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Tytuł:
Effects of incorporating granite powder in the mechanical properties of concrete
Autorzy:
Muñoz Pérez, Socrates Pedro
Atoche Zamora, Jorge Jr.
Powiązania:
https://bibliotekanauki.pl/articles/36061575.pdf
Data publikacji:
2023
Wydawca:
Szkoła Główna Gospodarstwa Wiejskiego w Warszawie. Wydawnictwo Szkoły Głównej Gospodarstwa Wiejskiego w Warszawie
Tematy:
concrete
granite powder
compressive strength
flexural strength
workability
Opis:
This study analyzes the effects of the incorporation of the granite powder (GP) as a partial replacement of the sand in the concrete in percentages of 10%, 15%, 20% and 30% to carry out a mix design of 210 kg·cm–2. Seeking to find an optimal proportion to increase its mechanical properties where the geotechnical characteristics of the aggregates were identified, workability, temperature, beams and concrete specimens were elaborated. The results of bending and compression tests were compared after 7, 14 and 28 days from setting between the standard concrete and the concrete incorporated with the GP. It is concluded that the optimal result was at 20% GP with 268.6 kg·cm–2, where the compressive strength increases by 13%, while its flexural property rupture modulus of 35 kg·cm–2 and workability are in an optimal range according to the stipulated parameters, thus allowing an important application for this waste in the construction industry, therefore contributing to recycling, environmental quality and the development of the usage of new materials.
Źródło:
Scientific Review Engineering and Environmental Sciences; 2023, 32, 1; 18-33
1732-9353
Pojawia się w:
Scientific Review Engineering and Environmental Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mechanical Properties of Polypropylene Composites with Different Reinforced Natural Fibers – A Comparative Study
Autorzy:
Simamora, Pintor
Simanjuntak, Josua
Sinulingga, Karya
Laksono, Andromeda Dwi
Powiązania:
https://bibliotekanauki.pl/articles/27323811.pdf
Data publikacji:
2023
Wydawca:
Polskie Towarzystwo Inżynierii Ekologicznej
Tematy:
polypropylene
natural fibre
tensile strength
modulus young
flexural strength
Opis:
Developing environmentally friendly and recyclable natural fiber-reinforced polymer composites has recently attracted researchers’ attention and interest. Herein, a comparative study was conducted to compare the mechanical properties of polypropylene (PP) composites with different natural fiber reinforcement, including palm fiber (Arenga pinnata), rice straw (Oryza sativa), coconut husk (Cocos mucifera), old world forked fern leaves (dicranopteris linearis), and snake plant (Sansevieria trifasciata). This study aimed to compare the influence of the five natural fiber materials on the tensile strength and flexural strength of PP composites. The natural fibers were chemically treated with a 5% NaOH solution for 2.5 hours. In the preparation of composites, polypropylene as the matrix is heated to 300 °C and mixed randomly with natural fibers. The test results indicate that the composite with the highest tensile strength (38% higher than the lowest) and flexural strength (102% higher than the lowest) is obtained using the PP composite with reinforced rice straw fiber. In contrast, the PP composites with palm fiber have the lowest tensile strength (72% from the highest tensile strength) and the lowest flexural strength (UFSmin) (62% from the highest flexural strength) corresponds to the PP composites with coconut fiber. This study revealed that the flexural strength of all composite samples was greater than that of pure PP.
Źródło:
Journal of Ecological Engineering; 2023, 24, 7; 311--317
2299-8993
Pojawia się w:
Journal of Ecological Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Microstructural, mechanical and pozzolanic characteristics of metakaolin-based geopolymer
Autorzy:
Abiodun, Yetunde Oyebolaji
Sadiq, Obanishola Muftau
Odeosun, Samson Oluropo
Powiązania:
https://bibliotekanauki.pl/articles/184351.pdf
Data publikacji:
2020
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
metakaolin
geopolymer concrete
compressive strength
flexural strength
reinforced concrete
Opis:
The use of cement contributes to global CO2 emission and this leads to the depletion of ozone layer, causing global warming. The quest to reduce or eliminate this problem has resulted in the discovery of metakaolin-based geopolymer as an alternative to the use of cement in construction work. In this study, metakaolin obtained as a result of kaolin calcination from some deposits in Nigeria; Ogun (Imeko), Edo (Okpela), Ondo (Ifon) and Ekiti (Isan-Ekiti) were characterized and used to determine the compressive and flexural strength of metakaolin-based geopolymer concrete (Mk-GPC). Cubes of 150 × 150 × 150 mm were used for the compressive strength test and reinforced concrete beams of size 150 × 250 × 2160 mm were produced to test for flexural strength. A water-absorption test was also carried out on Mk-GPC and the effect of ball-milling was assessed on the strength properties. The results from the various tests showed that 800°C for 1 hour of calcination of kaolin gives best combination of performance properties due to the presence of amorphous silica in metakaolin. Mk-GPC gave higher compressive strength and at an early age than ordinary Portland cement (OPC) concrete. The water absorption capacities of Mk-GPC were higher than the control samples. In the flexural strength test, the reinforced beams failed in flexural-shear mode and the shear capacities at 28-, 56- and 90-day curing age of the beams were between 0.656 and 0.938 MPa for Mk-GPC beams and between 0.563 and 0.844 MPa for the control beams. The moment capacities for the beams were between 19.25 and 33.25 (×10³ kgm²/s²) for Mk-GPC beams and were between 22.75 and 28.0 (×10³ kgm²/s²) for the control beams. The study has revealed that metakaolin-based geopolymer can serve as an alternative to cement for sustainable construction in the Nigerian construction industry.
Źródło:
Geology, Geophysics and Environment; 2020, 46, 1; 57-69
2299-8004
2353-0790
Pojawia się w:
Geology, Geophysics and Environment
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Flexural Properties of Thin Fly Ash Geopolymers at Elevated Temperature
Autorzy:
Ng, Yong-Sing
Liew, Yun Ming
Heah, Cheng Yong
Abdullah, Mohd Mustafa Al Bakri
Ng, Hui-Teng
Chan, Lynette Wei Ling
Powiązania:
https://bibliotekanauki.pl/articles/2134117.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
thin geopolymer
fly ash
elevated temperature
flexural strength
Opis:
This paper reports on the flexural properties of thin fly ash geopolymers exposed to elevated temperature. The thin fly ash geopolymers (dimension = 160 mm × 40 mm × 10 mm) were synthesised using 12M NaOH solution mixed with designed solids-to-liquids ratio of 1:2.5 and Na2SiO3/NaOH ratio of 1:4 and underwent heat treatment at different elevated temperature (300°C, 600°C, 900°C and 1150°C) after 28 days of curing. Flexural strength test was accessed to compare the flexural properties while X-Ray Diffraction (XRD) analysis was performed to determine the phase transformation of thin geopolymers at elevated temperature. Results showed that application of heat treatment boosted the flexural properties of thin fly ash geopolymers as the flexural strength increased from 6.5 MPa (room temperature) to 16.2 MPa (1150°C). XRD results showed that the presence of crystalline phases of albite and nepheline contributed to the increment in flexural strength.
Źródło:
Archives of Metallurgy and Materials; 2022, 67, 3; 1145--1150
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Enhancing the flexural load capacity of the reinforced concrete simply supported slabs using damaged tires strips (DTS)
Autorzy:
Ali, Saba
Alalikhan, Ahmed
Powiązania:
https://bibliotekanauki.pl/articles/35556446.pdf
Data publikacji:
2022
Wydawca:
Szkoła Główna Gospodarstwa Wiejskiego w Warszawie. Wydawnictwo Szkoły Głównej Gospodarstwa Wiejskiego w Warszawie
Tematy:
flexural strength
reinforced concrete slabs
damaged tires strips
Opis:
Damaged tires or ended-life tires represent a difficult problem due to their ability to sustain for a long time which are not able to be dissolved easily. Present study focuses on the ability of using the damaged tires strips (DTS) in the field of structural engineering as an innovative reinforcing material used additionally with the main reinforcement. The adopted technique in the present work represents a clean solution to reuse and recycle DTS to increase the ultimate flexural capacity of the reinforced concrete one-way and two-way slabs used in structural systems satisfying clean environment and economic considerations. The tests were conducted upon eight specimens of reinforced concrete one-way slabs (RCOWS) and two specimens of reinforced concrete two-way slabs (RCTWS) reinforced by the DTS as an additional reinforcement. Experimentally obtained results exhibited enhancement for the ultimate flexural load capacity of the RCOWS and RCTWS models reinforced by the DTS in the range of 16–80 and 14.28% respectively, compared to the original reference specimens.
Źródło:
Scientific Review Engineering and Environmental Sciences; 2022, 31, 2; 101-112
1732-9353
Pojawia się w:
Scientific Review Engineering and Environmental Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Influence of Material Configuration of Fibre-Metal Laminates with Alumina Core on Flexural Strength
Autorzy:
Frankiewicz, Mariusz
Karoluk, Michał
Dziedzic, Robert
Timmel, Tristan
Scholz, Peter
Powiązania:
https://bibliotekanauki.pl/articles/24201172.pdf
Data publikacji:
2022
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Lotnictwa
Tematy:
fibre-metal laminates
flexural strength
fatigue
composite materials
Opis:
Fibre metal laminates (FMLs) consisting of layers made of PA6 polyamide prepregs reinforced with glass and carbon fibres and an aluminium alloy core are the new variant of the other types used by aerospace FML materials such as GLARE or CARALL. By using a thermoplastic matrix, they can be shaped by stamping processes, which allows for a more efficient production process than classical laminating methods such as vacuum bagging. In addition to the improved impact energy absorption efficiency, the metallic core can be utilised to effectively bond the composite part to adjacent metallic structures. This article presents the influence of the material configuration of fibre-metal laminates consisting of continuous fibre-reinforced thermoplastic outer layers integrated with a layer of metallic aluminium alloy inserts - a number of layers, type and direction of reinforcing fibres - on the static and fatigue flexural properties. In this study, eight laminate configurations were prepared using a one-step variothermal consolidation process. The results showed that in the three-point flexural fatigue test, the samples exceeded 106 cycles at stresses <30% of the static bending strength. Laminates with predominantly longitudinally reinforced layers showed the highest fatigue strength among the FML samples analysed. The type of reinforcing fibres and the number of layers were less affected on the analysed mechanical properties.
Źródło:
Fatigue of Aircraft Structures; 2022, 14; 18--28
2081-7738
2300-7591
Pojawia się w:
Fatigue of Aircraft Structures
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of thermoplastic waste from production on the strength of cement mortars
Autorzy:
Pietrzak, Alina
Powiązania:
https://bibliotekanauki.pl/articles/29521074.pdf
Data publikacji:
2023
Wydawca:
Akademia Morska w Szczecinie. Wydawnictwo AMSz
Tematy:
cement mortar
thermoplastic wastes
flexural strength
compressive strength
polymer waste
Opis:
This paper presents study results on the effect of the addition of polymeric waste on selected mechanical properties (flexural and compressive strength) of cementitious composites with a special emphasis on cement mortars. This research focuses on cement mortars, commonly used in construction applications such as seaports and quays. Here, post-production waste from the production of automobile floor mats is ground to a fraction of 0–2 mm and used in the amounts of 5%, 7.5%, and 10% by weight of cement as an additive or substitute for sand. All the presented tests are conducted in accordance with PN-EN 197-1. The purpose of these tests is to determine the possibility of using thermoplastic waste as an aggregate substitute or additive in cement mortars. The conducted research confirmed the possibility of using the mentioned waste in cement mortar production technology in the amount of 5% as a substitute for sand.
Źródło:
Zeszyty Naukowe Akademii Morskiej w Szczecinie; 2023, 75 (147); 42-48
1733-8670
2392-0378
Pojawia się w:
Zeszyty Naukowe Akademii Morskiej w Szczecinie
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Preparation and performance evaluation of jute and glass composites of epoxy resin of (2E,6E)-2,6-bis (4-hydroxy benzylidene)-4-methylcyclohexanone
Autorzy:
Chopda, Jalpa V.
Sankhavara, Dharmesh B.
Patel, Jignesh P.
Parsania, P. H.
Powiązania:
https://bibliotekanauki.pl/articles/1075481.pdf
Data publikacji:
2019
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Composites
Diffusivity
Electric strength
Flexural strength
Photosensitive epoxy resin
Tensile strength
Volume resistivity
Water uptake
Opis:
Jute and glass composites were prepared by compressing molding technique at 150C for 3h under 20 MPa pressure. J-EMBHBC-DDS, J-EMBHBC-THPA, G-EMBHBC-DDS and G-EMBHBC-THPA showed 15, 15.1, 58.3 and 18.7 MPa tensile strength, respectively. J-EMBHBC-DDS and J-EMBHBC-THPA showed 22.9 and 19.4 MPa flexural strength, respectively. J-EMBHBC-DDM and G-EMBHBC-DDM showed 1.6×109 and 1.2×1012 ohm cm volume resistivity, respectively. J-EMBHBC-DDM and G-EMBHBC-DDM showed 2.8 and 11.2 kVmm-1, respectively. Water uptake in the composites was carried out in pure water and 10% each of aqueous HCl, H2SO4, HNO3, NaOH, KOH and NaCl solutions at 35 C as well as in boiling water. Composites showed high water uptake tendency and longer equilibrium time in different environments. High water uptake in the composites is due to presence of hydroxyl groups in celluloses and resins and also due to formation of micro cracks. Nature of the electrolytes also played an important role on water uptake behavior and diffusivity in the composites. Drastic reduction in equilibrium water uptake time was observed in boiling water.
Źródło:
World Scientific News; 2019, 129; 23-39
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Characterisation and Reverse Engineering of Eco-Friendly Historical Mortar: Qasr Tuba, Desert Castles in Jordan
Autorzy:
Ghrair, Ayoup M.
Said, Adi J.
Aldaoud, Naela
Miqdadi, Riham
Ahmad, Ahmad A. L.
Powiązania:
https://bibliotekanauki.pl/articles/1839137.pdf
Data publikacji:
2021
Wydawca:
Polskie Towarzystwo Inżynierii Ekologicznej
Tematy:
mortar
grog
lime
gypsum
Qasr Tuba
compressive strength
flexural strength
eco-friendly
historical restoration
Opis:
The purpose of this study was to investigate the mineral composition of the historical mortars of Qasr Tuba and to re-produce them for the restoration process. The mortar samples were collected from the foundation and walls of Qasr Tuba. The chemical and mineral composition of the mortar was determined using several techniques. In addition, the quantitative minerals content was recalculated for the mortar samples utilizing the material balances equation. Moreover, 12 mixtures of mortar were prepared and tested for fresh and hardened properties, according to their respective national and international standards. The results revealed that two types of mortar were used: (i) the lime-based mortar was used for the foundation and joint mortars in the lower parts of the building walls with a gypsum-hydrated lime ratio of 1:3; and (ii) the gypsum-based mortar was used as joint mortar in the upper parts of the building walls for baked bricks at a gypsum-hydrated lime ratio of 4:1. A pozzolanic reaction in the Qasr Tuba mortar produced a new formation of Xonotlite, Stratlingite, and calcium aluminium hydrate as a secondary cementing mineral. In conclusion, the use of hydraulic lime mortar was considered for building an environment for capturing the CO2 gas.
Źródło:
Journal of Ecological Engineering; 2021, 22, 3; 121-134
2299-8993
Pojawia się w:
Journal of Ecological Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Durability of hybrid fiber reinforced concrete at various environmental media
Autorzy:
Elhawary, Eslam Ibrahim Nasr
Elsafoury, Ashraf Hassan
Ahmad, Seleem Saleh Elsayed
Powiązania:
https://bibliotekanauki.pl/articles/35555212.pdf
Data publikacji:
2022
Wydawca:
Szkoła Główna Gospodarstwa Wiejskiego w Warszawie. Wydawnictwo Szkoły Głównej Gospodarstwa Wiejskiego w Warszawie
Tematy:
durability
hybrid fiber concrete
steel fiber
polypropylene fibre
compressive strength
splitting tensile strength
flexural strength
Opis:
Fiber’s addition to concrete mixture attracts researchers to determine the effect of fiber type on durability properties of hybrid performance concrete. In the present work, steel and polypropylene fibers are used in hybrid form in the experimental program. The objective of this paper is to investigate the mechanical properties of hybrid fiber reinforced concrete subjected to four various media: air, water, sodium chloride, and magnesium sulphate with a 7% concentration. The results showed that using hybrid fibers which consist of 1% steel fiber and 0.3% polypropylene fiber improved the compressive strength, splitting tensile strength, and flexural strength for different media for up to 360 days.
Źródło:
Scientific Review Engineering and Environmental Sciences; 2022, 31, 2; 88-100
1732-9353
Pojawia się w:
Scientific Review Engineering and Environmental Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Engineering properties of self-compacting concrete incorporating PET fibres and recycled fine concrete aggregates
Autorzy:
Bayah, Meriem
Debieb, Farid
Kadri, El-Hadj
Bentchikou, Mohamed
Powiązania:
https://bibliotekanauki.pl/articles/27314441.pdf
Data publikacji:
2023
Wydawca:
Politechnika Lubelska. Wydawnictwo Politechniki Lubelskiej
Tematy:
polyethylene terephthalate fibres
recycled fine concrete aggregates
flexural strength
self-compacting concrete
Opis:
Concrete is currently the most frequently used material in the building sector due to its favourable properties. However, the proliferation of waste poses a significant environmental problem. Over the past three decades, researchers have explored the use of construction and demolition waste (CDW) as well as plastic waste as aggregates, binders, and fibres in construction materials. This approach has emerged as a notable solution to address environmental and economic challenges. The objective of this research is to assess the impact of polyethylene terephthalate fibres (PETF) on the behaviour of self-compacting concrete (SCC) with recycled fine concrete aggregates (RFCA). Natural fine aggregates (NFA) were used as a substitute for RFCA at different mass fractions (0–100%). Additionally, four volumetric fractions (Vf) of PETF (ranging from 0.3% to 1.2%) were added, and the findings revealed an improvement in the flexural strength and modulus of elasticity of the composite material obtained. However, as the Vf content of PET fibres and RFCA increased, the compressive strength decreased, negatively affecting water absorption by immersion and capillary water absorption. Using 100% RFCA and 1.2% PETF enhanced the modulus of elasticity and flexural strength of recycled self-compacting concrete (RSCC) by up to 25% and 9%, respectively.
Źródło:
Budownictwo i Architektura; 2023, 22, 4; 71--95
1899-0665
Pojawia się w:
Budownictwo i Architektura
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analiza niezawodnościowa wytrzymałości kompozytów stomatologicznych poddanych zróżnicowanym procedurom fotopolimeryzacji
Reliability analysis of strength of dental composites subjected to different photopolymerization procedures
Autorzy:
Niewczas, A. M.
Pieniak, D.
Ogrodnik, P.
Powiązania:
https://bibliotekanauki.pl/articles/1366268.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Polskie Naukowo-Techniczne Towarzystwo Eksploatacyjne PAN
Tematy:
niezawodność
wytrzymałość na zginanie
kompozyty stomatologiczne
fotopolimeryzacja
reliability
flexural strength
dental composites
photopolymerization
Opis:
Celem badań była ocena wpływu wybranych procedur fotopolimeryzacji na wytrzymałość i niezawodność kompozytów stomatologicznych opartych na siloranach oraz kompozytów opartych na związkach metakrylanowych w warunkach testu na 3-punktowe zginanie. Badano kompozyty o nazwach handlowych: Filtek Siloran (FSi), Gradia Direct Anterior (GDA), Gradia Direct Posterior (GDP), Herculite XRV (H). Zastosowano fotopolimeryzację dwoma rodzajami światła: lampą diodową oraz lampą halogenową. Przyjęto czas naświetlania 40 sek. oraz 60 sek. Do badań wytrzymałości został zastosowany test na zginanie trójpunktowe (TFS). Przygotowano próbki do badań w formie belek prostopadłościennych o liczności N = 20 z każdego materiału. Wyznaczono wartość średnią i odchylenie standardowe dla każdego badanego wariantu. Do oceny istotności różnic przeprowadzono analizę wariancji. Następnie wyniki każdej próby aproksymowano dwuparametrowym rozkładem Weibull'a. Obliczono parametr skali rozkładu (jako wytrzymałość charakterystyczną) oraz parametr kształtu (jako wskaźnik niezawodności materiału). Wykazano, że w warunkach testu na 3-punktowe zginanie rodzaj lampy nie ma wpływu na wytrzymałość w przypadku kompozytu opartego na siloranach, natomiast umożliwia poprawę jego niezawodności. W przypadku konwencjonalnych materiałów opartych na metakrylanach zastosowanie lampy diodowej w miejsce lampy halogenowej obniża wytrzymałość materiału, jednak zwiększa jego niezawodność. Ponadto wykazano, że zwiększenie czasu naświetlania - w przypadku materiału FSi i lampy halogenowej zwiększa jego wytrzymałość, natomiast nie ma wpływu na niezawodność. W pozostałych przypadkach wytrzymałość na ogół pozostaje na stałym poziomie lecz zwiększa się niezawodność materiału.
The aim of this study was evaluation of chosen photopolymerization procedures on strength and reliability of dental composites based on siloranes and composites based on methacrylate compounds in 3-points bending test conditions. The following composites were tested: Filtek Siloran (FSi), Gradia Direct Anterior (GDA), Gradia Direct Posterior (GDP), Herculite XRV (H). Photopolymerization was conducted by means of two types of light: LED lamp and halogen lamp. Exposure times of 40 and 60 seconds were applied. For the strength studies a three-point bending test was used (TFS). Twenty rectangular beam-shaped samples (N=20) from each material were prepared for the studies. For each studied case an average value and standard deviation were determined. To assess significance of differences a variation analysis was performed. Then, the results from each specimen were approximated by two-parameter Weibull distribution. Distribution scale parameter was calculated (as a characteristic strength) and shape parameter (as a material reliability index). It has been demonstrated that in 3-point bending test conditions in case of silorane-based composite the type of lamp has no impact on the strength, however it can improve its reliability. In case of conventional methacrylate-based materials application of LED lamp instead of halogen lamp reduces material strength, but increases its reliability. Additionally, it has been shown that the extension of exposure time - in case of FSi material and halogen lamp, increases material strength, however it has no impact on reliability of the material.
Źródło:
Eksploatacja i Niezawodność; 2012, 14, 3; 249-255
1507-2711
Pojawia się w:
Eksploatacja i Niezawodność
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Piaskowce modyfikowane związkami krzemoorganicznymi oraz zmiany ich porowatości i wytrzymałości na zginanie pod działaniem siły skupionej
Sandstones modified with silico-organic compounds and changes of their porosity and flexural strength under concentrated load
Autorzy:
Rembiś, M.
Powiązania:
https://bibliotekanauki.pl/articles/183708.pdf
Data publikacji:
2010
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
piaskowce
strukturalne wzmacnianie
porowatość
wytrzymałość na zginanie
sandstones
structural strengthening
porosity
flexural strength
Opis:
Piaskowce pochodzące z 24 złóż usytuowanych w różnych regionach geologicznych Polski zaimpregnowano przy użyciu stosowanych w praktyce konserwatorskiej płynnych preparatów polimerowych do wzmacniania kamienia, w których substancją czynną są estry etylowe kwasu ortokrzemowego. Produkty ich kondensacji, utworzone w trakcie sezonowania zaimpregnowanych próbek piaskowców, charakteryzują się zróżnicowanym wykształceniem mikrostrukturalnym. Ograniczyły one porowatość piaskowców oraz zmieniły strukturę ich przestrzeni porowej. W znacznym stopniu zdeterminowało to efekt wzmocnienia, wyrażony wielkością ich wytrzymałości na zginanie pod działaniem siły skupionej. Wyraźną zmianę wartości tego parametru należy wiązać z przekroczeniem w piaskowcach, głównie liasowych, ciosowych i istebniańskich, progowej wielkości stężenia oligomerów tetraetoksysilanu (progu perkolacji). Zachodzi ono w przypadku zmniejszenia ich porowatości o 41-66%. Próg perkolacji nie został natomiast osiągnięty w części zaimpregnowanych piaskowców magurskich, krośnieńskich i godulskich, w których porowatość zmniejszyła się o wartość nieprzekraczającą 10%. W takich przypadkach wielkość wytrzymałości na zginanie pozostaje na takim samym poziomie jak przed impregnacją.
The sandstone samples representing 24 deposits localized in various geological regions of Poland were impregnated with liquid polymers, in which esters of the orthosilicic acid are active agents. Such preparations are commonly applied as stone strengtheners in conservation practices. The products of condensation of these polymers formed in the course of seasoning of the impregnated stone samples for 4 weeks have developed diversified microstructures. Their presence has lowered the porosity of the sandstones and changed the structure of the rock pore spaces. As a result, the sandstones have been strengthened as indicated by their values of the flexural strength under concentrated load. A distinct change of this parameter should be linked to exceeding of the threshold value of tetraetoxysilan oligomers concentration (percolation threshold) in the sandstones in question, mainly in their Liassic, Cretaceous and Istebna varieties. It has taken place in the samples with the porosity lowered at 41-66%. The percolation threshold has not been achieved in this part of the impregnated Magura, Krosno and Godula sandstones, in which their porosity has decreased at the value not exceeding 10%. In these cases, the value of the flexural strength under concentrated load remains at the same level as it was measured prior to impregnation.
Źródło:
Geologia / Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie; 2010, 36, 1; 67-108
0138-0974
Pojawia się w:
Geologia / Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Zeolit jako dodatek do zapraw i betonów
Zeolite as an additive for mortars and concretes
Autorzy:
Pietras, Maria
Konkol, Janusz
Powiązania:
https://bibliotekanauki.pl/articles/2067651.pdf
Data publikacji:
2020
Wydawca:
Politechnika Częstochowska
Tematy:
zeolite
mortar
flexural strength
compressive strength
fractography
zeolit
zaprawa
wytrzymałość na zginanie
wytrzymałość na ściskanie
fraktografia
Opis:
Zeolity są obecnie coraz częściej wykorzystywane w różnych dziedzinach przemysłu. Wnioski z licznych badań wskazują jednoznacznie na ich korzystne właściwości, które znajdują zastosowanie m.in. w budownictwie. Celem artykułu jest opisanie wpływu zeolitów na właściwości kompozytów cementowych oraz przedstawienie wyników badań własnych. Badanie przeprowadzono na zaprawie z dodatkiem zeolitu w ilości 10% masy cementu, określając wytrzymałość na zginanie i ściskanie po 3, 7 i 28 dniach dojrzewania. Przeprowadzono także badania fraktograficzne na uzyskanych w badaniu wytrzymałości na zginanie powierzchniach przełomów.
Nowadays, zeolites are being used more and more in various fields of industry. Conclusions from numerous studies indicate their favourable properties for use in construction and architecture. The aim of the article is to provide a description of zeolites` influence on the properties of cement composites and to present the author’s own test results. The tests were conducted on mortar with the addition of zeolite in the amount of 10% cement weight, and determined the flexural and compressive strength, after 3,7 and 28 days of curing. Some fractographic research was also conducted on the obtained results from the flexural strength test, and surface breakthroughs.
Źródło:
Zeszyty Naukowe Politechniki Częstochowskiej. Budownictwo; 2020, 26 (176); 149-155
0860-7214
Pojawia się w:
Zeszyty Naukowe Politechniki Częstochowskiej. Budownictwo
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of photopolymerization parameters on the mechanical properties of polymer : ceramic composites applied in the conservative dentistry
Autorzy:
Pieniak, D.
Niewczas, A. M.
Walczak, M.
Zamościńska, J.
Powiązania:
https://bibliotekanauki.pl/articles/951821.pdf
Data publikacji:
2014
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
kompozyt
materiał stomatologiczny
wypełnienie stomatologiczne
mikrotwardość
dental fillings
polymer-ceramic composites
flexural strength
microhardness
Opis:
In this paper the results of study of mechanical properties for four commercial polymer-ceramic composites applied in the conservative dentistry are presented, including one new silorane based composite and three standard composites based on methacrylate compounds. Influence of the type of light of diode and halogen polymerization lamps on the microhardness, flexural strength and elasticity were studied. Both exposed and unexposed specimens were taken into account. An exposure time was also differentiated (40 sec and 60 sec). Basic statistics of the analysed material parameters were determined. A post hoc test (Newman-Keuls) was performed in order to evaluate differences between microhardness of the studied materials, as well as Kruskal-Wallis test to evaluate differences in flexural strength and elasticity modulus of the material. It has been indicated that there is an impact of the type of lamp on the microhardness and flexural strength of composites with methacrylate matrix and lack of such impact in case of composites containing siloranes. Additionally, it has been found that an increase of photopolymerization time has a significantly different impact on the mechanical properties depending on the type of irradiated material.
Źródło:
Acta of Bioengineering and Biomechanics; 2014, 16, 3; 29-35
1509-409X
2450-6303
Pojawia się w:
Acta of Bioengineering and Biomechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
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