surface to exfoliation after 56 cycles of freezing-thawing in NaCl solution was tested. Based on the results obtained, it was found that when designing the composition of the concrete intended for the upper layer of the pavement, it is necessary to ensure high tensile strength, appropriate in the XF4 environment and with the decrease in the w / c < 0.4, a reduction in capillary porosity of the cement paste is obtained, and the same the durability of concrete is increased due to the improved strength parameters in the contact zone between coarse aggregate grains and cement paste. The research also showed a significant influence of proper cure on the mechanical properties and durability of pavement concrete.

PL

W artykule przedstawiono wyniki badań wpływu zastąpienia CEM I SR3/NA przez CEM III/A LH/HSR/NA na właściwości mechaniczne i trwałość betonu nawierzchniowego z odsłoniętym kruszywem. Użyto kruszywa granitowe i płukany piasek. Współczynnik woda/cement (w / c) w badanych betonach wynosił 0,35 i 0,4, a część cementu zastąpiono 5% dodatkiem naturalnej pucolany (zeolit). Badania wytrzymałości na ściskanie wykonano po 3, 7, 28 i 56 dniach, badania wytrzymałości na rozciąganie metodą rozłupywania oraz badania wytrzymałości na zginanie dwupunktowe. Przedstawiono charakterystykę porów powietrza oraz szybkość wchłaniania wody przez powierzchnię betonu próbek wyciętych z płyt z odsłoniętym kruszywem. Zbadano odporność powierzchni na złuszczanie po 56 cyklach zamrażania/rozmrażania w roztworze NaCl. Na podstawie uzyskanych wyników stwierdzono, że przy projektowaniu składu betonu przeznaczonego na górną warstwę nawierzchni należy zapewnić wysoka wytrzymałość na rozciąganie, właściwą w środowisku XF4. Zauważono, że jeśli wskaźnik w / c < 0,4 nastąpiło zmniejszenie porowatości kapilarnej zaczynu cementowego, a tym samym zwiększenie trwałości betonu dzięki poprawie parametrów wytrzymałościowych w strefie styku ziaren kruszywa gruboziarnistego z zaczynem cementowym. Badania wykazały również istotny wpływ prawidłowego utwardzenia na właściwości mechaniczne i trwałość betonu nawierzchniowego.

6

Soft computing approaches for comparative prediction of ram tensile and shear strength in aluminium–stainless steel explosive cladding

Saravanan S., Gajalakshmi K.

Archives of Civil and Mechanical Engineering

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2022

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Vol. 22, no 1

art. no. e42, 2022

EN

This study deals with the application of soft computing techniques viz., response surface methodology, artificial neural network, radial basis function network and support vector regression in analyzing and predicting the ram tensile and shear strengths of aluminium 5052–stainless steel 316 explosive clads, having different interlayer. 60 explosive cladding experiments were conducted, based on central composite design of experiments, by varying the process parameters viz., loading ratio (mass of the explosive/mass of the flyer plate: 0.6–1.0), distance of separation (6–10 mm), preset angle (6°–8°) and interlayer (aluminium 1100/pure copper/stainless steel 304). The responses viz., ram tensile and shear strengths obtained from 90% of the experiments and trial experiments are used for training artificial neural network, radial basis function network and support vector regression in a Matlab environment, altering training algorithms and number of neurons in the hidden layer. The remaining 10% of the experimental outcome is used for testing the developed models. Likewise in RSM, regression equations are generated for the responses, based on analysis of variance. All the four models are capable of predicting the ram tensile and shear strength effectively, as the average percentage deviation with the experimental outcome are less than 10%. Of the three models, artificial neural network model predicts the ram tensile strength and shear strength in a better manner.

7

Effect of using rice husk ash as partial replacement of cement on properties of fresh and hardened concrete

Ajwad Ali, Ahmad Sameel, Abdullah, Jaffar Syed Taseer Abbas, Ilyas Usman, Adnan Muhammad Ahmad

Architecture Civil Engineering Environment

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2022

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Vol. 15, no. 2

85--94

EN

Rice husk disposal has become a great challenge for Pakistan being one of the largest rice producer across the globe. Rice Husk Ash (RHA) contains sufficient pozzolanic properties which opens up opportunities for its usage as cementitious material as partial replacement of Ordinary Portland Cement (OPC). In this research RHA was added as cement replacement in different percentages by weight of cement i.e. 0%, 6%, 12%, 18% and 24% at constant mix ratio of 1:2:4 and water-cement ratio of 0.6 that is M15 grade concrete with a target strength of 15-20 MPa. The properties of concrete like workability, compressive strength, tensile strength, flexure strength, and water permeability were investigated by casting standard concrete samples in the form of cubes, cylinders and beams in addition to cost comparison study The outcomes show that workability of fresh concrete increases with an increase in RHA content and almost all concrete properties studied in this research gave more favorable results at 6% replacement level compared with the control mix.

8

Wpływ efektu gofrowania na wybrane właściwości tkanin gofrowanych

Matusiak Małgorzata

Technologia i Jakość Wyrobów

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2021

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R. 66

46--64

PL

Celem badań była ocena wpływu efektu gofrowania na wybrane właściwości tkanin gofrowanych. Badaniom poddano 9 wariantów tkanin gofrowanych bawełnianych o zróżnicowanej strukturze. Zróżnicowanie struktury uzyskano poprzez zmianę raportu pasków gofrowanych, tzn. ich szerokości oraz odległości między paskami, a także zastosowanie 3 rodzajów przędzy wątkowej. Zakres badań obejmował właściwości mechaniczne, termoizolacyjne i powierzchniowe. Przedstawione badania potwierdziły wpływ wariantu raportu pasków gofrowanych na właściwości mechaniczne i termo-izolacyjne tkanin gofrowanych bawełnianych. Wykazano również zależność pomiędzy parametrami charakteryzującymi geometryczna strukturę powierzchni tkanin gofrowanych a ich właściwościami mechanicznymi i termoizolacyjnymi.

EN

The aim of the research was to evaluate the influence of the seersucker effect on selected properties of the seersucker woven fabrics. Nine variants of cotton seersucker woven fabrics of various structure have been the objects of investigations. Diversification of the structure was obtained by changing the report of the seersucker effect i.e. width the puckered strips and distance between them, as well as the use of three types of weft yarns. The scope of the research included mechanical, thermal-insulation and surface properties. The presented research confirmed the influence of the variant of the puckered stripes report on the mechanical and thermal-insulating properties of the fabrics. The relationship between the parameters characterizing the geometric structure of the surface of seersucker woven fabrics and their mechanical and thermal-insulation properties was also demonstrated.

9

Technical Aspects of Measurements Using the Pull-Off Method

Skowera Karol, Foksa Anna

Structure and Environment

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2021

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Vol. 13, no. 3

83--89

EN

The article presents an analysis of the technical use aspects of the pull-off method for testing the repair layers applied to concrete elements, based on the standards requirements. The use of non-destructive testing methods is the only option in some cases. However, it is very important to pay attention to their proper use or even preparation for research. The pull-off method requires just such diligence to be able to properly interpret the obtained results. The article compares the results of the research in which the pull-off method was used in various configurations. The obtained measurement results were compared with each other and analyzed in terms of their usefulness.

PL

W artykule przedstawiono analizę technicznych aspektów użytkowania metody pull-off do badania warstw naprawczych nakładanych na elementy betonowe w oparciu o wymagania norm. W niektórych przypadkach jedyną opcją jest zastosowanie nieniszczących metod badawczych. Bardzo ważne jest jednak, aby zwracać uwagę na ich właściwe stosowanie, a nawet samo przygotowanie do badań. Metoda pull-off wymaga właśnie takiej staranności, aby móc właściwie zinterpretować uzyskane wyniki. W artykule porównano wyniki badań, w których zastosowano metodę pull-off w różnych konfiguracjach. Otrzymane wyniki pomiarów porównano ze sobą i przeanalizowano pod kątem ich przydatności.

10

Analiza wybranych właściwości wytrzymałościowych materiałów ABS i PC przetwarzanych techniką VC

Bernaczek Jacek

Przegląd Mechaniczny

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2021

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nr 6

20--24

PL

Publikacja obejmuje wyznaczenie oraz porównanie wytrzymałości na rozciąganie i zginanie modeli wytworzonych w procesie kształtowa- nia próżniowego z żywic poliuretanowych imitujących właściwościami materiały ABS i PC. Opracowano i przyrostowo wytworzono zespolone modele zestawów próbek wzorcowych do badań wytrzymałościowych zaopatrzone w zintegrowany układ zalewowo-odpowietrzający. Na jego podstawie opracowano formy silikonowe. Proces próżniowego odlewania przeprowadzono dla żywic poliuretanowych imitujących właściwościami mechanicznymi odpowiednio poliwęglan i ABS. Proces VC (Vacuum Casting) oraz obróbkę termiczną dla poszczególnych zestawów próbek zrealizowano wg indywidualnych kart materiałowych opracowanych przez producentów poszczególnych żywic. Wytrzymałość w statycznej próbie rozciągania i trzypunktowego zginania modeli testowych wyznaczono z wykorzystaniem specjalistycznego stanowiska badawczego. Przeprowadzono analizę porównawczą wyników uzyskanych w badaniach stanowiskowych z danymi deklarowanymi przez producentów poszczególnych materiałów.

EN

The publication covers the determination and comparison of the tensile and bending strength of models produced in the process of vacuum forming from polyurethane resins imitating the properties of ABS and PC materials. Complex models of sets of reference samples for strength tests were developed and incrementally produced integrated flood and vent system. On its basis, silicone forms were developed. The vacuum casting process was carried out for polyurethane resins imitating the mechanical properties of polycarbonate and ABS, respectively. The VC (Vacuum Casting) process and thermal treatment for individual sets of samples were carried out according to individual material cards prepared by the producer of individual resins. The strength of the static tensile and three-point bending test of the test models was determined using a specialized test stand. A comparative analysis of the results obtained through bench tests with the data declared by the producers of individual materials was carried out.

11

Analiza wyników badań fibrobetonu z włóknami polimerowymi

Blazy Julia, Drobiec Łukasz

Inżynieria i Budownictwo

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2021

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R. 77, nr 9-10

477--481

PL

Uzyskane z własnych badań wyniki porównano z istniejącymi w literaturze wzorami empirycznymi do określenia wytrzymałości na rozciąganie przy zginaniu fibrobetonów ze stalowym zbrojeniem rozproszonym. Zaproponowano własny wzór dotyczący betonów z włóknami syntetycznymi o nominalnej zawartości włókien ≤0,5% i smukłości do 200. Podjęto próbę klasyfikacji wytrzymałości przebadanych mieszanek zgodnie z Model Code 2010. Przeanalizowano wyniki energii pękania i zależności krzywych: siła - szerokość rozwarcia rysy; siła - ugięcie i siła - szerokość przemieszczenia końcówki rysy.

EN

The obtained results were compared with the empirical formulas existing in the literature for the calculation of the fiexural strength of fiber reinforced concretes with dispersed steel fibers. The new formula determined by the authors was also proposed for concrete with synthetic fibers with a nominal fiber content ≤0.5% and a slenderness of up to 200. In addition, an attempt was made to evaluate the strengths of tested concrete mixtures in accordance with the Model Code 2010. Finally, the fracture energy results and curve dependencies: force-crack mouth opening displacement; force-deflection and force-crack tip opening displacement were analyzed.

12

Wpływ obniżonej temperatury na wytrzymałość aluminium serii 5xxx

Dudda Waldemar, Miazio Łukasz

Hutnik, Wiadomości Hutnicze

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2021

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Vol. 88, nr 5-6

6--7

PL

W artykule przedstawiono badania nad wpływem niskiej temperatury na wytrzymałość aluminium 5754 i 5083. Wykonano próbę rozciągania statycznego w temperaturze pokojowej oraz ujemnej -20°C. Na podstawie przeprowadzonych prób rozciągania badanych stopów aluminium zaobserwowano niewielki wzrost właściwości wytrzymałościowych, tj. granicy plastyczności oraz wytrzymałości na rozciąganie.

EN

Research on low temperature contribution on the strength of 5754 and 5083 aluminum are presented in this article. Static tensile tests were carried out at room and negative temperature of -20°C. A slight increase in strength properties, i.e. the yield strength and the tensile strength of studied aluminum alloys, was observed on the basis of conducted tensile tests.

13

Mechanical properties and fatigue life detection of copper particle filled polyester composite material under rotating bending load

Hamzah Ahmed Fadhil, Al-Turaihi Ali S., Hunain Mustafa Baqir, Fadhel Essam Zuheir

Diagnostyka

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2021

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Vol. 22, No. 3

35--42

EN

In the present investigation, the fatigue life detection of composite material by adding copper particle of about than 25 μm diameter with 5, 10, 15 % volume fraction, as a reinforcements into the unsaturated polyester polymer composite material on fatigue life detection of composite material were studied experimentally and numerically. Composites were made using hand lay-up technique and evaluated for mechanical and fatigue properties in accordance with ASTM standards. The experimental results of the tensile test showed that adding 15% of copper particle in unsaturated polyester gives maximum ultimate tensile stress. Fatigue tests including test rod specimens made of composite materials under completely reversed cyclic loading in a rotating cantilever reversed bending machine. It is found that, the fatigue life and fatigue strength increase with increasing in the copper percentage volume fraction in unsaturated polyester resin compared with pure polyester composites. The experimental work was compared with numerical work, which was done by using ANSYS/19 and good agreement has been found. The maximum overall difference between the experimental and numerical work was around 9 %.

14

Investigation of thermal and mechanical characterizations of high-density polyethylene/date palm composites

Awad Sameer A

Composites Theory and Practice

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2021

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R. 21, nr 4

123--126

EN

The article aims to study the impact of date palm powder (DPP) on the mechanical and thermal characterizations of a high-density polyethylene (HDPE) matrix. HDPE composites enhanced with ratios varying from 5 to 20 wt.% DPP were produced by means of a twin-screw extruder. The results indicate that incorporating between 5 to 20 wt.% DPP in pure HDPE led to an increase in the tensile strength and Young’s modulus, while the elongation at break decreased. Furthermore, the results of thermal gravimetric analysis (TGA) revealed that incorporating DPP into pure HDPE improved the thermal stability owing to a reduction in the interfaces between DPP and the pure HDPE matrix, resulted in brittle behavior, and enhanced the great crosslinking of pure HDPE.

15

Effect of tungsten carbide on Al6061/SiC hybrid metal matrix composites

Vijay P, Brahma Raju K.V., Ramji K., Kamaluddin S

Composites Theory and Practice

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2021

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R. 21, nr 4

169--180

EN

Aluminium matrix composites (AMC) are mostly preferred for their high specific strength, high ductility, corrosion resistance and creep resistance. Various experimental investigations are conducted in the field of AMCs, which are widely applicable in several fields like aerospace (especially aircraft structures and fittings), marine fittings, automotive industries (connecting rods, pistons, brake rotors, and engine blocks), etc. The current work presents the effect of a tungsten carbide (WC) reinforced Al6061/SiC hybrid composites. In this study, the WC particle (3÷5 μm) content is varied from 0 to 6 wt.% in steps of 2 wt.%, while keeping the SiC particle (63 μm) content of 5 wt.% constant. The stir casting method was used to prepare these composites and the behaviour of the composites was studied to ascertain their mechanical and corrosion properties. From the obtained results, it was observed that the ultimate tensile strength, hardness, and corrosion resistance of the composites are enhanced by increasing the content of WC, whereas the wear loss (microns) decreased as the WC was increased up to 4 wt.%; later it increased drastically at 6 wt.% WC. The corrosion results reveal that the corrosion rate of the composites is lower than that of the monolithic alloy. SEM examination of the tensile fracture surface shows that there is a formation of larger shear lips in the base alloy and the composite with 5 wt.% SiC; however, they are reduced gradually by the additions of WC to the composite. The microstructure of the corroded surfaces reveals that the pit density was reduced for the composite with 6 wt.% WC compared to the other composites.

16

Analyzing mechanical behavior of ABS-SiO2 polymer-based nanocomposite based on ANOVA method

Afzali Mohammad, Asghari Vahid

Composites Theory and Practice

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2021

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R. 21, nr 3

61--69

EN

The fabrication of polymer-based nanocomposites by means of twin extruders is a typical method for manufacturing lightweight and high-strength structures. However, selection of the optimal parameters for this process to study the material characteristics is important. The primary aim of the present study was to ascertain the optimum extruder temperature and nanosilica content in an acrylonitrile-butadiene-styrene matrix composite. The response surface methodology was based on two factors and three levels. The identification of the effect of the parameters on the fatigue behavior of the fabricated composite was comprehensively analyzed. The results were analyzed using scanning electron microscopy (SEM). The obtained results revealed that up to 4% nano-SiO2 improves tensile strength and reduces the impact toughness. On the other hand, an increase in the extrusion temperature yields a higher impact toughness and lower tensile strength. The optimization results showed that 2.5% nanosilica and the extrusion temperature of 225°C result in the maximum tensile strength of 41 MPa, and impact toughness of 30 KJ/m2.

17

Experimental Investigation of Self-Compacting Concrete Containing Coir Fibres

Lakhiar Muhammad Tarque, Lakhiar Muhammad Tahir, Abdullah Abd Halid, Mohamad Noridah

Civil and Environmental Engineering Reports

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2021

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Vol. 31, no. 2

163--177

EN

Many researchers have investigated alternative sources to overcome the problem of conventional building material polluting the environment by the development of green self-compacting concrete in the construction industry. The best alternative solution is to utilise non-conventional construction materials like agricultural wastes. Meanwhile, self-compacting concrete (SCC) is considered as high strength as well as high-performance concrete. The demerits, which include tensile and flexural strength, can be improved by incorporating coir fibres. The utilisation of coir fibres also modifies self-compacting concrete performance after cracking and improves the toughness. This study defines an experimental investigation of the mechanical properties of self-compacting concrete containing coir fibres (CF) with different percentages being 0%, 0.2%, 0.5%, 1%, and 1.5% at 7- and 28-days water curing. The mechanical properties include the slump flow and compressive and tensile strength were examined. The outcomes demonstrated that a required slump flow for self-compacting concrete was achieved using coir fibres up to 1%, beyond which it reduced the slump significantly. The length of fibre and proportion of fibres directly affected the workability. The compressive strength was 10% to 15% enhanced with the incorporation of coir fibres up to 0.5%; after that, the strength was slightly reduced, and tensile strength was 30% to 50% improved compared to conventional self-compacting concrete up to 1% of coir fibres incorporation in the SCC mix, after which it rapidly reduced.

18

Effect of SiO2 flux on the depth of penetration, microstructure, texture and mechanical behavior of AA6063 T6 aluminum alloy using activated TIG welding

Kumar Rajiv, Vettivel S. C., Kumar Kansal Harmesh

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2021

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Vol. 69, nr 1

art. no. e136215

EN

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.

19

Secondary treated wastewater as a concrete component and its impact on the basic strength properties of the material

Ahmad Omar Asad, Ayyad Sami Mohammed

Archives of Civil Engineering

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2021

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Vol. 67, nr 1

571--583

EN

In Jordan, the unprecedented proliferation of building projects is anticipated to increase the potable water demand in the construction manufacturing. In the present work, secondary treated wastewater (STW) and potable water (PW) were used in the production of concrete mixes, which were subjected to testing after 3 to 28 days of curing to determine how the, mechanical properties of concrete was affected by the addition of secondary treated wastewater in various proportions (25-100%). Results indicated that the use of 25% and 75% of secondary treated wastewater in concrete production increased the compressive strength to 39 MPa after 28 days of curing. A more noticeable increment was recorded in tensile strength, which was double that achieved with the standard design. Overall, the compressive strength increased by 21.95% when secondary treated wastewater was used, while the expenditure related to water usage was halved. Furthermore, there was consistency between the results obtained from scaling up to actual ready-mix concrete production and the results of the empirical work.

20

Solid-state welding of ultrafine grained copper rods

Morawiński Łukasz, Jasiński Cezary, Ciemiorek Marta, Chmielewski Tomasz, Olejnik Lech, Lewandowska Małgorzata

Archives of Civil and Mechanical Engineering

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2021

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Vol. 21, no. 3

31--43

EN

The article focuses on the Direct Drive Rotary Friction Welding of ultrafine-grained copper rods, which feature increased mechanical properties and good electrical properties, yet are limited in size. The use of UFG metals is often limited by the too small dimensions of semi-finished elements produced by SPD methods. Therefore, the production of finished machine parts from UFG metals is currently economically unjustified. Dismissal of dimensional limitations can be done by introducing joining to technological processes. The proposed joining method does not lead to a melting of the material in the joining zone or excessive degradation of the UFG microstructure. To obtain the best results, the research used the method of low-energy welding of two kinds of specimens: with a flat or a conical contact surface. In the article, the authors present, by means of metallographic microsections and microhardness measurements, the influence of rotational speed, welding pressure and conical shape contact surface on the quality of the obtained joints. The conducted research made it possible to obtain good quality joints whose microhardness is reduced only by about 10% in comparison with the base material and the tensile strength dropped from only 397–358 MPa.