Initial State Sorption Measurements

2016 ◽  
Vol 824 ◽  
pp. 589-597
Author(s):  
Akos Lakatos
Keyword(s):  
Building Materials ◽  
Expanded Polystyrene ◽  
Point Of View ◽  
Building Structures ◽  
Fibrous Materials ◽  
Initial State ◽  
Insulating Materials ◽  
Building Physics ◽  
Short Time ◽  
Building Engineering

This paper highlights wetting measurements and results carried out on four different generally used construction and some insulating materials, executed in our Building Physics laboratory in University of Debrecen, Faculty of Engineering, Debrecen, Hungary. The measurements focused on the initial state of the water up-takin procedure (240 min wetting) only, waiting for the equilibrium moisture content was not a goal of this paper. Currently, Aereated concrete, small solid brick, Porotherm and ceramsite-concrete structural members are usually applied in building structures. The measurements of water sorption investigations are so significant from the point of view of thermal sizing of the buildings. To put it simply this article can be imagined as a short time wetting sorption database comparing with our previous results, besides this article can be very useful for everyone in building physics and in building engineering. In addition building materials, insulating materials were tested and will be put forward, as well, eg.: expanded polystyrene, extruded polystyrene, poly-urethane, and some fibrous materials. Totally, 11 materials were investigated, after drying in a Venticell 111 type desiccator apparatus at 343 K to changeless weight and then wetting in a Climacell 111 type climatic chamber, where the relative humidity was varied from 25% to 95% at 293K for 240 min. As result, new isotherm curves for this short time wetting will be presented and will be compared to the literature data, MSZ-04-140-2-1991.

Measurements of Thermal Properties of Different Building Materials

2014 ◽  
Vol 1016 ◽  
pp. 733-737 ◽  
Author(s):  
Akos Lakatos
Keyword(s):  
Thermal Properties ◽  
Building Materials ◽  
Measurement Methods ◽  
Point Of View ◽  
Laboratory Measurements ◽  
Insulating Materials ◽  
Flux Measurements ◽  
Thermal Properties Of Materials ◽  
Properties Of Materials ◽  
Building Physics

In this paper we present measurements and measurement methods carried out on construction and building materials in our Building Physics laboratory in University of Debrecen, Faculty of Engineering, Hungary. The investigations with different methods are so significant from the point of view of thermal sizing and designing of the buildings. The laboratory measurements of the thermal properties of materials and in-built structures are very important either for the manufacturers or the designers. In this communication the measurement result are presented. Thermal conductivities will be calculated after steady state thermal resistance measurements both from Calibration hot box (CC) and Heat Flux measurements carried out by Hukseflux (HF) apparatus. Calorific values of some insulating materials will be presented after combusting them in a CAL2K ECO type bomb calorimeter.

Comparison of the Thermal Properties of Different Insulating Materials

2014 ◽  
Vol 899 ◽  
pp. 381-386 ◽  
Author(s):  
Akos Lakatos
Keyword(s):  
Thermal Conductivity ◽  
Thermal Properties ◽  
Material Constant ◽  
Mineral Wool ◽  
Expanded Polystyrene ◽  
Point Of View ◽  
Building Structures ◽  
Transfer Coefficients ◽  
Insulating Materials ◽  
Thermal Insulating

Currently thermal insulating of the buildings is sorely needed from the point of view of energy as well as money savings. It is important to highlight that the most commonly used insulation materials in the building sector are the expanded polystyrene (EPS), the extruded polystyrene (XPS) and the fibrous (mineral, rock) ones. In this communication we confront 6 different insulating materials slabs (EPS 30, 100, 150, 200, a yellow XPS and a mineral wool by their thermal properties. Therefore two types of hypothetic building structures were created and they were insulated with the above presented materials from 0.01 m to 0.3 m thicknesses. For the calculations the thermal conductivity of each sample was determined using a Holometrix 2000 (HLS) heat flow meter. As a result their heat transfer coefficients, delaying abilities, energy storing capabilities and thermal diffusion coefficients were confronted. Besides a material constant had been defined and was paired with the measured thermal conductivity.

Problems of Current Classification of Building Materials in the Context of Solution of Structure Fire Safety

2014 ◽  
Vol 1057 ◽  
pp. 204-211
Author(s):  
Róbert Leško ◽  
Martin Lopušniak
Keyword(s):  
Fire Safety ◽  
Building Materials ◽  
Point Of View ◽  
Building Structures ◽  
Innovative Solutions ◽  
Energy Economy ◽  
Negative Impacts ◽  
Continuous Demand ◽  
New Procedures

Fire safety, as one of six basic requirements for structures in Slovakia, does not reflect the increase of innovative solutions during last years in the field of building industry. At the present time, energy economy of structures sets the character of structures forming the heat exchange envelope of the building. Continuous demand for the application of ecological materials increases requirements for optimizing the existing or creating new procedures in the solution of fire safety of structures. The existing classification of building structures appears, from the point of view of fire safety, as insufficient one. Comparative analysis of different structural compositions of external cladding is the method that demonstrates in this paper unsuitability of criteria set. The development of new procedures can make more effective and can optimize requirements without any negative impacts on resulting fire safety of the structure.

Case Studies of Rising Damp Treatment in Historical Buildings

2017 ◽  
Vol 10 ◽  
pp. 107-119
Author(s):  
A.S. Guimarães ◽  
J.M.P.Q. Delgado ◽  
V.P. de Freitas
Keyword(s):  
Building Materials ◽  
Ventilation System ◽  
Technical Specification ◽  
Residential Building ◽  
Ventilation Rate ◽  
Building Structures ◽  
Practical Application ◽  
Salt Damage ◽  
Building Physics ◽  
Rising Damp

Salt damage can affect the service life of numerous building structures, both historical and contemporary, in a significant way. Therefore, various conservation methods have been developed for the consolidation and protection of porous building materials exposed to the salt attack. As any successful treatment of salt damage requires a multidisciplinary attitude, many different factors such as salt solution transport and crystallization, presence and origin of salts in masonry, and salt-induced deterioration are to be taken into account. The importance of pre-treatment investigations is discussed as well; in a combination with the knowledge of salt and moisture transport mechanisms they can give useful indications regarding treatment options.Another important cause of building pathologies in buildings is the rising damp and this phenomenon it is particularly more severe with the presence of salts in water. The treatment of rising damp in historic building walls is a very complex procedure. At Laboratory of Building Physics (LFC-FEUP) a wall base hygro-regulated ventilation system was developed. This system patented, HUMIVENT, has been submitted to laboratorial monitoring and to in situ validation and a numerical simplified model was developed to facilitate the practical application. Having in mind the practical application of scientific and technological knowledge from Building Physics to practice, this paper presents the design of the system (geometry, ventilation rate and hygrothermal device), the detailing and technical specification of its different components and information about the implementation in three types of buildings: a church, a museum and a residential building.

scholarly journals Salt Damage and Rising Damp Treatment in Building Structures

2016 ◽  
Vol 2016 ◽  
pp. 1-13 ◽  
Author(s):  
J. M. P. Q. Delgado ◽  
A. S. Guimarães ◽  
V. P. de Freitas ◽  
Iñigo Antepara ◽  
Václav Kočí ◽  
...  
Keyword(s):  
Building Materials ◽  
Environmental Control ◽  
Treatment Options ◽  
Ventilation System ◽  
Mineral Wool ◽  
Building Structures ◽  
Salt Damage ◽  
Complex Procedure ◽  
Building Physics ◽  
Rising Damp

Salt damage can affect the service life of numerous building structures, both historical and contemporary, in a significant way. In this review, various damage mechanisms to porous building materials induced by salt action are analyzed. The importance of pretreatment investigations is discussed as well; in combination with the knowledge of salt and moisture transport mechanisms they can give useful indications regarding treatment options. The methods of salt damage treatment are assessed then, including both passive techniques based on environmental control, reduction of water transport, or conversion to less soluble salts and active procedures resulting in the removal of salts from deterioration zones. It is concluded that cellulose can still be considered as the favorite material presently used in desalination poultices but hydrophilic mineral wool can serve as its prospective alternative in future applications. Another important cause of building pathologies is the rising damp and, in this phenomenon, it is particularly severe considering the presence of salts in water. The treatment of rising damp in historic building walls is a very complex procedure and at Laboratory of Building Physics (LFC-FEUP) a wall base hygroregulated ventilation system was developed and patented.

Resistance of Binding Systems of Various Compositions to the Action of Molds

2020 ◽  
Vol 786 (11) ◽  
pp. 41-46
Author(s):  
V.V. STROKOVA ◽  
◽  
V.V. NELUBOVA ◽  
M.N. SIVALNEVA ◽  
M.D. RYKUNOVA ◽  
...  
Keyword(s):  
Aging Process ◽  
Building Materials ◽  
Environmental Safety ◽  
Fungal Resistance ◽  
Building Structures ◽  
Vital Activity ◽  
Regulatory Documents ◽  
Living Organisms ◽  
Biological Corrosion ◽  
Test Objects

The dynamic development of urbanization contributes to an increase in emissions of industrial waste, which is the cause dysfunction of the ecosystem balance and leads to the development of biological corrosion on building materials associated with the products of the vital activity of microorganisms. In this regard, it is necessary to assess the resistance of composites to predict the durability of building structures under conditions of biological influence of microorganisms. Binder systems of various compositions were studied: cementless nanostructured binders (NB) based on quartz sand and granodiorite, gypsum, Portland cement and alumina cement. The toxicity of binders was assessed by biotesting on living organisms – cladocerans Daphnia Magna – according to the criteria of the intensity of their growth and viability. As a result, the high environmental safety of NB is substantiated, and the ranking of the studied binders according to the degree of increase in their toxicity to test objects is presented. Fungal resistance was assessed by the ability of molds for growing and reproduction on the studied samples. It was found that the most active in terms of the development of binders were representatives of the genus Aspergillus, the intensity of growing of which in all variants did not decrease below 3 points. Gypsum and NB were especially vulnerable, where the degree of fouling repeatedly reached 5 points. Even the initially biostable cement, after the aging process, lost its stability at different extent. The obtained results indicate the need to increase the resistance of composites for various purposes under conditions of biocorrosion at the stage of design and updating of regulatory documents, including tests for fungal resistance in the list of mandatory.

scholarly journals Post-Fire Susceptibility to Brittle Fracture of Selected Steel Grades Used in Construction Industry—Assessment Based on the Instrumented Impact Test

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3922
Author(s):  
Mariusz Maslak ◽  
Michal Pazdanowski ◽  
Marek Stankiewicz ◽  
Paulina Zajdel
Keyword(s):  
Charpy Impact ◽  
Water Mist ◽  
Heating Regime ◽  
Building Structures ◽  
Initial State ◽  
Slow Cooling ◽  
Natural Fire ◽  
Development Scenarios ◽  
Steel Grades ◽  
Fire Conditions

The change in the value of the breaking energy is discussed here for selected steel grades used in building structures after subjecting the samples made of them to episodes of heating in the steady-state heating regime and then cooling in simulated fire conditions. These changes were recorded based on the instrumented Charpy impact tests, in relation to the material initial state. The S355J2+N, 1H18N9T steels and also X2CrNiMoN22-5-3 duplex steel were selected for detailed analysis. The fire conditions were modelled experimentally by heating the samples and then keeping them for a specified time at a constant temperature of: 600 °C (first series) and 800 °C (second series), respectively. Two alternative cooling variants were investigated in the experiment: slow cooling of the samples in the furnace, simulating the natural fire progress, without any external extinguishing action and cooling in water mist simulating an extinguishing action by a fire brigade. The temperature of the tested samples was set at the level of −20 °C and alternatively at the level of +20 °C. The conducted analysis is aimed at assessing the risk of sudden, catastrophic fracture of load-bearing structure made of steel degraded as a result of a fire that occurred previously with different development scenarios.

scholarly journals Architectural ruins: geoculture of the anatomy of buildings as illustrated by Casa Ippolito, Malta

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Lino Bianco
Keyword(s):  
Material Culture ◽  
Building Materials ◽  
Raw Materials ◽  
Primary Source ◽  
Secondary Sources ◽  
Non Invasive ◽  
History Of ◽  
Aerial Vehicle ◽  
Materials Used ◽  
Building Physics

AbstractRuins are a statement on the building materials used and the construction method employed. Casa Ippolito, now in ruins, is typical of 17th-century Maltese aristocratic country residences. It represents an illustration of secondary or anthropogenic geodiversity. This paper scrutinises these ruins as a primary source in reconstructing the building’s architecture. The methodology involved on-site geographical surveying, including visual inspection and non-invasive tests, a geological survey of the local lithostratigraphy, and examination of notarial deeds and secondary sources to support findings about the building’s history as read from its ruins. An unmanned aerial vehicle was used to digitally record the parlous state of the architectural structure and karsten tubes were used to quantify the surface porosity of the limestone. The results are expressed from four perspectives. The anatomy of Casa Ippolito, as revealed in its ruins, provides a cross-section of its building history and shows two distinct phases in its construction. The tissue of Casa Ippolito—the building elements and materials—speaks of the knowledge of raw materials and their properties among the builders who worked on both phases. The architectural history of Casa Ippolito reveals how it supported its inhabitants’ wellbeing in terms of shelter, water and food. Finally, the ruins in their present state bring to the fore the site’s potential for cultural tourism. This case study aims to show that such ruins are not just geocultural remains of historical built fabric. They are open wounds in the built structure; they underpin the anatomy of the building and support insights into its former dynamics. Ruins offer an essay in material culture and building physics. Architectural ruins of masonry structures are anthropogenic discourse rendered in stone which facilitate not only the reconstruction of spaces but also places for human users; they are a statement on the wellbeing of humanity throughout history.

Master curves for the response of layered systems to compressional seismic waves

1967 ◽  
Vol 57 (3) ◽  
pp. 515-543 ◽  
Author(s):  
Luis M. Fernandez
Keyword(s):  
Seismic Waves ◽  
Transfer Functions ◽  
Point Of View ◽  
Time Lags ◽  
Master Curves ◽  
Layer System ◽  
Crust And Upper Mantle ◽  
Response Characteristics ◽  
Families Of Curves ◽  
Short Time

abstract The layers of the earth's crust act as a filter with respect to seimic energy arriving at a given station. Consequently the motion recorded at the surface depends not only on the frequency content of the source and on the response characteristics of the recording instrument, but also on the elastic parameters and thicknesses of the transmitting layers. This latter dependence is the basis for a method of investigating the structure of the crust and upper mantle. To facilitate this investigation a set of master curves for the transfer functions of the vertical and horizontal component of longitudinal waves and their ratios is presented. The calculation of these curves is in terms of a dimensionless parameter. This calculation allows one to group the curves corresponding to different crustal models into families of curves. The characteristics of these curves are discussed from the point of view of their “periodicity” in the frequency domain and of their amplitude in order to investigate the influence of the layer parameters. Considerations, either of constructive interference or of Fourier analysis of a pulse multiply reflected within the layer system, reveal that the amplitudes of the transfer curves depend on the velocity contrasts at the interfaces of the system. The “periodicity” or spacing of the peaks depends on the time lags between the first arrivals and the arrivals of the different reverberations. Closely spaced fluctuations correspond to large-time lags, and widely spaced fluctuations to short-time lags.

scholarly journals Use And Comparison of Topis And Electre Methods In Personnel Selection

2018 ◽  
Vol 22 ◽  
pp. 01021 ◽  
Author(s):  
Bilgin Şenel ◽  
Mine Şenel ◽  
Gizem Aydemir
Keyword(s):  
Personnel Selection ◽  
Selection Process ◽  
Minimum Cost ◽  
Point Of View ◽  
Blue Collar Worker ◽  
Automotive Company ◽  
Worker Selection ◽  
Electre Method ◽  
The Right ◽  
Short Time

One of the most important function of human resources is personnel selection process. This process should be done professionally, in a short time and with minimum cost. After personnel selection process, performance of the hired person is very important for the permanence and success of the company. From this point of view, the aim of this study is to select a personnel among the candidates efficiently, with minimum cost and within a short time in one of the leading companies of Turkey in automotive sector. In order to select the right personnel all criterias which has great impact on blue collar worker selection was decided and these criterias are weighted. From the candidate pool of automotive company, appropriate candidates were selected by using TOPSIS AND ELECTRE method which are multi-criteria decision making methods

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