scholarly journals TO THE QUESTION OF CREATION OF SOIL BASES WITH IMPROVED WATERPROOFING, THERMAL INSULATING AND MECHANICAL PROPERTIES BY APPLICATION OF POLYMER CRYOGELS

2021 ◽  
pp. 43-48
Author(s):  
S.A. Dudnikova ◽  
V.Yu. Dudnikov ◽  
G.G. Osadchaya
Keyword(s):  
Mechanical Properties ◽  
Thermal Insulating

The effect of organofluorine additives on the morphology, thermal conductivity and mechanical properties of rigid polyurethane and polyisocyanurate foams

2021 ◽  
pp. 0021955X2098715
Author(s):  
Cosimo Brondi ◽  
Ernesto Di Maio ◽  
Luigi Bertucelli ◽  
Vanni Parenti ◽  
Thomas Mosciatti
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Cell Size ◽  
Flexural Properties ◽  
Anisotropy Ratio ◽  
Cell Content ◽  
Average Cell Size ◽  
Average Cell ◽  
Thermal Insulating ◽  
Liquid Type

This study investigates the effect of liquid-type organofluorine additives (OFAs) on the morphology, thermal conductivity and mechanical properties of rigid polyurethane (PU) and polyisocyanurate (PIR) foams. Foams were characterized in terms of their morphology (density, average cell size, anisotropy ratio, open cell content), thermal conductivity and compressive as well as flexural properties. Based on the results, we observed that OFAs efficiently reduced the average cell size of both PU and PIR foams, leading to improved thermal insulating and mechanical properties.

Microstructure and Mechanical Properties of Thermal Insulating Coating Prepared by Laser and Plasma

2020 ◽  
Vol 57 (15) ◽  
pp. 151405
Author(s):  
崔静 Cui Jing ◽  
郭玉珠 Guo Yuzhu ◽  
庞铭 Pang Ming ◽  
杨广峰 Yang Guangfeng
Keyword(s):  
Mechanical Properties ◽  
Thermal Insulating ◽  
Microstructure And Mechanical Properties

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.

scholarly journals Enhancing Properties of Aerospace Alloy Elektron 21 Using Boron Carbide Nanoparticles as Reinforcement

2019 ◽  
Vol 9 (24) ◽  
pp. 5470
Author(s):  
Sravya Tekumalla ◽  
Ng Joo Yuan ◽  
Meysam Haghshenas ◽  
Manoj Gupta
Keyword(s):  
Mechanical Properties ◽  
Boron Carbide ◽  
Compressive Loading ◽  
Hot Extrusion ◽  
Microstructural Characterization ◽  
Thermal Insulating ◽  
Damping Characteristics ◽  
B4c Particles ◽  
Superior Mechanical Properties ◽  
Melt Deposition

In this study, the effect of nano-B4C addition on the property profile of Elektron 21 (E21) alloys is investigated. E21 reinforced with different amounts of nano-size B4C particulates was synthesized using the disintegrated melt deposition technique followed by hot extrusion. Microstructural characterization of the developed E21-B4C composites revealed refined grains with the progressive addition of boron carbide nanoparticles. The evaluation of mechanical properties indicated a significant improvement in the yield strength of the nanocomposites under compressive loading. Further, the E21-2.5B4C nanocomposites exhibited the best damping characteristics, highest young’s modulus, and highest resistance to ignition, thus featuring all the characteristics of a material suitable for several aircraft applications besides the currently allowed seat frames. The superior mechanical properties of the E21-B4C nanocomposites are attributed to the refined grain sizes, uniform distribution of the nanoparticles, and the thermal insulating effects of nano-B4C particles.

scholarly journals Effect of thermal-treatment sequence on sound absorbing and mechanical properties of porous sound-absorbing/thermal-insulating composites

2016 ◽  
Vol 67 ◽  
pp. 06070
Author(s):  
Chen-Hung Huang ◽  
Cherng-Shiuan Tsay ◽  
Ching-Wen Lou ◽  
Yu-Chun Chuang ◽  
Ying-Huei Shih ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Thermal Treatment ◽  
Treatment Sequence ◽  
Thermal Insulating

scholarly journals Optically Active Polyurethane/Silica Aerogel Coated Cotton Fabrics for Thermal Protection

2021 ◽  
Vol 8 ◽  
Author(s):  
Ling Lin ◽  
Ziyin Li ◽  
Haiyan Mao ◽  
Wenyao Li ◽  
Chaoxia Wang
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Thermal Protection ◽  
Cotton Fabrics ◽  
Retention Performance ◽  
Thermal Insulating ◽  
Film Forming ◽  
Warmth Retention ◽  
Coated Fabrics ◽  
Coated Cotton

Application of SiO2 aerogel in thermal protective clothing has been limited due to its brittle nature, ordinary mechanical properties, and poor film forming performance. This work is aimed to develop thermal protective cotton fabrics by coating blended OPU/SiO2 aerogel with enhanced mechanical properties and thermal protection performance. The OPU/SiO2 aerogel composites with different ratio were applied onto cotton fabrics by knife-coating. The morphology, chemical component, crystalline structure, thermal stability and compression strength were characterized by scanning electron microscopy (SEM), Fourier transfer Infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TG) and compression test, respectively. Besides, the warmth retention performance and heat protection performance together with air and moisture permeability of the coated fabrics were studied. The results showed that OPU/SiO2 aerogel were successfully coated onto cotton fabrics with enhanced mechanical properties and thermal stability together with better film forming capacity. The heat transfer coefficient of the coated cotton fabrics was distinctly dropped due to the synergistic effect of OPU and SiO2 aerogel, which resulted in higher warmth retention. The OPU/SiO2 aerogel coated fabrics exhibited obvious heat insulation performance with its surface temperate almost 4°C than the uncoated fabrics. This work demonstrates a new strategy of fabricating stronger thermal insulating textiles using OPU/SiO2 aerogel composites.

Utilization of Lightweight Aggregate from Expanded Obsidian for Advanced Thermal Insulating Plasters Production

2011 ◽  
Vol 335-336 ◽  
pp. 1199-1203 ◽  
Author(s):  
Jiri Zach ◽  
Rudolf Hela ◽  
Jitka Peterková ◽  
Martin Sedlmajer
Keyword(s):  
Mechanical Properties ◽  
Thermal Insulation ◽  
Lightweight Aggregate ◽  
Foam Plastic ◽  
Carbon Particles ◽  
Thermal Insulating ◽  
Plastic Materials ◽  
Demand Factor ◽  
Insulation Systems ◽  
The Given

The thermal insulating of new and existing buildings is of a key influence in reduction of their energetic demand factor resulting in reduction of emissions of gases, carbon particles and dust which directly improves the environment. At development of light thermal insulation plasters with very low thermal conductivity the foam-plastic matters or light porous aggregates are frequently used at present. The foam-plastic materials do not appear as convenient ones in view of the environment and sustainable development as well. In the given case the thermal insulation plasters based on light cellular aggregates appear as more suitable. However a majority of light aggregates (for example expanded perlite) do not show a good ratio of insulation and mechanical properties. The paper describes a design and development of thermal insulation plasters based on expanded obsidian that can be used for thermal insulating of building constructions and for moisture sanitation. Considering the applied type of aggregates the materials show better ratio of thermal insulation and mechanical properties while in practice the plasters can be used as a full- value alternative for classical thermal insulation systems.

scholarly journals Effect of Polypropylene Fibres on the Thermal Conductivity of Lightweight Foamed Concrete

2018 ◽  
Vol 150 ◽  
pp. 03008 ◽  
Author(s):  
Ashfaque Ahmed Jhatial ◽  
Wan Inn Goh ◽  
Noridah Mohamad ◽  
U. Johnson Alengaram ◽  
Kim Hung Mo
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Compressive Strength ◽  
Urban Areas ◽  
Dry Density ◽  
Polypropylene Fibres ◽  
Conventional Concrete ◽  
Thermal Insulating ◽  
Foamed Concrete ◽  
Permanent Load

With the reduction in the permanent load on the structure and excellent insulation properties, the lightweight foamed concrete is a potential thermal insulating building material to counter the urban heat island effect, which increases the temperature of urban areas due to the concentration of infrastructures constructed using conventional concrete that absorbs the solar radiation. The lightweight foamed concrete whose dry density ranges from 400 kg/m3 to 1600 kg/m3, has lower thermal conductivity compared to conventional concrete. But reduced density attributes to reduced compressive strength. In this study, to enhance the mechanical properties, the foamed concrete of 1600 kg/m3 density is reinforced with polypropylene fibres (PP). Four percentages of PP fibres, 0% (controlled), 0.2%, 0.25% and 0.30% were added into the foamed concrete. The compressive strength as well as the thermal conductivity of foamed concrete reinforced with PP fibres were determined. Based upon the findings, the optimum percentage of PP was determined to be 0.20% which gave higher compressive strength while thermal conductivity of foamed concrete was observed to decrease upon addition of PP fibres. Thus, addition of PP fibres improves the thermal resistance in the foamed concrete along with enhancing the mechanical properties.

The Improvement of Thermal Insulating Concrete Panel

2018 ◽  
Vol 24 (5) ◽  
pp. 1
Author(s):  
Mohammed Ali Nasser Ali ◽  
Abdul Hadi Nema Khalif ◽  
Doaa Alaa Lafta
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Thermal Properties ◽  
Coarse Aggregate ◽  
Wood Ash ◽  
Mixing Ratio ◽  
Mixing Ratios ◽  
Thermal Insulating ◽  
Multi Stage ◽  
Third Stage

The Iraqi houses flattening the roof by a concrete panel, and because of the panels on the top directly exposed to the solar radiation become unbearably hot and cold during the summer and winter. The traditional concrete panel components are cement, sand, and aggregate, which have a poor thermal property. The usage of materials with low thermal conductivity with no negative reflects on its mechanical properties gives good improvements to the thermal properties of the concrete panel. The practical part of this work was built on a multi-stage mixing plan. In the first stage the mixing ratio based on the ratios of the sand to cement. The second stage mixing ratios based on replacing the coarse aggregate quantities with the Alabaster aggregates, and the third stage the mixing ratios based on the replacement of wood ash instead of the sand. While the fourth stage mixing ratios based on decreasing the thermal conductivity and increasing mechanical properties by adding a multilayer of a plastic net. The result shows that using a concrete panel with components (cement, sand, coarse aggregate, wood ash, and Alabaster aggregates) with a mass ratio of (1:1:2:1:1) and 3-plastic layers, gives the best improvement of the thermal properties. Where, the thermal conductivity is reduced by 42% and the specific heat increased by 41.2% as compared to the traditional concrete panel mixing ratio, with mechanical properties are agreed with the Iraqi standards.  

Development of Thermal Insulating Plasters with Regulated Capillary Activity

2014 ◽  
Vol 1000 ◽  
pp. 223-226
Author(s):  
Jiri Zach ◽  
Jitka Peterková ◽  
Martina Reif ◽  
Azra Korjenic
Keyword(s):  
Mechanical Properties ◽  
Open Porosity ◽  
Civil Engineering ◽  
Heat Insulation ◽  
Research Work ◽  
Raw Material ◽  
High Porosity ◽  
Thermal And Mechanical Properties ◽  
Thermal Insulating ◽  
Material Sources

The development of prospective, thermal insulating plasters that are applied during the reconstruction and rehabilitation of structures has taken place at the Faculty of Civil Engineering for many years. The main objective of the research work is to achieve the best ratio of thermal and mechanical properties, including high porosity. During the development of this test, testing recipes were tested, which were often used as alternative input materials. On the basis of the achieved results, optimal recipes were proposed with the stated requirements for heat insulation, mechanical properties and porosity. Due to the fact that during the reconstruction this often concerns structures loaded by increased structure, then such materials must have high open porosity. The article describes the study of moisture behaviour, particularly capillary activity for light thermal insulating plasters with the use of alternative raw material sources.

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