NUMERICAL SIMULATION OF THERMAL BRIDGES IN COMPOSITE BUILDING MATERIALS

2020 ◽  
Vol 12 (3) ◽  
pp. 261-273
Author(s):  
Mustapha Maliki ◽  
Nadia Laredj ◽  
Hanifi Missoum
Keyword(s):  
Numerical Simulation ◽  
Building Materials ◽  
Thermal Bridges

The Effect of Thermal Bridges on Energy Balance of Wood Frame Houses

2016 ◽  
Vol 824 ◽  
pp. 323-330 ◽  
Author(s):  
Tibor Varga ◽  
Rastislav Ingeli
Keyword(s):  
Energy Balance ◽  
Building Materials ◽  
Simulation Method ◽  
Critical Surface ◽  
Dynamic Boundary Conditions ◽  
Sandwich Construction ◽  
The Subject ◽  
Thermal Bridges ◽  
Wood Frame ◽  
Theoretical Results

In compliance with the today’s trend of designing sustainable and energy-saving architecture, it is necessary to firstly solve the factors influencing the energy balance. In this respect, the thermal bridges in buildings constitute a crucial factor. In case of their occurrence, the use of construction and insulation building materials is significant for finding the solution. The aim of this paper is to analyse the thermal bridges in buildings constructed on the basis of light constructions. The subject of analysis was an implemented wood frame house with common sandwich construction, designed in a low-energy standard. The house analysis is divided in theoretical and experimental part. The house in question has been directly exposed to dynamic boundary conditions. In order to analyse the thermal bridges, critical details have been selected methodically, verified by thermography. The experimental and theoretical results were compared by the simulation method for calculating critical surface temperatures. Both the measurements and results show how attention shall be paid to this issue at the project stage already. With increasing demands for overall energy balance of buildings, it is necessary to exactly define the critical details and consider the thermal bridges in the project documentation already.

scholarly journals Numerical simulation of degradation of porous building materials caused by freeze-thaw cycles

2019 ◽  
Vol 282 ◽  
pp. 02090
Author(s):  
Jiří Maděra ◽  
Jaroslav Kruis
Keyword(s):  
Numerical Simulation ◽  
Building Materials ◽  
Damage Model ◽  
Mechanical Analysis ◽  
Structural Elements ◽  
Volume Changes ◽  
Porous Building Materials ◽  
Freeze Thaw ◽  
Numerical Example ◽  
Isotropic Damage

Freeze-thaw cycles in porous building materials are studied in this contribution. Degradation and durability of many building materials as well as structural elements are tightly connected with the freeze-thaw cycles. The porosimetry curve and Gibbs-Thomson equation are used for estimates of volume changes caused by the freeze-thaw cycles. The volume changes are used in mechanical analysis based on the isotropic damage model. Numerical example documents the approach proposed.

scholarly journals The The Occurrence of Thermal Bridges in Hemp-Lime Construction Junctions

2019 ◽  
Author(s):  
Magdalena Grudzińska ◽  
Przemysław Brzyski
Keyword(s):  
Energy Efficient ◽  
Composite Structures ◽  
Building Materials ◽  
Thermal Transmittance ◽  
Timber Frame ◽  
Energy Efficient Buildings ◽  
Moisture Condensation ◽  
Thermal Bridges ◽  
Frame Construction ◽  
Insulating Properties

Thermal bridges increase heat losses in buildings and reduce the temperature of the internal envelope surface, causing moisture condensation and mould growth. This is an important issue for building materials based on organic components such as a hemp-lime composite, as they are particularly susceptible to biological degradation.The hemp-lime composite is used as a filling in timber frame construction. The increased cross-section of wooden elements together with the geometry change in the construction joints can form thermal bridges. The paper presents numerical analyses of temperature distribution in the area of construction elements connections, taking into account several variants of junctions: external walls, corners, and window placement in a wall. The thermal parameters of hemp-lime composites used in the analyses were obtained from the authors’ own research.Despite relatively good insulating properties, timber elements have a noticeable influence on the local increase of the heat transfer in hemp-lime composite structures, forming thermal bridges in the partitions themselves and in the construction nodes. However, the linear thermal transmittance coefficients in the presented joints were not very significant (in the range of 0.026 ÷ 0.092 W/(m·K) depending on the type of connection), proving the usefulness of this type of construction in energy-efficient buildings.

scholarly journals Experimental investigation of thermal bridges in building at real conditions

2018 ◽  
Vol 70 ◽  
pp. 03013
Author(s):  
Robert Smusz ◽  
Michał Korzeniowski
Keyword(s):  
Building Materials ◽  
Thermal State ◽  
Building Envelope ◽  
Heat Losses ◽  
Additional Heat ◽  
In Situ Ir ◽  
Thermal Bridges ◽  
Modern Technologies

In recent time the energy consumption of buildings may be reduced by the application of modern technologies in the construction industry. Modern building materials ensure a reduction of heat losses. However, studies show that thermal bridges may cause up to 30% of the additional heat losses through the building envelope. Therefore, a one key aspect in assessing the real thermal state of buildings is the identification of the heat losses through thermal bridges. The analytical, experimental and numerical methods are used for the assessment of thermal transmittance value of building. In the paper the authors present the experimental research on heat losses through the building under real winter conditions. Infrared thermovision technique has been used to the thermal bridges assessment in situ. IR thermography technique allowed the determination of the influence of thermal bridges on the additional heat losses. For the obtaining the surface emissivity the measurements have been also performed with the use of thermocouples system. Numerical validation of the experimental results has been performed.

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