scholarly journals The analysis of heat conductivity coefficient of the aerated concrete building barriers depending on moisture changes

2011 ◽  
Vol 8 (1) ◽  
pp. 107-116
Author(s):  
Zbigniew Suchorab ◽  
Danuta Barnat-Hunek
Keyword(s):  
Heat Conductivity ◽  
Building Materials ◽  
Winter Season ◽  
Time Domain Reflectometry ◽  
Heat Conductivity Coefficient ◽  
Water Desorption ◽  
Concrete Building ◽  
Absorbing Material ◽  
Aerated Concrete ◽  
Comfort Parameters

The article is sacrificed to the aerated concrete building barriers moisture phenomenon. Water, which increases heat conductivity of building materials is the reason of the increased heat loses during the winter season. The result of this phenomenon is the decrease of indoor heat comfort parameters. Aerated concrete is a strongly water absorbing material with elongated time of water desorption. Capillary-porous structure of the described medium makes is highly prone to water influence what is the reason of the detailed analysis of heat conductivity coefficient in relation to moisture. In this article it is analyzed and compared the influence of moisture changes on heat parameters of the aerated concrete with the bulk densities of 400 and 600 kg/m3 using the reflectometric techniques TDR (Time Domain Reflectometry).

scholarly journals Methodology of Moisture Measurement in Porous Materials Using Time Domain Reflectometry / Metodyka Prowadzenia Badań Wilgotności W Ośrodkach Porowatych Za Pomocą Reflektometrii W Domenie Czasu

2014 ◽  
Vol 19 (1-2) ◽  
pp. 97-107 ◽  
Author(s):  
Zbigniew Suchorab ◽  
Marcin K. Widomski ◽  
Grzegorz Łagód ◽  
Danuta Barnat-Hunek ◽  
Piotr Smarzewski
Keyword(s):  
Porous Materials ◽  
Time Domain ◽  
Building Materials ◽  
Capillary Rise ◽  
Time Domain Reflectometry ◽  
Gravimetric Measurement ◽  
Basic Principles ◽  
Measuring Setup ◽  
Measurement Methodology ◽  
Aerated Concrete

Abstract The article presents the description of measurement methodology of moisture transport in unsaturated porous materials using Time Domain Reflectometry (TDR) technique on the example of measurement of capillary uptake phenomenon in the sample of autoclaved aerated concrete (AAC). In the paper there are presented basic principles of the TDR method as a technique applied in metrology, its potential for measurement of moisture in porous materials like soils and porous building materials. Second part of the article presents the experiment of capillary rise process in the sample of AAC. Within the experiment moisture content was monitored in the sample exposed on water influence. Monitoring was conducted using TDR FP/mts probes. Preparation of the measuring setup was presented in detail. The TDR readouts post-processing, graphical presentations of the obtained results, short discussion and comparison of TDR readouts to gravimetric measurement were also presented.

Transient Pulse Method for Measuring of Heat Conductivity of Autoclaved Aerated Concrete

2014 ◽  
Vol 899 ◽  
pp. 466-469
Author(s):  
Marián Vertaľ ◽  
Dušan Katunský ◽  
Jozef Šimiček
Keyword(s):  
Water Content ◽  
Heat Conductivity ◽  
Building Materials ◽  
Pulse Method ◽  
Building Construction ◽  
Basic Material ◽  
Material Parameters ◽  
Aerated Concrete ◽  
Moisture Dependence ◽  
Stationary Measurement

The heat conductivity, specific heat and bulk density are the basic material parameters and thus indispensable. There are numbers of methods used for measurement of heat conductivity. However, the non-stationary (transient pulse method) measurements methods are preferred for description of heat conductivity moisture dependence. This article discusses on the establishment dependence of heat conductivity on water content for selected porous building materials by using non stationary measurement methods. Dependence of the thermal conductivity on the water content is necessary for coupled heat, air and moisture (HAM) simulation in building construction.

scholarly journals Analysis of Porous Structure in Autoclaved Materials Modified by Glass Sand

Crystals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 408
Author(s):  
Anna Stepien
Keyword(s):  
Computed Tomography ◽  
Building Materials ◽  
Micro Ct ◽  
Structure Building ◽  
Acoustic Insulation ◽  
Ct Analysis ◽  
Glass Sand ◽  
Aerated Concrete ◽  
Wall Construction ◽  
Dominant Phase

This paper describes the use of glass sand in the production of autoclaved bricks. Traditional autoclaved materials consist of SiO2, CaO, and H2O. The purpose of the tests is to analyze the possibility of using glass sand in autoclaved materials and to determine their properties and durability. Depending on the structure, building materials can have porosities ranging from 0% (glass, metals) to over 90% (thermal insulation materials such as aerated concrete). Porosity of materials is directly related to the strength of materials and their density, and further to the thermal and acoustic insulation properties of products used especially for external wall construction, i.e., bricks, concrete, and aerated concrete. This type of silicate brick is formed at a temperature of 203 °C, therefore the dominant phase forming the microstructure is tobermorite, in contrast to the C-S-H phase, which dominates in concretes and which is characterized by a larger specific surface. The nature of pores, their number, appearance and arrangement in the material can be studied using computer techniques (SEM, XRD, computed tomography, porosimetry). Computed tomography (micro-CT analysis) showed that the number of voids in the material modified by glass sand is about 20% in relation to the weight of the product. The density of the product with glass sand was determined to be 2.2 kg/dm3.

In situ seismic testing of a reinforced autoclaved aerated concrete building

ce/papers ◽  
2018 ◽  
Vol 2 (4) ◽  
pp. 253-258
Author(s):  
Furkan Gokmen ◽  
Baris Binici ◽  
Erdem Canbay ◽  
Alper Aldemir ◽  
Mustafa Kagan Ogdu ◽  
...  
Keyword(s):  
Seismic Testing ◽  
Autoclaved Aerated Concrete ◽  
Concrete Building ◽  
Aerated Concrete

Comparison of Building Construction and Life-Cycle Cost for a High-Rise Mass Timber Building with its Concrete Alternative

2020 ◽  
Vol 70 (4) ◽  
pp. 482-492
Author(s):  
Hongmei Gu ◽  
Shaobo Liang ◽  
Richard Bergman
Keyword(s):  
Life Cycle ◽  
Life Cycle Cost ◽  
Building Materials ◽  
Building Design ◽  
Cost Data ◽  
Construction Costs ◽  
High Rise ◽  
Front End ◽  
Concrete Building ◽  
Mass Timber

Abstract Mass timber building materials such as cross-laminated timber (CLT) have captured attention in mid- to high-rise building designs because of their potential environmental benefits. The recently updated multistory building code also enables greater utilization of these wood building materials. The cost-effectiveness of mass timber buildings is also undergoing substantial analysis. Given the relatively new presence of CLT in United States, high front-end construction costs are expected. This study presents the life-cycle cost (LCC) for a 12-story, 8,360-m2 mass timber building to be built in Portland, Oregon. The goal was to assess its total life-cycle cost (TLCC) relative to a functionally equivalent reinforced-concrete building design using our in-house-developed LCC tool. Based on commercial construction cost data from the RSMeans database, a mass timber building design is estimated to have 26 percent higher front-end costs than its concrete alternative. Front-end construction costs dominated the TLCC for both buildings. However, a decrease of 2.4 percent TLCC relative to concrete building was observed because of the estimated longer lifespan and higher end-of-life salvage value for the mass timber building. The end-of-life savings from demolition cost or salvage values in mass timber building could offset some initial construction costs. There are minimal historical construction cost data and lack of operational cost data for mass timber buildings; therefore, more studies and data are needed to make the generalization of these results. However, a solid methodology for mass timber building LCC was developed and applied to demonstrate several cost scenarios for mass timber building benefits or disadvantages.

THE INFLUENCE OF THE VALUE OF THE THERMAL FLUX SUPPLIED TO THE WALL ON THE SPATIAL DISTRIBUTION OF THE HEAT CONDUCTIVITY COEFFICIENT OF SUPERCRITICAL WATER IN THE CHANNELS

2017 ◽  
Author(s):  
Nataliia Fialko ◽  
◽  
Viktor Prokopov ◽  
Julii Sherenkovskiy ◽  
Sergey Aleshko ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Computer Modeling ◽  
Supercritical Water ◽  
Heat Conductivity ◽  
Thermal Flux ◽  
Heat Conductivity Coefficient ◽  
Tube System

The paper presents the results of computer modeling for research the regularities of the influence of the value of the thermal flux supplied to the tube system on the structure of the distribution of the heat conductivity of supercritical water in the channels.

scholarly journals Improvement of the Korean Design Criteria on Wall-To-Wall Junctions to Prevent Condensation in Apartment Houses

2019 ◽  
Vol 11 (12) ◽  
pp. 3272
Author(s):  
In Tae Hwang ◽  
Gil Tae Kim ◽  
Jung Hyun Yoo ◽  
Jong Sung Lee
Keyword(s):  
Building Materials ◽  
Winter Season ◽  
Thermal Conditions ◽  
Design Criteria ◽  
Indoor Temperature ◽  
The Past ◽  
Construction Design ◽  
Living Space ◽  
Significant Difference ◽  
Temperature And Humidity

Maintaining a proper temperature and humidity in a living space is very important for the health and comfort of apartment residents. Poor residential thermal conditions are recognized as a potential risk to the overall physical health. Thus, building development criteria that maintain an indoor environment separate from the outside environment have been continuously strengthened. However, this has not been the case in Korea, with regards to design criteria for the prevention of indoor condensation. In Korea, condensation occurs indoors frequently, during the winter season. When the outside temperature is low during the winter, a high indoor temperature and humidity would affect the indoor building materials and cause condensation. This study investigated and analyzed the indoor temperature and humidity during winter—when there is a significant difference in the outdoor and indoor temperatures—and conducted a survey on the residents’ lifestyles. Construction design criteria were found to be different from those of the past, and possible causes of changes in temperature and humidity were examined. We intended to establish enhanced design criteria that would prevent indoor condensation, by comparing our results to that of a study conducted in 2003.

Composite Binder for Structural Cellular Concrete

2019 ◽  
Vol 945 ◽  
pp. 53-58 ◽  
Author(s):  
M.Y. Elistratkin ◽  
E.S. Glagolev ◽  
M.V. Absimetov ◽  
V.V. Voronov
Keyword(s):  
Building Materials ◽  
Negative Impact ◽  
Average Density ◽  
Construction Costs ◽  
Competitive Situation ◽  
Composite Binder ◽  
Mineral Supplements ◽  
Autoclaved Aerated Concrete ◽  
Aerated Concrete ◽  
Cellular Concrete

Non-autoclaved aerated concrete is the only viable alternative to gas silicate when organizing its manufacture on the basis of regional small and medium capacity production. This aims to improvement the competitive situation on the building materials market and optimizing the construction costs. The possibility of expanding the application field of this material due to the increase in strength characteristics while maintaining an unchanged average density is of special interest. The guarantee of proposed solutions economic and technical efficiency is the transition from traditional portland cement to composite binders based on it. The article discusses the quantity and composition of the mineral supplements feasibility to optimize the binder properties of the problem peculiarities to reduce consumption of cement and chemical modifiers that increase the rate of curing and totals of non-autoclaved aerated concrete investigated compatibility issues between components to eliminate their negative impact on the formation of porous structure of the final product.

scholarly journals Capillary Uptake Monitoring in Lime-Hemp-Perlite Composite Using the Time Domain Reflectometry Sensing Technique for Moisture Detection in Building Composites

Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1677 ◽  
Author(s):  
Przemysław Brzyski ◽  
Zbigniew Suchorab
Keyword(s):  
Thermal Conductivity ◽  
Apparent Density ◽  
Time Domain ◽  
Building Materials ◽  
Gravimetric Method ◽  
Total Porosity ◽  
Time Domain Reflectometry ◽  
Partial Replacement ◽  
Wall Material ◽  
Capillary Uptake

The use of waste plants in the production of building materials is consistent with the principles of sustainable development. One of the ideas involves using hemp shives as an aggregate for the production of a composite used as a filling of the timber frame construction of the walls. The most important disadvantage of using the building materials based on organic components is their susceptibility to the water influence. The wall material is exposed to rising groundwater. The research part of the paper presented the preparation method and the investigation of the hemp-perlite-lime composites. Flexural and compressive strength, apparent density, total porosity, thermal conductivity, and mass absorptivity were examined. The main research part pertained to the analysis of capillary uptake occurrence in the composites, being the important phenomenon present in the external walls. The study on this phenomenon was carried out using the technique of indirect moisture evaluation—Time Domain Reflectometry (TDR). The indirect readouts were additionally verified with the traditional evaluation using the gravimetric method based on the PN-EN 1925 standard. The study proved that the tested composites were characterized by low apparent density, thermal conductivity, strength parameters, high total porosity, and mass absorptivity. The partial replacement of hemp shives by expanded perlite had a beneficial effect on the tested properties of composites.

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