scholarly journals Influence of production on hemp concrete hygrothermal properties: sorption, water vapour permeability and water absorption

2021 ◽  
Vol 2069 (1) ◽  
pp. 012004
Author(s):  
A Ruus ◽  
T Koosapoeg ◽  
M Pau ◽  
T Kalamees ◽  
M Põldaru
Keyword(s):  
Thermal Conductivity ◽  
Water Absorption ◽  
Water Vapour ◽  
Thermal Insulation ◽  
Building Material ◽  
Water Vapour Permeability ◽  
Wall Material ◽  
Vapour Permeability ◽  
Water Vapour Sorption ◽  
Negative Material

Abstract Hemp concrete is considered to be a carbon negative material. Hemp absorbs CO2 during the growth and lime needs CO2 for carbonation. The material, which has good thermal insulation properties, is used as a non-bearing wall material or plaster. For such use the hygrothermal properties of a material must be well known especially when indoor insulation is in focus. In the current study hemp concrete produced in two different ways was in focus and following the hygrothermal properties of hemp concrete as a building material were studied: water absorption (EN 1015-18), water vapour sorption (EN 12571), water vapour permeability (EN 12572) and thermal conductivity (EN 12667). The results of the study can be used in hygrotheramal calculations and modelling.

scholarly journals Data on thermal conductivity, water vapour permeability and water absorption of a cementitious mortar containing end-of-waste plastic aggregates

Data in Brief ◽  
2018 ◽  
Vol 18 ◽  
pp. 1057-1063 ◽  
Author(s):  
Luciano Di Maio ◽  
Bartolomeo Coppola ◽  
Luc Courard ◽  
Frédéric Michel ◽  
Loredana Incarnato ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Water Absorption ◽  
Water Vapour ◽  
Water Vapour Permeability ◽  
Vapour Permeability ◽  
Waste Plastic ◽  
Conductivity Water

scholarly journals Hygrothermal simulation of building performance: data for Scottish masonry materials

2021 ◽  
Vol 54 (4) ◽  
Author(s):  
P. F. G. Banfill
Keyword(s):  
Thermal Conductivity ◽  
Water Vapour ◽  
Material Properties ◽  
Simulation Software ◽  
Water Vapour Permeability ◽  
High Porosity ◽  
Water Absorption Coefficient ◽  
Vapour Permeability ◽  
Hygrothermal Simulation ◽  
Current Production

AbstractRetrofitting thermal insulation to solid masonry walls alters their hygrothermal behaviour, which can be modelled by hygrothermal simulation software. However, such software needs values of key material properties to ensure satisfactory results and until now data has not been available for Scottish masonry buildings. This work aims to contribute to a Scotland-specific dataset of material properties for use by designers working on such buildings. Thermal conductivity, water vapour permeability, sorptivity, water absorption coefficient, hygroscopic sorption, density and porosity were all determined experimentally for selected historic and contemporary masonry materials. Within the range of materials tested three groups of materials properties emerge. Natural hydraulic lime mortars, hot-mixed quicklime mortar and earth mortar all show comparatively low density, high porosity, low thermal conductivity, high water vapour permeability and variable but generally high hygroscopic sorption. Craigleith, Hailes and Giffnock sandstones, no longer available but obtained from conservation works on historic buildings, and Locharbriggs and Hazeldean sandstones, obtained from current production, all show intermediate values of these properties. Crathes granodiorite and Scottish whinstone (from current production) show high density, low porosity, high thermal conductivity, low water vapour permeability and low hygroscopic sorption. It is shown that these materials are all relevant to Scottish buildings constructed in traditional masonry and this paper presents the first comprehensive set of hygrothermal property data for them.

scholarly journals Effects of Nano-TiO2on the Toughness and Durability of Cement-Based Material

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Baoguo Ma ◽  
Hainan Li ◽  
Junpeng Mei ◽  
Xiangguo Li ◽  
Fangjie Chen
Keyword(s):  
Water Absorption ◽  
Water Vapour ◽  
Reaction Rate ◽  
Water Vapour Permeability ◽  
Hydration Reaction ◽  
X Ray Diffraction ◽  
Vapour Permeability ◽  
X Ray ◽  
Cement Mortars ◽  
Cement Based Materials

The effects of nano-TiO2(NT) on microstructures and mechanical properties of cement mortars were studied by scanning electron microscopy (SEM), X-ray diffraction (XRD), and mercury intrusion porosimetry (MIP). Results show that 3% NT can remarkably increase the tensile/flexural strengths (i.e., the toughness is improved) and promote the precipitation of AFt crystal. The flexural and tensile strengths have significant positive correlation to the formation amount of AFt. The pores of mortars can be significantly refined and shift to harmless pores by controlling the growth of CH crystal and increasing the hydration reaction rate. The durability of cement-based materials is discussed by testing their water absorption and water-vapour permeability. Results show that the addition of 3% NT can decrease the water absorption ratio by 40–65%, water absorption coefficients by more than 40%, and water-vapour permeability coefficients by 43.9%, indicating that 3% NT can effectively improve the compactness and durability of cement-based materials.

Thermo-physiological properties of 3D spacer knitted fabrics

2016 ◽  
Vol 28 (3) ◽  
pp. 328-339 ◽  
Author(s):  
Rajesh Mishra ◽  
Arumugam Veerakumar ◽  
Jiri Militky
Keyword(s):  
Thermal Conductivity ◽  
Water Vapour ◽  
Air Permeability ◽  
Water Vapour Permeability ◽  
Knitted Fabrics ◽  
Vapour Permeability ◽  
Content Type ◽  
Spacer Fabric ◽  
Multifilament Yarns ◽  
Spacer Fabrics

Purpose – The purpose of this paper is to investigate effect of material properties in 3D knitted fabrics on thermo-physiological comfort. Design/methodology/approach – In the present study six different spacer fabrics were developed. Among these six fabrics, it was classified into two groups for convenient analysis of results, the first group has been developed using polyester/polypropylene blend with three different proportion and second group with polyester/polypropylene/lycra blend having another three different composition. As a spacer yarn, three different types of 88 dtex polyester monofilament yarn and polyester multifilament yarns (167 dtex and 14.5 tex) were used and 14.5 tex polypropylene and 44 dtex lycra multifilament yarns were also used for the face and back side of the spacer fabrics (Table I). These fabrics were developed in Syntax Pvt Ltd Czech Republic. Findings – The main influence on the water vapour permeability of warp knitted spacer fabrics is the kind of raw material, i.e. fibre wetting and wicking. Also there is no correlation between air permeability and water vapour permeability. It is found that both air permeability and thermal conductivity are closely related to the fabric density. It is also found that the fabric characteristics of spacer fabric show a very significant effect on the air permeability, thermal conductivity and mechanical properties of spacer fabric. Therefore, selection of spacer fabric for winter clothing according to its fabric characteristics. Practical implications – The main objective of the present study is to produce spacer knitted 3D fabrics suitable for defined climatic conditions to be used as clothing or in sports goods. Originality/value – New 3D knitted spacer fabrics can be produced with improved comfort properties.

scholarly journals Determination of hygrothermal properties of cementitious mortar: The effect of partial replacement of cement by incinerated sewage sludge ash

2018 ◽  
Vol 42 (6) ◽  
pp. 771-787 ◽  
Author(s):  
Barbora Krejcirikova ◽  
Carsten Rode ◽  
Ruut Peuhkuri
Keyword(s):  
Thermal Conductivity ◽  
Sewage Sludge ◽  
Water Vapour ◽  
Sorption Isotherms ◽  
Water Vapour Permeability ◽  
Partial Replacement ◽  
Vapour Permeability ◽  
Sewage Sludge Ash ◽  
Sludge Ash ◽  
The Impact

Two sewage sludge ashes were used as substitutes for cement and their effect on the hygrothermal properties of mortar was examined. Different cement to ash ratios and two ash pre-treatment methods (water washing and grinding) were in focus. The impact of cement replacement by sewage sludge ashes on thermal conductivity, sorption isotherms, water vapour permeability and carbonation was described with standard cement-based mortar as the reference material. Measurement results showed that thermal conductivity decreased by 15% when 30% of the cement was replaced by sewage sludge ash. Water vapour permeability increased as the cement to ash ratio was reduced. Sorption was tested by two methods; although differences in the sorption isotherms of mortars were reported when a climatic chamber method was applied, no differences, or only minor differences, were observed with the desiccator method. Measurements revealed that cement-based mortar possessed a higher content of carbonate than cement-ash-based mortar, and it thus appears that the carbonation rate was higher when the cement content was high.

scholarly journals Thermophysiological Comfort Properties of Polyamide Pantyhose

2019 ◽  
Vol 27 (5(137)) ◽  
pp. 80-89
Author(s):  
Elena Tomovska ◽  
Lubos Hes
Keyword(s):  
Thermal Conductivity ◽  
Thermal Resistance ◽  
Water Vapour ◽  
Water Vapour Permeability ◽  
Evaporative Resistance ◽  
Vapour Permeability ◽  
Low Weight ◽  
Relative Water ◽  
Thermal Absorptivity

In this paper, the thermophysiological characteristics of low weight knitted polyamide and polyamide/elastane fabrics for pantyhose differing in terms of filament count were studied. Alambeta and Permetest devices were used to measure the thermal conductivity, thermal resistance, thermal absorptivity, evaporative resistance and relative water vapour permeability. The results indicated that fabrics made of finer filaments have lower thermal conductivity, thermal resistance, thermal absorptivity and evaporative resistance values.

scholarly journals PENGARUH PENAMBAHAN JUMLAH PIGMEN PADA LAPISAN DASAR (BASE COAT) PADA PROSES FINISHING TERHADAP SIFAT FISIK KULIT SAPI

2017 ◽  
Vol 41 (3) ◽  
pp. 307
Author(s):  
Gresy Griyanitasari
Keyword(s):  
Physical Properties ◽  
Water Absorption ◽  
Water Vapour ◽  
Coating Thickness ◽  
Water Vapour Permeability ◽  
High Quality ◽  
Vapour Permeability ◽  
Performance Requirements ◽  
Dry Water

ABSTRAKPermintaan kulit yang bermutu semakin meningkat  tetapi ketersediaannya semakin menurun. Teknologi pasca penyamakan (finishing) merupakan hal yang dapat dilakukan untuk menutupi kerusakan kulit. Salah satu bahan finishing kulit yang dapat digunakan untuk menutupi cacat kulit adalah pigmen. Penelitian ini bertujuan untuk mengetahui pengaruh penambahan jumlah pigmen pada lapisan dasar terhadap sifat fisik kulit tersamak. Kulit sapi yang sudah disamak ulang diberi perlakuan finishing dengan variasi pigmen 7,5; 10; 12,5; 15; dan 17,5% pada lapisan dasar. Hasil penelitian menunjukkan bahwa pigmen berpengaruh pada penyerapan air selama dua jam dan ketebalan lapisan finishing. Formulasi dengan berbagai variasi pigmen dalam penelitian ini memenuhi standard SNI 0234: 2009 Kulit Bagian Atas Alas Kaki-Kulit Boks dan ISO 20879: 2007 Footwear performance requirements for footwear-upper dari segi ketahanan gosok cat (kering dan basah), penyerapan air (2 dan 24 jam), dan permeabilitas uap air..(Kata kunci: “finishing, kulit sapi, pigmen, permeabilitas uap air”) ABSTRACTThe demand of high quality leather was increasing, but it’s availability was decrease. Finishing was technology to upgrade the quality of leather. Pigment  was one of the materials for finishing leather that can correcting grain. The aim of this research was to determine the best variation in addition of pigment as base coat on leather physical properties. Retanned cow leather was finished with 7,5; 10; 12,5; 15; and 17,5% of pigment as base coat. This study revealed pigment, as one of basecoat material, affected not only water absorption for two hous but also leather coating thickness. Finishing formulation used to finish leather, with pigment included, was met the requirements of  SNI 0234: 2009 Kulit Bagian Atas Alas Kaki-Kulit Boks dan ISO 20879: 2007 Footwear performance requirements for footwear-upper for rub fastness (wet and dry), water absorption (2 and 24 hours), and water vapour permeability.  (Keywords: “finishing, cow leather, pigment, water vapour permeability”)

scholarly journals IMPACT OF GRANULES FROM CRUSHED EXPANDED POLYSTYRENE PACKAGE ON PROPERTIES OF THERMO-INSULATING PLASTER

2014 ◽  
Vol 20 (4) ◽  
pp. 581-589 ◽  
Author(s):  
Jurga Šeputytė-Jucikė ◽  
Georgij Arsenij Sezeman ◽  
Marijonas Sinica ◽  
Modestas Kligys ◽  
Saulius Vaitkus
Keyword(s):  
Thermal Conductivity ◽  
Compressive Strength ◽  
Water Vapour ◽  
Adhesion Force ◽  
Lightweight Aggregate ◽  
Expanded Polystyrene ◽  
Water Vapour Permeability ◽  
Regression Equations ◽  
Vapour Permeability ◽  
Aerated Concrete

The paper deals with the use of lightweight porous aggregate, i.e. crushed expanded polystyrene package crumbs (EPSC) in the composition of thermo-insulating plaster. Its effectiveness is compared to that of spherical granules of expanded polystyrene – white coloured (EPS) and grey coloured (NEOPOR). The content of lightweight aggregate changed from 1.25 to 1.75 l/kg of dry mix. The investigation focused on properties of modified plaster, such as density, compressive strength, thermal conductivity and water vapour permeability. It was established that EPSC reduce density of plaster from 1350 to 530 kg/m3, improving such properties as thermal conductivity and water vapour permeability but decreasing compressive strength. In addition, the paper established the adhesion force of plaster (content of lightweight aggregate was 1.25 l/kg of dry mix) to ceramics, silicate and autoclaved aerated concrete masonry elements. The character of macrostructure of plaster was considered, as well as bonding with a coat of decorative paint. It was found that plaster with EPSC has similar properties to plasters with EPS and NEOPOR aggregates; however, in case of EPSC, the relative vapour resistance is better. The provided regression equations can be used for prediction of differently modified plasters.

Research on the Simulation of Hygrothermal Distribution of Stone Wool ETICS

2016 ◽  
Vol 858 ◽  
pp. 111-116
Author(s):  
Li Xin Sun ◽  
Zeng Feng Yan ◽  
Hui Zhou
Keyword(s):  
Moisture Content ◽  
Water Vapour ◽  
Thermal Insulation ◽  
Liquid Water ◽  
Composite System ◽  
Water Vapour Permeability ◽  
Outdoor Temperature ◽  
Vapour Permeability ◽  
Climate Zones ◽  
Stone Wool

Stone wool external thermal insulation composite system is used more and more in China now. Former studies in China simply consider that water vapour permeability of render coating should be equal to the water vapour permeability of stone wool. Neither is there any necessary indicator for the liquid water (wind-driven rain) for the system. Therefore, an important issue to be solved currently is how to propose reasonable indicators for water vapour and liquid water transfer performance in stone wool system for different climate zones in China. This research studied on the simulation of hygrothermal distribution of stone wool system. Simulations of stone wool systems were done under different outdoor temperature, humidity, wind driving rain and other conditions to analyze the moisture content in each layer of the system. Meanwhile, simulations of different render coating performances were also done to analyze the moisture content in each layer. Based on these, indicators for water vapour and liquid water were proposed, which provides a foundation for the stone wool external thermal insulation composite system standards in China.

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