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1
Content available Influence of waste ashes from biomass combustion on frost resistance of cement mortars
Jura Jakub
Zeszyty Naukowe Akademii Morskiej w Szczecinie
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2023
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nr 75 (147)
35--41
EN
This article presents the influence of ashes generated in the combustion processes of various types of biomasses on the durability (resistance to freezing and thawing after 25 cycles) of cement mortars. Three types of ashes were used for the tests: two fly ashes and one bottom ash. These differ in chemical composition and microstructure in the amounts of 10%, 20%, and 30% of the cement mass and are used as a substitute for standard sand. The ashes are characterized in terms of microstructure and chemical composition. The research shows that, regardless of the type of ash used, all the cement mortars containing ash are characterized by higher durability than the control mortars. Among the modified mortars, the smallest decrease in resistance (by 0.54%) to the process of freezing and thawing is shown by cement mortars containing 10% fly ash from the combustion process of biomass with the addition of sunflower, and the largest (by 7.56%) show mortars containing 30% bottom ash from the combustion of biomass with the addition of sunflower. These findings suggest that the incorporation of biomass ashes, particularly fly ash, into the cement matrix mixes has the potential to improve their durability for road infrastructure applications.
2
Content available Analysis of the impact of sludge and slag waste on the basic properties of cement mortars
Jura Jakub
System Safety : Human - Technical Facility - Environment
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2023
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Vol. 5, iss. 1
130--141
EN
The article examined the influence of two additives, which are post-production waste from metallurgical processes, on the basic properties of cement mortars. Sludge and slag waste were used for testing. Both wastes were examined in terms of their chemical composition using a spectrometer, their specific density and grain composition were determined. As part of the tests, a series of standard mortars were made and the results obtained for modified mortars were compared to them. The produced cement composites used waste in amounts of 5, 10, 15 and 20% of the cement mass, used as a substitute for standard sand. After preparing the standard mortar and mortars containing additives for each series, consistency tests were performed using the flow table method. After an appropriate maturing time, flexural and compression tests were performed for all mortar series after 7 and 28 days of maturing, as well as water absorption tests. The research shows that the addition of these two wastes thickens the fresh cement mortar (from 0.62 to 15 %). The use of such waste also results in a decrease in flexural strength after 7 and 28 days (for sludge from 5 to 21% and for slag from 2 to 11%). However, the compressive strength of mortars decreased by 11% in the case of the addition of 20% of sludge and was almost the same as that of the standard mortar after the addition of 20% of slag.
3
Content available Niemetaliczne zbrojenie FRP w kompozytach betonowych jako alternatywa dla prętów stalowych
Helbrych Paweł, Jura Jakub
Przegląd Budowlany
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2022
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R. 93, nr 11-12
107--110
PL
Niemetaliczne zbrojenie FRP jest coraz powszechniej stosowane w Polsce, ze względu na zastosowany materiał do ich produkcji można wyróżnić: pręty szklane (GFRP - Glass Fibre Reinforced Polymers), bazaltowe (BFRP - Basalt Fibre Reinforced Polymers), aramidowe (AFRP -– Aramid Fibre Reinforced Polymers) oraz węglowe (CFRP - Carbon Fibre Reinforced Polymers). Tego typu zbrojenie charakteryzuje wysoka wytrzymałość na rozciąganie, wysoka odporność na korozję, odporność na działanie agresywnych warunków środowiskowych oraz niska gęstość i liniowo-sprężysty charakter pracy w całym zakresie wytrzymałości. W przypadku elementów budowlanych zbrojonych prętami FRP zniszczenie następuje nagle, bez ostrzeżenia, nie ma możliwości wystąpienia odkształceń plastycznych. Pręty FRP ze wzglądu na swoje właściwości mechaniczne stanowią alternatywę dla prętów ze stali. Prognozuje się, że wartość rynkowa branży produkcji prętów FRP na świecie w 2026 r. wzrośnie do ponad 1,4 mld USD.
EN
Non-metallic FRP reinforcement is more and more commonly used in Poland, due to the material used for their production, the following can be distinguished: glass rods (GFRP - Glass Fiber Reinforced Polymers), basalt rods (BFRP - Basalt Fiber Reinforced Polymers), aramid rods (AFRP - Aramid Fiber Reinforced Polymers) and carbon (CFRP - Carbon Fiber Reinforced Polymers). This type of reinforcement is characterized by high tensile strength, high corrosion resistance, resistance to aggressive environmental conditions as well as low density and linear-elastic nature of work in the entire strength range. In the case of building elements reinforced with FRP rods, failure occurs suddenly, without warning, there is no possibility of plastic deformation. FRP bars, due to their mechanical properties, are an alternative to steel bars. It is forecast that the market value of the FRP rod industry in the world in 2026 will increase to over USD 1.4 billion.
4
Content available Thermal emissivity of tent fabric and its influence on the thermal insulation of tent walls
Ujma Adam, Jura Jakub
Budownictwo o Zoptymalizowanym Potencjale Energetycznym
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2021
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Vol. 10 Nr 2
15--22
EN
The article presents research aimed at determining the thermal properties of tent fabric and, as the final result, the value of the heat transfer coefficient of the thermal protection of a pneumatic tent. It was assumed that the thermal insulation capacity of the tent cover, consisting of two fabric layers separated by an air gap, was determined for two seasons, summer and winter. The tested material had two sides that differed in color, which resulted in obtaining a different value of the thermal emissivity coefficient. The thermal conductivity coefficient of the tent fabric was also measured with the use of a lammeter. The obtained data from the measurements were then used to determine the resistance to heat transfer on the tent surfaces, the thermal resistance of the partition, and finally the value of the heat transfer coefficient.
5
Content available Selection of the test method and its influence on the obtained results of soil strength parameters
Pietrzak Alina, Jura Jakub
Budownictwo o Zoptymalizowanym Potencjale Energetycznym
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2021
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Vol. 10 Nr 2
119--126
EN
The paper presents issues related to the methodology of measuring soil strength parameters. The laboratory methods for determining the shear strength of soil are described, with particular emphasis on the measurement of soil strength using the direct shear method and the triaxial compression apparatus. An attempt was made to determine the impact of the research methodology on the quality of the obtained strength parameters of the soil.
6
Content available Influence of type of biomass burned on the properties of cement mortar containing fly ash
Jura Jakub
Budownictwo o Zoptymalizowanym Potencjale Energetycznym
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2020
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Vol. 9 Nr 1
77--82
EN
The paper presents the issues related to the excessive use of natural resources and the possibility of its reduction through the use of ash deposited in landfills. Two different ashes from the combustion of various types of biomass (coconut shell and sunflower) were used and compared with each other. As part of the tests, the chemical composition of the ashes used was checked and samples of cement and standard mortars were made using the two types of fly ash. The research shows that the chemical composition is similar to the volatile chemical composition of conventional burning pavilions. It should be noted that the type and origin of the ash used for the results obtained is important. The use of ashes as a partial substitute for standard sand increased the compressive strength of all tested samples from 1 to over 17%. Ash additions reduced the compressive strength drop after frost resistance testing by 3 to 15%, and slightly increased the absorbency by 2 to 6% relative to control samples. An important advantage is that the use of ash as a substitute for standard sand allows you to reduce the consumption of natural resources.
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