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Tytuł:
Assessment of Fly Ash from Thermal Treatment of Sewage Sludge According to the Applicable Standards
Autorzy:
Rutkowska, Gabriela
Powiązania:
https://bibliotekanauki.pl/articles/24201787.pdf
Data publikacji:
2023
Wydawca:
Polskie Towarzystwo Inżynierii Ekologicznej
Tematy:
fly ash
sewage sludge
physical and chemical properties
concrete
compressive strength
heavy metals
Opis:
The restrictions on carbon dioxide emissions introduced by the European Union encourage experimental work on new generation materials containing smaller amounts of clinker. Currently, silica fly ash from the combustion of hard coal is widely used in cement and concrete technology in Europe and in Poland. Their wide application is mainly determined by their chemical and phase composition, especially pozzolanic activity, their high fineness, similar to cement. The aim of the research was to assess the properties of fly ash from thermal treatment of sewage sludge in terms of use in concrete technology in relation to EN 450-1, ASTM-C618-03 and ASTM C379-65T. The obtained test results confirm that the tested material has a different physicochemical composition and does not meet the requirements related to the use of ash in the production of concrete. In addition, the research showed the possibility of producing ordinary concrete, modified with fly ash from thermal treatment of sewage sludge. The average compressive strength for concrete containing 15% of ash from Cracow was set at 48.1 MPa and 49.2 MPa after 28 and 56 days of maturation, for ash from Warsaw at 42.0 MPa and 45.1 MPa, and for ash from Łódź at 36.2 MPa and 36.2 MPa. The determined concentrations of heavy metals are below the maximum values to be met when discharging waste water into the ground or water, the leaching limits required for accepting inert waste for disposal and for substances particularly harmful to the aquatic environment. On this basis, it was found that the migration of heavy metals from concretes with ash addition to the aquatic environment is insignificant and should not be a significant problem.
Źródło:
Journal of Ecological Engineering; 2023, 24, 3; 20--34
2299-8993
Pojawia się w:
Journal of Ecological Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparative analysis of natural nanosilica versus commercial nanosilica on compressive strength and durability of high-performance concrete
Autorzy:
Tjahjani, A.R. Indra
Fulazzaky, Mohamad Ali
Jonbi, Jonbi
Tinumbia, Nuryani
Meutia, Wita
Suraedi, Daral
Ranna, Prima
Powiązania:
https://bibliotekanauki.pl/articles/27312142.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
nanokrzemionka
materiał naturalny
materiał komercyjny
wytrzymałość na ściskanie
trwałość
beton wysokiej wytrzymałości
materiał ekologiczny
natural material
commercial material
nanosilika
compressive strength
durability
high performance concrete
eco-friendly material
Opis:
This study provides a comparative analysis of natural nanosilica (NSn), which is an extract of natural silica sand processed into nanosilica with commercial nanosilica (NSc) derived from semiconductor industrial waste, in 80 MPa high performance concrete (HPC). The percentage of using nanosilica is (3%, 5%, 10%, 15%) by weight of cement used directly and combined with 5% silica fume. Analysis was carried out through compressive strength test, durability through permeability test, rapid chloride penetration test (RCPT), and microstructure test through scanning electron microscopy (SEM). The results of the analysis show that natural nanosilica is equivalent to commercial nanosilica, in applications it is better to use silica fume incorporation. The optimum percentage of using NSn10% and (SF) 5%, while 5% NSc and 5% SF, in these proportions shows the best compressive strength and durability. It’s just that the use of natural nanosilika is 5% more than commercial nanosilika. The benefit of this research is that natural materials such as silica sand with high SiO2 content, can be processed into nanosilica as an advanced material, which can be used as an eco-friendly construction material.
Źródło:
Archives of Civil Engineering; 2023, 69, 3; 49--63
1230-2945
Pojawia się w:
Archives of Civil Engineering
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:
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:
Efficiency comparison of mixture formulations in the stabilisation/solidification of the loess silt contaminated with zinc in terms of mechanical properties
Autorzy:
Lal, Agnieszka
Fronczyk, Joanna
Franus, Małgorzata
Powiązania:
https://bibliotekanauki.pl/articles/27314384.pdf
Data publikacji:
2023
Wydawca:
Politechnika Lubelska. Wydawnictwo Politechniki Lubelskiej
Tematy:
loess silt
alternative binder
activator
unconfined compressive strength
Opis:
The effectiveness of various types of binders in stabilizing/solidifying (S/S) contaminated soils is strongly dependent on the type of soil and contaminants present. The literature abounds with studies of stabilisation/solidification of clayey soils, which provides a background for initial assumptions in design of the method application for contamination of this type of soil. However, studies on the stabilisation/solidification of loess silt contaminated with heavy metals are not available. Filling this deficiency is important in order to ensure the rapid adoption of the most effective remedies in case of contamination and their immediate implementation in the subsoil. This paper has enabled the determination of the most effective mixture among the examined for the remediation of loess silt contaminated with zinc in terms of compressive strength. Strengths were determined with the implementation of 30% Portland cement (2.63 MPa), 30% of fly ash-cement mixture (2.21 MPa), an incinerated sewage sludge ash-cement mixture (0.93 MPa) and mixtures in which cement was replaced by an MgO activator (0.18 MPa for fly ash and 0.63 MPa for incinerated sewage sludge ash). In addition, the determination of strength was carried out for samples containing a mixture of fly ash, activator and cement (0.26 MPa) and incinerated sewage sludge ash, activator and cement (0.26 MPa), with weight ratios of 5:4:1 respectively. In summary, fly ash and cement in a 2:1 ratio can be considered the most effective binding mix in terms of unconfined compressive strength increase.
Źródło:
Budownictwo i Architektura; 2023, 22, 1; 25--35
1899-0665
Pojawia się w:
Budownictwo i Architektura
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of ground waste glass addition on concrete prepared with their participation properties
Autorzy:
Jeleniewicz, Katarzyna
Rutkowska, Gabriela
Żółtowski, Mariusz
Kula, Dorota
Powiązania:
https://bibliotekanauki.pl/articles/29521052.pdf
Data publikacji:
2023
Wydawca:
Akademia Morska w Szczecinie. Wydawnictwo AMSz
Tematy:
sustainable development
glass waste
concrete
properties
frost resistance
compressive strength
Opis:
Caring for the environment, in accordance with the principles of sustainable development, as well as the increase in the standard of living of society, introduces the need to conduct proper waste management. Construction is an industry with great potential for the management of glass waste as part of material recycling. The construction sector is characterized by high material consumption, with a limited amount of natural resources, meaning that research is constantly being performed on the possibility of replacing them with other common ingredients. A feature of the building materials industry is also the pursuit of continuous improvement of the properties of manufactured materials. The paper presents the research results on the impact of the partial replacement of Portland cement and aggregate with glass waste on strength parameters and frost resistance. For the purpose of experimental work, a concrete mix based on the C20/25 standard concrete with CEM I 42.5R Portland cement, in which from 0 to 20% of the cement or aggregate weight is replaced with glass waste (i.e., glass flour and glass cullet), is designed. In the test range, the glass flour slightly affected the deterioration of the compressive strength, while the glass cullet had no effect on the compressive strength after 56 days of maturation. Moreover, the addition of glass flour increases the bending strength, while the addition of glass cullet maintains a comparable bending strength compared to the reference concrete. The obtained concretes are frost-resistant concrete F150.
Źródło:
Zeszyty Naukowe Akademii Morskiej w Szczecinie; 2023, 73 (145); 46-53
1733-8670
2392-0378
Pojawia się w:
Zeszyty Naukowe Akademii Morskiej w Szczecinie
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Investigating the effects of nano-blast furnace slag powder on the behaviour of composite cement materials
Autorzy:
Kadhim, M. J.
Hasan, L. M.
Kamal, H. M.
Powiązania:
https://bibliotekanauki.pl/articles/24200642.pdf
Data publikacji:
2023
Wydawca:
Stowarzyszenie Komputerowej Nauki o Materiałach i Inżynierii Powierzchni w Gliwicach
Tematy:
environmentally friendly cement
nano-blast furnaces slag
cement substitute
compressive strength
water absorption
cement
żużel wielkopiecowy
substytut cementu
wytrzymałość na ściskanie
absorpcja wody
Opis:
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.
Źródło:
Journal of Achievements in Materials and Manufacturing Engineering; 2023, 116, 1; 5--10
1734-8412
Pojawia się w:
Journal of Achievements in Materials and Manufacturing Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Natural jute laminate for the improvement of strength properties of concrete specimen
Autorzy:
Zulfikar, Achmad Jusuf
Yaakob, Mohd Yuhazri
Umarfaruq, Hel Mee
Syah, Rahmad
Powiązania:
https://bibliotekanauki.pl/articles/38912467.pdf
Data publikacji:
2023
Wydawca:
Instytut Podstawowych Problemów Techniki PAN
Tematy:
natural fiber composite
jute fabric
compressive strength
splitting tensile strength
vacuum bagging.
Opis:
In the last decade, the exploration and investigation of natural ingredients as alternative materials for metal substitutes have been continuously conducted to produce eco-friendly products with sufficiently good strength. The climate and geography of countries like Indonesia provide that such materials are available abundantly and can be easily replanted. Thus, these materials have considerable potential for application in various products. The purpose of this study is to analyze the compressive and tensile strength of a cylindrical column concrete structure reinforced externally with laminate composite materials derived from jute fabric sheets. The specimen manufacturing method uses a vacuum bagging technique with the specimen size specified in the ASTM C39 test standard. After manufacturing, the specimens underwent the treatment of immersion in clean water for 28 days, followed by drying at room temperature for additional 28 days. The column concrete specimens were wrapped with laminate composite materials with variations in several layers of jute fabric. Compressive strength and splitting tensile tests were conducted according to ASTM C39 and ASTM C496 test standards, respectively. The test results showed that applying laminate composite sheaths on the outer surface of the column concrete structure resulted in an increase in strength of up to 100% for both compressive strength and splitting tensile strength. The magnitude of such an increase in strength is reported in this article.
Źródło:
Engineering Transactions; 2023, 71, 4; 507-518
0867-888X
Pojawia się w:
Engineering Transactions
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ocena wybranych właściwości mechanicznych i fizycznych akrylowych cementów kostnych o niskiej lepkości
Evaluation of the mechanical and physical properties of low viscosity acrylic bone cements
Autorzy:
Zając, Zuzanna
Łagan, Sylwia
Liber-Kneć, Aneta
Powiązania:
https://bibliotekanauki.pl/articles/52936092.pdf
Data publikacji:
2023
Wydawca:
Politechnika Śląska. Katedra Biomechatroniki
Tematy:
cement kostny
wytrzymałość na ściskanie
zwilżalność
bone cement
compressive strength
wettability
Opis:
Celem pracy było porównanie właściwości mechanicznych i fizycznych powierzchni cementów kostnych stosowanych w ortopedii. Właściwości mechaniczne określono za pomocą statycznej próby jednoosiowego ściskania, kąt zwilżania wyznaczano przy użyciu goniometru optycznego, a swobodną energię powierzchniową obliczono według modelu Owensa-Wendta. Rozpatrzono dwa stany materiału (początkowy i po inkubacji). Proces inkubacji zmienił charakter powierzchni na hydrofilowy i spowodował wzrost wartości składowej polarnej swobodnej energii powierzchniowej. Otrzymane krzywe ściskania dla badanych stanów są podobne, ukazując obszar liniowy, jak i plastyczny, z umowną granicą plastyczności.
The aim of this work was comparison mechanical and physical properties of bone cements used in human and animal orthopedics. The mechanical properties were determined by compression tests, a contact angle was observed with a goniometer and the surface free energy was calculated by Owens-Wendt model. Two states of material (initial and after incubation) were considered. The incubation process changed the nature of the surface to hydrophilic and caused an increase in the polar component of the surface free energy. The obtained compression curves are similar, showing both linear and plastic regions, with an conventional yield point.
Źródło:
Aktualne Problemy Biomechaniki; 2023, 23; 35-42
1898-763X
Pojawia się w:
Aktualne Problemy Biomechaniki
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optimizing the Width and Compressive Strength of Artificial Protective Pillar in the Mining of Medium-Thick Coal Seams in Quang Ninh Using the Numerical Model
Autorzy:
Bui, Manh Tung
Dinh, Van Cuong
Powiązania:
https://bibliotekanauki.pl/articles/27323230.pdf
Data publikacji:
2023
Wydawca:
Polskie Towarzystwo Przeróbki Kopalin
Tematy:
medium thick coal seam
entry gate road
artificial support pillar
pillar width
compressive strength
górnictwo
filary
koszty
Opis:
Currently, in many countries with the coal mining industry, the technology of using artificial pillars has been successfully applied to replace coal pillars to protect the entry gate road, thereby reducing the rate of resource loss, as well as the cost of entry gate road, and mining costs. However, in order to optimize the required width and compressive strength of artificial pillars with thickness, slope angle and mining depth, more detailed studies are required for each specific geological condition. This research uses Phase 2 numerical simulation software to analyze the stability of artificial protective pillar of the roadway prepared in the mining of medium-thick coal seams in the Quang Ninh coal region (Vietnam). The research results show that the relationship between the width of the artificial pillar and the slope angle follows the rule of a linear function. The size of the artificial protection pillar increases according to the mining depth. When the mining depth is 350m, the size of the pillar changes from 1.0 ÷ 2.4m, and to 1.4 ÷ 2, 8m at a depth of 500m. When the slope angle increases, the required pillar width also increases. That is due to the fact that at a large slope angle, the pressure acting on the pillar is not at the center, but deflects to the side adjacent to the entry gate road that needs to be protected, the compression force is not distributed evenly. The required compressive strength of the artificial pillar varies according to the condition of the slope angle, when the seam slopes 10°, the required compressive strength is from 8 to 12 MPa, when the slope angle increases to 20°, the required compressive strength of the pier increases to 18 ÷ 28 Mpa, but when the slope angle increases to 35°, the required compressive strength of the pillar tends to decrease to 16 ÷ 17 MPa. Thus, when operating in the corresponding conditions, it is necessary to choose the size and required compressive strength of the artificial pillar to ensure the working capacity of the pillar.
Źródło:
Inżynieria Mineralna; 2023, 2; 143--154
1640-4920
Pojawia się w:
Inżynieria Mineralna
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Performance of self-compacting concrete cast in hot weather conditions
Autorzy:
Khalil, Hossam S.
Abd Elhameid, Mohamed W.
Badawy, Amal A.
Powiązania:
https://bibliotekanauki.pl/articles/36065966.pdf
Data publikacji:
2023
Wydawca:
Szkoła Główna Gospodarstwa Wiejskiego w Warszawie. Wydawnictwo Szkoły Głównej Gospodarstwa Wiejskiego w Warszawie
Tematy:
self-compacting concrete
rheological properties
compressive strength
splitting tension
silica fume
fly ash
hot weather
casting
retarder
Opis:
This work focused on how self-compacting concrete (SCC) performs in situ in hot weather conditions at an ambient temperature of about 35°C. Tests for the rheological properties and compressive and splitting tensile strength aspects were carried out. The results of SCC mix ingredients on the rheological and hardened features of SCC mix were studied. Variations in the amount of portland cement content (CC), water to cement ratio (w/c), coarse to fine aggregate ratio (C : F), chemical admixture ratio, and pozzolanic admixture ratio were considered. Optimum values were obtained for these ingredients, which satisfied the SCC rheological characteristics and gave a 28-day compressive strength of 42 MPa, and 52 MPa after 28 days and 56 days, respectively. These optimum constituent values were 450 kg·m–3 of cement, 0.45 water cementitious ratio, and a coarse to fine material ratio of 1 : 0.8, a high range superplasticizer of 2%, and a mineral admixture of either 5% silica fume or 25% fly ash as a substitute for a similar amount cement.
Źródło:
Scientific Review Engineering and Environmental Sciences; 2023, 32, 3; 284-302
1732-9353
Pojawia się w:
Scientific Review Engineering and Environmental Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Review of basic equations for evaluating drilling efficiency
Przegląd podstawowych równań oceny wydajności wiercenia
Autorzy:
Mehtiyev, Rafail K.
Tanriverdiyev, Yusif A.
Powiązania:
https://bibliotekanauki.pl/articles/31348240.pdf
Data publikacji:
2023
Wydawca:
Instytut Nafty i Gazu - Państwowy Instytut Badawczy
Tematy:
rock matrix
compressive stress
tensile stress
rock strength
drilling velocity
hardness coefficient of rock
matryca skalna
naprężenie ściskające
naprężenie rozciągające
wytrzymałość skały
prędkość wiercenia
współczynnik twardości skały
Opis:
The main goal of the reviewed article is to provide statistically determined relationships between the parameters of disintegration processes and the properties of rocks. The results of theoretical and experimental studies are discussed and analysed in the article. In relation to drilling, the formulas of drilling speed, depending on various parameters as an indicator that fully reflects the efficiency of the process, are given and compared. Thus, the drilling speed for percussion drilling is related to the characteristics of the rock and, at the same time, taking into account the constructional characteristics of the drilling tool. In percussion drilling, a new formula for drilling speed is presented, considering each impact and the frequency of the impact. The expression for the drilling speed was determined taking into account the degree of crushing of the rock matrix during drilling. Thus, the drilling speed is determined by considering the contact strength of the rock being drilled in the mechanical drilling method. The distribution of the stress state in the drilling zone was determined. Also, the shape and development characteristics of the cracks formed in the rock during the operation of the drilling tool (especially the dynamic percussions of the tool in the bottom zone of the well) were investigated. It should be noted that the energy intensity of the drilling process in the rock was determined by studying the next stages of the process of breaking the rock. The technical and economic indicators of the drilling works have been evaluated. Corresponding mathematical formulas are presented as a reliable calculation of drilling rates. The relevant mechanical and geophysical properties of the excavated rocks were considered. In the article, the drilling tools are selected depending on the drilling method, physical-mechanical properties of the rocks and geological conditions of the rock mass. The results of the obtained studies can be used in the design of the technological parameters of the drilling. The observations and results expressed in the article have a theoretical and practical aspect.
Głównym celem recenzowanego artykułu jest przedstawienie statystycznie określonych zależności między parametrami procesów rozwiercania a właściwościami skał. W artykule omówiono i przeanalizowano wyniki badań teoretycznych i eksperymentalnych. W odniesieniu do wiercenia podano i porównano wzory prędkości wiercenia w zależności od różnych parametrów jako wskaźnika w pełni odzwierciedlającego efektywność procesu. Zatem prędkość wiercenia przy wierceniu udarowym jest związana z charakterystyką skały i jednocześnie uwzględnia cechy konstrukcyjne narzędzia wiertniczego. Dla wiercenia udarowego przedstawiono nowy wzór na prędkość wiercenia uwzględniający każde uderzenie i częstotliwość uderzenia. Wyrażenie na prędkość wiercenia wyznaczono z uwzględnieniem stopnia zmiażdżenia matrycy skalnej podczas wiercenia. Tak więc prędkość wiercenia jest określana z uwzględnieniem wytrzymałości kontaktowej skały wierconej metodą wiercenia mechanicznego. Określono rozkład stanu naprężeń w strefie wiercenia. Zbadano również kształt i charakterystykę pęknięć powstających w skale podczas pracy narzędzia wiertniczego (zwłaszcza dynamicznych udarów narzędzia w strefie dennej otworu). Należy zaznaczyć, że energochłonność procesu wiercenia w skale została wyznaczona poprzez badanie kolejnych etapów procesu kruszenia skały. Tym samym dokonano oceny wskaźników techniczno-ekonomicznych prac wiertniczych. Odpowiednie wzory matematyczne przedstawiono jako rzetelny schemat obliczania postępu wiercenia. Uwzględniono odpowiednie właściwości mechaniczne i geofizyczne wydobytych skał. W artykule dokonano doboru narzędzi wiertniczych w zależności od metody wiercenia, właściwości fizyko-mechanicznych skał oraz warunków geologicznych górotworu. Wyniki uzyskanych badań mogą być wykorzystane w projektowaniu parametrów technologicznych prac wiertniczych. Przedstawione w artykule obserwacje i wyniki mają aspekt teoretyczny i aplikacyjny.
Źródło:
Nafta-Gaz; 2023, 79, 10; 670-677
0867-8871
Pojawia się w:
Nafta-Gaz
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The effect of air-entraining agent on the properties of mortars
Wpływ domieszki napowietrzającej na właściwości zapraw
Autorzy:
Blikharskyy, Zinoviy
Markiv, Taras
Sobol, Khrystyna
Turba, Yurii
Selejdak, Jacek
Powiązania:
https://bibliotekanauki.pl/articles/27312161.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
domieszka napowietrzająca
mrozoodporność
trwałość
wytrzymałość na ściskanie
zaprawa
air entraining agent
compressive strength
durability
frost resistance
mortar
Opis:
The effect of the air-entraining agent on properties of mortar mixtures as well as on the compressive strength of hardened mortars was the objective of this study. Such mortars contain a certain amount of evenly spread closed air-voids pores with dimensions of 0.02-0.05 mm. On the one hand, the presence of a large volume of such air bubbles results in the reduction of mechanical properties of mortar. On the other hand, the use of this technological approach improves rheological properties of mortar mixture. The effect of the air entrainment on the flow, density, volume of entrained air of mortar mixture and compressive strength of hardened mortar was established. Obtained results show substantial increasing in the mortar flow at cement to sand ratio 1:2 by 1.8 times. The further decrease of C:S ratio results in a slight increase of the flow and even negligible its decrease at C:S = 1:4 compared to the reference mortar. The increase of the volume of entrained air results in the decrease of the density and compressive strength of mortar, but improve the resistance to freezing/thawing cycles. The results of this study can be a guide for mortar mix design to choose the most appropriate mix proportion to produce economically efficient mortars.
Celem badań był wpływ domieszki napowietrzającej na właściwości mieszanek zaprawowych oraz wytrzymałość na ściskanie zapraw. Zaprawy takie zawierają pewną ilość równomierne rozprowadzonych, zamkniętych porów powietrznych o wymiarach 0,02–0,05 mm. Z jednej strony, obecność dużej ilości takich pęcherzyków powietrza powoduje obniżenie właściwości mechanicznych zaprawy. Z drugiej strony, zastosowanie tego podejścia technologicznego poprawia właściwości reologiczne mieszanki zaprawy. Określono wpływ domieszki napowietrzającej na urabialność, gęstość, objętość wprowadzonego powietrza oraz wytrzymałość na ściskanie zaprawy. Uzyskane wyniki wskazują na znaczny, 1,8-krotny wzrost rozpływu zaprawy przy stosunku cementu do piasku 1:2. Dalsze zmniejszanie stosunku C:S powoduje niewielki wzrost urabialności, a nawet znikomy jego spadek przy C:S = 1:4 w porównaniu do zaprawy wzorcowej. Wzrost objętości wprowadzonego powietrza powoduje zmniejszenie gęstości i wytrzymałości na ściskanie zaprawy, ale poprawia mrozoodporność. Wyniki badań mogą być wskazówką przy projektowaniu zapraw, aby wybrać najbardziej odpowiednie proporcje mieszanki w celu wytworzenia ekonomicznie efektywnych zapraw.
Źródło:
Archives of Civil Engineering; 2023, 69, 3; 147--156
1230-2945
Pojawia się w:
Archives of Civil Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ultrasonic P- and S-Wave Reflection and CPT Soundings for Measuring Shear Strength in Soil Stabilized by Deep Lime/Cement Columns in Stockholm Norvik Port
Autorzy:
Lindh, Per
Lemenkova, Polina
Powiązania:
https://bibliotekanauki.pl/articles/31339810.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
civil engineering
soil stabilization
compressive strength
cement
lime
seismic waves
Opis:
In this research project, the measurements of the ultrasonic P- and S-waves and seismic cone penetration testing (CPT) were applied to identify subsurface conditions and properties of clayey soil stabilized with lime/cement columns in the Stockholm Norvik Port, Sweden. Applied geophysical methods enabled to identify a connection between the resistance of soil and strength in the stabilized columns. The records of the seismic tests were obtained in the laboratory of Swedish Geotechnical Institute (SGI) through estimated P- and S-wave velocities using techniques of resonance frequency measurement of the stabilized specimens. The CPT profiles were used to evaluate the quality of the lime/cement columns of the reinforced soil by the interpretation of signals. The relationship between the P- and S-waves demonstrated a gain in strength during soil hardening. The quality of soil was evaluated by seismic measurements with aim to achieve sufficient strength of foundations prior to the construction of the infrastructure objects and industrial works. Seismic CPT is an effective method essential to evaluate the correct placement of the CPT inside the column. This work demonstrated the alternative seismic methods supporting the up-hole technology of drilling techniques for practical purpose in civil engineering and geotechnical works.
Źródło:
Archives of Acoustics; 2023, 48, 3; 325-346
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Water absorption, impact resistance and strength reliability of concrete incorporating sintered fly ash aggregate under drop weight impact load
Autorzy:
Baskaran, Ranjith Babu
Nagarajan, M.
Powiązania:
https://bibliotekanauki.pl/articles/38891513.pdf
Data publikacji:
2023
Wydawca:
Instytut Podstawowych Problemów Techniki PAN
Tematy:
sintered fly ash aggregate
water absorption
compressive strength
impact test
reliability analysis
Opis:
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.
Źródło:
Engineering Transactions; 2023, 71, 2; 197-211
0867-888X
Pojawia się w:
Engineering Transactions
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-15 z 216

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