BazTech - Yadda

1

Wpływ rodzaju popiołu na wybrane właściwości wytworzonych na ich bazie mieszanin wodnych

Pierzyna Piotr

Rynek Energii

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2024

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Nr 1

69--74

PL

W artykule przedstawiono możliwość zastosowania w górnictwie podziemnym dwóch rodzajów popiołów lotnych pochodzących z energetyki zawodowej spalającej węgiel kamienny. Badaniom podano mieszaniny wytworzone z popiołów lotnych pochodzących z kotła konwencjonalnego bez produktów odsiarczania spalin (10 01 02) oraz kotła fluidalnego z produktami odsiarczania spalin (10 01 82). Mieszaniny sporządzono wykorzystując wodę kopalnianą o gęstości 1023 g/dm3. Badane mieszaniny miały konsystencję płynną o rozlewności w zakresie 160-280 mm. Mając na uwadze uzyskane wyniki badań oraz wytyczne normy PN-G 11011:1998 należy stwierdzić, że w zakresie omawianych parametrów mieszaniny wytworzone na bazie popiołu pochodzącego z kotła fluidalnego (10 01 82) spełniają jej wymagania w zakresie rozlewności 160-240 mm, jedynie w technologii doszczelniania. W technologii podsadzki zestalanej żadna z zbadanych mieszanin nie spełnia ww. normy. Ponadto stosując w górnictwie podziemnym mieszaniny z popiołu lotnego bez produktów odsiarczania spalin pochodzącego z kotła konwencjonalnego należy dokładnie rozważyć jego możliwość, technologię w której ma być stosowany, a przede wszystkim miejsce jego aplikacji.

EN

The paper presents the possibility of using two types of fly ash from utility power plants burning hard coal in underground mining. Mixtures made from ﬂy ash from a conventional boiler without ﬂue gas desulphurisation products (10 01 02) and a fluidised bed boiler with ﬂue gas desulphurisation products (10 01 82) were tested. The mixtures were prepared using mine water With a density of 1023 g/dm3. The tested mixtures were of liquid consistency with a ﬂowability of 160-280 mm Taking into account the obtained test results and guidelines of the PN-G 11011:1998 standard, it should be stated that, in terms of the discussed parameters, mixtures produced on the basis of ash from the ﬂuidised bed boiler (10 01 82) meet its requirements in the range of ﬂowability of 160-240 mm, only in the case of the backﬁlling technology. In solidifying backﬁll . technology, none of the mixtures tested comply with the aforementioned standard. In addition, when using ﬂy ash mixtures without ﬂue gas desulphurisation products from a conventional cat (10 01 02) in underground mining, careful consideration must be given to its feasibility, the technology in which it is to be used and, above all, where it is to be applied.

2

Management of fly ash from biomass combustion

Maj Izabella

Rynek Energii

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2024

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Nr 1

75--81

EN

The efficient management of biomass fly ash is a key factor for the circular economy. Fly ash is produced in large quantities during biomass combustion and may be utilized for various applications, for both environmental and financial benefits. The main limitation of biomass fly ash utilization is its unrecognized potential caused by a lack of consistent law regulations. In this paper, possible paths of biomass fly ash management are discussed. The compositions of 4 fly ashes derived from biomass combustion in Polish units are presented, together with 2 examples of phosphorous-rich ashes. The five most promising ways of management are elaborated: concrete and cement production, phosphorous recovery and fertilizers, composites, ceramics, and sorbents. The latest state-of-the-art research regarding each path is briefly reviewed and current law regulations are introduced. Limitations for the safe management of biomass ash are also discussed.

PL

Zagospodarowanie popiołów lotnych z biomasy jest ważnym elementem gospodarki o obiegu zamkniętym (GOZ). Popiół lotny powstaje W znacznych ilościach podczas spalania biomasy, a jego odpowiednie zagospodarowanie może przynieść zarówno korzyści dla środowiska, jak i oszczędności finansowe. Głównym ograniczeniem wykorzystania popiołów lotnych z biomasy jest brak odpowiednich uregulowań prawnych, co powoduje również słabe rozpoznanie możliwości użycia popiołów. W artykule przedstawiono składy 4 popiołów lotnych pochodzących ze spalania biomasy W polskich obiektach energetyki zawodowej oraz 2 przykłady popiołów szczególnie bogatych w fosfor. Omówiono pięć najbardziej obiecujących sposobów wykorzystania: produkcja betonów i cementu, odzysk fosforu i zastosowanie jako nawozy, składnik kompozytów, materiały ceramiczne oraz sorbenty. Przedstawiono aktualne regulacje prawne oraz dokonano krótkiego przeglądu najnowszych badań dotyczących poszczególnych ścieżek. Omówiono także ograniczenia w zakresie bezpiecznego zagospodarowania popiołów z biomasy.

3

Badania nad przygotowaniem nowego ekologicznego granulatu ceramicznego dla budownictwa

Wang Yifei

Przemysł Chemiczny

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2023

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T. 102, nr 8

795--798

PL

Poferment z fermentacji biomasy (DR) i popiół lotny (FA) zmieszano z biowęglem z osadów ściekowych (SSC) w stosunku 10:10:80 i spiekano w temp. 1050°C. Produkt został zgranulowany z przeznaczeniem na materiały budowlane i przetestowany zgodnie z chińskimi normami krajowymi. Wszystkie wskaźniki jakości granulatu spełniły wymagania chińskich norm krajowych dla granulatu budowlanego. Wskaźnik potencjalnego ryzyka ekologicznego związanego z obecnością metali ciężkich był niski, a produkt był bezpieczny.

EN

Biomass fermentation digestate and fly ash were mixed with sludge biochar in the ratio of 10:10:80 and sintered at 1050°C. The product was pelletized to building materials and tested according to China national stds. All the qual. indicators of the pellets met the requirements of the China national stds. for construction pellets. The potential ecol. risk index of heavy metals was low, and the product was safe.

4

Performance of self-compacting concrete cast in hot weather conditions

Khalil Hossam S., Abd Elhameid Mohamed W., Badawy Amal A.

Przegląd Naukowy Inżynieria i Kształtowanie Środowiska

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2023

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Vol. 32, No. 3

284--302

EN

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.

5

Wytrzymałość na zginanie oraz ściskanie materiałów geopolimerowych otrzymanych z wykorzystaniem odpadów poprodukcyjnych

Kaźmierowski Hubert, Prałat Karol, Koper Artur

Przegląd Budowlany

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2023

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R. 94, nr 7-8

147--150

PL

Artykuł przedstawia wstępne wyniki badań wytrzymałości na zginanie oraz ściskanie innowacyjnych materiałów geopolimerowych. Geopolimery zostały wykonane według dwóch receptur. Pierwszy produkt był próbą kontrolną (odniesienia), a drugi - próbą modyfikowaną (docelową). Przedstawione zostały również wyniki badań gęstości otrzymanych materiałów budowlanych. Wykazano możliwości zastąpienia czystych chemicznie substratów w procesie geopolimeryzacji materiałami odpadowymi.

EN

The article presents the preliminary results of bending and compressive strength tests of innovative geopolymer materials. Geopolymers were made according to two recipes. The first product was the control (reference) sample and the second was the modified (target) sample. The results of density tests of the obtained building materials were also presented. The possibilities of replacing chemically pure substrates in the geopolymerization process with waste materials have been demonstrated.

6

Semi-quantitative analysis study of the impact of microwave treatment on fly ash

Ma Xian Yun, Nie Yi Miao, Guo Jia Le, Chen Yang, Chang Zhen Jia, Wang Ling, Liu Shu Xian, Wang Long

Physicochemical Problems of Mineral Processing

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2023

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Vol. 59, iss. 6

art. no. 174897

EN

Pre-processing provides an effective way for fly ash's high value-added utilization. However, the shortcomings of pre-processing methods such as grinding and flotation are apparent with many disadvantages that make it more challenging to use efficiently. Microwave heating helps the SiO2-Al.2O3 bond break, not only can make the structural change of the material can also promote the chemical reaction process. In the article, XRD, SEM, FT-IR, ammonia nitrogen adsorption, and other methods were used to analyze the changes in the properties of fly ash before and after microwave pre-treatment, the change in adsorption performance of fly ash before and after microwave treatment was analyzed. The study found that under microwave conditions of 600 W and 15 min, the adsorption rate of ammonia nitrogen by fly ash reached a maximum of 29.67%. The intensity of mullite and amorphous diffraction peaks decreased after 20 min at 600 W. The Si-O-(Si, Al) and Si-O-(Si) bonds showed significant changes at 15 min and 20 min under 600 W conditions. Based on the results, the microwave conditions were selected at 600 W for different periods, and semi-quantitative analysis was carried out by XRD-Rietveld, infrared peak fitting, and nuclear magnetic resonance. The XRD-Rietveld analysis showed that the amorphous phase content reached 46.18% at 15 min. In the infrared peak fitting, the fitting area at 1300-900 cm-1 and 600-400 cm-1 peaks at 56.92% at 25 min and 17.5% at 15 min, respectively. The silicon-oxygen network's degree of connection and polymerization was reduced after 15 min of microwave treatment for the nuclear magnetic resonance analysis. By combining specific surface area measurements, it was discovered that the maximum specific surface area attained a value of 3.122 m2/g at 15 min.

7

Wybrane właściwości gruntowych materiałów kompozytowych jako materiału konstrukcyjnego do budowy niskich nasypów obwałowań przeciwpowodziowych

Brzeziński Bartłomiej, Olchawa Andrzej, Wierzbicka Marianna

Materiały Budowlane

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2023

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nr 6

32--36

PL

W artykule przedstawiono wyniki badań laboratoryjnych właściwości fizycznych i mechanicznych (zagęszczalności, ściśliwości, przewodności hydraulicznej oraz wytrzymałości na ścinanie) gruntowych materiałów kompozytowych stanowiących mieszaninę torfu, popiołu lotnego i wapna hydratyzowanego. W świetle uzyskanych wyników, parametry geotechniczne wszystkich kompozytów są porównywalne, co stanowi, że o przydatności materiału może decydować kryterium roboczego przedziału wilgotności.

EN

The paper presents the results of laboratory tests of physical and mechanical properties (compaction, compressibility, hydraulic conductivity, and shear strength) of ground composite materials made of peat, fly ash and hydrated lime. The results showed that the geotechnical parameters of the all composites are comparable. Given to these properties it may be accepted that range of working moisture is most usefulness parameter to assessment of composite as an embankment construction material.

8

Study of the possibility of using sulfur asphalt and sulfur concrete in road construction

Bieliatynskyi Andrii, Yang Shilin, Krayushkina Kateryna, Shao Meiyu, Ta Mingyang

Materials Science Poland

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2023

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Vol. 41, No. 2

244--262

EN

The introduction of new effective road construction materials for pavements and foundations of highways is an urgent task, including the development and application of resource-saving technologies aimed at the use of low-demand, large-tonnage mineral materials, semi-finished products, industrial waste, and their by-products. Research on this topic has shown that sulfur and sulfur-containing waste, as well as modified technical sulfur when used as a binder, should be widely used in sulfur structural and road concrete in liquid, granular, or lumpy form. Ferrous cakes from the Pobug Nickel Plant or “tailings” of sulfur ore flotation can be used as fillers for sulfur binder. Having a high specific surface, they will have a positive effect on the structure formation of sulfur during the crystallization of the melt in the direction of strengthening the structure. Their high acid resistance should significantly increase the corrosion resistance of sulfur concretes. Granular slag from a metallurgical plant can be used as a fine aggregate. Overburden rocks in the form of gabbro-dolerites, dolerites, and basalts can be used as acid-resistant large aggregates. To reduce the fragility of the sulfur binder, plasticizing additives such as naphthalene, chlorinated paraffin, and bitumen can be introduced. The results obtained in this study confirm a decrease in the cost in the production of asphalt and cement concrete and the possibility of expanding the range of building materials with new road-building mixtures. Also, the test results showed that when temperature was decreased, the strength characteristics of sulfur concrete in the temperature range 0°C to −60°C increased by 7%. Low water absorption of sulfur concrete (0.1%–0.3%) versus cement concrete (2%–4%), which positively affected the strength and operational characteristics, was revealed.

9

Residual fly ash from pyrometallurgical processes as a partial replacement for Portland cement in mortars: a study of structural evolution and determination of compressive strength

Juarez-Tapia J. C., García-Ortiz H., Pérez-Labra M., Romero-Serrano J. A., Reyes-Pérez M., Hernández-Ramirez A., Acosta-Sanchez V., Teja-Ruiz A. M., Reyes-Dominguez I.A.

Materials Science Poland

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2023

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Vol. 41, No. 4

120--131

EN

Mortar mixtures were prepared by partial replacement of Portland cement with 0%, 10%, and 15% of residual fly ash to determine the structural evolution and compressive strength at 3, 7, 14, and 28 days. Portlandite, calcite, ettringite, iron oxide, silicon oxide, and sillimanite were identified in the standard mortar, and, additionally, magnetite was identified in the mortar with 10% and 15% fly ash. X-ray diffraction peaks corresponding to portlandite and ettringite increased in intensity with increasing curing time as a result of the consolidation of mineral species. The SEM analysis revealed that the standard mortar contained mainly portlandite and ettringite at 28 days, while the samples with 10% and 15% fly ash contained particles of fly ash coated with portlandite and ettringite, particles with a smooth surface, and particles of fly ash with signs of attack on their surfaces. The sc increased when the age of the mortar and the substitution of Portland cement by fly ash was increased from 3 to 28 days and from 0 to 15%, respectively.

10

Hydration, Microstructure, and Properties of Fly Ash–Based Geopolymer: A Review

Khawaji Mohammad

Materials Science Poland

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2023

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Vol. 41, No. 2

263--287

EN

Geopolymers have gained attention as a potential eco-friendly alternative to Portland cement, primarily due to their reduced carbon dioxide emissions and the opportunity to repurpose industrial waste materials. Fly ash (FA), a byproduct of coal combustion, has been favored as a raw material for geopolymer concrete owing to its widespread availability and high concentrations of alumina and silica. The development and application of fly ash–based geopolymer concrete can contribute significantly to production of sustainable construction materials. An in-depth analysis of fly ash–based geopolymer concrete has been conducted to explore its potential as a substitute for traditional concrete. This review encompasses the underlying reaction mechanism, strength, long-term durability, and microstructural characteristics of geopolymer concrete. The present review paper shows that adding the optimal quantity of fly ash improves the performance of fly ash–based geopolymer when exposed to extreme durability conditions, as well as improving strength properties. The microstructural analysis shows that when fly ash is added, the microstructure of the concrete matrix would be dense and packed. However, challenges remain in adopting fly ash–based geopolymer concrete for large-scale construction projects, as the existing literature presents inconsistencies in the reported strength, durability, and test results. Further research is necessary to consolidate knowledge on the behavior and mechanism of fly ash–based geopolymer concrete and to ultimately provide comprehensive data to support its widespread implementation in the construction industry.

11

Gravity and electrostatic separation of unburned coal from a selected fly ash

Wierzchowski Krzysztof, Klupa Agnieszka, Białecka Barbara, Całus Moszko Joanna

Journal of Sustainable Mining

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2023

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Vol. 22, iss. 1

33--40

EN

Unburned coal grains make it difficult to use fly ash economically, which causes energy losses in the fuel. The article presents the possibilities of separating unburned coal from selected fly ash. In order to assess the possibility of separation of unburned carbon, the analysis of grain density and ash composition was used. Unburned coal was separated by four methods – one wet gravity and three dry methods. It has been found that despite very fine ash grains, the quality and quantity of separation products are significantly dependent on the separation method used and the separated grains’ qualitative characteristics. The analysis of the coal grains under an electron microscope has revealed that they contain mineral inclusions. Their presence enables selective separation of carbon without first grinding the middling grains. The most advantageous results of the separation of unburned coal were obtained by the electrostatic separation method. Separated coal can be used in high-value carbon applications.

12

Studies on Adsorption of Petroleum Products under Static Conditions

Sabadash Vira, Lysko Vitaliy

Journal of Ecological Engineering

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2023

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Vol. 24, nr 10

40--46

EN

This paper provides an overview of the adsorption of petroleum products, focusing on various aspects such as adsorbent types, mechanisms of adsorption, factors influencing efficiency, kinetics, equilibrium, practical applications, and environmental implications. It explores the properties and characteristics of adsorbents, including activated carbon, zeolites, clay minerals, silica gel, and others, highlighting their interaction with petroleum products. The article delves into the theories and mechanisms governing the adsorption process, discussing physical and chemical adsorption as well as the role of forces like van der Waals, hydrogen bonding, and electrostatic interactions. The results of experimental investigations were conducted to evaluate the adsorption capacities of various adsorbents for petroleum products. The adsorption performance, kinetics, and equilibrium behavior of different adsorbents were analyzed, providing insights into their effectiveness in removing petroleum contaminants from aqueous solutions. The adsorption kinetics and equilibrium studies were explored through mathematical models like Langmuir and Freundlich isotherms. The practical applications of adsorption in the petroleum industry were discussed, including removing pollutants from wastewater, gas and diesel purification, and desulfurization. The environmental implications of adsorption technology in mitigating oil spills and reducing petroleum-related pollution were addressed. The conclusion emphasizes the significance of these studies in enhancing understanding, developing efficient solutions, and addressing environmental challenges associated with the petroleum industry. Ongoing research in this field aims to further improve adsorption processes for a more effective and sustainable approach.

13

Characteristics of Silica Powder Extracted from Fly Ash of Coal Fired Power Plant – Effect of Heat Treatment Process

Nurmalita Nurmalita, Abdulmadjid Syahrun Nur, Setiawan Adi, Idroes Rinaldi, Jalil Zulkarnain

Journal of Ecological Engineering

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2023

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Vol. 24, nr 9

282--292

EN

Fly ash waste is a by-product of coal burning at PLTU Nagan Raya, Aceh Province, Indonesia. Since 2017, the coal used is a mixture of 90% Kalimantan coal (sub-bituminous) and 10% local Nagan Raya coal (lignite) which is still young so that the mineral ash content is still high. Silica is among the interesting minerals to be extracted from fly ash, given its wide range of benefits. This paper describes the process of extracting silica from fly ash at the Aceh power plant through the leaching method using a chemical solution and heating for 2 and 4 hours at a temperature of 100˚C. The difference in heat treatment aimed to study the changes in properties and obtain the best method in the silica extraction process. The effect of heat treatment on silica characteristics was studied based on X Ray Diffraction (XRD) test for phase identification, Scanning Electron Microscopy (SEM) test for morphological identification, Energy Dispersive X-Ray Spectroscopy (EDS) test for mineralogy element identification, Fourier Transform Infra-Red (FTIR) test for identification of functional groups and surface chemistry, and differential calorimetric analysis/ thermogravimetric (DSC/TGA) test for identification of thermal properties. As a result, it was found that fly ash still contains unburned carbon, which significantly affects its color, and has the potential for application as a hydrogen storage material because its pore diameter structure is larger than 0.7 nm. The silica extracted from fly ash is capable of achieving a purity of up to 87% and exhibits excellent thermal stability, especially at temperatures between 120–300 °C; thus, it has the potential to be a catalyst material in the adsorption-desorption reaction of hydrogen by magnesium, although further research is still needed.

14

Assessment of Fly Ash from Thermal Treatment of Sewage Sludge According to the Applicable Standards

Rutkowska Gabriela

Journal of Ecological Engineering

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2023

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Vol. 24, nr 3

20--34

EN

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.

15

Research of Building the Reasonable Mixing Ratio between Waste Rock and Fly Ash as Backfill Material in Mongduong-Cocsau Area, Quang Ninh, Vietnam

Nguyen Phi Hung, Nguyen Cao Khai, Nguyen Thi Kim Thanh

Inżynieria Mineralna

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2023

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no. 2, vol. 1

257--265

EN

The coal mining industry in Quang Ninh province is primarily focused on serving thermal power plants which has resulted in a substantial amount of waste rock and ash. This way has not only narrowed the used land but also had a negative impact on the environment. However, the economic development plan for the province until 2030 emphasizes the development of a greener economy. Therefore, balancing between economic growth and environmental protection is one of the significant challenges of this province. To solve the problem of waste rock and ash dumps, some methods have been proposed. It tends to use waste materials for backfilling the underground mines, this can help to minimize the bad impact on the environment. Additionally, Another solution is to handle the waste in abandoned mining areas, or use them as construction materials. These ways are expected to partially reduce the bad effects of waste rock and ash dumps on the environment. In the world, there are many studies on filling using waste rock and fly ash, but in Vietnam this issue is quite new. In order to turn waste rock and fly ash into filling materials, the article researches on a laboratory scale, the ability of transportation in hydraulic pipelines, level of the water separation and shrinkage of mixtures of rock and fly ash in the Mong Duong – Coc Sau area with the different proportions. The results of the experiments show that the area has appropriate mixing ratio as 70–73% of waste rock and 30–27% of fly ash, this ratio satisfies the transportation conditions in the pipeline and the shrinkage rate of 8, 8–12.3%. The indicators in experiments show that it is able to take waste rock into mined underground area to fill, which prevents displacement of strata from mining, protects the underground water flow, and also reduces negative impact of waste rock on environment.

16

Wpływ początkowej wilgotności mieszaniny gruntowo-popiołowej na jej właściwości

Knapik-Jajkiewicz Karolina

Inżynieria i Budownictwo

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2023

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R. 79, nr 11-12

579--582

PL

W artykule przedstawiono wyniki badań próbek mieszaniny gruntu drobnoziarnistego z dodatkiem 40% popiołu lotnego pochodzącego z procesu fluidalnego spalania węgla. Mieszaniny przygotowano z użyciem wody destylowanej, stosując wodę destylowaną w ilości potrzebnej do uzyskania wilgotności 50% i 100%. Wykonane badania obejmowały analizę termograwimetryczną, badania z wykorzystaniem dyfraktometru rentgenowskiego, badania odczynu pH oraz ściśliwości w edometrze oraz obliczenia współczynnika filtracji na podstawie badań edometrycznych. Zauważono nieznaczny wpływ wilgotności początkowej na wartość pH oraz skład fazowy mieszanin. Obliczone wartości współczynnika filtracji wskazują na większą wodoprzepuszczalność mieszanin o podwyższonej wilgotności oraz na redukcję wodoprzepuszczalności w ciągu pierwszych 7 dni niezależnie od wilgotności początkowej mieszanin. Badania edometryczne potwierdzają redukcję ściśliwości mieszanin o wilgotności 50% i 100% wraz z upływem czasu. Jednakże zastosowanie wyższych wartości obciążenia pionowego dla mieszanin o znacznej wilgotności może prowadzić do załamania struktury materiału, która uległa wzmocnieniu we wcześniejszym czasie i obserwowania znacznych przyrostów odkształcenia objętościowego wraz ze wzrostem obciążenia.

EN

This paper presents the tests results performed on samples of fine grained soil and fly ash from fluidized bed combustion, added in quantity 40%. Mixes were prepared with the use of distilled water in amount necessary to obtain water content equal to 50% and 100%. The performed tests included thermogravimetric analysis, X-ray diffraction analysis, the pH measurements, oedometer tests and calculations of permeability coefficient based on the oedometer tests. A slight effect of the initial water content on the pH value and the phase composition of the mixes were observed. The calculated values of permeability coefficient indicate higher water conductivity of the mix with high initial water content and a reduction of permeability during first 7 days of curing time, regardless of the initial water content. Oedometer tests confirm reduction of the compressibility of both mixes with 50% and 100% water content over the time. However, the use of high values of vertical load may lead to the collapse of structure previously strengthened and high volumetric strains may be observed with load increment.

17

Wpływ dodatku wapna na skład fazowy i ściśliwość mieszaniny kaolinu i popiołu lotnego

Knapik-Jajkiewicz Karolina

Inżynieria i Budownictwo

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2023

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R. 79, nr 5-6

261--266

PL

W artykule przedstawiono wyniki badań mieszanin wykonanych na bazie gruntu drobnoziarnistego z dodatkiem popiotu lotnego z fluidalnego spalania węgla w ilości 10-40% i wapna w ilosci 1-4%. Określono różnice w składzie fazowym, ściśliwości i pęcznieniu mieszanin wykonanych z udziałem i bez udziału wapna. Zauważono pozytywny wpływ wapna na uzyskane wartości maksymalnego odkształcenia objętościowego w wyniku działającego naprężenia pionowego oraz na pęcznienie mieszanin.

EN

This paper presents the tests results of mixes prepared on the basis of fine grained soil with addition of 10-40% fly ash from fluidized bed combustion and 1-4% lime. Differences in phase composition, compressibility and swelling of mixes with and without lime were determined. A positive effect of lime on the obtained values of maximum volume strains upon an acting stress was observed, as well as reduction of swelling in soil-fly ash mixes with lime.

18

Effectiveness of fly ash on the stabilization/solidification of Zn-contaminated soil

Chen Yan, Zhu Shengyuan, Fang Wei, Huang He, Qin Hao, Hu Shengtao, Wu Yuzhao

Environment Protection Engineering

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2023

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Vol. 49, nr 3

15--29

EN

As a solid waste, the associated disposal cost of fly ash is really high. Previous studies suggested that the utilization of fly ash to treat heavy metal-contaminated soils was a new cost-effective method of disposal of it. Therefore, the effectiveness of fly ash stabilized/solidified Zn-contaminated soils has been investigated by unconfined compressive strength (UCS) and toxicity characteristics leaching procedure (TCLP) tests. Quantitative analysis of the soil microstructure was conducted by processing the X-ray diffraction (XRD) and scanning electron microscope (SEM) images. Mercury intrusion porosimetry (MIP) was carried out to illustrate the size and proportion of pore size for specimens under different ratios. The results of the tests showed an improvement in the UCS, which further increased as the content of binders was raised. Binder content would have little influence on the development of strength if the binder content exceeds a threshold value. The leached Zn2+ concentration of stabilized specimens was significantly decreased compared to that of untreated. Quantitative analysis confirmed that the addition of the binders resulted in the amount of hydration product, reduction of porosity, and a really random pores orientation, which was responsible for the improvement of the strength and leaching properties of the Zn2+ contaminated soils.

19

Wytwarzanie przyjaznej dla środowiska, wysokowytrzymałej zaprawy naprawczej do renowacji obiektów zabytkowych

Tombulca Can, Çavuş Murat

Cement Wapno Beton

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2023

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R. 28, nr 3

194--205

PL

W pracy badano zaprawy naprawcze ze sztucznymi i naturalnymi dodatkami pucolanowymi do renowacji obiektów zabytkowych. Do zapraw wapiennych wprowadzono sztuczną pucolanę - popiół lotny wapienny klasy C oraz pucolanę naturalną w postaci zeolitu. Do przygotowania zapraw wykorzystano dwa różne rodzaje kruszyw: naturalny piasek rzeczny i cegłę łamaną. Łącznie wyprodukowano 18 zapraw, z czego dwie były zaprawami odniesienia. W pierwszej grupie zapraw badano popiół lotny będący główną pucolaną, w zaprawach z obu rodzajami kruszywa przy 20%, 40% i 60% zastąpieniu wapna popiołem. W drugiej serii zapraw jako zamiennika wapna zastosowano popiół lotny i zeolit w różnych proporcjach. W zaprawie odniesienia zastosowano samo wapno powietrzne. Po 28, 56 i 90 dniach dojrzewania zapraw oznaczono właściwości mechaniczne, fizyczne i skład fazowy. Porównując zaprawy z dodatkiem pucolany z zaprawami odniesienia, zauważono, że pucolany zapewniają znaczną poprawę właściwości fizycznych i mechanicznych zapraw naprawczych. O ile zaobserwowano znaczną poprawę właściwości fizycznych zapraw, w których jako jedyną pucolanę zastosowano popiół lotny, to właściwości mechaniczne były lepsze w zaprawach z zeolitem.

EN

In this study, repair mortars with artificial and natural pozzolan additives were produced for the restoration of historical buildings. Class C fly ash, an artificial pozzolan and zeolite the natural pozzolan, were substituted into these lime-based mortars. Two different aggregate types were used in the preparation of the mortars: natural river sand and crushed brick. A total of 18 batches of mortars were produced, two of which were reference batches. In the first group of batches, fly ash, which is the major pozzolan, was tested in both aggregate groups in 20%, 40%, and 60% ratios of lime substitution. In the second group of batches, fly ash and zeolite were used in different proportions as lime substitution. In the reference series, air lime was used alone. At the end of the 28, 56, and 90 days curing period, mechanical, physical properties, and phase composition of the mortars were determined. When the pozzolan-added mortars were compared with the reference mortars, it was observed that pozzolans provided significant improvements in the physical and mechanical properties of the repair mortars. While significant improvements were observed in the physical properties of the mortars where fly ash was used as the only pozzolan, mechanical properties were better in the mortars with zeolite.

20

Effects of crumb rubber and styrene-butadiene rubber additives on the properties of asphalt binder and the Marshall performance properties of asphalt mixtures

Khan Diyar, Ali Basit, Li Peilong, Hasan Mohd Rosli Mohd, Karim Fazli, Khan Noman

Budownictwo i Architektura

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2023

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Vol. 22, no 4

147--161

EN

The primary aim of this study is to evaluate the impact of incorporating crumb rubber (CR) and styrene-butadiene rubber (SBR) additives, ranging from 0% to 5% by weight of bitumen, on the performance of a bituminous concrete mixture using the wet process. Laboratory experiments, including the Marshall test, were conducted to establish the optimum bitumen content (OBC) for the hot mix. The study focuses on determining the optimal proportions of CR and SBR to achieve maximum strength. The results show that increasing the proportions of both CR and SBR leads to significant improvements in strength, with the maximum stability recorded at 16.14 kN and a flow of 1.23 mm for a mix containing 5% CR and 4% SBR. The findings further suggest an inverse relationship between CR content and strength, while an increasing SBR content enhances strength. Consequently, the optimal proportions for incorporating CR and SBR additives are identified as 5% and 4%, respectively.