Preface of the “Computational modeling and experimental assessment of transport processes in building materials and their multi-layered systems”

Abstract Besides the formation of Friedel salt the transport and binding of chlorides in concrete is mainly defined by the electrochemical double layer at the interface between cement matrix and pore solution. Due to the alkaline pore solution the surface of hardened cement paste is negatively charged which may change to positive values by the potential regulating calcium ions. Inverting of the surface charge leads to an attraction of anions and therefore, to an adsorption of chloride ions in the diffuse part of the electrochemical double layer. Influence from outside like sulphates and carbon dioxide may lead to a decomposition of Friedel salt. Apart from these effect temperature, pH-value and certain environmental conditions affects the electrochemical double layer as well. The chloride equilibrium is mainly controlled by adsorbed ions in the electrochemical double layer. The model presented here is relevant for the assessment of ion transport processes in mineral building materials. Continuing investigations may lead to optimize transport models and a better evaluation of the critical chloride threshold value in reinforced concrete.

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Applicability Analysis of Selected Methods of Determining the Moisture Content of Highly Porous Thermal Insulations

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.824.3 ◽

2016 ◽

Vol 824 ◽

pp. 3-10

Author(s):

Lubor Kalousek ◽

Roman Brzoň ◽

Zuzana Fišarová

Keyword(s):

Thermal Insulation ◽

Building Materials ◽

New Materials ◽

Experimental Assessment ◽

Measuring Devices ◽

Internal Side ◽

Building Practice ◽

Thermal Insulations ◽

Highly Porous ◽

Interior Side

Spray foam thermal insulations are one of new materials, which are now considerably applied in building practice and which are therefore also the aim of current research. In building practice is an effort to apply these materials to very rugged surfaces in both the external and the internal side of the structure. On the interior side, however, the application is connected with the risk of condensation, which is difficult to verify by the measurement. The contribution is focused just on the comparison of methods and measuring devices designed for immediate detection of moisture in the material of sprayed polyurethane foam. The samples of thermal insulation, which have undergone exposing of humidity in accordance with Czech Standards, were compared by the experimental assessment. The obtained results were compared and evaluated, while as expected, the moisture measuring of highly porous thermal insulation is significantly more difficult than the measuring of thermal insulations made of conventional homogeneous building materials.

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COMPUTATIONAL ANALYSIS OF HEAT AND MASS TRANSPORT IN CHARACTERISTIC DETAIL OF INTERIOR THERMAL INSULATION SYSTEM

Proceedings of International Structural Engineering and Construction ◽

10.14455/isec.res.2020.7(1).str-38 ◽

2020 ◽

Vol 7 (1) ◽

Author(s):

Jiří Maděra ◽

Jan Kočí ◽

Václav Kočí

Keyword(s):

Computational Modeling ◽

Thermal Insulation ◽

System Application ◽

Building Materials ◽

Wood Fiber ◽

Mineral Wool ◽

Point Of View ◽

Insulation Materials ◽

Beneficial Effects ◽

The Right

Computational modeling represents useful tool for the assessment of newly designed or refurbished building materials and structures. Especially, when complex buildings elements need to be assessed from a hygrothermal point of view, the computational modeling is the right approach with desired power and accuracy. In this paper a historical wall element is investigated using two-dimensional simulation in order to study the effect of application of several insulation materials in various scenarios. In total two insulation materials are investigated (mineral wool, wood fiber boards) that are applied in three different scenarios. All simulations are performed under real climatic load. The results of the computational simulations reveal potential weak points in system application and can provide engineers and designers with valuable recommendations and practical information. The best results were obtained for thermal insulation from mineral wool. On the other hand, an improper system application can lead to a significant devaluation of the beneficial effects on the thermal performance of the studied brick element.

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