scholarly journals Lightweight Vapor-Permeable Plasters for Building Repair Detailed Experimental Analysis of the Functional Properties

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2613
Author(s):  
Martina Záleská ◽  
Milena Pavlíková ◽  
Adam Pivák ◽  
Anna-Marie Lauermannová ◽  
Ondřej Jankovský ◽  
...  
Keyword(s):  
Added Value ◽  
Salt Crystallization ◽  
Mechanical Resistance ◽  
High Porosity ◽  
Transport Parameters ◽  
Culture Heritage ◽  
Heritage Buildings ◽  
Historical Culture ◽  
Materials Used ◽  
Repair Mortars

Three types of lightweight plasters for building repair were prepared and tested. The composition of plasters was designed in respect to their compatibility with materials used in the past in historical masonry. For the hardened plasters, detailed testing of microstructural and macrostructural parameters was realized together with the broad experimental campaign focused on the assessment of mechanical, hygric, and thermal properties. As the researched plasters should find use in salt-laden masonry, specific attention was paid to the testing of their durability against salt crystallization. The mechanical resistance, porosity, water vapor transmission properties, and water transport parameters of all the researched plasters safely met criteria of WTA directive 2-9-04/D and standard EN 998-1 imposed on repair mortars. Moreover, the tested materials were ranked as lightweight plasters and due to their low thermal conductivity they can be used for the improvement of thermal performance of repaired masonry. The salt crystallization test caused little or no damage of the plasters, which was due to their high porosity that provided free space for salt crystallization. The developed plasters can be recommended for application in repair of damp and salt masonry and due to their compatible composition also in historical, culture heritage buildings. The added value of plasters is also their good thermal insulation performance.

scholarly journals Effect of Aggregate and Binder Type on the Functional and Durability Parameters of Lightweight Repair Mortars

2021 ◽  
Vol 13 (21) ◽  
pp. 11780
Author(s):  
Martina Záleská ◽  
Milena Pavlíková ◽  
Martin Vyšvařil ◽  
Zbyšek Pavlík
Keyword(s):  
Water Vapor ◽  
Salt Crystallization ◽  
Porous Space ◽  
High Porosity ◽  
Lightweight Aggregates ◽  
Expanded Perlite ◽  
Hydraulic Lime ◽  
Natural Hydraulic Lime ◽  
Binder Type ◽  
Repair Mortars

The subject matter of the work presented here is the development and evaluation of novel lightweight mortars that meet the functional and technical criteria imposed on repair mortars. In a broad experimental campaign, lime, natural hydraulic lime, and lime–cement mortars were designed and tested. Lightweight aggregate, expanded perlite, granules from expanded glass and zeolite were used as full replacements for quartz sand. The hardened mortars were tested at the ages of 28 days and 90 days. The conducted tests and analyses were focused on the assessment of structural, mechanical, hygric and thermal parameters. The salt crystallization resistance and effect of salt presence on the hygroscopicity of the investigated mortars were also investigated. The use of lightweight aggregates in the composition of mortars resulted in their high porosity, low density, satisfactory mechanical parameters, improved water vapor transmission capability and water absorption. The mortars with expanded perlite and glass granulate were ranked among thermal insulation mortars of classes T1 and T2, respectively. The use of lightweight aggregates enabled the development of mortars with great durability in terms of salt action, which was almost independent of binder type. The ability to accommodate water vapor was increased by the effect, i.e., the use of lightweight aggregates and the presence of salt in mortars increased porous space. Taking into account the compatibility, functional, and technical criteria, lime- and natural hydraulic lime-based lightweight mortarswere classified as repair mortars, providing improved thermal performance. The lime–cement lightweight plasters can be recommended only for repair of building structures where cement and lime–cement materials were original applied.

scholarly journals Hygric Properties of Machine-Made, Historic Clay Bricks from North-Eastern Poland (Former East Prussia): Characterization and Specification for Replacement Materials

Materials ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 6706
Author(s):  
Maria Tunkiewicz ◽  
Joanna Misiewicz ◽  
Pawel Sikora ◽  
Sang-Yeop Chung
Keyword(s):  
Historic Buildings ◽  
Micro Computed Tomography ◽  
Existing Building ◽  
Clay Bricks ◽  
North Eastern ◽  
Heritage Buildings ◽  
Experimental Laboratory ◽  
Materials Used ◽  
East Prussia

This paper deals with the hygric characterization of early 20th century machine-made clay bricks, representative of great number of historical buildings in north-eastern Poland. Heritage buildings have a high potential for adaptive reuse, which is strictly connected with an urge for knowledge about the properties of these existing building envelopes. To better understand the hygric behavior of historic buildings, various experimental laboratory tests, including density, water absorption, compressive strength and freeze-thaw resistance, were conducted. In order to assess the microstructural characteristics of the tested bricks, mercury intrusion porosimetry (MIP) and X-ray micro-computed tomography (micro-CT) tests were performed. These tests were conducted on clay bricks from historic buildings, as well as on those that are currently being produced, in order to identify the relationship between the materials used in the past and the replacements produced presently. This paper addresses the lack of systematic application of existing standards for evaluating the state of the conservation of historic bricks and for establishing the specifications for replacement bricks. The results of conducted study and further research will be the basis for creating a historic materials database. It would be a useful tool for selecting bricks that correspond with the historically used materials and help to maintain homogenous structure of the restored buildings.

scholarly journals Agricultural Biogas—An Important Element in the Circular and Low-Carbon Development in Poland

Energies ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1733 ◽  
Author(s):  
Arkadiusz Piwowar
Keyword(s):  
Renewable Resources ◽  
Agricultural Production ◽  
Agricultural Sector ◽  
Raw Materials ◽  
Added Value ◽  
Low Carbon ◽  
Present Generation ◽  
The Social ◽  
Energy Economy ◽  
Materials Used

The agricultural sector can play an important role in the transformation of the energy economy in Poland. Special attention in this paper has been paid to the development of the agricultural biogas market in Poland. The considerations mainly concern organizational and economic aspects. Agricultural biogas plant represents the circular cycle of matter and energy. It enables the establishment of low-carbon, resource-efficient links between the agriculture and energy sectors. This is an important element of the circular economy, where waste from agricultural production and the agri-food industry, coming from renewable resources, is transformed into goods with a higher added value. The social and economic needs of the present generation and future generations are considered. The paper presented the characteristics of the Polish market, i.e., the number of entities, the number and location of plants, as well as the production volumes. Analyses were performed in the area of raw materials used to produce agricultural biogas. The analyses were carried out between 2011 and 2018. According to analyses, the potential of the agricultural biogas market in Poland is currently being used to a small extent. It is necessary not only to provide institutional support but also to increase the awareness of farmers and managers in agri-food companies of the possibility of using production waste for energy purposes.

scholarly journals Comparative study of the flexural properties of ABS, PLA and a PLA–wood composite manufactured through fused filament fabrication

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
J.A. Travieso-Rodriguez ◽  
R. Jerez-Mesa ◽  
Jordi Llumà ◽  
Giovanni Gomez-Gras ◽  
Oriol Casadesus
Keyword(s):  
Additive Manufacturing ◽  
Acrylonitrile Butadiene Styrene ◽  
Nozzle Diameter ◽  
Bending Test ◽  
Mechanical Resistance ◽  
Fused Filament Fabrication ◽  
Content Type ◽  
Layer Height ◽  
Maximum Deformation ◽  
Materials Used

Purpose The aim of this paper is to analyze the mechanical properties of acrylonitrile-butadiene-styrene (ABS) parts manufactured through fused filament fabrication and compare these results to analogous ones obtained on polylactic acid (PLA) and PLA–wood specimens to contribute for a wider understanding of the different materials used for additive manufacturing. Design/methodology/approach With that aim, an experimental based on an L27 Taguchi array was used to combine the specific parameters taken into account in the study, namely, layer height, nozzle diameter, infill density, orientation and printing velocity. All samples were subjected to a four-point bending test performed according to the ASTM D6272 standard. Findings Young’s modulus, elastic limit, maximum stress and maximum deformation of every sample were computed and subjected to an analysis of variance. Results prove that layer height and nozzle diameter are the most significant factors that affect the mechanical resistance in pieces generated through additive manufacturing and subjected to bending loads, regardless of the material. Practical implications The best results were obtained by combining a layer height of 0.1 mm and a nozzle diameter of 0.6 mm. The comparison of materials evidenced that PLA and its composite version reinforced with wood particles present more rigidity than ABS, whereas the latter can experience further deflection before break. Originality/value This study is of interest for manufacturers that want to decide which is the best material to be applied for their application, as it derives in a practical technical recommendation of the best parameters that should be selected to treat the material during the fused filament fabrication process.

Ultra-low density aerogel optical applications

1993 ◽  
Vol 8 (2) ◽  
pp. 352-355 ◽  
Author(s):  
S.P. Hotaling
Keyword(s):  
Surface Topology ◽  
Low Density ◽  
High Porosity ◽  
Fractal Surface ◽  
Surface Geometry ◽  
Surface Machining ◽  
Low Weight ◽  
Optical Applications ◽  
Materials Used ◽  
Reflective Coatings

Despite the extremely low density and the hence low weight of aerogel materials, the applicability of these materials to reflective applications has had little attention due to the high porosities exhibited by the materials. This high porosity yields an intrinsically rough but uniform surface topology for aerogel of density in the low hundreds of milligrams per cubic centimeter and a fractal surface geometry for lower density aerogel (densities of the order of tens of milligrams per cubic centimeter). This paper presents new results of aerogel materials used as ultra-light substrates for reflective coatings by way of surface machining, polishing, and planarization prior to metallization, and the optical characterization thereof.

Green maintenance for heritage buildings: paint repair appraisal

2017 ◽  
Vol 35 (1) ◽  
pp. 63-89 ◽  
Author(s):  
Brit Anak Kayan
Keyword(s):  
Decision Making ◽  
Carbon Emissions ◽  
Maintenance Phase ◽  
Content Type ◽  
Embodied Carbon ◽  
Heritage Buildings ◽  
Materials Used ◽  
Maintenance Model ◽  
Practical Implications ◽  
Calculation Procedures

Purpose Sustainability encapsulates economic, environmental and societal domains. In order to conform to these domains, the efficiency of maintenance and repair of heritage buildings is no exception. Emergently, environmental considerations for sustainable heritage buildings repair have become increasingly important. The purpose of this paper is to present a decision-making process based on “Green Maintenance Model” – an appraisal approach based on life cycle assessment (LCA) of paint repair options for heritage buildings. Design/methodology/approach Calculation procedures of Green Maintenance model within selected boundaries of LCA enable evaluation of carbon emissions, in terms of embodied carbon expenditure, expended from paint repair for heritage buildings during maintenance phase. Findings “Green Maintenance” model could be understood as a carbon LCA of paint repair and has been recognized in reducing carbon emissions. Significantly, the model underpins decision-making for repair options for heritage buildings. Practical implications It must be emphasized that the calculation procedures of Green Maintenance model is not limited to heritage buildings and can be applied to any repair types, materials used and building forms. More importantly, this model practically supports environmentally focused conservation and promotes sustainable repair approach. Social implications The implementation of Green Maintenance model highlights the efficiency of repairs options that may be adopted. Originality/value Green Maintenance shows that generated environmental maintenance impact from repair options relays the “true” embodied carbon expenditure contextualized within the longevity of repair and its embodied carbon. This will consequently allow rationale in appraisal of repair options.

scholarly journals Quantitative evaluation of deterioration in west wind-room in the Palace Museum

2019 ◽  
Vol 282 ◽  
pp. 02092
Author(s):  
Yan Ma ◽  
Zhenyi Kong ◽  
Yonghui Li ◽  
Xiaogu Zhang ◽  
Shuichi Hokoi ◽  
...  
Keyword(s):  
Quantitative Evaluation ◽  
Moisture Transfer ◽  
Salt Crystallization ◽  
Indoor Temperature ◽  
Salting Out ◽  
West Wind ◽  
Heritage Site ◽  
Heritage Buildings ◽  
Environment Control ◽  
World Cultural Heritage

The Palace Museum in Beijing is a world cultural heritage site. Surviving nearly 600 years, heritage buildings in the Palace Museum have been deteriorated by salting out, exfoliation, cracking and so on. For the purpose of quantitative evaluation on current environment risks and proposing conservation approaches, heat and moisture transfer on buildings was simulated by a numerical model and the West Wind-room in the Hall of Mental Cultivation (Yangxin Dian) in the Palace Museum was taken as example. The results indicated that to reduce freezing-thawing cycles, the indoor temperature should be increased during December to early February. Indoor temperature and humidity should be controlled to a more stable and lower level to decrease the damaging from salt crystallization and hydration. And attention should be paid to more salting-out resulted by evaporation increase in spring and autumn. The results will provide support to environment control of Chinese traditional buildings.

Investigation of current state of pre-consumer textile waste generated at Lithuanian enterprises

2017 ◽  
Vol 29 (4) ◽  
pp. 491-503 ◽  
Author(s):  
Vaida Dobilaite ◽  
Gene Mileriene ◽  
Milda Juciene ◽  
Virginija Saceviciene
Keyword(s):  
Statistical Data ◽  
Added Value ◽  
Waste Generation ◽  
Content Type ◽  
Textile Waste ◽  
Textile Fibres ◽  
Current State ◽  
Not Otherwise Specified ◽  
Business Cases ◽  
Materials Used

Purpose Production and consumption of textile garments contribute significantly to environment problems. The purpose of this paper is to perform the evaluation of textile waste generated at Lithuanian clothing enterprises based on statistical data analysis and business cases studies. Design/methodology/approach For the evaluation of real situation of waste generation in companies, an original methodology was developed and used during investigation. In order to get an overall view, statistical data of waste generation and management in Lithuania were also analysed. Waste accounting covered data such as wastes from unprocessed textile fibres and wastes from processed textile fibres and textiles (not otherwise specified). Findings The investigation showed that the amount of cutting waste reaches 20-25 per cent of the total quantity of materials used for production. It was found that the waste is not sorted in Lithuanian clothing enterprises and is disposed in landfills in most cases, notwithstanding the positive tendencies of recycling of waste that were observed during past year. However, a practical recycling strategy and broader perception of developing products with greater added value from waste are missing in Lithuania. Originality/value In this research, a simple methodology was developed for determining the quantity of the textile waste generated by enterprises, the introduction of which would allow us to expect better results in waste accounting and management. The results of investigation are useful to gain in-depth understanding of waste generation in various countries.

scholarly journals Cold Sprayed Tungsten Armor for Tokamak First Wall

2021 ◽  
Author(s):  
Jan Cizek ◽  
Monika Vilemova ◽  
Frantisek Lukac ◽  
Martin Koller ◽  
Jan Kondas ◽  
...  
Keyword(s):  
Magnetic Fields ◽  
Specific Surface ◽  
Cold Spraying ◽  
High Porosity ◽  
First Wall ◽  
Power Sources ◽  
Strong Magnetic Fields ◽  
Hot Plasma ◽  
Materials Used ◽  
First Time

Abstract Owing to the COVID situation and transfer of manuscripts from ITSC 2020; this paper presents a shortened version of experiments and results that were recently published in a standard journal. For more details; please refer to the source [1]. Numerous obstacles are still to be resolved before power sources based on nuclear fusion could be employed. One of the major challenges are the materials used for construction of the main reactor vessels. In tokamaks; torus-shaped fusion facilities confining the hot plasma by strong magnetic fields; the innermost chambers are to be coated with dense coatings of W-based alloys. So far; the attempts for such coatings formation by other methods failed due to oxidation; high porosity; insufficient adhesion; high specific surface; or even insufficient thickness below 10 μm. Cold spraying seems a promising technology for the task. Here we demonstrate a successful fabrication of thick W; W-Cr and W-Cr-Ti coatings prepared without oxidation of the metals. For the first time in history; a deposition of 80 μm-thick coating of pure W was achieved.

scholarly journals FEM Analysis of the Welding Seams Geometry in Case of Fillet Welds

2021 ◽  
Vol 343 ◽  
pp. 03006
Author(s):  
Claudiu Babiş ◽  
Andrei Dimitrescu ◽  
Ana Maria Alecusan ◽  
Marcela Babiş
Keyword(s):  
Weld Seam ◽  
Welding Process ◽  
Fem Analysis ◽  
Geometric Shape ◽  
Fillet Welds ◽  
Mechanical Resistance ◽  
Filler Materials ◽  
Welding Seam ◽  
Welding Regime ◽  
Materials Used

The role of the welding seam is to achieve the non-removable joint between two or more parts. In principle, three geometric profiles of the welding seams can be obtained: straight profile; concave profile and convex profile. In practice, this geometric shape of the weld seam profile is very important, both in terms of the resistance of the joint to static stresses and in terms of its fatigue life. There are many factors that can influence the geometric shape of the weld seam: the welding process; welding regime; the nature of the filler materials used, the rehabilitation techniques applied and others. Often, this geometric shape of the weld bead is neglected, which is particularly dangerous due to the fact that an improper geometric shape can generate low mechanical strength in static loads or poor fatigue strength in variable loads. An optimum of the geometric configuration of the welding must be found, which reconciles both situations: the mechanical resistance in case of static stresses and also the fatigue resistance in case of variable loads. In this paper, an analysis will be made with finite elements for the straight and convex profile of the welding seams in the case of fillet welds subjected to fatigue. Several elements will be considered such as: damage; total deformation; fatigue sensitivity versus loading history; equivalent von Misses stress; safety factor.

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