bluuebunny/crossref_metadata_2025_split huggingface dataset:
Laboratory Tests on Composite Beam - Accuracy of Modal Analysis Results
Authors: Sokol Milan , Sismisova Zuzana 
Published: September 2019

Abstract
The primary aim of this research was to verify accuracy of results of the modal analysis on the composite beam. The research is based on the identification technique, which determines structural characteristics from the measured values of dynamic response. The method uses measured data to optimal update of the stiffness matrix to get numerical model that matched with measured data. This can be used for further calculation to determine the effect of damage to the stiffness of the beam. The experimental beam was made of wooden boards and plasterboards, which were attached to each other by a lot of screws. It was simply supported beam of total length 4m. The stiffness characteristic of beam was determined from experimental measurement of the beam deflection from a load. A total of 24 accelerometers were placed along of the beam. Accelerometers were recording vertical acceleration and the acceleration measurement record lasted for 60 seconds. We gained amplitude spectrum of acceleration from the measured acceleration values by using the fast Fourier transform (FFT). The first eigenfrequencies were determined from the amplitude spectrum. The measured value of first frequencies was f1 = 11.7Hz while the calculated value of first frequency was f1 = 11.6Hz. Other frequencies and shapes were also calculated and measured. When comparing them we need to be careful. The spacing of the transducers very well describes the vertical bending shapes while there is little information about torsional vibration shapes. We are planning extend these results by measurement with a pair of accelerometers located along the beam to verify torsional mode-shapes too. The conclusions and results of this experiment are used in calculations for system identification and determination the change in stiffness value of the damaged beam. The beam corrupted by removing the screws from the beam has changed the stiffness properties of the beam. This change is reflected as increment/decrement of original stiffness matrix - adjusted stiffness matrix.
Solution of Integral Equations Arising in Mathematical Problems of Construction Science, using the Bogolyubov – Krylov method
Authors: Koshev Alexander , Kuzina Valentina 
Published: September 2019

Abstract
The possibility of a numerical solution of construction problems leading to Fredholm integral equations of the first and second kinds is considered. The following problems of building sciences, for example, lead to such equations: in the theory of elasticity – elastoplastic torsion of bodies, stress concentration in a body during its bending; in the theory of vibrations, in the mechanics of structural failure – in the formation of cracks; when studying non-stationary phenomena in solids – non-stationary heat transfer, quasistatic viscoelasticity, propagation of longitudinal and transverse waves and other processes. According to the formulas of numerical integration, the problem can be reduced to a system of linear algebraic equations with a matrix of coefficients, which can be ill-conditioned, and the task is classically incorrect. This circumstance complicates its decision by traditional methods. To solve ill-posed problems similar to the problem in question, there are classical regularization methods. However, the numerical implementation of regularizing algorithms is not always easy to implement. In this regard, the goal of our study was to develop a numerical method for solving the Fredholm integral equations of the first and second kinds, which allow solving such problems without using regularization methods. The authors propose to solve problems of this type on the basis of the Bogolyubov – Krylov formula for representing certain integrals, in the form of finite-dimensional sums. At the same time, it becomes possible to use a non-uniform grid of nodes for splitting the integration interval. To efficiently define the set of nodes for splitting the integration interval, it is proposed to use a priori information about the properties of the solution of the problem. For example, the number of split points of the integration interval increases where the intended solution undergoes the most rapid changes, and decreases in areas where the intended solution is close to linear. The optimal arrangement of the splitting nodes of the integration interval makes it possible to increase the conditionality of the system of linear equations corresponding to the difference analogue of the problem and, thereby, to prevent the divergence of the iterative process. The article provides an example of calculating the optimal arrangement of the nodes splitting the integration interval when solving a test problem.
Mathematical Modeling of the Process of Humid Absorption in a Porous Medium on the Example of Moisture of Lime Composites
Authors: Kuzina Valentina , Koshev Alexander , Sukhov Ivan 
Published: September 2019

Abstract
A mathematical description of the dependence of the equilibrium moisture content of the porous material of the lime composite on the relative humidity of the air - curves of moisture adsorption in the material under study is considered. Mathematical modeling of the moisture absorption process was performed on the basis of the representation of a certain elementary volume of a lime composite in the form of a volume-porous medium with averaged physicochemical parameters. Mathematical modeling is used for theoretical study of the laws of the process of wetting dry construction mixes. Comparison of calculated and experimental data is carried out, their good consistency is shown. The moistened material is a material with a developed surface throughout the volume and can be considered as a porous medium with effective characteristics distributed throughout the volume, such as porosity, thermal conductivity, mass diffusivity, adsorption characteristics, etc. In the process of moistening the material of the medium at each point of the porous space, an adsorption reaction occurs moisture, which has its macro and microkinetic patterns. Moist air is supplied to the internal, hard-to-reach areas of the porous material due to diffusion and air flow caused by various reasons. The speed of the microscopic reaction of wetting the surface of the composite granules should be taken into account in accordance with the theory of the dependence of the moisture content of the material on the relative humidity of the air. Analysis of the type of sorption curves makes it possible to notice that for a mathematical description of experimental dependence, it is advisable to distinguish two sections on each curve: a section with a bulge up and a segment with a bulge down. The basic equation of moisture transfer in a porous medium is a three-dimensional parabolic differential equation. Under certain conditions, the process of moistening a porous material has the same regularities on any straight line perpendicular to the air-medium interface, which makes it possible to reduce the equation to one-dimensional in spatial variables. The presented calculation results show that the value of the diffusion coefficient significantly affects the process of moistening a porous material and can be used as a measure of the possible moisture content of the composite.
Natural thermal loads and their influence on airfield concrete slabs
Authors: Malgorzata Linek , Patrycja Piotrowska-Nowak 
Published: September 2019

Abstract
The article presents theoretical aspects of the influence of environmental changes on the extent of the recognized stress in the case of airfield concrete slab. Analyses included actual measurement data from 34 weather stations located within the area of Poland. The results obtained between 2000 and 2016 were used to prepare climatic data base of the selected regions. The analyses included maps of typical values taking into consideration daily, monthly and annual variations. In case of exemplary data from Kielce station, the influence of external conditions on the extent of the registered stress and deformations of airfield concrete slab was determined. According to the obtained test results, the significant influence of environmental conditions on changes of concrete slab strains was confirmed. Recommendations aiming at limiting negative influence of environmental conditions on concrete slab strains were suggested in case of the analysed area.
Optimisation of the innovative hydraulic binder composition for its versatile use in recycled road base layer
Authors: Mazurek Grzegorz , Iwanski Marek 
Published: September 2019

Abstract
The paper presents results obtained on the basis of tests carried out using the innovative hydraulic binder intended for a recycled base layer with foamed bitumen. The tested hydraulic binder consisted of three components: cement, hydrated lime and fines. The analysis includes: final time of mortar setting, volume change in mortar, compressive strength after 7 and 28 days of curing, bending strength after 7 and 28 days of curing. The analysis relied in identifying optimal compositions of innovative binder components in terms of its suitability for pavement recycled base layer. Optimisations considered obtaining a two variant such as: quick-setting and a normal-setting hydraulic binder. The analysis of test results indicate that there are solutions for binder compositions that meet the requirements for normal-setting of hydraulically bound base layer in recycled technology. In the scope of obtaining a quick-setting binder, at least 80% of cement binder in the innovative hydraulic binder composition is required.
Impact of Shocks on Cargo Securing During the Road Transport
Authors: Vlkovsky Martin , Binar Tomas , Svarc Jiri , Nemec Petr , Bucsuhazy Katerina 
Published: September 2019

Abstract
The paper deals with the impact of shocks on cargo securing during the road freight transport. Commonly used methods of cargo securing do not take into account the different quality of roads, therefore the cargo securing doesn´t have to comply with principles of safe fastening. The paper highligths the different values of shocks and inertia forces on different quality roads (highway and 3rd class road) based on data of conducted transport experiments. The resulting shocks (values of acceleration coefficients) are statistically significantly higher on 3rd class road than on highway even at half average speed. The optimization of calculation using acceleration coefficients and their correlation with the resulting inertia forces is included in separated part. The output of the paper is a methodical procedure to optimize the cargo securing during the road transport.
Optimization of inventory costs management in the construction enterprise
Authors: Rzepecki Lukasz 
Published: September 2019

Abstract
During planning the execution of each construction project, the factors that may affect the effectiveness of its realization should be analyzed in detail. The costs of execution construction projects are significantly influenced by (apart from technical factors) decisions in the field of inventory management, among others, variability of environmental conditions, prices of construction products, the ability to acquire local suppliers, distance of transport, limited size of storage for construction products as well as the individual character of the project. In projects related to the buildings erection and other construction works, there are many logistical tasks in the area of supply in construction products, raw materials, equipment, as well as in the area of financial and information flow. Taking into account the large share of material costs, inventory management in the costs of projects realization and the high potential for their reduction, every enterprise operating in the construction industry should pay a great importance to the supply logistics sector. Determination of the size and delivery times of construction products, as well as the transport routes, storage and reloading locations are decision-making problems that are solved by management of both the enterprise and the construction projects. The paper presents a proposal for a methodology, which allows to determination and comparison of the inventory management costs in enterprise conducting parallel works on several construction sites. Mathematical models have been developed which simulate the functioning of supply logistics systems and allow, through their solution, to determination of the minimum logistics costs with optimal arrangements for the supply schedule (delivery volumes in subsequent periods of the project execution). This is the foundation for the selection of the optimal variant of a supply chain management. The practical application of the methodology proposed is illustrated using an example.
Improving Living Conditions in Mass Housing of the Prefabrication Era: The User’s Point of View
Authors: Ostanska Anna 
Published: September 2019

Abstract
Maintenance of the housing stock of the mass prefabrication era poses a particular challenge due to the scale of the task. Prefabricated blocks of flats are the home of almost 50% of inhabitants of Polish cities - a home that is still in good technical condition and still desirable (good location, shortage of flats in the market). However, in the light of the present-day performance requirements, this housing stock calls for improvements, necessary to prevent loss of value and increase in maintenance cost. In the course of programming the estate modernization, the planner needs not only to select technically and economically justified measures, but also to assure they are approved by the owners of the apartments. The residents are rarely aware of what is technically possible in terms of retrofitting buildings and the estate infrastructure. Moreover, they may be unaware of what kind of long-term consequences are to be expected if improvements are implemented, and what if they are not. As observed in practice, a constructive dialogue between the housing estate management and the residents occurs rarely. Therefore, in order to examine the user’s point of view, the author designed and implemented an extensive survey project. The surveys are intended to be conducted every five years in consultation with the estate manager. They allow not only to passively observe the evolution of user preferences towards particular improvement proposals (changes in preferences caused by changing needs as well as a result of implemented modernization and renovation activities), but also to stimulate interest in upgrading the housing environment (e.g. improving accessibility, switching to renewable energy sources). The article presents the results and conclusions of two cycles of surveys in one of housing estates in Lublin, south-eastern Poland. Such results may provide the estate manager with useful input for retrofitting projects.
Creating a Smart City – Supporting Management of Regional Project Initiatives
Authors: Brudnicka Anna , Rybka Adam 
Published: September 2019

Abstract
Smart cities are developing fast and introducing new practices and services that have a strong impact on policy making and planning, while also interacting with urban facilities. It is now needed to understand the smart city’s contribution in the overall urban planning and vice versa, to recognize urban planning offers in the context of an intelligent city. The article is an attempt to preliminary analysis of the forms of innovation in small urban models for sustainable development, which can be used in an smart city. The structure of the review has been developed on the basis of conceptual framework of off-grid complex that unite selected regional specialties, the strategy of sustainable development and the process of connections, which has been chosen as a method of identifying paths of research in defined area. The result show that innovative projects for sustainable development strategy can be implemented using selected elements of data cloud computing, which would allow in the future strategy building in the cities based on selected categories of technologies and taking coherent actions in the area of innovative projects. The concept combines a variety of innovative technologies, where the outputs of one system are inputs of another. Further research is also required to develop appropriate measurement criteria for determining the effectiveness of strategies. The concept defined its main components, and outlines future directions to improve it.
Optimisation of Surface Finishes for Oriented Strand Board in Order to Increase Its Moisture Resistance
Authors: Kratochvilova Erika , Patloka Jiri , Slanhof Jiri 
Published: September 2019

Abstract
The purpose of the research is the optimisation of surface finishes for application to oriented strand board (OSB) in order to increase its moisture resistance. The aim of the research is to compare test specimens with different types of coating, spray, primer and waterproofing under predefined conditions and different forms of moisture exposure. The paper contains a definition of the basic material, test specimens and test methods, and covers 8 different types of surface finish materials selected for application to the test specimens. The results include graphs showing growth in humidity over time, specifically graphs showing the causal relationship between increases in weight and moisture absorption, as well as graphs depicting swelling in thickness. The results are also discussed. In the conclusion the results are evaluated and an outline of the next steps to take with regard to further research is formulated. The results are of benefit to all subjects concerned with wooden structures in which OSB is used, both at the design stage and at the stage of the preparation and execution of construction with respect to unpredictable weather conditions that can irreparably damage unprotected structures. In addition, these are results which are important for the operation of buildings during which a suitable surface finish can alleviate the consequences of later accidents and defects. They may also be beneficial during the construction of buildings from structural insulated panels who’s facing most often consists of OSB. Construction periods tend to be adversely affected by changes in the weather. The application of suitable surface finishes to OSB immediately during the prefabrication stage could eliminate this issue.
Stefan Kuryłowicz. Architecture of change 1989 - 2011
Authors: Goncikowski Marcin 
Published: September 2019

Abstract
The work of prof. arch. Stefan Kuryłowicz (1949-2011) marked a new chapter in the history of Polish architecture. His activity concurred with a profound socio-economic change that took place after the overthrow of the communist regime. For Polish architecture, this situation was a deeply pioneering one, as it brought the need of developing new types of buildings and a necessity to develop a different standard of architectural services. Design activities of prof. Stefan Kuryłowicz were combined with didactic and scientific work at the Faculty of Architecture of the Warsaw University of Technology. The result of his academic involvement were publications containing texts referring to: the theory of architecture, principles of practicing the profession and analysis of the change of public spaces. The paper shows architectural works of prof. Kuryłowicz and his theoretical description of the discipline on the background of the time in which both, building design and theory, were created and formulated by him. The main theme of theoretical achievements of prof. Stefan Kuryłowicz is the relationship of built architectural work and concepts of idea, expression and message. The idea is understood as principles formulated at the design concept stage. Expression of the work - as the sum of materially built means, that may realize the idea. The message - as a result of activities of all parties involved in the team’s creation of the architectural object and the influence of the environment of realisation shaped a part of the meaning of the architecture. The message in his interpretation becomes a way of denoting a part of the possible meaning of architecture. The analysed objects are: competition works from which a set of buildings of the Baltic Opera in Gdańsk (1973) and a set of buildings of Operetta Dolnośląska in Wrocław (1975) were selected, sacral buildings from which the church in Nowy Dwór Mazowiecki (1979-1984) was chosen, commercial buildings of public utility - Fuji Film (1993), Zielna Point (1998), Nautilius (1996), Focus (1997), PLL LOT (1999), housing - Eko-Park estate (2002) and the National Forum of Music (2008). Buildings - awarded regularly - have become the determinant of the typology for Polish architecture in the environment of freedom after the transition of 1989. Prof. Stefan Kuryłowicz died in a plane crash in Spain in 2011.
How Relevant is Energy Efficiency in The Marketing of Homes? Evidence from Real Estate Agents in Spain
Authors: Marmolejo-Duarte Carlos , Spairani Silvia , Moral Consuelo del , Delgado Luis , Egusquiza Aitziber , Ai Chen 
Published: September 2019

Abstract
In order to foster informed transactions, the Energy Performance of Buildings Directive has made it mandatory to get an Energy Performance Certificate in the marketing of the Communitarian Real Estate. Due to energy savings and environmental preservation, it is expected that efficient buildings do receive an increased willingness to pay. The evidence coming from a number of statistical studies has confirmed the existence of such premium. Nevertheless, such finding is contradictory in relation to the conclusions of opinion-based studies. This paper seeks to study whether energy efficiency drives market price and the marketing of homes in Spain. In doing so, a survey applied to realtors across the country has been implemented. The results are in line with other opinion-based studies pointing out that energy performance has a negligible impact on the marketing of homes. Furthermore, real estate agents suggest that companion policies in the sphere of subsidies and fiscal exceptions are needed in order to bring energy efficiency to the first line of elicitation attributes in the residential market.
Effect of Adhesion Between EPS Granules and Cement Matrix on the Characteristics of Lightweight Concretes
Authors: Major Maciej , Halbiniak Jacek 
Published: September 2019

Abstract
The paper presents the results of examinations of the effect of modification of EPS granulate on the compressive strength of lightweight concrete composites. EPS granulate was used to volumetrically replace mineral aggregate with the amount of 50% and 75%. Modification of EPS granulate consisted in coating with cement slurry and cement slurry with silica dust. It was found that the coating of the EPS granulates followed by preparation of the concrete mix leads to an increase in adhesion of EPS to the cement matrix. This results in significantly higher compressive strength compared to concrete based on unmodified EPS aggregate. Concrete made with 50% of EPS granules previously coated with cement slurry with silica dust obtained an average compressive strength of 18.3 MPa, which was by 18.1% higher than that of concrete with unmodified EPS.