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Tytuł:
Effect of geotextile reinforcement on shear strength of sandy soil: laboratory study
Autorzy:
Denine, S.
Della, N.
Muhammed, R. D.
Feia, S.
Canou, J.
Dupla, J.-C.
Powiązania:
https://bibliotekanauki.pl/articles/178921.pdf
Data publikacji:
2016
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
sand
behaviour
geotextile
undrained
confining pressure
excess pore pressure
strength ratio
Opis:
This paper presents results of a series of undrained monotonic compression tests on loose sand reinforced with geotextile mainly to study the effect of confining stress on the mechanical behaviour of geotextile reinforced sand. The triaxial tests were performed on reconstituted specimens of dry natural sand prepared at loose relative density (Dr = 30%) with and without geotextile layers and consolidated to three levels of confining pressures 50, 100 and 200 kPa, where different numbers and different arrangements of reinforcement layers were placed at different heights of the specimens (0, 1 and 2 layers). The behaviour of test specimens was presented and discussed. Test results showed that geotextile inclusion improves the mechanical behaviour of sand, a significant increase in the shear strength and cohesion value is obtained by adding up layers of reinforcement. Also, the results indicate that the strength ratio is more pronounced for samples which were subjected to low value of confining pressure. The obtained results reveal that high value of confining pressure can restrict the sand shear dilatancy and the more effect of reinforcement efficiently.
Źródło:
Studia Geotechnica et Mechanica; 2016, 38, 4; 3-13
0137-6365
2083-831X
Pojawia się w:
Studia Geotechnica et Mechanica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effects of Hydrated Lime on Moisture Susceptibility of Asphalt Concrete
Autorzy:
Al-Marafi, Mohammad Nour Ibrahim
Powiązania:
https://bibliotekanauki.pl/articles/2024016.pdf
Data publikacji:
2021
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
indirect tensile strength
modified asphalt mixture
nano hydrated lime
tensile strength ratio
moisture damage
Opis:
Moisture damage is one of the most critical distresses affecting asphalt pavement. The use of mineral fillers such as hydrated lime can increase the moisture resistance of the asphalt mixtures. In this study, the effects of hydrated lime (HL) and nano hydrated lime (NHL) were investigated on the moisture susceptibility of modified asphalt mixtures. The asphalt mixtures were modified using HL and NHL with varying percentages of each additive. The indirect tensile strength (ITS) test was performed to investigate moisture susceptibility. This test was carried out with three types of asphalt mixtures including, normal asphalt mixture without additives, modified asphalt mixture with HL, and modified with NHL. The results showed that the addition of HL and NHL as mineral fillers enhanced the performance of the mixtures against moisture damage. The highest increase in ITS value under dry conditions was observed in the modified mixtures with 20% HL and 20% NHL, and under wet conditions it was observed at 30% HL and 20% NHL. The results also indicated that the addition of 20% HL and 30% NHL increased the value of tensile strength ratio (TSR) by 78.6% and 70.6%, respectively.
Źródło:
Advances in Science and Technology. Research Journal; 2021, 15, 2; 13-17
2299-8624
Pojawia się w:
Advances in Science and Technology. Research Journal
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
First ply failure analysis of laminated composite beam for different boundary conditions under thermo mechanical loading
Autorzy:
Choudhury, Arnab
Mondal, Samar Chandra
Sarkar, Susenjit
Powiązania:
https://bibliotekanauki.pl/articles/264855.pdf
Data publikacji:
2020
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
współczynnik wytrzymałości
włókno
współczynnik kształtu
kompozyty
first ply failure load
fiber orientation angle
aspect ratio
hybrid composite beam
strength ratio
Opis:
Failure analysis of a laminated composite beam subjected to uniformly distributed load and thermal load is studied for different boundary conditions and fiber orientation angles, based on first ply failure load. Three different boundary conditions are studied: simply supported, fixed-fixed and fixed-free. The strength ratio is computed and compared for different failure theories. The effect of fiber orientation angle and aspect ratio on the strength ratio based on first ply failure load is presented in the paper. The strength ratio and transverse deflection are determined for Graphite/Epoxy and Glass/Epoxy composite and their hybrid combinations to find out the optimum hybrid composite beam with minimum weight, deflection and cost. The problem is solved in MATLAB platform. The mode of failure of the composite beam is determined by using maximum stress theory.
Źródło:
International Journal of Applied Mechanics and Engineering; 2020, 25, 1; 12-26
1734-4492
2353-9003
Pojawia się w:
International Journal of Applied Mechanics and Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Failure analysis of laminated composite plate under hygro-thermo mechanical load and optimisation
Autorzy:
Choudhury, A.
Mondal, S. C.
Sarkar, S.
Powiązania:
https://bibliotekanauki.pl/articles/264515.pdf
Data publikacji:
2019
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
współczynnik wytrzymałości
kompozyt hybrydowy
obciążenia
first ply failure load
last ply failure load
strength ratio
fiber orientation angle
hybrid composite
Opis:
Failure analysis of laminated composite plates for different mechanical, thermo mechanical and hygro-thermo mechanical loads for different ply thicknesses, stacking sequences, fiber orientation angles and composite material systems is presented in the paper. A comparative study of different failure theories is also presented in the paper. The effect of fiber orientation angles on the first ply failure load is also studied. A hybrid composite laminate is developed based on the first ply failure load which minimizes weight and cost. The last ply failure load based on fully discounted method is calculated for different stacking sequences. An optimum composite material system and laminate layup is studied for a targeted strength ratio which minimizes weight.
Źródło:
International Journal of Applied Mechanics and Engineering; 2019, 24, 3; 509-526
1734-4492
2353-9003
Pojawia się w:
International Journal of Applied Mechanics and Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Polymer matrix composite laminate under hygrothermal exposure
Autorzy:
Kormaníková, E.
Powiązania:
https://bibliotekanauki.pl/articles/131582.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Komisja Inżynierii Budowlanej PAN Oddział w Katowicach
Tematy:
polymer matrix composites
laminate plate
hygrothermal model
mechanical characteristics
thermal strength of ratio
moisture strength of ratio
internal forces
kompozyty z osnową polimerową
płyta laminowana
model higrotermiczny
właściwości mechaniczne
wytrzymałość cieplna
wilgotność
siły wewnętrzne
Opis:
The static load model of laminate with the hygrothermal load is considered in the paper. The corresponding ply properties are calculated using Mori-Tanaka method. A parametric study is conducted by varying the fiber volume fraction in one laminate layer and the fiber orientation of the angle plies in the laminate. The internal forces of laminate plate with symmetric and unsymmetric stacking of layers are investigated.
Źródło:
Roczniki Inżynierii Budowlanej; 2016, 16; 49-54
1505-8425
Pojawia się w:
Roczniki Inżynierii Budowlanej
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Undrained shear and pore space characteristics of treated loose sands with lime-activated zeolite in saturated settings
Autorzy:
Jamhiri, Babak
Pakbaz, Mohammad Siroos
Powiązania:
https://bibliotekanauki.pl/articles/1838092.pdf
Data publikacji:
2020
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
lime alkali
compressive strength
shear strength
void ratio
pore water pressure
B-ratio
wapno alkaliczne
wytrzymałość na ściskanie
wytrzymałość na ścinanie
ciśnienie wody
Opis:
This research investigates the mechanical behavior of artificially cemented sandy soils formed by lime alkali activation of natural zeolite under saturation settings. In order to verify the bar capability of cemented sands with this new method, an analysis of the undrained shear strength of the soil with pore water pressure ratio measurements was performed from the interpretation of the results of unconfined compression tests. The effect of zeolite-lime blend on treated sands was also visualized by scanning electron microscopy. For the studied soils, it was concluded from the unconfined compression stress values that the soil is fully capable of withstanding compressions due to overburden pressure. Additionally, this study seeks to evaluate the effect of the void ratio on the pore space and undrained shear strength. The results showed that pore water B-ratio increases with the decrease of the void ratio. Moreover, with the increase of zeolite content, confining pressure, and curing age, the peak failure strength increases. The results indicated a promising consistency of treated samples with lime and zeolite under various values of undrained shearing and B-ratios, making this method an ideal treatment for loose sand deposits.
Źródło:
Civil and Environmental Engineering Reports; 2020, 30, 2; 105-132
2080-5187
2450-8594
Pojawia się w:
Civil and Environmental Engineering Reports
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Stress-strain response of sheared wheat granular material stored in silos using triaxial compression tests
Autorzy:
Zeng, C.
Gu, H.
Wang, Y.
Powiązania:
https://bibliotekanauki.pl/articles/2082870.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Instytut Agrofizyki PAN
Tematy:
wheat granular
void ratio
confining pressure
shearing velocity
strength
dilatancy
Opis:
Wheat granular material stored in silos usually suffers shearing loads, which induces complex stress-strain response during the silo filling and discharging process. In order to guarantee the safe storage of these granular materials, it is necessary to investigate the shearing behaviour of wheat granular material in silos. In this paper, a series of triaxial tests were conducted on wheat granular material by using a modified double cell triaxial system. The stress-strain responses including the volumetric strain behaviour were examined considering the effect of the initial void ratio, confining pressure and shearing velocity. Different shearing states were discussed to obtain their strength parameters in various conditions. The results show that the shearing characteristics of wheat granular material are influenced by the shearing velocity. The friction angles increase with the decreasing void ratio at different states. The final volumetric strain decreases with increasing confining pressure, and the dilation is diminished. The dilatancy behaviour was quantitatively evaluated based on Row’s theory for wheat granular material. The stress-strain relationship of wheat granular material was then determined.
Źródło:
International Agrophysics; 2020, 34, 1; 103-114
0236-8722
Pojawia się w:
International Agrophysics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of storage time and temperature on Poisson ratio of tomato fruit skin
Autorzy:
Kuna-Broniowska, I.
Gladyszewska, B.
Ciupak, A.
Powiązania:
https://bibliotekanauki.pl/articles/25051.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Instytut Agrofizyki PAN
Tematy:
storage time
storage temperature
Poisson ratio
tomato
fruit skin
material strength
plant cultivar
greenhouse tomato
Opis:
The results of studies investigating the effects of storage time and temperature on variations in Poisson ratio of the skin of two greenhouse tomato varieties – Admiro and Encore were presented. In the initial period of the study, Poisson ratio of the skin of tomato fruit cv. Admiro, stored at 13°C, varied between 0.7 and 0.8. After the successive 10 days of the experiment, it decreased to approximately 0.6 and was stabilized until the end of study. By contrast, the skin of tomatoes cv. Encore was characterized by lower values and lower variability of Poisson ratio in the range of 0.4 to 0.5 during storage. The examinations involving tomato fruit cv. Admiro stored at 21°C were completed after 12 days due to fruit softening and progressive difficulty with preparing analytical specimens. The value of Poisson ratio for both varieties stored at roomtemperature fluctuated throughout the experiment to approximate 0.5.
Źródło:
International Agrophysics; 2012, 26, 1
0236-8722
Pojawia się w:
International Agrophysics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Parametry wytrzymałościowe fluidalnego popiołu lotnego z Elektrowni „Połaniec”
Mechanical Properties of Fluidized Fly Ash from Power Station “Połaniec
Autorzy:
Gruchot, A.
Zydroń, T.
Gałowicz, E.
Powiązania:
https://bibliotekanauki.pl/articles/1818638.pdf
Data publikacji:
2015
Wydawca:
Politechnika Koszalińska. Wydawnictwo Uczelniane
Tematy:
fluidalny popiół lotny
wytrzymałość na ścinanie
wskaźnik nośności CBR
wytrzymałość na ściskanie
budownictwo drogowe
fluidized fly ash
shear strength
CBR ratio
compressive strength
road construction
Opis:
Production of electricity and heat energy in Poland is largely based on the combustion of coal and lignite in power plants. Combustion of coal is associated with the production of significant quantities of wastes. Given the possibilities of their using, the most important product of combustion is fly ash and recently – fluidized fly ash. Tests on properties of fluidized fly ash are mainly focused on determining the impact of its addition on the mechanical properties of concrete or the setting time of self-hardening slurries, while little is known about its mechanical parameters. The aim of the study was to determine the impact of density, moisture content and maintenance duration on shear strength, CBR ratio and compressive strength of fluidized fly ash from Power Plant "Połaniec". The study was performed in terms of assessing their possibility of use for the purpose of road construction. CBR ratio was determined at three various values of moisture content determined from compaction curve of the fly-ash. CBR ratio tests were done for samples directly after compaction and after 4 days of the soaking in water. Shear strength was determined in a direct shear apparatus on samples compacted at a moisture content close to the optimum and three values of the compaction index IS = 0.90, 0.95 and 1.00. Determination of compressive strength was carried out on samples immediately after preparation and after 7, 14, 28 and 42 days of air, air-water and air-water maintenance process including 3, 7, and 14 cycles of freezing and de-freezing. The results revealed that in accordance with the geotechnical nomenclature the tested fluidized fly-ash's grain-size distribution corresponds to sandy silts. The fly-ash has high value of maximum dry density. CBR ratio of fly-ash samples after 4 days of soaking in water were very high and ranged from 199 to 277%. It can be underline that in case of both tests series, the obtained CBR indexes were positively correlated with increasing initial moisture content of tested samples. The parameters of the shear strength were high. It was stated that the higher values of compaction indexes, the higher values of the angle of internal friction and cohesion were obtained. The compressive strength of samples was high, ranging from over 2.2 MPa to approximately 6.0 MPa. The largest increase in strength was obtained after 7 days of maintenance. The maximum values of compressive strength after 42 days of maintenance, were obtained for samples which were subjected to air and air-water maintenance process. Freeze-thaw resistance index value obtained for a short 3 cycles of freezing and de-freezing process was greater than 1.0, which means that tested fly-ash was not prone to freezing process. Increasing number of freezing and de-freezing cycles affected the freeze-thaw resistance index value, which was well below 1.0, indicating a significant loss of compressive strength. To sum up, the test results on the fluidized fly ash from Power Plant "Połaniec" revealed that the fly-ash has good compaction properties, bearing capacity and shear strength. In contrast, the particle size of the fly-ash is unfavorable from the viewpoint of its use in road embankments. In turn, the results of the CBR and compressive strength tests confirmed the presence of hydration properties of fluidized fly ash thus indicating the possibility of its use in road hydraulic binders.
Źródło:
Rocznik Ochrona Środowiska; 2015, Tom 17, cz. 2; 1622-1641
1506-218X
Pojawia się w:
Rocznik Ochrona Środowiska
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Porównanie charakterystyk różnych wytrzymałości betonu żwirowego o zmiennym wskaźniku w/c
Comparison of different strength characteristics of gravel concrete with variable index w/c
Autorzy:
Fic, S.
Szewczak, A.
Powiązania:
https://bibliotekanauki.pl/articles/390089.pdf
Data publikacji:
2017
Wydawca:
Politechnika Lubelska. Wydawnictwo Politechniki Lubelskiej
Tematy:
współczynnik w/c
wytrzymałość na uderzenie
współczynnik intensywności naprężeń
w/c ratio
impact strength
stress intensity coefficient
Opis:
Beton, jako uniwersalny, kompozytowy materiał, jest eksploatowany w konstrukcjach pod wpływem różnych, złożonych obciążeń statycznych, dynamicznych, wpływom środowiska zewnętrznego, np. nagłe uderzenia, temperatura, wilgotność. Zapewnienie konstrukcjom betonowym bezpiecznej eksploatacji i trwałości to zadania stawiane w okresie projektowania polegające na wykonaniu badań mieszanek i próbek betonowych. Badania służą jak najdokładniejszemu odwzorowaniu pracy betonu w warunkach naturalnych z uwzględnieniem obciążeń w czasie eksploatacji. Badania betonu w laboratorium dotyczą ustalenia wytrzymałości na ściskanie (fc), rozciąganie (fct); w obszarze trwałości: mrozoodporności, odporności na korozję, wpływu wysokiej temperatury, nasiąkliwości. W przypadku trwałości betonu ustala się zmianę dynamicznego modułu sprężystości Ed, współczynnik intensywności naprężeń (KIC), lub wpływ obciążeń dynamicznych na trwałość i wytrzymałość betonu – obecnie badania te stanowią prężnie rozwijającą się grupę testów, co ma także związek z pojawianiem się nowych rodzajów cementów, kruszyw a w konsekwencji betonów nowej generacji, tj. BWW, BUWW, BSZ. Poszukuje się również możliwości modyfikacji i zwiększenia trwałości tradycyjnych betonów. Niewątpliwie, na wszystkie w/w cechy betonu decydujący wpływ ma wskaźnik w/c, jako główny parametr strukturotwórczy definiujący układ matryca-kruszywo. W artykule przedstawiono analizę porównawczą kilku cech wytrzymałościowych betonu, w zależności od w/c (wartości 0,4-0,7). Przyjęto stałą ilość kruszywa grubego (żwiru). Analizowano wpływ wskaźnika w/c na: fc, fct, KIC, Ei betonu żwirowego.
Concrete, as a universal, composite material, is used in structures under the influence of various static, dynamic loads, influences of the external environment, such as sudden impacts, temperature, humidity. Ensuring concrete constructions for safe operation and durability are tasks placed in the design phase, consisting in the testing of mixtures and concrete samples. The studies serve as the most accurate representation of concrete in natural conditions, taking into account the loads during operation. Concrete testing in the laboratory relates to the determination of the compressive strength (fc), the tensile strength (fct); in the area of durability: frost resistance, corrosion resistance, influence of high temperature, absorbability. In the case of concrete durability, the dynamic modulus of elasticity Ed, the stress intensity index (KIC), or the impact of dynamic loads on the durability and strength of concrete are determined – nowadays, they are a rapidly growing test group, which is also related to the emergence of new types of cements, aggregates and consequently new generation concrete, i.e. HSC, UHSC, HPC. Also looking for opportunities to modify and enhance the durability of traditional concrete. Undoubtedly, for all of the aforementioned features of the concrete, the w/c ratio is the decisive factor as the main structural parameter defining the matrix system – aggregate. The paper presents comparative analysis of several strengths of concrete, depending on w/c (values of 0.4-0.7). A fixed amount of aggregate (gravel) was assumed. The influence of the w/c ratio on: fc, fct, KIC, Ei of gravel concrete was analyzed.
Źródło:
Budownictwo i Architektura; 2017, 16, 3; 155-166
1899-0665
Pojawia się w:
Budownictwo i Architektura
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-10 z 25

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