The Effect of Biomass-based Fly Ash on Properties of Cement PastesPokorný, J
doi: 10.1088/1742-6596/2911/1/012018pmid: N/A
Portland cement constitutes the traditional binding material which is beneficial due to its relatively high initial strength and good resistance against different surrounding conditions. Nevertheless, its production relates to negative aspects, such as habitat disruption, biodiversity loss and considerable carbon footprint. The inclusion of biomass-based fly ash (BA) serving like ordinary Portland cement (OPC) substitution on behaviour of cement pastes was examined in this paper. Physical and mechanical properties, and liquid water transport of cement pastes with 10 – 20 mass% of BA content and maintained w/c of 0.4 were evaluated and compared with reference plain paste. Obtained experiment results pointed out on the active pozzolanic character and partial filler effect of BA particles in the combination with OPC. However, the optimal substitution of OPC with BA up to 15 mass% helped to reduce liquid water transport and to improve mechanical resistance of produced pastes.
The potential of using artificial intelligence in the processing of data measured by TDR for mass moisture conversion of porous building materialsMikušová, D; Suchorab, Z; Trník, A; Paśnikowska-Łukaszuk, M
doi: 10.1088/1742-6596/2911/1/012024pmid: N/A
Accurate determination of moisture in buildings helps to prevent many problems, structural or health and hygiene. The Time Domain Reflectometry (TDR) technique can be used to determine moisture in buildings. This technique offers the possibility to perform measurements directly in the field without major destruction of the measured buildings. This technique is an indirect measurement technique, where the apparent permittivity of the environment is measured. To convert apparent permittivity into moisture content (volumetric or mass), empirical or physical models are used. Empirical models are developed specifically for the measured material and show greater accuracy than physical models. A prerequisite for the correct determination of moisture is a model with the greatest possible accuracy. This paper presents the possibility of using Machine Learning in the processing of data measured by TDR for volumetric water content. Machine Learning as a subdomain of Artificial Intelligence creates a mathematical model for predicting new data based on input and output data. This potential is precisely due to the model’s ability to learn from training data.
The evaluation of building materials moisture using the Analysis of CovarianceJastrzębska, M; Futa, A
doi: 10.1088/1742-6596/2911/1/012032pmid: N/A
The paper presents the evaluation of some building materials moisture using the Analysis of Covariance (ANCOVA). The readouts present the dependence between the moisture of material, evaluated gravimetrically and permittivity values determined by TDR technique. Thanks to the ANCOVA method, it is possible to determine the moisture content in the particular materials regardless of the sensor construction and type of material. Additionally, in order to compare, the data obtained in the research also were analyzed using the traditional linear regression models.
Residual physical properties of thermally loaded alkali activated slagKeppert, M; Pommer, V; Kulhavá, K; Koňáková, D; Vejmelková, E; Černý, R
doi: 10.1088/1742-6596/2911/1/012028pmid: N/A
One of possible application fields of Alkali activated aluminosilicates (AAA) lies in their higher thermal stability compared to Portland cement based systems. AAA may be thermally loaded just moderately (e.g. thermal insulating foams) or more intensively (refractory AAA concrete; ceramics derived from AAA). Thermal loading is obviously causing number of physical and chemical alterations in the material which are reflected by development of functional properties of the material – primarily by its strength. Blast furnace slag is one of the traditional precursors for alkali activated materials. As the first step of the research, the effect of activator composition and dosage (mix of potassium silicate and potassium hydroxide) on the mechanical properties of activated slag was examined in broad range of Si/Al and Al/K ratios. Secondly the selected mixtures were thermally loaded to 200, 600, 800, 1000 and 1200 °C and their residual physical characteristics were determined. The heating to 200 °C caused strengthening of the all materials due to curing of geopolymeric structure. Later, at higher temperatures, the strength decreased alongside with gradual dehydroxylation and shrinkage of the material. However the loading at 1200 °C caused – in some mixtures – significant strengthening due to crystallization of new mineral phases.
FEM verification of natural convection loop modelBulatović, G; Bokes, P
doi: 10.1088/1742-6596/2911/1/012013pmid: N/A
We compare the analytical results for a natural convection loop model with two-dimensional finite element method (FEM) simulations. We set the values for FEM simulations parameters to reflect oil circulation in a distribution transformer. We find that the calculated characteristics for the two approaches differ by less than 3%. This discrepancy is explained in terms of the variations in the fluid velocity profile.
Peer Review Statementdoi: 10.1088/1742-6596/2911/1/011002pmid: N/A
All papers published in this volume have been reviewed through processes administered by the Editors. Reviews were conducted by expert referees to the professional and scientific standards expected of a proceedings journal published by IOP Publishing.• Type of peer review: Single anonymous• Conference submission management system: Morressier• Number of submissions received: 36• Number of submissions sent for review: 36• Number of submissions accepted: 34• Acceptance Rate (Submissions Accepted / Submissions Received × 100): 94.4%• Average number of reviews per paper: 2• Total number of reviewers involved: 11• Contact person for queries:Name: Anton TrnikAffiliation: Department of Physics, Faculty of Natural Sciences and Informatics, Constantine the Philosopher University in NitraEmail: [email protected]
The Characterization of Properties of Hard Historical RendersPokorný, J; Fořt, J; Šál, J; Javorský, D
doi: 10.1088/1742-6596/2911/1/012017pmid: N/A
Rendering materials combine two fundamental functions – create protective layers on a substrate and provide decorative and architectural appear of a building’s facade. In particular, many historical buildings are unique with their facades due to the incorporation of different decorative elements, such as plinths, lining cronies, reliefs etc. The composition of mortars used for renders contained many different components in view of binders and filler materials in the past. This fact in combination with conditions which are facades exhibited (weathering, increased moisture and others) effect their appear and overall durability. This paper is focused on the collection procedure of historical renders from two buildings located in the South bohemian region, and further the description and discussion of physical and mechanical properties of rendering materials samples are provided. These pilot data showed that one of examined buildings to some repairs were subjected historically, and for the second one partially different materials from the point of in their quality were used, although the outer facade layer (stucco) was uniform. The mapping of historical renders properties is essential for obtaining important data set for formulation of compatible composites intended for renovation interventions and local repairs.
Evaluation of radionucłides transport parameters based on time dependent concentration profilesKoci, V; Kucerakova, M; Zelenka, J; Drab, M; Vratislav, S; Kalvoda, L; Medved, I
doi: 10.1088/1742-6596/2911/1/012021pmid: N/A
Alkali-activated aluminosilicate samples were prepared to be for testing and determination of radionuclides transport parameters. A solution of GdNO3 was put in contact with a face side of a prismatic specimen (lateral sides were sealed to make sure one-dimensional transport mode prevails) and the solution concentration in space and time were monitored and recorded using neutron radiography. The concentration profiles in different times were then processed (Stefan-Bolzmann transformation) and evaluated to obtain the diffusion coefficients. Within the evaluation, theoretical binding isotherms of Gd were used which corresponded to various levels of concentration. In this way, a sensitivity analysis was performed to investigate and quantify the impact of an isotherm variation on the diffusion coefficients values obtained. It has been found, a 10% variation in the binding isotherm values led to a difference in diffusion coefficient of up 30%. Beside concentration profiles measurement, an increased attention should be also paid also to a precise determination of binding isotherms.
The influence of 3D printing temperature on the impact strength of polylactidePaśnikowska-Łukaszuk, M; Urzędowski, A; Szulżyk-Cieplak, J; Wlazło, M; Zaburko, J
doi: 10.1088/1742-6596/2911/1/012030pmid: N/A
3D printing is one of the most developing technologies currently. There are many materials present on the market that allow you to get quite good and durable prints. One of the most commonly used materials is polylactide. The article presents the results of research on the influence of 3D stamping temperature on the impact strength of PLA filament using the Charpy test method. The paper presents the results of the impact strength of PLA samples as a function of printing temperature. In the paper compare samples printed at temperatures of 185 °C, 200 °C, and 210 °C. The highest moment of force was obtained for the 5th sample printed at a temperature of 185 °C, and the lowest for the 5th sample printed at a temperature of 200 °C, however, the values between subsequent measurements differ by a maximum of 0.11 [kpm].