Wyniki wyszukiwania - BazTech

1

Paper-sawdust composites: fabrication and comparison in terms of heat transfer and strength properties

Robert Ubong Williams, Ekong Sylvester Andrew, Akpan Samuel Sunday, Etuk Sunday Edet, Inyang Namdie Joseph, Agbasi Okechukwu Ebuka

Structure and Environment

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2023

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Vol. 15, no. 1

38--49

EN

This study was designed to examine the feasibility of recycling cassava effluent, sawdust, and unused paper products to enhance their utilization for beneficial purpose. Waste newspaper paste (WNP), Waste writing-paper paste (WWP), and Waste carton paper paste (WCP) were prepared and then used separately to similarly fabricate composite panels with Sawdust particle (SDP) proportioned at 0%, 25%, 50%, 75%, and 100% by weight. The binder used was cassava starch slurry prepared from the effluent. Bulk density, water absorption, thermal conductivity, specific heat capacity, thermal diffusivity, nailability, and flexural strength were determined for the developed samples. From the results obtained, the samples were found to be light-weight and their thermal insulation performance improved with increasing proportions of the SDP. Though samples containing the WCP exhibited the best satisfactory performance, it was found that all the studied samples could perform more effectively and efficiently as ceilings compared to some of those reported in the literature. From scientific-economic viewpoint, valorizing the above-mentioned wastes as described in this paper could help to protect the environment and also yield value-added insulation ceilings for enhancement of sustainable building construction especially in tropical areas.

PL

Celem pracy było określenie możliwości recyklingu ścieków z manioku, trocin i odpadowych materiałów papierniczych w celu ich szerszego wykorzystania. Nitki z makulatury gazetowej (WNP), nitki z makulatury z papieru do pisania (WWP) i nitki z makulatury z kartonu (WCP) zostały przygotowane, a następnie użyte osobno do wytworzenia paneli kompozytowych z dodatkiem trocin (SDP) przy udziale masowym 0%, 25%, 50 %, 75% i 100%. Zastosowanym spoiwem była przygotowana z odcieku zawiesina skrobi z manioku. Dla przygotowanych próbek określono gęstość nasypową, nasiąkliwość, przewodność cieplną, ciepło właściwe, dyfuzyjność cieplną, zdolność do wbijania gwoździ i wytrzymałość na zginanie. Na podstawie uzyskanych wyników stwierdzono, że próbki miały małą gęstość objętościową, a ich właściwości termoizolacyjne poprawiały się wraz ze wzrostem udziału trocin (SDP). Chociaż próbki zawierające WCP wykazywały najlepsze właściwości, stwierdzono, że z wszystkich badanych próbek można wytworzyć sufity o lepszych właściwościach w porównaniu z podobnymi opisanymi w literaturze. Z naukowo-ekonomicznego punktu widzenia zastosowanie wyżej wymienionych odpadów, jak opisano w tym artykule, może pomóc w ochronie środowiska, a także w uzyskaniu bardziej ciepłochronnych stropów, a co za tym idzie przyczyni się do rozwoju bardziej zrównoważonego budownictwa, zwłaszcza w obszarach tropikalnych.

2

Właściwości fizyczne mieszaniny polilaktyd/skrobia termoplastyczna

Fabijański Mariusz, Garbarski Jacek

Przemysł Chemiczny

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2023

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T. 102, nr 9

954--958

PL

Przedstawiono wyniki badań właściwości mieszaniny PLA/TPS. Granulki polilaktydu (PLA) i skrobi termoplastycznej (TPS) w proporcjach masowych 25, 50 i 75% mieszano w mieszalniku bębnowym, a następnie mieszano w stanie stopionym i formowano we wtryskarce ślimakowej. Próbki polimerów analizowano pod kątem udarności, twardości i nasiąkliwości. Mieszaniny PLA/TPS wykazywały istotnie większą udarność niż każdy z materiałów składowych z osobna. Udarność była nawet dwukrotnie większa, co wskazywało na występowanie zjawiska synergizmu.

EN

Polylactide (PLA) and thermoplastic starch (TPS) granules in mass proportions of 25, 50, 75% were mixed in a drum mixer, and then meltmixed and shaped using a screw injection molding machine. Polymer samples were analyzed for impact strength, hardness and water absorption. The PLA/TPS mixts. showed a significantly higher impact strength than each of the component materials separately. The impact strenght was even twice as high, which indicated the occurrence of the synergism phenomenon.

3

Analiza numeryczna osuszania przegrody zewnętrznej na podstawie danych eksperymentalnych

Major Maciej, Kosiń Mariusz

Materiały Budowlane

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2023

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nr 7

1--5

PL

W artykule przedstawiono wyniki badań oraz analizy numerycznej zagadnień związanych z wilgotnością przegrody budowlanej wykonanej w technologii lekkiego szkieletu stalowego. Rezultatem badań było sporządzenie izoterm sorpcji oraz nasiąkliwości materiałów tworzących przegrodę. Na ich podstawie przeprowadzono symulację osuszania naturalnego przegrody przy założeniu, że materiały ją tworzące są nasączone wodą. Analiza numeryczna pozwoliła oszacować ubytek wody w przegrodzie zewnętrznej w zależności od początkowego stanu jej zawilgocenia w przyjętych okresach obliczeniowych.

EN

The article covers the results of research and numerical analysis of issues related to the humidity of a building partition made in the technology of a light steel skeleton. The result of the research was the preparation of the sorption isotherm and water absorption of the materials forming the barrier. On their basis, a simulation of the natural drying of the partition was carried out, assuming that the materials forming it are soaked with water. Numerical analysis, depending on the initial moisture level of the external partition, allowed to estimate the loss of water in the partition in the adopted calculation periods.

4

Investigating the effects of nano-blast furnace slag powder on the behaviour of composite cement materials

Kadhim M. J., Hasan L. M., Kamal H. M.

Journal of Achievements in Materials and Manufacturing Engineering

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2023

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Vol. 116, nr 1

5--10

EN

Purpose: Attributable to the depletion of raw materials and for sustainability purposes in construction works. Therefore, this study looked into the effects of nano blast furnace slag (BFS) on the microstructure, mechanical properties, and durability of mortar. BFS was substituted for cement at various weight percentages of 0, 1, 1.5, 3, 5, and 7%. Design/methodology/approach: A suspension of water and Nano blast furnace slag was made using ultrasonic mixers to prepare the samples. The suspension was combined with cement and sand using 1 cement, 0.5 water, and 2.75 sand in the mixture to make cement mortar. The mixture was then shaped, left in the mould for 24 hours, and then allowed to cure for 7, 14, 28, 60, and 91 days. SEM was used to investigate the microstructure before and after cement replacement. The mechanical characteristics were evaluated by testing the compressive strength and the surface hardness. While the durability was assessed using the water absorption ratios. Findings: The results revealed that increasing the BFS in the mortar improved mechanical characteristics and durability by up to 3% of BFS. Replacing Nano-blast furnace slag for a portion of the cement is a proposed solution to address the problems of environmental pollution and resource consumption caused by cement production. Research limitations/implications: Another sustainable material needs to be used for additional investigation. We may evaluate more properties and use different weight percentages. Practical implications: Each year, a significant amount of slag is produced as a result of the iron industry, endangering the environment. There have been numerous initiatives to reduce slag’s negative environmental consequences. Using slag to replace some of the cement is one of the options to eliminate this byproduct and reduce excessive cement use. Originality/value: This study investigates the possibility of using a blast furnace blast within the Nanoscale to replace some of the cement used in the construction due to the positive impact on the environment to get rid of industrial byproducts and decrease the use of cement.

5

Water absorption, impact resistance and strength reliability of concrete incorporating sintered fly ash aggregate under drop weight impact load

Baskaran Ranjith Babu, Nagarajan M.

Engineering Transactions

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2023

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Vol. 71, iss. 2

197--211

EN

ASTM and ACI methods were used to determine the water absorption and impact resistance of M30 grade concrete containing different percentages of sintered fly ash aggregate (SFA) ranging from 20%, 40%, 60%, 80%, and 100%. In the concrete laboratory, the parameters of the concrete mix, including fresh density, slump value, dry density, compressive strength, and impact resistance, were determined. The fresh and dry densities of concrete mix decrease as the quantity of SFA used as substitute increases. The 100% substitution of SFA in concrete results in a slump value of 200 mm, a fresh density of 1946 kg/m3 , a dry density of 1911 kg/m3 , and water absorption of 3.5%, with a compressive strength of 12.3 MPa. For the drop weight impact resistance test, reliability analysis was conducted to determine the level of reliability of each concrete mix for varying SFA. Using reliability analysis, the failure analysis owing to impact load determined the energy absorption of the concrete mix.

6

Preparation and characterization of silicone rubber socket liners modified by nanoparticles additives

Ameer Z.J.A.

Archives of Materials Science and Engineering

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2023

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Vol. 119, nr 1

21--30

EN

Purpose: The upper part of the prosthesis is called a socket, which contacts the amputated part. While wearing the prosthesis, there are several problems that the patient may suffer from, such as shear force between the socket and amputated part, pressure on the bony prominences, sweating, and bacteria generation, all leading to skin problems and a bad smell. It makes the patient refuse to wear the prosthesis because it is uncomfortable. Therefore, the aim of this study was comfortable lining from silicone rubber which cross-links at room temperature, with properties corresponding to the needs of this application, such as stress distribution, moisture absorption, and antibacterial. Design/methodology/approach: In the current work, silicone rubber was selected with the addition of nano-fillers (ZnO, Mg(OH)2, and Chitosan). Mechanical and physical properties were studied (tensile strength, tear strength, hardness, water absorption, porosity, and antibacterial). Findings: Chitosan showed the highest effect on the mechanical properties of silicon, as it achieved the highest value of tensile strength of 2.2 MPa elongation of 572%, tear strength 13.9 kN/m, and shore A hardness of 33.3. While the highest value of the modulus, 0.636 MPa was achieved by adding ZnO. The results also showed an increase in the water absorption and the porosity, which were the highest values at 1.6 % and 0.24%, respectively with the addition of Mg(OH)2. The samples showed a clear resistance to preventing the microorganism’s growth. Research limitations/implications: Manufactured linings require additional improvement in mechanical properties by mixing more than one type of additives mentioned in the research. Thus, physical and biological properties can be obtained simultaneously with mechanical properties. Practical implications: The above results qualify the silicone rubber composites for use as a socket liner due to their flexibility and ability to absorb water in addition to their resistance and prevent the growth of fungi and bacteria. Originality/value: The method of preparation and properties of the lining material and additives qualify it for such applications as physical and biological properties.

7

Evaluation of thermophysical and strength properties of composite panels produced from sugarcane bagasse and waste newspapers

Etuk Sunday Edet, Robert Ubong Williams, Agbasi Okechukwu Ebuka, Inyang Namdie Joseph

Advances in Materials Science

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2023

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Vol. 23, nr 1(75)

19--31

EN

Large quantities of waste newspapers and sugarcane bagasse are prevalently discarded by open burning or indiscriminate dumping, thereby posing severe danger to the environment and public health. This study sought to examine the feasibility of managing the wastes by recycling them into value-added products for building construction. Composite panels were fabricated using waste newspaper paste (WNP) with sugarcane bagasse particles (SBP) varied at 0, 25, 50, 75, and 100 % by weight of the composite mix. Epoxy resin was thoroughly mixed with its hardener and applied as binder. The samples were developed in triplicates per proportion of the SBP adopted and then dried completely before their thermophysical and strength properties were evaluated. It was observed that variations in mean values of water absorption (28.57 – 39.43 %), thickness swelling (6.21 - 8.33 %), specific heat capacity (1232 - 1312Jkg-1K-1) trended positively with increasing proportions of the SBP. Whereas nailability remained 100.0 % in all the cases, bulk density (689.4 - 640.5 kgm-3), thermal conductivity (0.1186 - 0.1163 Wm-1K-1), thermal diffusivity (1.396 - 1.384 x 10-7 m2s-1), and flexural strength (2.572 - 2.280 N/mm2) correlated inversely with the added fractions of the SBP. Generally, it was found that the samples could perform satisfactorily if applied as ceiling or partition elements in building design. Therefore, recycling of sugarcane bagasse and waste newspapers as described in this study could serve as a promising way of solving their disposal problems and also enhance achievement of low-cost and safe buildings.

8

Water absorption kinetics of bitumen modified cement mortars

Trykoz Liudmyla, Rezunenko Maryna, Pustovoitova Oksana, Semenova-Kulish Victoria, Borodin Dmytro

Roads and Bridges - Drogi i Mosty

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2022

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Vol. 21, no. 2

167--178

EN

Concrete permeability is a major factor that affects durability and reliability of structures – bridges, tunnels, culvert pipes, etc. It is important to identify effective methods of protection of such structures against water penetration, for example by using a modifying substance. Samples of cement mortar composites were used for water absorption simulation. Bitumen emulsion was used as a modifying agent. According to the water absorption kinetics, the following parameters of the pore microstructure of the mortar composite were estimated: the index of mean size of open capillary pores, closed porosity, and the index of size uniformity. The research has shown that the addition of bitumen emulsion decreases the pore space and macrocapillaries (from 23.91% to 6.61%), water absorption (3 times), and the index of mean size of open capillary pores (from 0.69 to 0.3) of modified mortars.

PL

Odpowiednio niska przepuszczalność betonu to jeden z głównych czynników zapewniających trwałość i niezawodność konstrukcji budowlanych – mostów, tuneli, przepustów itd. Istotne jest zidentyfikowanie skutecznych metod zabezpieczenia takich konstrukcji przed wnikaniem wody, na przykład za pomocą dodatków modyfikujących. Badania nasiąkliwości przeprowadzono na próbkach zaprawy cementowej zawierającej dodatek emulsji asfaltowej. Na podstawie kinetyki wnikania wody w próbki oszacowano następujące parametry uzyskanej mikrostruktury porów: wskaźnik średniej wielkości otwartych porów kapilarnych, porowatość zamkniętą oraz wskaźnik jednorodności wielkości otwartych porów kapilarnych. Wyniki wykazały, że dodatek emulsji asfaltowej zmniejszył objętość porów i makrokapilar (z 23,91% do 6,61%), nasiąkliwość (trzykrotnie) oraz wskaźnik średniej wielkości kapilar otwartych (z 0,69 do 0,3) zapraw poddanych modyfikacji dodatkiem.

9

Feasibility study of palm oil boiler ash (POBA) as a partial replacement of sand in foamed concrete

Mohamed Yousuff Mohamed Khatif Tawaf, Sharipudin Siti Shahidah, Mohammad Shahrul Nizam, Roslan Azmi, Michael Zeno, Shahrul Azhar Ilya Izyan, Zainal Abidin Nurrul Amilin

Przegląd Naukowy Inżynieria i Kształtowanie Środowiska

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2022

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Vol. 31, No. 1

3--13

EN

A study was conducted to explore the effect of palm oil boiler ash (POBA) on foamed concrete by varying the percentage of POBA over sand quantities (0, 4, 8 and 12%). This paper primarily discusses the water absorption test, uniaxial compressive strength, and dry density findings. It indicates that substituting sand with POBA greatly enhances the strength of foamed concrete. When the quantity of POBA was raised up to 12% throughout all curing times, the compressive strength steadily increased in the range of 4.34–13.50 N·mm–2. Furthermore, the dry density of foamed concrete was shown to be directly related to the fraction of POBA in the mixture. The dry density of foamed concrete increases as the amount of POBA increases. Despite this, water absorption shown that increasing POBA increases water absorption percentage in foamed concrete from 7.4 to 10.4%. This is due to the fact that a composition with a high POBA percentage will generate more pores than a mixture with a low POBA percentage.

10

Wpływ czynników środowiskowych na wybrane właściwości grubowarstwowych asfaltowych powłok modyfikowanych polimerami

Francke Barbara

Materiały Budowlane

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2022

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nr 3

6--11

PL

W artykule przeanalizowano wpływ agresywnego działania wód gruntowych na wybrane właściwości warstw hydroizolacyjnych wykonywanych z grubowarstwowych powłok polimerowo-asfaltowych, ze szczególnym uwzględnieniem nasiąkliwości tych powłok. Oceniono również, jak zmienia się odczyn pH wody w kontakcie z grubowarstwowymi powłokami asfaltowo-polimerowymi. Analizy te uzupełniono wnioskami, publikowanymi wcześniej w literaturze technicznej, dotyczącymi wpływu podwyższonej nasiąkliwości tych powłok na zachowanie funkcji wodoszczelności oraz podatności powłok na zawilgocenie w efekcie działania wody o różnym pH. W badaniach wykorzystano m.in. metodę badawczą ujętą w normach PN-EN oraz metody własne.

EN

The manuscript analyzes the impact of the aggressive action of groundwater on selected properties of waterproofing layers made of polymer modified bituminous thick coatings, with particular emphasis on the water absorption of these coatings. It was also assessed how the pH of water changes in contact with polymer modified bituminous thick coatings. The analyzes were supplemented with conclusions previously published in the technical literature, regarding the impact of increased water absorption of the above-mentioned coatings to maintain the water-tightness function and the susceptibility of such coatings to moisture as a result of the action of water with different pH. The research used, inter alia, research methodology included in PN-EN standards, supplemented with tests performed using own methods.

11

Propozycja wykorzystania betonów geopolimerowych do prefabrykatów o podwyższonej izolacyjności cieplnej

Nietupski Adam, Bołtryk Michał, Pawluczuk Edyta, Kalinowska-Wichrowska Katarzyna, Spodzieja Szymon

Materiały Budowlane

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2022

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nr 4

34--37

PL

W artykule zaproponowano zastosowanie geopolimerów na bazie kruszywa sztucznego do produkcji elementów prefabrykowanych o podwyższonej izolacyjności. Przeprowadzono eksperyment o zmiennej zawartości popiołu lotnego (PL) i mieszaniny popiołowo-żużlowej (MPŻ) oraz różnym stężeniu aktywatora NaOH. Zastosowana metoda zagęszczania w postaci wibroprasowania umożliwia wytworzenie drobnowymiarowych elementów ściennych i stropowych o dobrych właściwościach izolacyjnych przy wytrzymałości na ściskanie ok. 15 MPa.

EN

The article proposes the use of geopolymers on artificial aggregate for prefabricated elements with increased insulation. An experiment was carried out with a variable content of fly ash (PL) and a mixture of ash and slag (MPŻ) and a different concentration of NaOH activator. The applied method of compaction in the form of vibropress allows the production of small-sized wall and ceiling elements with good insulating properties and a compressive strength of about 15 MPa.

12

Badania betonu w górnym pierścieniu kopuły Hali Stulecia we Wrocławiu

Moczko Andrzej, Moczko Mateusz

Materiały Budowlane

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2022

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nr 11

174--176

PL

W artykule przedstawiono wyniki badania jakości betonu w górnym pierścieniu kopuły Hali Stulecia we Wrocławiu, przeprowadzonego w ramach prac remontowych tego obiektu. Obejmowało ono określenie rzeczywistej wytrzymałości betonu na ściskanie na podstawie badania odwiertów rdzeniowych oraz z wykorzystaniem metody „pull-out”, a także oznaczenie nasiąkliwości oraz ocenę stopnia jego karbonatyzacji. Uzyskane wyniki wykazały, że badany beton charakteryzuje się zaskakująco dobrymi cechami fizyczno-mechanicznymi. Jego parametry wytrzymałościowe odpowiadają obecnym wymaganiom stawianym klasie wytrzymałości C20/25, a bardzo dobrą jakość badanego betonu potwierdziły także wyniki nasiąkliwości, której wartości były zbliżone do 5%. Zbadane parametry są z jednej strony unikatowym źródłem informacji o jakości betonu z początku XX wieku, a z drugiej pozwalają na ocenę trwałości tego tworzywa po upływie stulecia.

EN

The paper presents results of the concrete quality tests in the upper ring of the Centennial Hall dome in Wroclaw, carried out as part of the renovation works of this facility. The tests included the determination of the actual compressive strength of concrete on the basis of core drilling tests and the "pull-out" measurements, as well as determination of the water absorption of the tested concrete and assessment of its carbonation degree. The obtained results showed that the tested concrete is characterized by surprisingly good physical and mechanical properties. Its strength parameters correspond to the current requirements for the C20/25 strength class, and the high quality of the tested concrete was also confirmed by the results of the water absorption determination, the values of which were close to 5%. The obtained results are, on the one hand, a unique source of information about the quality of concrete from the beginning of the 20th century, and, on the other hand, allow for the assessment of the conditions of durability of this material after a century.

13

Three-phases bubble column to polyethylene terephthalate depolymerization for cement mortar composites improvement

Hameed A. M., Alzuhairi M., Ibrahim S. I.

Journal of Achievements in Materials and Manufacturing Engineering

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2022

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Vol. 112, nr 1

5--12

EN

Purpose: This paper aims to prepare depolymerized polyethylene terephthalate (DPET) powder from recycled plastic water bottles. Adding this DPET powder to the cement mortar was also studied. Design/methodology/approach: The adopted PET depolymerization process includes the usage of both ethylene glycol (EG) as solvent and nano-MgO as a catalyst. A bubble column reactor was designed for this process. Five different mortar groups were made; each has different DPET content of 0%, 1%, 3%, 6% and 9% as a sand replacement. The flexural strength testand the water absorption measurement are done after two curing periods: 7 and 28 days. Findings: The research finding demonstrated that the flexural strength of mortar was reduced by increasing the DPET powder percentage and the maximum dropping was 15% when 9% of DPET was added. The ability of the mortar to absorb the water was reduced by 14.5% when DPET powder was 9%. The mortar microstructure is featured with fewer cavities and porosity. Research limitations/implications: This work’s employed bubble column technique is limited only to the laboratory environment and needs to be scaled up within industrial mass production. For future research, it is suggested to decrease depolymerization time by using smaller pieces of plastic water bottle waste and trying other types of nanocatalyst. Practical implications: The modified mortar can be utilized in areas where moisture, rainfalls, and sanitation systems exist. Originality/value: The article claims that depolymerized waste PET improves chemical process efficiency by lowering reaction time and improving mass and heat transfer rates. Besides, this approach saves money. It is found out that the depolymerized plastic waste is much more functional due to its high cohesion capability than being used as small PET pieces.

14

Research on diatomite from Polish deposits and the possibilities of its use

Marczyk J., Pławecka K., Hebdowska-Krupa M., Nykiel M., Łach M.

Journal of Achievements in Materials and Manufacturing Engineering

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2022

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Vol. 115, nr 1

5--15

EN

Purpose: Diatomite from a deposit in Jawornik Ruski (Poland) has been selected as the material for study. The paper aimeds to show the possibility of using diatomite from the Carpathian Foothills as a sorbent of petroleum substances. Design/methodology/approach: Diatomite in the delivery condition (DC) and diatomite after calcination were used for this study. The material was calcined at 600, 650, 750, 850 and 1000°C. The diatomaceous earth was then granulated. The morphology of diatomite was observed using SEM. Particle size distribution was determined by Laser Particle Analyzer, chemical composition was determined by XRF, and mineralogical composition by XRD. Specific surface area, pore volume and pore size were determined. Thermal analysis (TG, DTA) was carried out. Absorption capacity tests were performed and the effect of diatomite addition on water absorption of concrete samples was determined. Findings: Within the framework of the study, it was shown that diatomite from the Jawornik deposit could be successfully used as a sorbent for petroleum substances. The absorption capacity of calcined at 1000°C diatomaceous earth was 77%. The obtained result exceeds the effectiveness of previously used absorbents, for which the sorption level is 60-70%. This allows commercial use of diatomite from deposits in Poland. In addition, water absorption tests have shown that diatomaceous earth can successfully replace cement used in concrete productione. The most favourablee effect on the reduction of water absorption is the addition of diatomite in the amount of 10%. Practical implications: The properties of diatomaceous earth from the Jawornik Ruski deposit indicate its high potential for use in the synthesis of geopolymers, which is important not only from an economic but also from an ecological point of view. Originality/value: The novelty of this work is the demonstration of the possibility of using diatomite as a sorbent of petroleum substances with high efficiency, exceeding the previously used sorbents.

15

Modyfikowanie nienasyconych żywic poliestrowych nanododatkami

Stępka Dominik

Inżynieria Materiałowa

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2022

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Vol. 43, nr 4

10--12

PL

W pracy przedstawiono różnego rodzaju podejście do kwestii modyfikacji żywic poliestrowych przy użyciu nanododatków. Poruszono zagadnienia nasiąkliwości kompozytów na bazie żywic, ich ognioodporności, a także udarności i wytrzymałości na zginanie. Zwrócono szczególną uwagę na metody z którymi wiąże się najbardziej korzystne rokowania.

EN

The paper presents a different approach to the modification of polyester resins with the use of nano-additives. The issues of absorbability of resinbased composites, their fire resistance, as well as impact strength and flexural strength were discussed. Particular attention was paid to the methods with the most favorable prognosis.

16

An ecological protection for wood material by hydrolyzed feather keratin

Turan Mazlum, Yeniocak Mehmet, Goktas Osman, Saltik Burcin, Alma M. Hakki

Drewno : prace naukowe, doniesienia, komunikaty

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2022

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Vol. 65, nr 209

art. no. 1644-3985.397.10

EN

Within the scope of this study, the hydrolyzed keratin which is an ecological and harmless material, was applied to the wood material surfaces by dipping and spraying method in different concentration rate 1%, 3% and 5%. Within the scope of the research, as wood materials Scots pine (Pinus sylvestris L.) and beech (Fagus orientalis L.) were used. Wood samples were exposed to white and brown rot fungi for 16 weeks and water absorption rate tests for 48-hour period to in order to determine protection performances. According to the results of the water absorption tests, it was observed that the keratin concentrations reduced the water absorption of wood material at least 7 times than control samples. Keratin concentrations were determined to reduce mass loss by at least 50% compared to control samples against rot fungus. As a result; it has been determined that keratin has positive effects on the protection of wood material in tests and that keratin substance can be applied as a natural preservative on wooden surfaces.

17

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.

18

Wpływ popiołu lotnego i popiołu z wytłoczyn z trzciny cukrowej na trwałość betonu lekkiego w badaniach doświadczalnych

Gunasekaran M., Palanisamy T.

Cement Wapno Beton

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2022

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R. 27, nr 5

355--370

PL

Beton lekki szybko uzyskuje uznanie w szerokim zakresie zastosowań w budowie konstrukcji betonowych. Jest to materiał dostosowany do konkretnych zastosowań, posiadający korzystne właściwości. W artykule przeprowadzono doświadczalną analizę i badanie wpływu popiołu lotnego i popiołu z wytłoczyn z trzciny cukrowej na wytrzymałość i trwałość betonu lekkiego. Trwałość może być zdefiniowana jako zdolność materiału do wytrzymania wpływu jego otoczenia, które działa na pogorszenie jakości betonu. Nasiąkliwość i podciąganie kapilarne badano dla betonów o zróżnicowanej procentowej zawartości popiołu lotnego i popiołu z wytłoczyn, z trzciny cukrowej. Zarówno w przypadku popiołu lotnego, jak i popiołu z wytłoczyn z trzciny cukrowej stwierdzono, że zwiększenie procentowego udziału zamiennika prowadzi do zwiększenia nasiąkliwości betonu lekkiego. Wyniki są rozpatrywane i przedstawione na podstawie przeprowadzonych badań. Wykazano, że zwiększenie dodatku popiołu powoduje większą wytrzymałość.

EN

Lightweight concrete [LWC] is rapidly reaching its full potential for a broad range of applications in the construction of concrete structures. It is tailor-made material for specific applications having beneficial properties. Therefore, the paper is devoted to the experimental analysis and study of fly ash and bagasse ash on the durability properties of lightweight concrete. Durability can be defined as the ability of the material to withstand the effects of its environment which are influencing the deterioration of concrete. The saturated water absorption and sorptivity was studied through experimental investigations, by varying the percentage of fly ash and bagasse ash content. Both fly ash and bagasse ash shows that the increase in the percentage of replacement leads to the more absorption of lightweight concrete. The results are investigated and presented on the studies conducted as follows, showing that the increases in the percentage of replacement, strength also increased.

19

Development of engobe coating compositions for clinker and facing bricks

Khomenko Olena, Sribniak Nataliia, Zaichuk Oleksandr

Budownictwo o Zoptymalizowanym Potencjale Energetycznym

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2022

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Vol. 11

215--222

EN

This article deals with the basic principles of developing engobe compositions for facing and clinker ceramic bricks. The microstructure features of ceramic bricks have been studied, which must be considered when choosing the engobe composition and engobe products’ technology. The expediency of using alkaline and substandard kaolins as the main raw material, which improves the conditions for sintering ceramic coatings by applying the single annealing technology of construction ceramics, has been studied. Due to its higher annealing reactivity, compared to traditional clay materials, the experimental raw material in the engobe composition improves the adhesion of the coating to the ceramic base and increases the strength of the decorative and protective layer.

20

Influence of micro synthetic fibers confinement on properties of lightweight foamed concrete

Mydin Md Azree Othuman

Archives of Civil Engineering

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2022

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Vol. 68, nr 3

411--428

EN

In this investigation, the confinement effects of micro synthetic fibers on lightweight foamed concrete (LFC) were examined. The parameters evaluated were porosity, water absorption, shrinkage, compressive strength, flexural strength and tensile strength. Three densities were cast which were 600 kg/m3, 1100 kg/m3, and 1600 kg/m3. Besides, the number of layers (1 to 3 layers) of micro synthetic fibers was also being examined. Based on the result obtained, the porosity improved by 8.0% to 16.3%, 13.8% to 25.6%, and 9.3% to 24.5% for the LFC with densities of 600 kg/m3, 1100 kg/m3, and 1600 kg/m3 confined with 1 layer, 2 layers, and 3 layers of micro synthetic fibers, respectively. Besides, for the water absorption test, the enhancements were 6.9% to 15.6%, 20.0 to 27.1%, and 12.2 to 29.6% for the respective densities and number of layers of micro synthetic fibers employed, while the drying shrinkage improved by 48.5% to 76.8%, 57.4% to 72.1%, and 43.2 % to 68.2% for the respective densities and number of layers of micro synthetic fibers employed. For the strength properties, a confinement with 3 layers of micro synthetic fibers showed significant results, where enhancements of 153% (600 kg/m3), 97% (1100 kg/m3), and 102% (1600 kg/m3) were obtained for the compression strength; 372% (600 kg/m3), 258% (1100 kg/m3), and 332% (1600 kg/m3) for the bending strength; and 507% (600 kg/m3), 343% (1100 kg/m3), and 332% (1600 kg/m3) for the splitting tensile strength, respectively, compared to the control LFC.