Wyniki wyszukiwania - BazTech

1

Beton zbrojony włóknami pozyskanymi ze zużytych maseczek ochronnych

Szpetulski Jacek, Stawiski Bohdan, Michalska Klaudia

Przegląd Budowlany

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2024

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R. 95, nr 1-2

92--95

PL

Produkcja odpadów medycznych na świecie jest bardzo duża, co przekłada się na zaśmiecenie środowiska. W ostatnim czasie produkcja odpadów medycznych została znacznie zwiększona z powodu przeciwdziałania wirusowi SARS-CoV-2, który wywołuje chorobę zwaną COVID-19 i przyczynił się do powstania pandemii. W celu zapobiegania zarażeniu się wirusem SARS-CoV-2 stało się powszechne używanie maseczek ochronnych, a tym samym na wysypiskach przybyło w ogromnym stopniu odpadów w postaci zużytych maseczek. Wychodząc naprzeciw ochronie środowiska zaproponowano metodę przetwarzania maseczek ochronnych, w sposób umożliwiający ich powtórne użycie do produkcji fibrobetonu. W artykule zaprezentowano wyniki badań wytrzymałości na ściskanie i na rozciąganie betonu zbrojonego włóknami pozyskanymi ze zużytych maseczek ochronnych składających się z warstw włókniny polipropylenowej. Wyniki badań betonu zbrojonego włóknami stanowiącymi 0,05% objętości mieszanki betonowej oraz 0,2% objętości mieszanki betonowej porównano z wynikami betonu referencyjnego.

EN

The production of medical waste in the world is very large, which translates into environmental pollution. Recently, the production of medical waste has been significantly increased due to the counteraction of the SARS-CoV-2 virus, which causes the disease called COVID-19 and contributed to the creation of the pandemic. In order to prevent infection with the SARS-Co-V-2 virus, it has become common to use protective masks, and thus a huge amount of waste in the form of used masks has arrived in landfills. To meet environmental protection, a method of processing protective masks was proposed in a way that allows their reuse for the production of fiber-reinforced concrete. The article presents the results of testing the compressive of concrete and the tensile strength of concrete reinforced with fibers obtained from used protective masks consisting of layers of polypropylene non-woven fabric. The test results of concrete reinforced with fibers constituting 0.05% of the concrete mix volume and 0,2% of the concrete mix volume were compared with the results of the reference concrete.

2

Zależność pomiędzy przyrostem wytrzymałości na ściskanie i granicznymi naprężeniami przyczepności w okresie dojrzewania betonu - weryfikacja założeń EC2

Śliwka Andrzej, Wieczorek Barbara, Wieczorek Mirosław

Materiały Budowlane

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2024

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nr 3

6--12

PL

Podjęto badania w celu weryfikacji określania granicznych naprężeń przyczepności na podstawie chwilowej wytrzymałości betonu na ściskanie w okresie jego dojrzewania. Przedstawiono wyniki badań przyczepności prętów gładkich do betonu, które wskazują na rozwój przyczepności w okresie dojrzewania betonu proporcjonalny do rozwoju wytrzymałości na ściskanie. Porównano wyniki badań z wynikami obliczeń z wykorzystaniem wzorów empirycznych przedstawionych w EC2.

EN

Research was undertaken to verify the possibility of determining the limit stresses of adhesion on the basis of the instantaneous compressive strength of concrete during the maturation period. The results of tests on the adhesion of smooth bars to concrete are presented. Research indicates that the development of adhesion during the concrete maturation period is proportional to the development of compressive strength. The test results were compared with the results of calculations using the empirical formulas presented in EC2.

3

Ultralekki pianobeton z dodatkiem materiału zmiennofazowego do stosowania jako termoizolacja

Klemczak Barbara, Koenders Eduardus A. B., Jonkers Henk, Fachinotti Victor, Mankel Christoph, Röser Frank, Dolado Jorge S., Erkizia Edurne, Dauvergne Jean-Luc, Ortega Amaya, Zanoni Francesca, Červenka Jan, Düngfelder Michael, Stunz Christina, Zhilyaev Dmitry, Kolev Vesselin A.

Materiały Budowlane

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2024

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nr 2

45--49

PL

W artykule przedstawiono wybrane wyniki projektu NRG-STORAGE, którego celem jest opracowanie ultralekkiego pianobetonu z dodatkiem materiału zmiennofazowego (PCM), który ma zdolność do magazynowania i uwalniania ciepła. Uzyskane wyniki pokazały, że badany pianobeton o gęstości objętościowej 240 kg/m3 z dodatkiem 10% PCM charakteryzuje się wystarczającą wytrzymałością mechaniczną jako materiał termoizolacyjny, dobrymi właściwościami termofizycznymi oraz zdolnością do akumulacji i oddawania ciepła.

EN

The article presents selected results of the NRG-STORAGE project, aiming to develop ultralight foamed concrete with the addition of phase change material (PCM), which has the ability to store and release heat. The obtained results showed that the tested foamed concrete with a bulk density of 240 kg/m3 and with the addition of 10% PCM is characterised by sufficient mechanical strength for thermal insulation applications, good thermophysical properties, and the ability to accumulate and release heat.

4

Efektywność stosowania zbrojenia spoin wspornych w ściskanych murach z ABK

Drobiec Łukasz

Materiały Budowlane

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2024

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nr 1

67--68

5

The performance of CFRP-strengthened heat-damaged metakaolin-based geopolymer concrete cylinders containing reclaimed asphalt aggregate

Abadel Aref A.

Materials Science Poland

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2024

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Vol. 42, No. 2

125--142

EN

Concrete structures are extremely vulnerable to fire damage, which greatly undermines their structural strength and durability. Recently, there has been a concerted effort to develop sustainable concrete materials. Geopolymer concrete (GPC) is a promising substitute for conventional cement concrete due to its use of recycled materials. However, despite the positive effect it has on the environment, GPC is susceptible to heat, which can cause it to deteriorate over time. In response to this issue, the use of carbon-fiber reinforced polymer (CFRP) has been proposed as a means of strengthening heat-damaged GPC. This study aims to investigate the effectiveness of CFRP-strengthened heat-damaged metakaolin-based GPC made from reclaimed asphalt pavement (RAP) aggregate. Three concrete mixtures were used, in which the conventional aggregate was substituted with RAP aggregate at 0%, 25%, and 50% replacement levels. In addition, the concrete cylinders were tested under ambient conditions and subjected to 300◦C. The results indicated that the substitution with 25% RAP aggregate significantly reduced compressive strength by 39.1%, while 50% replacement resulted in a 66.8% decrease compared with the control mixture. The use of CFRP sheets to strengthen heat-damaged GPC specimens was proven to be effective in increasing the resistance of the heated specimens and restoring the compressive strength and confinement energy to their original state before reaching the ultimate failure point. The use of CFRP sheets significantly increased compressive strengths, with increases ranging from 87.7% to 368.8% at 26◦C and 58.8% to 153.9% at 300◦C, compared with each mixture’s unstrengthened control specimen.

6

The influence of nano-SiO2 emulsion on sulfate resistance of cement-based grouts

Li Shuiping, Yuan Bin, Cheng Jian, Yu Xiaocheng, Wei Chao, Wu Qisheng, Zhang Youchao

Materials Science Poland

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2024

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Vol. 42, No. 1

116--125

EN

Sulfate attack is one of the most significant durability issues for cement-based grouts, which are widely used to repair concrete structures in sulfate-rich environments. The purpose of this study was to investigate the impact of nano-SiO2 emulsion on the sulfate resistance of cement-based grouts. The durability of the mixes was evaluated on the basis of weight loss and compressive strength. X-ray diffraction (XRD) and scanning electron microscopy (SEM) of hardened grout matrix were used to analyze the hydration products and microstructure of the hardened grout matrix. The results indicate that the hydration degree of nano-SiO2-modified samples is higher than that of the control sample. The compressive strength from highest to lowest was 16 NSE, 10 NSE, NSP, and the control sample. The XRD and SEM results suggest that the deterioration of properties may be attributed to the formation and growth of ettringite (AFt) crystals, which may result in crack generation and extension and in the corrosion of gypsum, leading to exfoliation. The addition of nano-SiO2 to cement-based grouts through a preprepared emulsion, which facilitates dispersion within the cement matrix, has the potential to reduce AFt and gypsum contents, enhance microstructure density, decrease the migration channels of SO4-2, and ultimately improve the resistance to sulfate attack. This work will provide a novel route to enhance the sulfate resistance of cement-based grouts, which may be serviced in a sulfate-rich environment.

7

Enhancing durability and sustainability in concrete with fibre-reinforced composites

Salmi Abdelatif

Journal of Water and Land Development

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2024

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no. 61

48--54

EN

This paper presents a study focused on two pivotal innovations in the field of fibre-reinforced concrete (FRC) to significantly enhance its durability and sustainability in construction. First, our research investigates the application of advanced self-healing mechanisms in FRC. By embedding microcapsules containing healing agents within the concrete matrix, we achieved a remarkable reduction in crack propagation and improved structural integrity. Our results demonstrate that the self-healing FRC exhibited a 30% increase in compressive strength and a 40% reduction in crack width, leading to a longer service life for concrete structures. Second, we explore the integration of sustainable materials in FRC production. By incorporating locally sourced and recycled materials, we successfully reduced the environmental impact associated with FRC manufacturing. Our findings reveal a substantial reduction in carbon emissions, with a 25% decrease in the overall carbon footprint of FRC production. This innovation not only contributes to a greener construction industry but also aligns with sustainability goals and regulations. This research underscores the transformative potential of self-healing mechanisms and sustainable material integration in FRC, offering tangible results in terms of increased durability and reduced environmental impact. These innovations promise to reshape the construction landscape, aligning it with the principles of sustainability and long-term structural resilience.

8

Właściwości samozagęszczalnego betonu z popiołem lotnym poddanego wewnętrznej pielęgnacji

Shanmugapriyan J., Chinnaraju K.

Cement Wapno Beton

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2024

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R. 29, nr 1

2--15

PL

Właściwa pielęgnacja i optymalizacja procesu dojrzewania betonu mają znaczący wpływ na jego właściwości transportowe, co z kolei wpływa na jego właściwości mechaniczne i trwałość. W niniejszym artykule zbadano wpływ popiołu lotnego na wewnętrzną pielęgnację i właściwości mieszanki betonu samozagęszczalnego w różnych warunkach otoczenia. Do badań wybrano dwa materiały do wewnętrznej pielęgnacji: lekkie kruszywo keramzytowe [LECA] oraz polimer superabsorbujący [SAP]. Przedstawiono właściwości takie jak sorpcyjność, odporność na penetrację jonów chlorkowych oraz migrację jonów chlorkowych w próbkach betonów ze zmiennym udziałem procentowym popiołu lotnego w zakresie 30% ÷ 50% w różnych warunkach dojrzewania, mianowicie konwencjonalnym dojrzewaniu w warunkach otoczenia, dojrzewaniu z ograniczonym dostępem powietrza z dodatkami do wewnętrznej pielęgnacji oraz dojrzewaniu w warunkach otoczenia z dodatkami do wewnętrznej pielęgnacji. Wyniki wskazują, że szczelność betonu poprawiła się wraz ze zwiększeniem udziału procentowego popiołu lotnego dzięki obecności wody pochodzącej z wewnętrznej pielęgnacji, wpływającej na proces hydratacji oraz popiołu lotnego, który obniża ciepło hydratacji i skurcz spowodowany wysychaniem. Efektywność wewnętrznej pielęgnacji również poprawiła się wraz ze zwiększeniem udziału popiołu lotnego w próbkach. W warunkach otoczenia, mieszanki z zamianą popiołu lotnego powyżej 45% wykazały najlepsze właściwości mechaniczne, z powodu zmiany struktury porowatości prowadzącej do lepszych właściwości transportowych betonu [mniejszej przepuszczalności].

EN

Proper curing of concrete has a major beneficial effect on the transport properties of concrete which in turn influences its durability. This paper attempts to study the effect of fly ash on the transport properties of internally cured Self-Compacting Concrete specimens under ambient conditions. Two internal curing materials, Lightweight Expanded Clay Aggregates [LECA] and Superabsorbent Polymer [SAP] were chosen for the study. Properties such as sorptivity, resistance to chloride ion penetration and chloride ion migration specimens with varying percentages of fly ash replacement from 30% to 50% are presented under different curing conditions namely conventional curing, sealed curing with internal curing materials and ambient curing with internal curing materials. The results showed that the impermeability of concrete improved with an increasing percentage of fly ash replacements owing to the presence of internal curing water to improve hydration along with fly ash that moderates the heat of hydration and drying. The internal curing efficiency also improved with the increase in the percentage of fly ash replacement. Under ambient conditions, the mixes with fly ash above 45% replacement have shown very good mechanical and durability properties indicating a refined pore structure leading to enhanced transport properties.

9

Enhanced Concrete Performance and Sustainability with Fly Ash and Ground Granulated Blast Furnace Slag – A Comprehensive Experimental Study

Cheruvu Rajasekhar, Rao Burugupalli Kameswara

Advances in Science and Technology. Research Journal

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2024

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Vol. 18, no 3

161--174

EN

This research paper explains in detail how well regular concrete works and how well concrete with fly ash and ground granulated blast furnace slag (GGBS) as a substitute for cement. Through a series of experiments, the objective of the study is to perform an experimental approach that promote the usage of partial replacement-based concrete that can replace the conventional concrete and to promote the sustainable development. a dedicated methodology is developed for the study, focussing on the mechanical and durability properties of the materials with inducing sustainable materials. The methodology study examines at the mechanical properties, durability, and microstructural attributes of the concrete blends. Cement concrete specimens with binder ratios (%) of 0.3, 0.4, and 0.5 were tested for compressive strength, rapid chloride permeability, SEM, and XRD at 28, 56, and 90 days. Fly ash and GGBS were used to partially replace cement at 0% to 70% for all binder ratios by weight of cement. There were optimal replacement percentages for each binder ratio and fly ash and GGBS partially substituted concrete had similar or enhanced mechanical properties to conventional concrete. The novelty of the study is to incorporate microstructure analysis for the same samples that shall enable to analyse the behaviour of the partial replaced materials with conventional concrete. In connection with the results, the study had found lower RCPT values in partial replacement concrete specimens, fly ash and GGBS increased chloride ion resistance. SEM and XRD analyses revealed the concrete mixtures' microstructural properties and phase composition, showing how supplementary cementitious materials refine pore structure and provide durable hydration products. This study shows that fly ash and GGBS can improve concrete performance and reduce impact on environment and applications in construction.

10

Effect of cement dosing without additions (CPA) on high-performance and ordinary concrete based glass powder as fine partial cement replacement - a comparative study

Aissat-Arab Bahia, Mehaddene Rachid

Advances in Materials Science

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2024

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Vol. 24, nr 1(79)

17--31

EN

The main objective of this paper research is a comparative study on the effect of the glass powder (GP) substitute from collected and recycled glass waste, as a fine partial cement replacement on the mechanical performance and durability of high performance concrete (HPC) and ordinary concrete (OC). For this two cement dosing were used of 400 kg/m3 to formulate OC and 450 kg/m3 to formulate HPC, and GP as considered binder like cement and not as fine addition, hence binder represent the sum of cement with GP (L=C+GP) with which will be made our two concretes formulation. Two ratios were used for the Water/Binder (W/B), the first W/B=0.35 for the HPC and the second W/B=0.5 for the OC, this ration is very important to fix the concentration of superplasticizer. A percentage of 10% and 20% substitution of cement CPA without additions noted CEM I 52.5 by the glass powder with fineness of 3600 cm 2/g are used. The evaluation of the compressive strength was followed from 7 to 365 days in order to study the behavior of the GP at different ages affected by the cement dosing and the ratio W/B compared to the reference concrete without GP for the two concretes HPC and OC. At 28 days the strengths of concretes with GP is affected by the replacement of a quantity of cement since the two reference concretes were superior but beyond this age an inverse behavior is noticed such that results obtained at age of 365 days seem to be advantageous in terms of savings in the quantity of cement used by interpreting the compressive strength, and the decrease in quantity of water in the mixtures offers a remarkable difference between the two concretes studied by using 20 % of GP as replacement of cement.

11

Influence of ground waste glass addition on concrete prepared with their participation properties

Jeleniewicz Katarzyna, Rutkowska Gabriela, Żółtowski Mariusz, Kula Dorota

Zeszyty Naukowe Akademii Morskiej w Szczecinie

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2023

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nr 73 (145)

46--53

EN

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.

12

Effect of thermoplastic waste from production on the strength of cement mortars

Pietrzak Alina

Zeszyty Naukowe Akademii Morskiej w Szczecinie

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2023

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nr 75 (147)

42--48

EN

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.

13

Compressive and Tensile Strength of Nano-clay Stabilised Soil Subjected to Repeated Freeze–Thaw Cycles

Roustaei Mahya, Sabetraftar Mahdi, Taherabadi Ehsan, Bayat Meysam

Studia Geotechnica et Mechanica

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2023

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Vol. 45, nr 3

221--230

EN

Improvement of the mechanical properties of clayey soils by additional elements to enhance the strength under numerous freezing and thawing cycles has been considered as a serious concern for engineering applications in cold regions. The objective of the current study is to investigate the effect of nano-clay as a stabiliser on the mechanical properties of clay. To this end, the clay specimens were prepared by adding various percentages of nano-clay ranging from 0.5% to 3% by dry weight of soil and were experimentally tested under the uniaxial compression and tensile splitting tests under different curing times (0, 7 and 28 days) after experiencing various freeze–thaw cycles ranging from 0 to 11. It can be concluded from the results that nano-clay particles may be used as a stabiliser in geotechnical applications to improve soil property. The results indicate that the optimum moisture content (OMC) of specimens increases and the maximum dry density (MDD) decreases with the increasing nano-clay content. The specimens containing about 1% nano-clay recorded maximum values of unconfined compressive strength (UCS) as well as tensile strength. For example, the addition 1% nano-clay increased the UCS and tensile values of clay specimens under the curing time of 28 days by 34% and 247%, respectively. In addition, the long-term durability of specimens against freeze–thaw cycles increases further with the addition of nano-clay content ranging from 2% to 3%.

14

Use of reclaimed asphalt pavement (RAP) as aggregate for production of cement-bound granular mixtures

Majer Stanisław, Budziński Bartosz

Roads and Bridges - Drogi i Mosty

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2023

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Vol. 22, no. 4

527--532

EN

Asphalt concrete from old pavements may be reused as a semi-product in production of new bituminous mixtures or recycled in place using the cold-in-place recycling method. The first of the two above-mentioned recycling methods is appropriate when dealing with uniform materials, coming from bituminous pavements whose parameters are either known or can be reliably determined. The second method comes into play when dealing with old pavements in which the mixes used for the respective layers included different bituminous binders, typical of local roads in Poland. Smaller size jobs are an example of works for which cold-in-place recycling methods are not practicable. Fortunately, there is an option of using the old asphalt or reclaimed asphalt pavement (RAP) as aggregate in production of cement-bound mixtures. This paper describes the study on determination of their properties. These properties included density, compressive strength at different temperatures, split tensile strength and Marshall stability. The results of the relevant tests, which were carried out as part of this study, showed suitability of RAP as aggregate used for production of cement stabilised base mixtures.

PL

Destrukt asfaltowy może stanowić półprodukt w nowych mieszankach mineralno-asfaltowych jak i być wykorzystywany do mieszanek w technologii recyklingu na zimno. Pierwsza technologia jest właściwa w sytuacji kiedy destruktu jest jednorodny i pochodzi z nawierzchni o znanych lub możliwych do ustalenia parametrach. Druga technologia może być wykorzystana do przetwarzania starych nawierzchni asfaltowych, o zmiennych parametrach (różne warstwy z różnym lepiszczem), które nadal dominują na drogach lokalnych. Technologie na zimno z różnych względów nie zawsze mogą być zastosowane, np. w sytuacji, której przewidywany zakres prac jest niewielki. Alternatywą może być wykorzystania destruktu asfaltowego jako kruszywo do wykonania mieszanek stabilizowanych spoiwem. Autorzy przeprowadzili program badawczy, który miał na celu określenie parametrów mieszanek stabilizowanych spoiwem cementowym z wykorzystaniem destruktu. W badaniach określono takie cechy jak: gęstość, wytrzymałość na ściskanie w różnych temperaturach, wytrzymałość na rozciąganie przy rozłupywaniu, badanie stabilności wg Marshalla. Na podstawie przeprowadzonych badań, ustalono, że destrukt asfaltowy może zostać z powodzeniem wykorzystany jako kruszywo do produkcji mieszanki związanej spoiwem cementowym.

15

Influence of partial replacement of cement CEM I 42.5R by milled limestone on the propeties of cement pastes and mortars

Tkaczewska Ewelina

Roads and Bridges - Drogi i Mosty

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2023

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Vol. 22, no. 2

119--139

EN

Paper analyses the properties of cement pastes and mortars prepared with a mixture of Portland cement (PC) and milled limestone (ML) in the amount of 5%, 15%, 30%, 35%, 40% and 50% by weight. For cement pastes, the hydration heat, standard consistency and initial setting time were studied. For cement mortars, the compressive strength was determined. As the share of ML increases, the rate of hydration heat release decreases. Compared to control cement, cement with up to 35% ML shows similar initial setting time, while at the share of 40% and 50% ML the initial setting time is noticeably shortened. Cement containing 5% and 15% ML is in the strength class of 42.5R, while that with 30% and 35% ML is in the strength class of 32.5N. At 40% and 50% ML, cements do not meet the requirements of the PN-EN 197-1:2012 standard with respect to the strength class.

PL

Przedmiotem artykułu jest analiza właściwości zaczynu i zaprawy przygotowanych z mieszaniny cementu portlandzkiego CEM I 42,5R (CEM I) i mielonego wapienia (ML) w ilości 5%, 15%, 30%, 35%, 40% i 50% masy spoiwa. Badania właściwości zaczynów cementowych obejmowały ciepło hydratacji, konsystencję normową i początek czasu wiązania. W przypadku zapraw cementowych określono ich wytrzymałość na ściskanie. Ze wzrostem udziału wapienia następuje zmniejszenie szybkości wydzielania ciepła hydratacji. Cement zawierający do 35% ML wykazuje zbliżony czas początku wiązania w stosunku do cementu kontrolnego, natomiast przy udziale 40% i 50% ML czas początku wiązania ulega wyraźnemu skróceniu. Cement z dodatkiem 5% i 15% ML osiąga klasę wytrzymałości 42,5R, natomiast cement z dodatkiem 30% i 35% ML – jedynie klasę wytrzymałości 32,5N. Przy dodatku 40% i 50% ML cement nie spełnia wymagań normy PN-EN 197-1:2012 odnośnie klasy wytrzymałości.

16

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.

17

Effects of incorporating granite powder in the mechanical properties of concrete

Muñoz Pérez Socrates Pedro, Atoche Zamora Jorge Jr.

Przegląd Naukowy Inżynieria i Kształtowanie Środowiska

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2023

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Vol. 32, No. 1

18--33

EN

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.

18

Experimental matrix palm oil empty fruit bunch composite concrete K300 (POEFB-cc K300) as a reinforcement of concrete road structures

Fahrizal, Arifin Muhidin, Nasution Lukman Hakim, Ahmad Anuar

Przegląd Elektrotechniczny

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2023

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R. 99, nr 7

74--77

EN

Experimental matrix Palm Oil Empty Fruit Bunch K300 Composite Concrete (POEFB-CC: K300) was carried out to reinforce the structure of concrete roads by maximizing the use of Empty Fruit Bunch (EFB) fibers in the concrete mixture. This study began with previous experiments, namely on K225 concrete, to determine the best percentage and size of EFB fibers added to the standard concrete mixture. It was found that the best addition is 1% and 5% with POEFB fiber sizes of 5 mm to 0.1 mm. The experimental and matrix analysis on the POEFB-CC: K300 matrix with the percentage and size of EFB fibers was the same as the experimental results on K225 concrete. The experimental and analysis presented in this study is the type of concrete K300 standard age of 28 days, using 72 experiments matrix POEFB-CC: K300 in the form of cubes, cylinders and beams according to the sample size of the Indonesian National Standard 03-2834-2000 (INS 03-2834-2000), and the main mixture of concrete according to INS 2847: 2013. Meanwhile, experimental analysis according to INS 03-1974-190, and INS 4331: 2011 had proven that the average compressive strength value of the POEFB-CC: K300 matrix in the addition of 1% and 5% of fibers measuring 5 mm to 0.1 mm is still within the standard K300 compressive strength value range; where the Compressive Strength value was 287.36kg/cm 2 at 1%, and 280.59kg/cm 2 at 5% for POEFB-CC: K300matrix: Medium K300 on standard K300 concrete was 240kg/cm 2 to 300kg/cm 2 . As for the average value of matrix bending strength exceeded the standard K300 concrete bending strength value, namely 34.82 MPa on the X (MX) array matrix, 32.95 MPa on MY and 36.29 MPa on MZ; while in K300 concrete the standard bending strength value was 29.4 MPa. The results of this analysis proved that the addition of 1% EFB fiber and 5% measuring 5 mm to 0.1 mm can increased the bending strength of standard K300 concrete with compressive strength still within the permissible limits of the standard. So it was recommended to use 1% and 5% EFB fibers measuring 5mm to 0.1 mm in standard K300 concrete mixtures, and other types of concrete to increase the structural strength of various types of concrete roads according to the POEFB-CC: K300 matrix: K300; and EFB is no longer considered waste.

PL

Matryca eksperymentalna Palm Oil Empty Fruit Bunch K300 Composite Concrete (POEFB-CC: K300) została przeprowadzona w celu wzmocnienia konstrukcji dróg betonowych poprzez maksymalizację wykorzystania włókien Empty Fruit Bunch (EFB) w mieszance betonowej. Niniejsze badanie rozpoczęto od wcześniejszych eksperymentów, a mianowicie na betonie K225, w celu określenia najlepszego udziału procentowego i wielkości włókien EFB dodawanych do standardowej mieszanki betonowej. Stwierdzono, że najlepszym dodatkiem jest 1% i 5% przy wielkości włókien POEFB od 5 mm do 0,1 mm. Analiza eksperymentalna i matrycowa na osnowie POEFB-CC: K300 z procentem i rozmiarem włókien EFB była taka sama jak wyniki eksperymentalne na betonie K225. Eksperyment i analiza przedstawiona w tym opracowaniu dotyczy betonu typu K300 o standardowym wieku 28 dni, przy użyciu 72 eksperymentów macierzowych POEFB-CC: K300 w postaci kostek, walców i belek zgodnie z wielkością próbki Indonezyjskiej Normy Narodowej 03- 2834-2000 (INS 03-2834-2000), a mieszanka betonu głównego wg INS 2847:2013. Tymczasem analiza eksperymentalna wg INS 03-1974-190 oraz INS 4331:2011 wykazała, że średnia wytrzymałość na ściskanie wartość POEFBCC: osnowa K300 z dodatkiem 1% i 5% włókien o średnicy od 5 mm do 0,1 mm mieści się nadal w standardowym zakresie wartości wytrzymałości na ściskanie K300; gdzie wartość wytrzymałości na ściskanie wynosiła 287,36 kg/cm 2 przy 1% i 280,59 kg/cm 2 przy 5% dla POEFB-CC: matryca K300: Średnia K300 na standardowym betonie K300 wynosiła od 240 kg/cm 2 do 300 kg/cm 2. średnia wartość wytrzymałości na zginanie osnowy przekroczyła normę wytrzymałości na zginanie betonu K300, tj. 34,82 MPa na matrycy X (MX), 32,95 MPa na MY i 36,29 MPa na MZ; natomiast w betonie K300 standardowa wartość wytrzymałości na zginanie wynosiła 29,4 MPa. Wyniki tej analizy wykazały, że dodatek 1% włókna EFB i 5% włókna o wymiarach 5 mm do 0,1 mm może zwiększyć wytrzymałość na zginanie standardowego betonu K300 przy wytrzymałości na ściskanie wciąż mieszczącej się w granicach dopuszczalnych przez normę. Zalecono więc stosowanie 1% i 5% włókien EFB o wymiarach od 5mm do 0,1mm w standardowych mieszankach betonowych K300 oraz innych rodzajach betonu w celu zwiększenia wytrzymałości strukturalnej różnego rodzaju dróg betonowych wg POEFB-CC: macierz K300: K300; a EFB nie jest już uważany za odpad.

19

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.

20

Perspektywy zastosowania betonu hydraulicznego w budownictwie pozaziemskim ze względu na konsystencję mieszanki

Mrozek Magdalena, Mrozek Dawid

Przegląd Budowlany

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2023

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R. 94, nr 9-10

73--76

PL

Jednym z istotnych problemów przy projektowaniu bazy pozaziemskiej jest dobór odpowiedniego materiału konstrukcyjnego. Autorzy niniejszego artykułu przygotowują się do serii badań materiałów, których podstawą byłby symulant regolitu. Są one jednak kosztowne i wymagają dobrego przygotowania. Pierwszym etapem jest przeprowadzenie badań materiału znanego i łatwo dostępnego, jakim jest beton, w warunkach obniżonego ciśnienia. Artykuł prezentuje wyniki testów odpowiadających na pytanie, w jaki sposób konsystencja mieszanki betonowej dojrzewającej w próżni wpływa na parametry stwardniałego betonu, takie jak gęstość oraz wytrzymałość na ściskanie.

EN

One of the significant problems in the design of an extraterrestrial habitat is the selection of a suitable structural material. The authors of this paper are preparing for a series of material tests based on a regolith simulant. However, these are expensive and require good preparation. The first step is to test a material that is known and readily available, such as concrete, under reduced pressure. This article presents the results of experiments answering the question: how does the consistency of a concrete mixture matured in a vacuum affect the parameters of the hardened concrete, such as density and compressive strength.