2023 - Repozytorium publikacji - Politechnika Gdańska

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Determination of t8/5 cooling times for underwater local dry welding of steel
- Grzegorz Rogalski
- Aleksandra Świerczyńska
- Dariusz Fydrych
2023 MARINE STRUCTURES
Knowledge of thermal history is the basic condition for studying the structure - properties of welded joints. The determinant of thermal history is the thermal cycle, whose in-situ measurements are still a big challenge. Water as the welding environment complicates this issue even more. The article presents a method to determine an equation for calculating t8/5 cooling times for underwater gas metal arc welding of unalloyed steels using the local dry cavity method. The work uses the contact method of temperature measurements with the use of thermocouples to obtain the temperature changes of the points of welded joints covered by the thermal field. On this basis, the values of the t8/5 cooling times were determined. A regression analysis of the Response Surface Method was used to determine the equation, which resulted in a second-order model with interactions. Statistically significant factors were determined (thickness of welded elements and heat input value) and the model veracity was confirmed as the assumptions of normality and homogeneity of variance (homoscedasticity) of the residuals were met. The t8/5 cooling time values depend on the thickness of the welded elements and heat input value in a nonlinear way. In terms of the test conditions, the cooling times ranged from 3.0 to 7.7 s. The equation allowed for the calculation of t8/5 cooling times during underwater welding of unalloyed steels using the local dry cavity method based on the variability of the experimental conditions with satisfactory accuracy.
Determination of the Major By-Products of Citrus hystrix Peel and Their Characteristics in the Context of Utilization in the Industry
- Martyna Lubinska-Szczygeł
- Anna Kuczyńska-Łażewska
- Małgorzata Rutkowska
- Żaneta Polkowska
- Elena Katrich
- Shela Gorinstein
2023 Pełny tekst MOLECULES
Kaffir lime (Citrus hystrix) is a popular citrus in Southeast Asia. Despite the growing interest in the peel of the fruit, the leaves are the most frequently used part of the fruit. The aim of the study was to determine the main by-products of the peel, such as pectins, minerals, essential oil, and bioactive compounds, and to evaluate the possibility of using them in various branches of industry. In the study of the essential oil obtained by hydrodistillation performed using the TGA chromatography technique (GC-MS), sabinene (31.93%), β-pinene (26%), and limonene (19%) were selected as the most abundant volatile compounds. Nine microelements (Fe, Zn, Cu, Mn, Co, Ni, Cr, Mo, and V), four macroelements (Mg, Ca, K, and Na), and seven ballast substances (Cd, Hg, Pb, Al, V, Sr, and Pt) were also determined using the microwave plasma-atomic emission spectrometry technique (MP-AES). In the case of microelements, iron 32.72 ± 0.39 mg/kg DW (dry weight) had the highest concentration. In the case of macroelements, the calcium content was 9416 ± 34 mg/kg DW. Optimization of the pectin extraction was also performed by selecting citric acid and obtaining a yield of 7.6–17.6% for acid extraction and 9.9–28.2% for ultrasound-assisted extraction (UAE), depending on the temperature used. The obtained pectins were characterized by the degree of methylation, galacturonic acid content, 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging, and DSC (differential scanning calorimetry) analysis. Among bioactive compounds, the contents of polyphenols (22.63 ± 2.12 mg GAE/g DW), flavonoids (2.72 ± 0.25 mg CE/g DW, vitamin C (2.43 ± 0.19 mg Asc), xantoproteins + carotenes (53.8 ± 4.24 ug), anthocyanins (24.8 ± 1.8 mg CGE/kg DW), and chlorophylls A and B (188.5 ± 8.1, 60.4 ± 3.23 µg/g DW) were evaluated. Antioxidant capacity using (cupric ion-reducing antioxidant capacity) CUPRAC and DPPH assays was also provided with the results of 76.98 ± 8.1, and 12.01 ± 1.02 µmol TE/g DW, respectively.
Developing Materials for Biodegradable Otolaryngological Stents
- Marta Razimowicz
- Przemysław Gnatowski
- Paweł Szarlej
- Edyta Piłat
- Maciej Sienkiewicz
- Justyna Kucińska-Lipka
2023 Pełny tekst Chemistry & Chemical Technology
Materials for otolaryngological stents have to be characterized by good tensile strength, wear resistance, biocompatibility, and specific degradation time. This work aimed to synthesize polyurethanes based on various biodegradable polyol blends. Their biodegradability and mechanical properties were tested and compared to commercial BIOFLEX material.
Development and application of asphalt binder relaxation test in different dynamic shear rheometers
- Johannes Büchner
- Dawid Ryś
- Stefan Trifunović
- Michael P. Wistuba
2023 CONSTRUCTION AND BUILDING MATERIALS
In this study, a novel relaxation test is proposed to evaluate asphalt binder low temperature properties using a Dynamic Shear Rheometer (DSR) with parallel plates of 4 mm in diameter. Three rheometers from three different manufacturers are used to analyze seven asphalt binders. Different material parameters are derived which are useful to evaluate and discriminate different asphalt binders. Test results of all three instruments from different manufacturers are judged identical. Finally, results are compared to results from low temperature tests using a Bending Beam Rheometer (BBR) and a linear correlation is identified for the characteristic m-value from BBR testing.
Development and evaluation of RADA-PDGF2 self-assembling peptide hydrogel for enhanced skin wound healing
- Milena Deptula
- Joanna Sawicka
- Piotr Sass
- Paweł Sosnowski
- Przemyslaw Karpowicz
- Małgorzata Zawrzykraj
- Anna Wardowska
- Anna Tymińska
- Maria Dzierżyńska
- Zuzanna Pietralik-Molińska
- Barbara Peplińska
- Jacek Zielinski
- Karolina Kondej
- Maciej Kozak
- Paweł Sachadyn
- S. Rodziewicz-Motowidło
- Michal Pikula
2023 Pełny tekst Frontiers in Pharmacology
Background: Wound healing complications affect numerous patients each year, creating significant economic and medical challenges. Currently, available methods are not fully effective in the treatment of chronic or complicated wounds; thus, new methods are constantly sought. Our previous studies showed that a peptide designated as PDGF2 derived from PDGF-BB could be a promising drug candidate for wound treatment and that RADA16-I can serve as a release system for bioactive peptides in wound healing. Based on that, in this work, we designed a new self-assembling hydrogel RADA-PDGF2, connecting both peptides by a sequence specific for neutrophil elastase, and evaluated its activity in wound healing. Methods: The physicochemical properties of the designed scaffold were analyzed using transmission electron microscopy, atomic force microscopy, cryoSEM microscopies, and circular dichroism spectroscopy. The enzymatic cleavage was performed using human neutrophil elastase and monitored using high performance liquid chromatography and MS spectroscopic techniques. The aforementioned techniques (HPLC and MS) were also used to assess the stability of the peptide in water and human plasma. The biological activity was analyzed on human skin cells using a colorimetric XTT test, collagen synthesis evaluation, and a migration assay. The biocompatibility was analyzed with LDH cytotoxicity assay and flow cytometric analysis of activation of immune cells. Finally, RADA-PDGF2 activity in wound healing was checked in a mouse dorsal skin injury model. Results: The analysis showed that RADA-PDGF2 can self-assemble, form a hydrogel, and release a bioactive sequence when incubated with human elastase. It shows pro-proliferative and pro-migratory properties and accelerates wound closure in the mouse model compared to RADA16-I. In addition, it is not cytotoxic to human cells and does not show immunogenicity. RADA-PDGF2 seems to be a promising drug candidate for wound management.
Development and validation of an eco-compatible UV–Vis spectrophotometric method for the determination of Cu2+ in aqueous matrices
- Prisco Prete
- Davide Iannaccone
- Antonio Proto
- Marek Tobiszewski
- Raffaele Cucciniello
2023 Pełny tekst ANALYTICAL AND BIOANALYTICAL CHEMISTRY
Cu 2+ are ubiquitous ions in the ecosystem and are responsible of serious environmental pollution. Indeed, the development of sensitive methods for Cu 2+ detection is an urgent demand. In this work, we proposed a new spectrophotometric method for Cu 2+ determination in different water matrices (distilled water, drinking water, wastewater, and river water). The method employs a bio-based organic ligand namely tetrasodium iminodisuccinate (IDS) able to form a stable complex with the analyte with a maximum absorption at 710 nm. Within the linear range of 6.3–381 mg L −1 , the limit of detection (LOD) was deter- mined to be as 1.43 mg L −1 . Moreover, the recovery data of the spiked analysis of drinking/river/wastewater water samples were also satisfactory and verified the feasibility of the method for the analysis of Cu 2+ in natural conditions. Finally, the AGREE assessment tool was used for a quantitative evaluation of the proposed method and reference method, in agreement with the green analytical chemistry principles. The results showed the lower environmental impact of the proposed method and the suitability of this novel approach for Cu 2+ in water matrices.
Development and validation of lumbar spine finite element model
- Tomasz Wiczenbach
- Łukasz Pachocki
- Karol Daszkiewicz
- Piotr Łuczkiewicz
- Wojciech Witkowski
2023 Pełny tekst PeerJ
The functional biomechanics of the lumbar spine have been better understood by finite element method (FEM) simulations. However, there are still areas where the behavior of soft tissues can be better modeled or described in a different way. The purpose of this research is to develop and validate a lumbar spine section intended for biomechanical research. A FE model of the 50th percentile adult male (AM) Total Human Model for Safety (THUMS) v6.1 was used to implement the modifications. The main modifications were to apply orthotropic material properties and nonlinear stress-strain behavior for ligaments, hyperelastic material properties for annulus fibrosus and nucleus pulposus, and the specific content of collagenous fibers in the annulus fibrosus ground substance. Additionally, a separation of the nucleus pulposus from surrounding bones and tissues was implemented. The FE model was subjected to different loading modes, in which intervertebral rotations and disc pressures were calculated. Loading modes contained different forces and moments acting on the lumbar section: axial forces (compression and tension), shear forces, pure moments, and combined loading modes of axial forces and pure moments. The obtained ranges of motion from the modified numerical model agreed with experimental data for all loading modes. Moreover, intradiscal pressure validation for the modified model presented a good agreement with the data available from the literature. This study demonstrated the modifications of the THUMS v6.1 model and validated the obtained numerical results with existing literature in the sub-injurious range. By applying the proposed changes, it is possible to better model the behavior of the human lumbar section under various loads and moments.
Development of a new generation of unmanned surface and underwater vehicles using the advanced technologies and achievements towards the application of control systems by the artificial intelligence AI.
- Mirosław Gerigk
- Mateusz Gerigk
2023 Per mare ad astra
The operation of offshore structures at sea requires implementation of the advanced systems of permanent monitoring of work of such the installations. Novel solutions concerning such the systems should be associated with application of unmanned maritime surface and underwater platforms. The unmanned maritime platforms are and will be based on application of the newest achievements of some important technologies. Between these technologies is an important role to be played by the AI artificial technology used by the advanced control systems. The implementations of the advanced systems of permanent monitoring of work of offshore installations using the AI-based systems may provide an increase of the level of functionality, performance and safety of such the structures and systems. This paper presents a general approach to further development of the AUV Autonomous Underwater Vehicle and USV-WIG Unmanned Surface - Wing in Ground Vehicles equipped with a control system based on the AI technology. It is shown within the paper that it is relatively easy to develop an idea of implementation of the AUV and USV-WIG unmanned maritime vehicles but in the same time it is difficult task indeed to reach a level of real applications. The paper presents a general approach to the AUV and USV-WIG vehicle designs. A complexity of an approach to a vehicle design is shown by using the performance-oriented risk-based method. The main design drives are presented too. A brief description concerning a control system for both the AUV and USV-WIG vehicles based on the mini-brain AI control system is described. Some results of research in this area are presented. In final part of the paper the practical remarks and conclusions are given.
Development of a new green analytical methodology for the determination of phthalates in single-use babies diapers using ultrasound-assisted extraction and polypropylene porous membrane
- Anna Rożańska
- Opas Bunkoed
- Justyna Płotka-Wasylka
2023 MICROCHEMICAL JOURNAL
A green extraction strategy was developed and utilized for the extraction and determination of phthalates. The extraction is based on ultrasound-assisted extraction and a polypropylene porous membrane. The Box-Behnken model was performed to optimize the extraction condition. The optimal extraction conditions are 5.5 mL of ethyl acetate, 10 min of extraction time and 55 C for extraction temperature. The developed green extraction method was successfully applied to extract target phthalate from baby's diapers. Under the optimal condition, the developed method provided acceptable recoveries in the range of 87 to 102% with a relative standard deviation lower than 13%. The developed method exhibited good linearity in the range of 0.05 to 10.0 µg g-1 with a coefficient of determination greater than 0.992 (R2). Applied the developed method coupled with the gas chromatography-mas spectroscopy (GC-MS) method, benzyl butyl phthalate (BBP) and dioctyl phthalate (DOP) were found in some diaper samples. While low concentrations of diisononyl phthalate (DINP) and diisodecyl phthalate (DIDP) were detected in almost all diaper samples. The greenness of the developed method was also evaluated. The developed method can be used as an alternative simple, green and efficient strategy for the determination of phthalates in baby diapers. In sum, the presented article is the first step in raising awareness about carcinogenic impurities to which infants and older children are exposed.
Development of a simulation model of the activities of a transport and forwarding enterprise in the organization of international road cargo transportation
- Ievgenii Lebid
- Nataliia Luzhanska
- Iryna Lebid
- Alexander Mazurenko
- Maksym Roi
- Ievgen Medvediev
- Tetiana Sotnikova
- Serhii Hrevtsov
2023 Pełny tekst Eastern-European Journal of Enterprise Technologies [ Восточно-Европейский журнал передовых технологий ]
The object of this study is the process of planning the work of a transport and forwarding company when serving different categories of customers who need organizational support for the delivery of goods by road transport in international traffic. The solved problem is due to the need to devise recommendations for organizing the work of forwarders when interacting with customers of transport and forwarding services that export or import different categories of cargo. A simulation model of the transport and forwarding company’s work in customer service was developed and implemented in the GPSS World simulation automation package. The model provides for the optimization of organizational and management processes in cooperation with customers of transport and forwarding services. When developing the model, the duration of the types of work in which freight forwarders are involved in the export and import of goods by road transport was taken into account. The model also predicts the probability of errors in the forwarder’s work and the duration of their elimination. The application of the developed model in practice will enable the owners of transport and forwarding companies to plan the full-time number of forwarders and the duration of service provision under different conditions of interaction with customers. The simulation results reflect the performance indicators of the enterprise in serving different categories of customers. This will make it possible to optimize the work of the enterprise by planning personnel support. At the same time, the duration of transport and forwarding services will be reduced by 10–15 %, the capacity of the enterprise will increase by 6–11 %, and the reliability of service provision will increase by 8–14 %
Development of a spray-ejector condenser for the use in a negative CO2 emission gas power plant
- Paweł Madejski
- Krzysztof Banasiak
- Paweł Ziółkowski
- Dariusz Mikielewicz
- Jarosław Mikielewicz
- Tomasz Kuś
- Michał Karch
- Piotr Michalak
- Milad Amiri
- Paweł Dąbrowski
- Kamil Stasiak
- Navaneethan Subramanian
- Tomasz Ochrymiuk
2023 Pełny tekst ENERGY
One promising solution for developing low-emission power technologies is using gaseous fuel combustion in pure oxygen when the exhaust gas mixture is composed of H2O and CO2, and where CO2 is separated after steam condensation. The paper presents the results of computational analyses providing to the Spray-Ejector Condenser (SEC) development, which is one of the crucial components of the negative CO2 gas power plant (nCO2PP) cycle development. The proposed design of the ejector-condenser to ensure the high effectivity of vapor condensation and CO2 compression with preparation to separation, ready for application in gas power cycle, is a novelty of this research. Different computational techniques leading to the development and better understating of ejector operation were applied. The main operating conditions in the characteristic connected with the developed nCO2pp cycle points were investigated to evaluate the impact of the operating conditions on SEC performances. The amount of motive water needed for the cooling purpose is susceptible to the inlet water pressure and temperature and strongly affects the generated pressure of the suction stream. The preliminary results confirm that the SEC's basic design and geometrical dimensions can be applied in the negative CO2 power plant cycle. Results from CFD modeling give the possibility to investigate the turbulent flow of water/steam/CO2 mixture together with the condensation process occurring at this same time. It is found that the average droplet diameter and motive water supplying method significantly effects the condensation intensity. The further direction of the presented computational research activities and results is to test various designs of Spray-Ejector Condensers that will enable the evaluation of the direct contact condensation process and develop the final geometrical design.
Development of iron doped strontium titanates as oxygen electrode for solid oxide fuel cells
- Aleksander Mroziński
2023 Pełny tekst
Producing efficient solid oxide fuel cells (SOFC) without the use of harmful elements is one of the current challenges. Increasing the safety of people and reducing production costs is possible, among others, thanks to the use of iron doped strontium titanates as porous oxygen electrodes. In this thesis, the results of research on iron doped strontium titanates as potential oxygen electrodes for SOFC are presented. The research focused on: 1. Solid state reaction synthesis of iron doped strontium titanates with different amounts of substituted iron (SrTi1-xFexO3-δ, STFx) and materials with different nonstoichiometry in the strontium sublattice (SrxTi0.3Fe0.7O3-δ, STF-x). Electrical and microstructural studies have proven that these materials can be an alternative to those currently used not only at 800 °C but also at 700 °C. 2. Determining the electrochemical processes occurring in the STFx and STF-x materials during the oxygen reduction reaction and distinguishing which process limits the yield depending on the material used. Thanks to electrochemical impedance spectroscopy, a distribution of relaxation times analysis and microstructural studies, it was possible to identify the electrochemical processes occurring in these porous cathodes and indicate which ones limit the efficiency of the electrodes depending on the stoichiometry.
Development of novel optoelectronic sensory structures utilising colour centres in nanodiamonds and their interactions with analytes
- Maciej Głowacki
2023
The goal of this dissertation was to develop and assess surface modifications of fluorescent nanodiamonds (NDs) for optical sensing. Three modification routes were tested, each aimed at a different application. Modification with poly-L-lysine (pLys) was verified for optical sensing of pH via an interrelationship between electrically negative (NV¯) and neutral (NV0) nitrogen-vacancy centres. Immobilisation of Ochratoxin A (OTA), one of the most common mycotoxins, was examined for optical investigation of interactions between the toxin and DNA in various comestible liquids. Attachment of hyperbranched polyglycerol (HPG) was tested for creation of a biomarker characterised by excellent colloidal stability in a broad pH range, in highly ionic environments and physiological media while maintaining a stable optical response. Moreover, the aim of the dissertation was to exploit techniques for depositing fluorescent NDs on glass structures to create composite platforms suitable for integration with modern optoelectronic systems used in magnetic field sensing. Matrix-assisted pulsed laser evaporation (MAPLE) was tested to obtain patterns of the diamond particles on glass coverslips for 3D sensing of the magnetic fields. Dip coating was examined to cover glass rods with the fluorescent diamond particles for drawing a composite fibre with the particles in its core. A microfluidic system was assembled to infuse anti-resonant hollow-core fibres (ARHCFs) with suspensions of fluorescent diamond particles to create platforms for optical sensing of magnetic field gradients.
Development of the Polish energy sector through transformation and harmonization with the European energy and climate policy
- Waldemar Kamrat
2023 Gaz, Woda i Technika Sanitarna
The paper presents the dilemmas of energy sector development vs European energy policy due to the way of energy transition. The identification of barriers and opportunities for the development of the power industry is presented. The possibilities of using modern energy technologies for the processes of energy transformation are described. The path useful to achieving climate and energy goals is determined. The new method of electricity demand forecasting taking into account the demographic situation, which allows for precise determination of demand is presented. Energy policy determinants in Poland are defined. The Polish energy sector possibilities of energy transition are described.
Development of the System Assurance Reference Model for Generating Modular Assurance Cases
- Andrzej Wardziński
- Aleksander Jarzębowicz
2023
Assurance cases are structured arguments used to demonstrate specific system properties such as safety or security. They are used in many industrial sectors including automotive, aviation and medical devices. Larger assurance cases are usually divided into modules to manage the complexity and distribute the work. Each of the modules is developed to address specific goals allocated to the specific objects i.e. components of the system’s architecture. Such goals are applicable for given conditions of use, for instance, operational modes or target environments. It is recommended that the complete context of each of the argument modules, encompassing information about systems/components, goals and conditions of use, is described explicitly to enable efficient management and proper use of each module. This becomes even more important for component-based design, including the use of out-of-context components. In this paper, we describe a concept of a generic System Assurance Reference Model (SARM), which bridges the gap between assurance cases and the related context models. We identify the key factors that condition the high-level assurance case structure, explain how they can drive its decomposition into assurance case modules and outline the process of creating and using context models. We present a prototype solution which implements the SARM model and enables automatic data flow between models and assurance cases.
DevEmo—Software Developers’ Facial Expression Dataset
- Michalina Manikowska
- Damian Sadowski
- Adam Sowiński
- Michał Wróbel
2023 Pełny tekst Applied Sciences-Basel
The COVID-19 pandemic has increased the relevance of remote activities and digital tools for education, work, and other aspects of daily life. This reality has highlighted the need for emotion recognition technology to better understand the emotions of computer users and provide support in remote environments. Emotion recognition can play a critical role in improving the remote experience and ensuring that individuals are able to effectively engage in computer-based tasks remotely. This paper presents a new dataset, DevEmo, that can be used to train deep learning models for the purpose of emotion recognition of computer users. The dataset consists of 217 video clips of 33 students solving programming tasks. The recordings were collected in the participants’ actual work environment, capturing the students’ facial expressions as they engaged in programming tasks. The DevEmo dataset is labeled to indicate the presence of the four emotions (anger, confusion, happiness, and surprise) and a neutral state. The dataset provides a unique opportunity to explore the relationship between emotions and computer-related activities, and has the potential to support the development of more personalized and effective tools for computer-based learning environments.
Diagnostic Analysis of Exhaust Gas with A Quick-Changing Temperature from a Marine Diesel Engine Part II / Two Factor Analysis
- Patrycja Puzdrowska
2023 Pełny tekst Polish Maritime Research
The article presents a continuation of research carried out to determine the effect of input parameters (changes in engine structure parameters) on selected output parameters (diagnostic measures), based on quickly changing exhaust gas temperature. A method of determining the simultaneous influence of two input factors (the structure parameter and the engine load) on one output factor was presented, as well as an evaluation of which of the analysed input factors has a stronger influence on the output parameter. The article presents the stages of the experimental research conducted and statistical inference based on the results. Three changing parameters for the structure were reviewed: the active cross sectional area of the inlet air channel, the injector opening pressure and the compression ratio. Based on the quickly changing temperatures of the exhaust gases, three diagnostic measures were defined and subjected to statistical tests. The following data were averaged over one cycle for a 4-stroke engine operation: the intensity of changes, the specific enthalpy and the peak-to-peak value of the exhaust gas temperature. The results of the two-factor analysis are presented. Conclusions on the analysis are given and a criterion for the selection of a diagnostic measure, depending on the analysed parameter of the structural design of the diesel engine, is proposed. The previous part of the article presented the results of the first stage of the elimination study: the one-factor statistical analysis (randomised complete plan). This paper presents the results of the second stage of the studies: two-factor analysis (block randomised plan), where the significance of the effect of changing the values of the structural parameters on the diagnostic measures were analysed in the background of a variable engine load. The next (third) part will present the results of the calculations and analysis of the interaction coefficient of significance.
Diagnostyka cienkościennych żelbetowych sklepień kolebkowych w budynku zabytkowym. Część II
- Tomasz Majewski
- Maciej Niedostatkiewicz
2023 Pełny tekst Przegląd Budowlany
W artykule przedstawiono opis oraz wyniki oceny stanu technicznego konstrukcji przekrycia Hali Głównej Dworca Kolejowego Gdańsk Główny. Ze względu na prowadzone prace związane z remontem kapitalnym Dworca Głównego PKP w Gdań- sku zaistniała konieczność przeprowadzenia rewitalizacji poddasza Hali Głównej, obejmująca między innymi jego termomodernizację (ocieplenie wysklepek) oraz zabezpieczenie elementów wiązarów dachowych przed pożarem. W celu oceny stanu technicznego skle- pień oraz poziomu wytężenia elementów konstrukcyjnych dachu wykonano szereg badań i pomiarów, w tym skanowanie zbroje- nia żelbetowych sklepień kolebkowych z zastosowaniem detekto- ra ferromagnetycznego w celu oceny średnicy, rozstawu i grubo- ści otulenia prętów zbrojenia łupin oraz badania ultradźwiękowe betonu przy użyciu betonoskopu w celu oszacowania wytrzyma- łości betonu na ściskanie, jego jednorodności oraz grubości płasz- cza powłoki. W artykule przedstawiono wyniki wykonanych badań i analiz, które pozwoliły na zaproponowanie sposobu naprawy cien- kościennych sklepień żelbetowych typu Rabitza.
Diagnostyka i naprawy dylatacji konstrukcyjnych w płytach posadzkowych. Część II
- Sylwia Świątek-Żołyńska
- Maciej Niedostatkiewicz
- Sebastian Kasprzak
2023 Pełny tekst Przegląd Budowlany
W artykule przedstawiono najczęściej spotykane uszkodzenia dylatacji konstrukcyjnych w płytach posadzkowych na gruncie wraz z omówieniem sposobów naprawy. Dylatacje konstrukcyjne w płytach posadzkowych najczęściej realizowane są z wykorzystaniem dylatacji systemowych, które w trakcie dłu- goletniej eksploatacji ulegają naturalnemu zużyciu lub uszkodze- niom mechanicznym. W artykule omówiono istotne aspekty tech- nologiczno-materiałowe w zakresie demontażu starych i montażu nowych systemowych dylatacji konstrukcyjnych z uwzględnie- niem funkcji obiektu. Przedstawiono również przypadki połącze- nia starych płyt posadzkowych z nowo wykonywanymi, a także rozwiązania w zakresie remontów i napraw dylatacji w bramach przejazdowych oraz szczelin skurczowych.
Diagnostyka, naprawy i wzmacnianie elementów żelbetowych uszkodoznych w następstwie skurczu
- Maciej Niedostatkiewicz
- Tomasz Majewski
2023 Pełny tekst
W artykule opsano wpływ zjawisk reologicznych: skurczu i pełzania na wytężenie i zarysowanie żelbetowych elementów konstrukcyjnych