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Decision-support tools for diagnosing and selecting the optimal method of repairing buildings
This study introduces an innovative algorithm that leverages Terrestrial Laser Scanning (TLS) and the Fuzzy Analytic Hierarchy Process (FAHP) for the optimization of building repair methodologies. Focusing on multi-criteria decision-making (MCDM), it showcases a methodology for evaluating and selecting the most effective repair strategy for building elements, balancing various conflicting criteria. The research applies TLS for rapid and accurate geometric data acquisition of engineering structures, demonstrating its utility in structural diagnostics and technical condition assessment. A case study on a single-family residential building, experiencing floor deformation in a principal ground-floor room, illustrates the practical application. Maximum deflection and floor deflection distribution were measured using TLS. Utilizing FAHP for analysis, the decision model identifies the most advantageous repair method from a building user’s perspective. This approach not only provides a systematic framework for selecting optimal repair solutions but also highlights the potential of integrating advanced scanning technologies and decision-support methods in the field of building materials and structural engineering.
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.
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."
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.
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.
Numerical analysis of the ground temperature function depending on edge thermal insulation parameters for shallow slab foundations
Elastic Analysis of Three-Layer Concrete Slab Based on Numerical Homogenization with an Analytical Shear Correction Factor
Sandwich structures are widely used in construction, as well as in the aviation, spaceship, and electronics industries. The interesting result, among others, is the fact that individual layers can be freely selected to meet the planned requirements. In the case of sandwich structures in construction, they must meet the requirements of load-bearing capacity, thermal, and acoustic insulation, and additionally, they must be resistant to biological and chemical corrosion. The paper presents calculation algorithms for Hoff’s three-layer panels. In the first case, the well-known and proven method of finite differences in variation terms was used, assuming actual geometrical and material parameters. In the second case, the numerical homogenization method of the layered panel was used, replacing the stiffnesses of individual layers with a homogeneous equivalent plate with substitute stiffness corrected in shearing by an analytically derived shear correction factor. A comparative analysis of the results of the calculations with the use of both approaches was carried out. A good agreement between the displacement values and the calculated cross-sectional forces was obtained. On this basis, it can be assumed that the static analysis of a slab by simplified methods using numerical homogenization with an analytical shear correction factor is appropriate and can be applied to layer structures.
Influence of Variable Moisture Conditions on the Value of the Thermal Conductivity of Selected Insulation Materials Used in Passive Buildings
The interest in passive construction that has low demand for thermal energy continues to grow every year. It is related to both the reduction in maintenance costs of buildings and the growing environmental awareness in societies. Passive houses are characterised by very good thermal insulation properties of their external partitions. This paper presents the results of tests on the thermal conductivity for three different types of building materials, assuming their use as thermal insulation. The materials were subjected to water absorption tests during long-term immersion. The purpose of this study was to simulate water absorption caused by long-term water exposure. The tests were carried out on a perlite concrete block, a sheet of polyurethane foam applied by spraying and expanded clay in a loose form in three different fractions. The tested insulation materials were selected due to their different form, structure, and porosity characteristics, which largely determined the value of the thermal conductivity. A perlite concrete block is a new, innovative product, of which manufacturer’s data are not yet available as the product is currently at the stage of detailed research. The results were analysed statistically and used in graphs to show the dependence of the value of the thermal conductivity on moisture content of the samples. The purpose of this study was to indicate the importance of the proper incorporation of insulation materials into buildings, their storage before construction and use in the post-construction phase. Building standards for passive houses place high demands on materials used. In order to fully enjoy the advantages of passive buildings, i.e., lower energy consumption and benefits for the natural environment due to lower consumption of energy generated from non-renewable energy sources, it is necessary to use certified building materials and ensure proper use of objects. The studies quoted in this paper indicate to what extent the influence of moisture content negatively affects the properties of insulation materials in external partitions.
Modele pracy termoizolacji w obszarze wieńca w dachach z kratownic prefabrykowanych
Artykuł podejmuje problematykę zapewnieniaciągłości termoizolacji w obszarze wieńca w dachach wykonanychz kratownic prefabrykowanych, stanowiących coraz popularniejszerozwiązanie w budownictwie mieszkaniowym. W pracyzidentyfikowano kluczowe wyzwania techniczne, główniezwiązane z trudnościami w integracji warstw termoizolacyjnychz konstrukcją dachową i elewacją. Przeprowadzono analizę wybranychwariantów rozwiązań termoizolacyjnych, oceniając ichefektywność cieplno-wilgotnościową oraz pozostałe aspektyistotne dla poprawności i trwałości zastosowanych rozwiązań.Wyniki badania podkreślają znaczenie właściwego projektowaniadetali konstrukcyjnych, które pozwalają zminimalizować stratyciepła i zapobiec potencjalnym problemom związanym z zawilgoceniem.Artykuł dostarcza praktycznych wskazówek dlaarchitektów i inżynierów, wspierając ich w tworzeniu bardziejefektywnych, trwałych i zgodnych z nowoczesnymi standardamirozwiązań budowlanych.
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.
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.
Diagnostics and Multi-criteria Analysis of Methods for Drying Buildings After Flooding. Case Study
This article presents guidelines for moisture and mycological diagnosis procedures for buildings after flooding. This paper proposes a division of the diagnostic procedure according to the medium of action and collects and presents methods for drying building elements. 54 companies dealing with drying were analyzed. The task of dehumidification is to use various methods to reduce the moisture level of building partitions to the equilibrium moisture level. An analysis of dehumidification methods in terms of ease of application, duration of the dehumidification process and level of structural interference is presented. In Poland, there are no guidelines formulated in legal acts or instructions regarding the procedure for moisture diagnostics and nor drying. It was noted that in situ studies cannot always lead to determining the actual values of mass moisture and thus to creating a real model of partition drying.
Experimental evaluation of the size and distribution of lateral pressure on the walls of the excavation support
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.
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
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.
