scholarly journals Electrical Impedance Used for Measurement of Moisture Distribution in Thermal Insulation Plasters

2019 ◽  
Author(s):  
Jitka Peterková ◽  
Martin Sedlmajer ◽  
Magdaléna Michalčíková ◽  
Jana Pařílková
Keyword(s):  
Thermal Insulation ◽  
Electrical Impedance ◽  
Building Materials ◽  
Negative Influence ◽  
Moisture Distribution ◽  
Masonry Construction ◽  
Thermal Insulating ◽  
Non Destructive ◽  
Insulating Properties

High moisture in building materials has a negative influence on their physical and thermal insulating properties. When building materials incorporated in a structure exceed the maximum permissible moisture, the material could change its properties to such an extent that its next usage is unfeasible. In case of thermal insulating materials, it causes serious degradation of thermal insulating properties. During the development of advanced thermal insulation plasters, long-term laboratory experiments were performed using masonry construction fragments, which focused on the study of their moisture proportions. For this purpose a new non-destructive method of electrical impedance was used, which enables measurements on defined levels in a matrix of test samples. Results obtained by measurements made on the surface of the samples were compared with the results obtained by a capacitive hygrometer. It was concluded that these methods provided similar results. The least moisture sensitive was the mixture, which was applied on masonry pillar E. In comparison with used thermal insulation plasters commonly used today this plaster shows considerably lower value of mass moisture under laboratory conditions, 1.38%. This pillar also exhibited the most uniform course of conductance measured along its height. 

scholarly journals Sound-Absorbing and Thermal-Insulating Properties of Cement Composite Based on Recycled Rubber from Waste Tires

2021 ◽  
Vol 11 (6) ◽  
pp. 2725
Author(s):  
Jakub Svoboda ◽  
Tomáš Dvorský ◽  
Vojtěch Václavík ◽  
Jakub Charvát ◽  
Kateřina Máčalová ◽  
...  
Keyword(s):  
Building Materials ◽  
Absorption Capacity ◽  
Acoustic Properties ◽  
Strength Characteristics ◽  
Cement Composites ◽  
Waste Tires ◽  
Natural Aggregate ◽  
Thermal Insulating ◽  
Recycled Rubber ◽  
Insulating Properties

This article describes an experimental study aimed at investigating the potential use of recycled rubber granulate from waste tires of fractions 0/1 and 1/3 mm in cement composites as a 100% replacement for natural aggregates. The use of waste in the development and production of new building materials represents an important aspect for the sustainability and protection of the environment. This article is focused on the sound-absorbing and thermal-insulating properties of experimental cement composites based on recycled rubber from waste tires. The article describes the grain characteristics of recycled rubber, sound absorption capacity, thermal conductivity and strength characteristics. The results of this research show that the total replacement of natural aggregate with recycled rubber in cement composites is possible. Replacing natural aggregate with recycled rubber has significantly improved the thermal and acoustic properties of the prepared cement composites, however, at the same time; there was also the expected decrease in the strength characteristics due to the elasticity of rubber.

Investigation of Thermal Insulation Materials Based on Easy Renewable Row Materials from Agriculture

2011 ◽  
Vol 335-336 ◽  
pp. 1412-1417 ◽  
Author(s):  
Jiri Zach ◽  
Jitka Peterková ◽  
Vít Petranek ◽  
Jana Kosíková ◽  
Azra Korjenic
Keyword(s):  
Thermal Insulation ◽  
Building Materials ◽  
Raw Materials ◽  
Building Construction ◽  
Materials Development ◽  
Insulation Materials ◽  
Thermal Insulating ◽  
Plastic Materials ◽  
Energy Consuming ◽  
Rock Wool

Production of building materials is mostly energy consuming. In the sphere of insulation materials we mostly see rock wool based materials or foam-plastic materials whose production process is demanding from material aspect and raw materials aspect as well. At present the demand for thermal insulation materials has been growing globally. The thermal insulation materials form integral part of all constructions in civil engineering. The materials mainly fulfill the thermal insulating functions and also the sound-insulating one. The majority of thermal insulation materials are able to fulfill both of the functions simultaneously. The paper describes questions of thermal insulation materials development with good sound properties based on natural fibres that represent a quickly renewable source of raw materials coming from agriculture. The main advantage of the materials are mainly the local availability and simple renewability of the raw materials. In addition an easy recycling of the materials after their service life end in the building construction and last but not least also the connection of human friendly properties of organic materials with advanced product manufacture qualities of modern insulation materials.

Development of New Advanced Plasters with Waste Fibers Content

2018 ◽  
Vol 276 ◽  
pp. 248-253
Author(s):  
Jiří Zach ◽  
Jitka Peterková ◽  
Vítězslav Novák
Keyword(s):  
Mechanical Properties ◽  
Building Materials ◽  
Raw Materials ◽  
Cellulose Fibers ◽  
Positive Influence ◽  
Point Of View ◽  
Pet Bottles ◽  
Thermal Insulating ◽  
Insulating Properties ◽  
Recycled Waste

The paper deals with the possibilities of using secondary raw materials in the development of new advanced lightweight plasters. It was about fibers from recycled waste materials (waste paper, PET bottles, tyres) and recycled insulation (stone wool). The aim of adding fibers to these lightweight building materials was improvement of mechanical properties, improvement thermal insulation properties and reduction of crack sensitivity. It can be stated, based on the evaluation of the selected measurements, that both types of cellulose fibers and fibers from recycled tyres had positive influence on the mechanical properties, namely in the case of compressive strength. From the point of view of thermal insulating properties, it can be said that only 2 types of fibers have reduced the value of the thermal conductivity. They were mixtures with stone fibers and with recycled tyres fibers. Both of these mixtures also showed the lowest average values of bulk density. Based on the carried out research works can be it concluded that the use of recycled tyres fibers show as optimal.

Wrong expectation of superinsulation behavior from largely-expanded nanocellular foams

Nanoscale ◽  
2020 ◽  
Vol 12 (24) ◽  
pp. 13064-13085 ◽  
Author(s):  
Piyapong Buahom ◽  
Chongda Wang ◽  
Mohammed Alshrah ◽  
Guilong Wang ◽  
Pengjian Gong ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Thermal Insulation ◽  
Cellular Structure ◽  
Thermal Insulating ◽  
Insulating Properties

This work aims to predict the thermal conductivity of microcellular and nanocellular thermal insulation foams to explore the correlation between the cellular structure and the thermal insulating properties.

3D Data for Calculation of Capillary Conductivity Coefficient

2013 ◽  
Vol 688 ◽  
pp. 180-184
Author(s):  
Jan Škramlík ◽  
Miloslav Novotný ◽  
Ondřej Fuciman ◽  
Karel Šuhajda
Keyword(s):  
Porous Material ◽  
Continuity Equation ◽  
Building Materials ◽  
Construction Material ◽  
Accurate Method ◽  
Building Construction ◽  
Moisture Distribution ◽  
3D Data ◽  
Negative Effect ◽  
Non Destructive

The moisture in building construction material affects the physical properties of buildings and he may lead to their degradation. With few exceptions, building materials are almost never dry. For the expected negative effect of moisture on building materials of structures is needed accurate method of determining the characteristics of their moisture as possible. The capillary conductivity coefficient characterizes transfer of liquid moisture in porous material. The method for its determination is experimentally arranged in such a way that it is possible to apply diffusion equation derived from the Luikov equation that is a phenomenological description of liquid moisture transport in porous materials as well as from the continuity equation, which expresses the classic conservation of matter principle. To records of the moisture distribution has been developed the methodology for measuring of moisture in the porous material, using microwave radiation. The calculation of the capillary conductivity coefficient and its dependence is based on the moisture curves in 3 D in non-stationary state of wetting, determined by non-destructive method.

Potential of Cork Cement Composite as a Thermal Insulation Material

2015 ◽  
Vol 666 ◽  
pp. 17-29 ◽  
Author(s):  
Sukhdeo R. Karade
Keyword(s):  
Thermal Insulation ◽  
Building Materials ◽  
Environmental Concern ◽  
Cement Composite ◽  
Mineral Wool ◽  
Comfort Level ◽  
Environmental Benefits ◽  
Insulation Material ◽  
Thermal Insulating ◽  
The Impact

The growing environmental concern throughout the globe has led architects & engineers to design energy efficient buildings. Consequently, they are looking for building materials that can reduce the energy consumption in buildings to maintain the comfort level. Use of proper thermal insulating materials can reduce the energy required for heating or cooling of the buildings. Presently mineral wool and various foams are used for this purpose. Efforts are being made to use wastes in making thermal insulation materials so that the impact on environment can be further reduced. Cork granules are obtained as waste from the cork processing industries that make ‘bottle stoppers’ as a main product. These granules have a low density and could be used as lightweight aggregates for making concrete with low thermal conductivity. This article describes the physico-mechanical properties of lightweight cementitious composites made using cork granules. Further, environmental benefits of their application in thermal insulation of buildings has been discussed.

Study of Heat Transfer Process in Structure of Thermal Insulating Materials Based on Natural Fibers

2014 ◽  
Vol 1000 ◽  
pp. 227-230 ◽  
Author(s):  
Jiri Zach ◽  
Jitka Peterková ◽  
Martin Sedlmajer ◽  
Azra Korjenic
Keyword(s):  
Building Materials ◽  
Natural Fibers ◽  
Natural Fibre ◽  
Heat Transfer Process ◽  
Heat Propagation ◽  
Natural Fibres ◽  
Low Carbon ◽  
Insulating Materials ◽  
Thermal Insulating ◽  
Insulating Properties

Natural fibre based thermal insulating materials belong to progressive building materials representing one of the possible ways in sustainable development and which are characterised with low carbon trace and low value of primary bound energy. In case of industrially produced insulating materials (for instance using thermal connection method) the insulating materials based on natural fibres showed comparable properties with industrially produced insulating materials on building markets. In the view of thermal insulating properties the natural insulating material show slightly different behaviour in comparison with synthetic insulating materials which is caused by fibrous structure of insulating materials and low thermal conductivity of natural fibres (contrary to glass or mineral fibres). The paper describes results of research oriented on study of heat propagation within materials based on natural fibres originated from agriculture and stockbreeding.

scholarly journals Indirect measurements of water content using TDR-inferred dielectric permittivity and electrical resistivity

2019 ◽  
Vol 92 ◽  
pp. 02005
Author(s):  
Bruna de Carvalho Faria Lima Lopes ◽  
Laís de Carvalho Faria Lima Lopes ◽  
Alessandro Tarantino
Keyword(s):  
Electrical Conductivity ◽  
Dielectric Permittivity ◽  
Moisture Content ◽  
Water Content ◽  
Time Domain Reflectometry ◽  
Moisture Distribution ◽  
Salt Mines ◽  
Destructive Measurement ◽  
Non Destructive

The measurement of moisture distribution in Engineered Barrier Systems (EBS) in salt mines and deep geological disposals is essential in order to monitor fluid ingress and record data for long-term security analyses. Additionally, soil moisture content has influence over the mechanical properties of the soil as well as plant growth, soil stability and contaminant transport to cite some. Therefore, finding affordable and reliable ways to determine moisture content, quickly and in the field without sampling, is of great interested among people in different subject areas. Time-domain reflectometry (TDR) has become a recognized electromagnetic method for non-destructive measurement of dielectric permittivity and electrical conductivity of moist porous materials. It turns out that both these measurements depend on the material moisture content, among other things. This paper presents a series of calibration tests performed on soil samples. TDR probes were used to obtain the dielectric permittivity and electrical conductivity of the samples. As a consequence, relationships between these measurements and the samples' volumetric water content were later established. These relationships can then be used to indirectly determine that important information of water content on similar soil material using cheap, quick and non-destructive TDR probes.

Study of Hygrothermal Behavior of Insulation Materials Based on Natural Fibers

2015 ◽  
Vol 1124 ◽  
pp. 97-102
Author(s):  
Jiri Zach ◽  
Jitka Peterková
Keyword(s):  
Building Materials ◽  
Natural Fibers ◽  
Natural Fibre ◽  
Heat Propagation ◽  
Natural Fibres ◽  
Low Carbon ◽  
Insulating Materials ◽  
Thermal Insulating ◽  
Hygrothermal Behavior ◽  
Insulating Properties

Natural fibre based thermal insulating materials belong to progressive building materials representing one of the possible ways in sustainable development and which are characterised with low carbon trace and low value of primary bound energy. In case of industrially produced insulating materials (for instance using thermal connection method) the insulating materials based on natural fibres showed comparable properties with industrially produced insulating materials on building markets. In the view of thermal insulating properties the natural insulating material show slightly different behavior in comparison with synthetic insulating materials which is caused by fibrous structure of insulating materials and low thermal conductivity of natural fibres (contrary to glass or mineral fibres). The paper describes results of research oriented on study of heat propagation within materials based on natural fibres originated from agriculture and stockbreeding.

Fabrication of boron nitride nanosheet/polymer composites with tunable thermal insulating properties

2019 ◽  
Vol 43 (12) ◽  
pp. 4878-4885 ◽  
Author(s):  
Jianyun He ◽  
Shijun Liu ◽  
Yunqi Li ◽  
Shangjing Zeng ◽  
Yanlong Qi ◽  
...  
Keyword(s):  
Boron Nitride ◽  
Polymer Composites ◽  
Thermal Insulation ◽  
Thermal Insulating ◽  
Boron Nitride Nanosheet ◽  
Insulation Performance ◽  
Insulating Properties ◽  
Thermal Conductivities

Introduction of hydroxylated hBN improved the thermal insulation performance in binary composites, but enhanced the thermal conductivities in the ternary formula.

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