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Influences of a variety of reinforcements on the durability of reinforced bitumen sheets operating at variable temperatures
This manuscript provides an overview of the most commonly-produced bitumen roofing sheets, focusing on the types of reinforcements used for their production and the reinforcements’ effects on the durability of tensile mechanical properties of roofing sheets under thermal loads. The paper includes the analysis of working conditions of roof coverings in the mid-European transitional climate, i.e., exposed to temperatures passing through 0 °C for three seasons in a year, periodic exposure to negative temperatures reaching −15 °C and positive temperatures up to +70 °C, justifying the above-mentioned emphasis on thermal load. It draws attention to technical problems related to the cooperation of roofing sheets with roofing substrates, with particular emphasis on concrete substrates. For the purposes of the work, the analyses were carried out with regard to the assessment of the service life of roof coverings made of various reinforcements working in conditions of variable temperatures and thus exposed to the transfer of thermal movements of substrate plates. The analyses also included the impact of different coefficients of thermal expansion of the materials in contact with other materials within roof coverings on the incidence of damage to cover layers. Particular attention was paid to the conditions resulting from the production process of roofing sheets effect on the durability of roof coverings made of these materials. Additionally, there were set directions for further work to calculate the impact of stresses, arising in layers of roof coverings during their operation in changeable negative and positive temperatures, on the incidence of mechanical damage to these coverings.
Digital Twin Model for Predicting Hygrothermal Performance of Building Materials from Moisture Permeability Tests
Moisture transport in building materials significantly influences their durability, mechanical integrity, and thermal performance. This study presents an experimental investigation of moisture permeability in a range of traditional and modern wall elements, including autoclaved aerated concrete (ACC), ceramic blocks, silicate blocks, perlite concrete blocks, and concrete units. Both vapor diffusion and capillary transport mechanisms were analyzed under controlled climatic conditions using gravimetric and hygrometric methods. Among the tested materials, autoclaved aerated concrete (AAC) was selected for detailed numerical modeling because of its high porosity, strong capillarity, and widespread use in modern construction, which make it especially vulnerable to moisture-related degradation. Based on the experimental findings, a digital twin was developed to simulate hygrothermal behavior of walls made of ACC under various environmental conditions. The model incorporates advanced moisture transport equations, capturing diffusion and capillary effects while considering real-world variables, such as relative humidity, temperature fluctuations, and wetting–drying cycles. Calibration demonstrated strong agreement with experimental data, enabling reliable predictions of moisture behavior over extended exposure scenarios. This integrated approach provides a robust engineering tool for assessing the long-term material performance of AAC, predicting degradation risks, and optimizing material selection in humid climates. The study illustrates how coupling experimental data with digital modeling can enhance the design of moisture-resistant and durable building envelopes.
Geoenvironmental Hazards in Development Planning
The usability of the natural environment for settlement can be analysed based on geoenvironmental conditions: groundwater levels, terrain elevations, subsoil construction suitability. They are all important elements of urban development planning. Developing a method for selecting areas with favourable construction conditions and determining future urban development trends based on geoenvironmental conditions is essential for proper formation of space for construction purposes. This article presents a proprietary approach to determining geoenvironmental indicators and the ongoing correlational changes in these indicators, which are the basis for choosing optimal areas for construction. The selected geoenvironmental factors influence the development and spatial growth of cities. The research area is located within a small agglomeration inhabited by up to 20,000 residents. Direct results concerning geoenvironmental data and urban development were obtained from an area of 9 km2. Within this area, data were collected on subsoil conditions, terrain elevations, groundwater levels, and the spatial pattern of development throughout the historical evolution of the agglomeration up to the present day. The analysis also identified the points in the city’s development history when local flooding or other environmental hazards occurred, which may have resulted from improper urban growth tendencies. Interpretation of the resulting graphs, particularly the interactions between geoenvironmental conditions (indicators) and development during the studied periods, can support urban planning processes.
Analiza cech materiałowych bloczków z perlitobetonu poddanych działaniu czynników atmosferycznych
Obecnie, w przypadku dużych inwestycji budowlanychoraz zmian klimatycznych obejmujących gwałtowne zjawiskapogodowe, trudno jest wypracować w harmonogramieprac budowlanych odpowiedni termin wykonywania prac. Gwałtowneulewy zdarzają się w miesiącach uznawanych wcześniejza odpowiednie do wykonywania niektórych prac budowlanych.W artykule poruszono zagadnienia stosowania zawilgoconychmateriałów podczas budowy przegród ściennych oraz wpływunadmiaru wilgoci na ich dalsze użytkowanie na przykładziebloczków z perlitobetonu. W pracy odniesiono się do wcześniejwykonanych badań dotyczących badania wilgoci, współczynnikaprzewodzenia ciepła, wytrzymałości oraz pokazano prototypowysposób odwzorowania niekorzystnych warunków atmosferycznychdla ściany z bloczków z perlitobetonu poddawanychsystematycznemu zawilgoceniu
Metody obliczania studni opuszczanych
W pracy przedstawiono metody obliczania studniopuszczanych, uwzględniając metody tradycyjne oraz współczesnenumeryczne metody obliczeniowe. Omówione zostały najważniejszezagadnienia, na które należy zwrócić uwagę przy projektowaniustudni, takie jak: zapewnienie studni pogrążalności,w przypadku posadowienia w gruntach nawodnionych, zagwarantowaniestudni stateczności na wypór, zaprojektowanie podwzględem wytrzymałościowym płaszcza studni, noża studni, korkabetonowego studni oraz płyty dennej, jak również uwzględnienietechnologii wykonywania studni.
Implementation of the Results of Experimental Studies with the Use of the Sclerometric Method of Plane Elements in Wooden Buildings
Wood is one of the basic building materials. It is a completely biodegradable raw industrial commodity, the resources of which, with proper forest management, are virtually inexhaustible. Additionally, its acquisition and processing does not require large inputs of fossil fuels. At the same time, forest areas which we obtain wood from neutralize the negative effects of producing and acquiring other raw materials, as one hectare of pine forest (the most popular in Poland) can absorb approx. 20–30 tons of CO2. Wood is characterised by low thermal and electrical conductivity, having simultaneously high sound insulation, which perfectly meets the requirements of the present market and its regulations. This study aimed at verifying the technical parameters of wood, i.e., its bending strength, with the use of an innovative method of the correlation between the bending strength measured along and across wood fibres. The procedure was envisaged as effective for testing the strength of beams in historic buildings, in which—due to their valuable structure—only a limited number of sample holes can be made. The aim of this experiment was to create tables and diagrams, from which, based on the correlation between the side and the head of the beam, using in situ tests and the sclerometric method, it will be possible to derive the bending strength of existing wooden beams. In the study of spruce and pine wood, a correlation between the recess from the side and the recess from the head was found, ranging from 0.64 to 0.76, with an average of 0.72 for spruce elements, and 0.66–0.84, with an average of 0.70 for pine elements. This means that when testing an element fixed in a building, measuring the parameters from the head of the beam with a Schmidt hammer (often such elements are more easily accessible, i.e., on the building facade), the obtained values should be multiplied by 0.72 for spruce elements and by 0.70 for pine elements to obtain the strength of the beam. The authors of this article indicate that the confirmation of this observation requires conducting further research on various types of wood. It should also be noted that the material collected from one batch of sawn timber had a different structure, which was proved by analysing it using SEM imaging. Modeling wood numerically is, to some extent, a simplified issue that assumes wood to be an orthotropic, homogeneous (homogeneous) material. In fact, wood is an anisotropic, very heterogeneous material. The analysis of wood (on the technical scale, construction wood) as an anisotropic material is practically impossible. Adopting wood as an isotropic material is too simplistic. Therefore, the most appropriate methods of strength testing are destructive methods, as all non-destructive methods should not be used without verifying the results with other methods. The results obtained by non-destructive testing pose great difficulties in their interpretation. Obtaining reliable results of experiments entails collecting a large number of research samples. The method described in this paper will allow for obtaining the necessary data for effective expertise assessment regarding the safety level of structural elements in historic wooden load-bearing structures, which is crucial for making conservation decisions.
Efficient Load-Bearing Capacity Assessment of a Degraded Concrete Manhole Using Sectional Homogenization
This study addresses a practical and efficient approach to evaluating the load-bearing capacity of severely degraded concrete manholes. Concrete deterioration, often advanced and highly irregular, can be captured accurately through surface scanning to create a detailed model of the damaged structure and also to build a simplified modeling to enable rapid engineering-level assessment, filling a critical gap in infrastructure maintenance. The repair strategy involves applying an internal polyurea layer, a variable-thickness polyurethane foam layer depending on the degree of localized degradation, and an external polyurea layer to restore the original shape of the manhole. However, these repairs do not fully restore the manhole’s original load-bearing capacity. A full 3D model, encompassing millions of finite elements, would provide a detailed analysis of strength reductions but is impractical for engineering applications due to computational demands. An alternative approach utilizing sectional homogenization is proposed, where sectional properties are sequentially averaged to calculate effective parameters. This approach enables the use of only a few hundred shell elements, each representing thousands of elements from the detailed 3D model, thus providing a rapid, engineering-level assessment of load-bearing reductions in degraded manholes. The study finds that while the repair method restores up to 76% of bending stiffness in heavily corroded sections, it does not fully recover the original load-bearing capacity.
Optimization of Rectangular Tank Cross-Section Using Trust Region Gradient Method
"In various industries, rectangular tanks are commonly used for storing liquids and other materials. The design and optimization ofthese tanks are crucial for ensuring structural integrity and material efficiency. Traditional designs often utilize constant wallthickness, which does not align optimally with the stress distribution, leading to potential overuse of materials and increased costs.Recent studies have shown that tanks with variable wall thickness, such as trapezoidal cross-sections, can better match stressdistributions, particularly under hydrostatic loads, resulting in more efficient use of materials. This research aims to build uponprevious studies by introducing an advanced optimization algorithm based on the Trust Region Gradient Method to further refinethe cross-sectional design of rectangular tanks. The primary objective is to minimize the material usage while maintainingstructural safety and performance under various load conditions, including hydrostatic pressure and thermal effects. The proposedalgorithm iteratively adjusts the tank's wall thickness, seeking an optimal configuration that reduces bending moments andmaterial costs. Initial static calculations is verified using the finite difference method, emphasizing energy minimization conditionsfor elastic strain in bent plates on elastic foundations. This approach is compared with traditional discretization methods tovalidate accuracy. The trust region method is then applied to optimize the design, with a focus on achieving a balance betweenstructural integrity and economic feasibility. Preliminary results indicate that the trust region gradient method can significantlyenhance the design process, leading to substantial material savings and improved structural performance. The algorithm'seffectiveness is demonstrated through case studies comparing tanks with constant and variable wall thickness. This researchcontributes to sustainable construction practices by promoting designs that use materials more efficiently and meet safetystandards."
Selected aspects of the design and construction of reinforced concrete sunk wells
The article provides basic information on the design and construction of sunk wells. Sunk wells are enginee-ring structures commonly used in construction, particularly under difficult soil conditions or when construction sites have a small area. Sunk wells are made using the “cut and lower” method, which means that the first segment to be lowered is equipped with a cutting-edge section (bottom blade) that cuts into the soil and the structure sinks into it. In design, it is necessary to take into account the phased execution of these structures and their spatial work. The article presents the loads working during the construction and operation of sunk wells, as well as the assumptions and guidelines for static calculations and dimensioning. When the sunk well steining is significantly high (the well is embedded deep), concreting and lowering are most often performed in two or three segments. The article describes the subsequent steps taken during the implementation of sunk wells, constantly changing static diagrams and the method of adopting them in calculations. It also presents the method of lowering sunk wells with possible implementation difficulties. The article is supplemented with exemplary drawings of the steining reinforcement, cutting-edge section and bottom plate of the well and the photos of selected realizations.
Evolution of Energy Efficiency of Buildings Using the Guidelines of the European Green Deal Plan
In contemporary literature, there are not many analyses taking into account changing heat transfer coefficients over the years and examining and comparing the variability of insulation thickness in different thermal standards. The article presents the evolution of energy demand taking into account the requirements of the Green Deal. The analysis was carried out using two materials, showing how their thickness changed in relation to the evolving energy requirements. The research was illustrated with an example of thermal modernization for a building in specific time periods. The analysis was carried out using a numerical program, comparing warming variants for individual years using the Index of annual primary energy demand. Following the requirements contained in the EPDB directive, a comprehensive reduction of the penetration coefficients for building partitions was proposed and requirements for the mandatory use of mechanical ventilation and photovoltaics were introduced.
Biocementation as a Pro-Ecological Method of Stabilizing Construction Subsoil
The principle of sustainable development imposes an obligation on societies to manage natural resources rationally and to care for the quality of the environment, by, among other things, reducing CO2 emissions. Alternative ways of stabilising building substrates by increasing their shear strength (cu) are increasingly being sought. This paper presents how microorganisms can influence cu and thus the load-bearing capacity of building substrates. Tests were performed in a triaxial compression apparatus in three variants. The first variant of testing was carried out on cemented soil samples, which were cemented in situ. The next two series of tests were performed on reconstructed samples, i.e., natural soil and soil inoculated with a solution of Sporosarcina pasteurii bacteria. The results obtained show that carbonate cementation increases the shear strength of the soil; in addition, this biomineralization-induced cementation gives higher cu results than natural carbonate cementation.
Analiza wrażliwości ustroju nośnego konstrukcji nawystąpienie oddziaływania o charakterze wyjątkowym
W artykule przedstawiono wrażliwość elementówkonstrukcyjnych budynku na oddziaływanie o charakterze wyjątkowym.Podjęto się analizy awarii budynku mieszkalnego po uderzeniusamochodem ciężarowym. W obliczeniach uwzględnionoróżne symulacje obciążeń ze względu na prędkość poruszającegosię pojazdu. Celem przeprowadzonych badań i analiz byłowskazanie uszkodzeń konstrukcji nośnej obiektu wynikającychz oddziaływań wyjątkowych. Wnioski wynikające ze skutków katastrofywskazują na konieczność uwzględniania zdarzeń wyjątkowychoddziaływania pojazdów na konstrukcje budynków lubteż wyznaczenia stref bezpiecznych w obrębie dróg.
Three-layer Repair Coating System for Manholes, Pump Stations, and Tanks in Aggressive Sulfate Environment
Advancements in the repair and protection of water and wastewater infrastructure are now focused on using an innovative material called polyurea. Distinguished by its rapid curing time and versatile applications, polyurea is applied using a spray gun with high-pressure pumps. The introduction of new building materials is part of ongoing efforts to meet stringent environmental, health, and performance standards, and polyurea offers significant improvements by eliminating solvents and volatile organic compounds (VOCs). This paper presents a technological protocol starting with inspection and cleaning, followed by drying, and ending with the application of three layers: a moisture-blocking base layer, a rigid polyurethane middle layer for structural reinforcement, and a final sealing and anti-corrosion layer. This innovative method ensures a homogeneous, seamless structure, enhances construction durability, and accelerates the repair process, allowing immediate resumption of operation. Designed specifically for aggressive wastewater environments, this system is characterized by excellent corrosion resistance, making it ideal for water and wastewater infrastructure elements such as reinforced concrete manholes, sewage pumping stations, and tanks. Customizable polyurea properties allow personalization based on environmental aggressiveness, structure size, and abrasion resistance, representing a significant advancement in infrastructure maintenance technology. The paper showcases this modern repair and renovation method, highlighting its applications, benefits, and potential to revolutionize water and wastewater infrastructure maintenance in challenging conditions. The effectiveness of this solution is also compared with traditional methods, demonstrating the superiority of the three-layer system in terms of waterproofing, sulfuric acid resistance, monolithic structure, and application time.
Optimal Design of Rectangular Tank Walls With Ribs Using Numerical Models and Global Optimization
This paper addresses the optimization of the cross-section in rectangular above-ground tank walls, incorporating vertical ribs and an optional top ring. The objective is to minimize the volume of concrete used, while maintaining key performance criteria such as keeping the maximum tensile stress below the material’s allowable limit and minimizing deflections. The analysis is performed using the finite element method (FEM), with the optimization handled through a local gradient-based algorithm (trust region method), supported by a multistart technique to navigate the complexity of the design space and avoid suboptimal solutions. The results demonstrate that this approach effectively reduces concrete consumption without exceeding the tensile stress limits or causing excessive deflection, offering more efficient and cost-effective designs for rectangular tanks used in water storage applications. This method provides valuable insights into the balance between material usage and performance constraints, contributing to sustainable engineering practices.
Application of Experimental Studies of Humidity and Temperature in the Time Domain to Determine the Physical Characteristics of a Perlite Concrete Partition
These days, the use of natural materials is required for sustainable and consequently plus-, zero- and low-energy construction. One of the main objectives of this research was to demonstrate that pelite concrete block masonry can be a structural and thermal insulation material. In order to determine the actual thermal insulation parameters of the building partition, in situ experimental research was carried out in real conditions, taking into account the temperature distribution at different heights of the partition. Empirical measurements were made at five designated heights of the partition with temperature and humidity parameters varying over time. The described experiment was intended to verify the technical parameters of perlite concrete in terms of its thermal insulation properties as a construction material used for vertical partitions. It was shown on the basis of the results obtained that the masonry made of perlite concrete blocks with dimensions of 24 × 24.5 × 37.5 cm laid on the mounting foam can be treated as a building element that meets both the structural and thermal insulation requirements of vertical single-layer partitions. However, it is important for the material to work in a dry environment, since, as shown, a wet perlite block has twice the thermal conductivity coefficient. The results of the measurements were confirmed, for they were known from the physics of buildings, the general principles of the formation of heat and the moisture flow in the analysed masonry of a perlite block. Illustrating this regularity is shown from the course of temperature and moisture in the walls. The proposed new building material is an alternative to walls with a layer of thermal insulation made of materials such as polystyrene or wool and fits into the concept of sustainable construction, acting against climate change, reducing building operating costs, improving living and working conditions as well as fulfilling international obligations regarding environmental goals.
