scholarly journals Emissivity of Building Materials for Infrared Measurements

Sensors ◽  
2021 ◽  
Vol 21 (6) ◽  
pp. 1961 ◽  
Author(s):  
Eva Barreira ◽  
Ricardo M. S. F. Almeida ◽  
Maria L. Simões
Keyword(s):  
Moisture Content ◽  
Surface Temperature ◽  
Building Materials ◽  
Initial Conditions ◽  
Construction Materials ◽  
Fundamental Aspect ◽  
Infrared Measurements ◽  
Dry Conditions ◽  
Emissivity Measurement ◽  
Definition Of

Infrared thermography (IRT) is a technique increasingly used in building inspection. If in many applications it is sufficient to analyze the thermal patterns, others exist in which the exact determination of the surface temperature is a fundamental aspect. In these circumstances, the emissivity of the surfaces assumes special relevance, being probably the most important property in the definition of the boundary conditions. However, information on the uncertainty involved in its measurement, as well as the conditions that influence it, is scarce. This article presents an innovative contribution both to the characterization of the emissivity of various construction materials, and to the discussion of emissivity measurement procedures and the attendant uncertainty. In this sense, three experimental campaigns were carried out: T.I, preliminary tests to assess the initial conditions required for an accurate IRT measurement of the emissivity (reference tape and position of the camera); T.II, assessment of the emissivity of nine different building materials, in dry conditions, using the emissometer and the IRT and black tape methods; and T.III, assessment of the emissivity of three materials during the drying process. The results confirmed that emissivity is a crucial parameter for the accurate measurement of surface temperature. Emissivity measurements carried out with IRT (black tape method) and with the emissometer returned meaningful differences when compared with the values available in the literature. This disagreement led to surface temperature differences of up to 7 °C (emissometer versus reference values). This research also highlighted that the moisture content of the materials influences the emissivity values, with fluctuations that can be greater than 10%, and that the effect of moisture is visible even for low values of moisture content.

scholarly journals PECULIARITIES OF MATERIAL RESOURCE MANAGEMENT OF ENTERPRISES OF BUILDING MATERIALS

2021 ◽  
Author(s):  
Iryna Hobyr ◽  
Lidiia Hobyr
Keyword(s):  
Inventory Management ◽  
Building Materials ◽  
Construction Materials ◽  
Design And Technology ◽  
Resource Saving ◽  
New Production ◽  
Utilization Factor ◽  
Resources Management ◽  
Material Resources ◽  
Definition Of

In a market economy, it becomes important to improve the organization of enterprise management and, above all, the production process, efficient use of financial, material resources and inventories. Effective management of material resources increases profits and provides the necessary investment. To maintain high profitability and liquidity, the management of current activities of enterprises, in particular inventory management plays a significant role. The categorical apparatus of material resources management at the enterprise is considered, the definition of “material resources” is generalized, the definition of "material resources management" is offered, and also the system of material resources management at the enterprise is considered. In the management of material resources at the enterprise there are 2 approaches – logistics and reengineering. The main tasks of the mechanism of management of material resources of the enterprise of building materials are defined. These are: increasing the efficiency of material resources and choosing cheap sources of funding; introduction of new production, resource-saving technologies; minimization of costs for procurement, production and marketing activities; increasing the interest of employees of all services in the effective performance of their duties; product quality management. The analysis of efficiency of use of material resources at the enterprises of building materials which has shown, that manufacture of production is rather material-intensive is carried out. This is evidenced by the share of material costs in the cost of work, and the value of the utilization factor of materials indicates the economical use of material resources in production. Reserves for improving the efficiency of material resources at construction materials enterprises have been identified. The ways of the most rational use of material resources of construction materials enterprises are offered, in particular it is improvement of a design and technology of manufacturing of products, introduction of more progressive norms of expenses of resources, use of substitute materials, and reduction of losses at stages of transportation, storage and industrial use.

scholarly journals Time Domain Reflectometry (TDR) technique – A solution to monitor moisture content in construction materials

2020 ◽  
Vol 172 ◽  
pp. 17001
Author(s):  
Teresa Stingl Freitas ◽  
Ana Sofia Guimarães ◽  
Staf Roels ◽  
Vasco Peixoto de Freitas ◽  
Andrea Cataldo
Keyword(s):  
Moisture Content ◽  
Time Domain ◽  
Building Materials ◽  
Correct Diagnosis ◽  
Construction Materials ◽  
Gravimetric Method ◽  
Reference Method ◽  
Time Domain Reflectometry ◽  
Relative Dielectric Permittivity ◽  
Porous Building Materials

Measuring moisture content in building materials is crucial for the correct diagnosis of buildings’ pathologies and for the efficiency evaluation of the treatment solution applied. There are several different techniques available to measure the moisture content in construction materials. However, perform long-term minor-destructive measurements is still a great challenge. The TDR – Time Domain Reflectometry – technique is commonly used for moisture content measurements in soils, but is considered a relatively new method with regard to its application in construction materials. In the present state of research, the current use of the TDR technique for monitoring moisture content in all types of consolidated porous building materials is not possible yet. Indeed, the empirical conversion functions proposed for soils are mostly not suitable for building materials. Furthermore, to successfully use the TDR technique, a good contact between the TDR probe and the material under study is required, which may be difficult to achieve in hard materials. In this paper, the TDR technique was implemented in two limestone walls constructed in the lab to test experimentally the efficiency of a wall-base ventilation channel to speed up drying after a flood. Each wall was equipped with four two-rod TDR probes for continuous monitoring the moisture content in both situations: with and without the ventilation channel. All the equipment used, procedures followed during the drilling until the probes’ final installation, as well as the individual calibration required for each probe are explained in detail. Instead of using unsuitable functions proposed for soils, the evaluation of the moisture content from the apparent relative dielectric permittivity measured was established using as reference method the gravimetric method. The results obtained suggest that the TDR technique is suitable for moisture content monitoring in consolidated porous building materials.

scholarly journals Is the Time-Domain Reflectometry (TDR) Technique Suitable for Moisture Content Measurement in Low-Porosity Building Materials?

2020 ◽  
Vol 12 (19) ◽  
pp. 7855 ◽  
Author(s):  
Teresa Stingl Freitas ◽  
Ana Sofia Guimarães ◽  
Staf Roels ◽  
Vasco Peixoto de Freitas ◽  
Andrea Cataldo
Keyword(s):  
Soil Moisture ◽  
Moisture Content ◽  
Time Domain ◽  
Building Materials ◽  
Construction Materials ◽  
Gravimetric Method ◽  
Time Domain Reflectometry ◽  
Advantages And Disadvantages ◽  
The Time Domain ◽  
Low Porosity

Measuring moisture content in building materials is essential both for professional practice and for research. However, this is a very complex task, especially when long-term minor destructive measurements are desired. The time-domain reflectometry (TDR) technique is commonly used for soil moisture measurements, but its application in construction materials is considered a relatively new method, particularly for low-porosity building materials. The major obstacles to its current use in construction materials are (1) the difficulty of ensuring good contact between the TDR probe and the material, and (2) the lack of appropriate conversion functions between the measured relative permittivity and the moisture content of building materials. This paper intends to contribute to overcoming these difficulties by explaining in detail all the required steps to monitor moisture content in real-scale limestone walls. For that, a device is presented to guarantee the correct installation of the TDR probes on the walls, and a calibration procedure through the gravimetric method is proposed to avoid the use of an unsuitable calibration function developed for soil moisture measurements. In addition, the importance of the individual probe calibration is discussed, as well as TDR advantages and disadvantages for construction materials. The results obtained so far reveal that the TDR technique is suitable to detect moisture content variations in limestone, which is a low-porosity building material.

Traditional Building Materials for Innovative Envelope

2012 ◽  
Vol 253-255 ◽  
pp. 358-366
Author(s):  
Grazia Lombardo
Keyword(s):  
Building Materials ◽  
Construction Materials ◽  
Building Design ◽  
Natural Stone ◽  
Technological Innovations ◽  
Sustainable Building ◽  
Existing Building ◽  
First Results ◽  
Traditional Construction ◽  
Definition Of

The present paper is part of a research that is developed within the sustainable building design through the revisiting of the traditional construction materials. The results obtained show that the natural stone, enhanced by technological innovations, are often capable of providing excellent performance. Based on the tests, it was possible to verify and validate the hypothesis that the proposed new system of external vertical opaque enclosure consisting in a panel in dry-assembled and pre-compressed blocks of natural stone through reinforcing steel, has good performances when used both in the case of new design in the case of recovery of modern buildings, when the intervention is being addressed within of an overall building improvement regarding the security, sustainability, functionality and image. This paper reports the first results obtained by the study of the feasibility of the envelope being tested, through the definition of all the details of links with the existing building structure.

scholarly journals Influence of moisture content on the mechanical properties of selected wood-based composites

BioResources ◽  
2020 ◽  
Vol 15 (3) ◽  
pp. 5503-5513
Author(s):  
Conrad M. Sala ◽  
Eduardo Robles ◽  
Aneta Gumowska ◽  
Anita Wronka ◽  
Grzegorz Kowaluk
Keyword(s):  
Mechanical Properties ◽  
Moisture Content ◽  
Modulus Of Elasticity ◽  
Wood Quality ◽  
Construction Materials ◽  
Modulus Of Rupture ◽  
Slight Reduction ◽  
Furniture Industry ◽  
Different Types ◽  
Dry Conditions

Wood quality depends on many circumstances, as it is sensitive to changing properties, depending on the environment. This work evaluates the influence of moisture content of selected wood-based composites on their basic mechanical properties, i.e., modulus of rupture and modulus of elasticity. The selected panels were divided by application in construction materials and furniture materials, which demand specific conditions during service-life. The increase of moisture content in different types of wood-based panels resulted in a slight reduction of the modulus of rupture and the modulus of elasticity. Boards for use in dry conditions, mainly in the furniture industry, were more sensitive to lowering their modulus of elasticity with higher board moisture content compared with those designed for humid conditions, mainly from the building industry.

scholarly journals Mortars with Recycled Aggregates from Building-Related Processes: A ‘Four-Step’ Methodological Proposal for a Review

2021 ◽  
Vol 13 (5) ◽  
pp. 2756
Author(s):  
Federica Vitale ◽  
Maurizio Nicolella
Keyword(s):  
Building Materials ◽  
Thermal Analyses ◽  
Construction Materials ◽  
Physical And Mechanical Properties ◽  
Research Trends ◽  
Mix Design ◽  
Recycled Aggregates ◽  
Design Parameters ◽  
Natural Aggregates ◽  
By Products

Because the production of aggregates for mortar and concrete is no longer sustainable, many attempts have been made to replace natural aggregates (NA) with recycled aggregates (RA) sourced from factories, recycling centers, and human activities such as construction and demolition works (C&D). This article reviews papers concerning mortars with fine RA from C&D debris, and from the by-products of the manufacturing and recycling processes of building materials. A four-step methodology based on searching, screening, clustering, and summarizing was proposed. The clustering variables were the type of aggregate, mix design parameters, tested properties, patents, and availability on the market. The number and the type of the clustering variables of each paper were analysed and compared. The results showed that the mortars were mainly characterized through their physical and mechanical properties, whereas few durability and thermal analyses were carried out. Moreover, few fine RA were sourced from the production waste of construction materials. Finally, there were no patents or products available on the market. The outcomes presented in this paper underlined the research trends that are useful to improve the knowledge on the suitability of fine RA from building-related processes in mortars.

scholarly journals Application of Plastic Wastes in Construction Materials: A Review Using the Concept of Life-Cycle Assessment in the Context of Recent Research for Future Perspectives

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3549
Author(s):  
Tulane Rodrigues da Silva ◽  
Afonso Rangel Garcez de Azevedo ◽  
Daiane Cecchin ◽  
Markssuel Teixeira Marvila ◽  
Mugahed Amran ◽  
...  
Keyword(s):  
Life Cycle Assessment ◽  
Life Cycle ◽  
Solid Waste ◽  
Building Materials ◽  
Construction Materials ◽  
Plastic Waste ◽  
Plastic Wastes ◽  
Solid Waste Generation ◽  
Alternative Processes

The urbanization process contributes to the growth of solid waste generation and causes an increase in environmental impacts and failures in the management of solid waste. The number of dumps is a concern due to the limited implementation and safe disposal of this waste. The interest in sustainable techniques has been growing in relation to waste management, which is largely absorbed by the civil construction sector. This work aimed to review plastic waste, especially polyethylene terephthalate (PET), that can be incorporated with construction materials, such as concrete, mortars, asphalt mixtures, and paving. The use of life-cycle assessment (LCA) is related, as a tool that allows the sustainability of products and processes to be enhanced in the long term. After analyzing the recent literature, it was identified that studies related to plastic wastes in construction materials concentrate sustainability around the alternative destination of waste. Since the plastic waste from different production chains are obtained, it was possible to affirm the need for a broader assessment, such as the LCA, providing greater quantification of data making the alternative processes and products more sustainable. The study contributes to enhance sustainability in alternative building materials through LCA.

scholarly journals Rock Emissivity Measurement for Infrared Thermography Engineering Geological Applications

2021 ◽  
Vol 11 (9) ◽  
pp. 3773
Author(s):  
Simone Mineo ◽  
Giovanna Pappalardo
Keyword(s):  
Surface Temperature ◽  
Infrared Thermography ◽  
High Sensitivity ◽  
Point Of View ◽  
Rock Surface ◽  
Rock Types ◽  
Ornamental Stones ◽  
Emissivity Measurement ◽  
Laboratory Tool ◽  
Non Destructive

Infrared thermography is a growing technology in the engineering geological field both for the remote survey of rock masses and as a laboratory tool for the non-destructive characterization of intact rock. In this latter case, its utility can be found either from a qualitative point of view, highlighting thermal contrasts on the rock surface, or from a quantitative point of view, involving the study of the surface temperature variations. Since the surface temperature of an object is proportional to its emissivity, the knowledge of this last value is crucial for the correct calibration of the instrument and for the achievement of reliable thermal outcomes. Although rock emissivity can be measured according to specific procedures, there is not always the time or possibility to carry out such measurements. Therefore, referring to reliable literature values is useful. In this frame, this paper aims at providing reference emissivity values belonging to 15 rock types among sedimentary, igneous and metamorphic categories, which underwent laboratory emissivity estimation by employing a high-sensitivity thermal camera. The results show that rocks can be defined as “emitters”, with emissivity generally ranging from 0.89 to 0.99. Such variability arises from both their intrinsic properties, such as the presence of pores and the different thermal behavior of minerals, and the surface conditions, such as polishing treatments for ornamental stones. The resulting emissivity values are reported and commented on herein for each different studied lithology, thus providing not only a reference dataset for practical use, but also laying the foundation for further scientific studies, also aimed at widening the rock aspects to investigate through IRT.

scholarly journals Fire Resistance Behaviour of Geopolymer Concrete:An Overview

Buildings ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 82
Author(s):  
Salmabanu Luhar ◽  
Demetris Nicolaides ◽  
Ismail Luhar
Keyword(s):  
Compressive Strength ◽  
Thermal Resistance ◽  
Building Materials ◽  
Elevated Temperatures ◽  
Construction Materials ◽  
Flexural Behavior ◽  
Thermal Shrinkage ◽  
Physico Chemical ◽  
The Impact ◽  
Loss Of Strength

Even though, an innovative inorganic family of geopolymer concretes are eye-catching potential building materials, it is quite essential to comprehend the fire and thermal resistance of these structural materials at a very high temperature and also when experiencing fire with a view to make certain not only the safety and security of lives and properties but also to establish them as more sustainable edifice materials for future. The experimental and field observations of degree of cracking, spalling and loss of strength within the geopolymer concretes subsequent to exposure at elevated temperature and incidences of occurrences of disastrous fires extend an indication of their resistance against such severely catastrophic conditions. The impact of heat and fire on mechanical attributes viz., mechanical-compressive strength, flexural behavior, elastic modulus; durability—thermal shrinkage; chemical stability; the impact of thermal creep on compressive strength; and microstructure properties—XRD, FTIR, NMR, SEM as well as physico-chemical modifications of geopolymer composites subsequent to their exposures at elevated temperatures is reviewed in depth. The present scientific state-of-the-art review manuscript aimed to assess the fire and thermal resistance of geopolymer concrete along with its thermo-chemistry at a towering temperature in order to introduce this novel, most modern, user and eco-benign construction materials as potentially promising, sustainable, durable, thermal and fire-resistant building materials promoting their optimal and apposite applications for construction and infrastructure industries.

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