Evaluation of Functional Approaches to Describe the Moisture Diffusivity of Building Materials

2009 ◽  
pp. 55-55-16 ◽  
Author(s):  
Gregor Scheffler ◽  
John Grunewald ◽  
Rudolf Plagge
Keyword(s):  
Building Materials ◽  
Moisture Diffusivity

scholarly journals Comparison of different methods for determining the moisture diffusivity of porous building materials

2019 ◽  
Vol 282 ◽  
pp. 02023
Author(s):  
Peng Ren ◽  
Chi Feng ◽  
Hans Janssen
Keyword(s):  
Data Processing ◽  
Calcium Silicate ◽  
Building Materials ◽  
Moisture Diffusivity ◽  
Ceramic Brick ◽  
Step Method ◽  
Ray Method ◽  
Porous Building Materials ◽  
X Ray ◽  
The Common

This paper compares the X-ray method, the ruler method and the multi-step method to non-destructively determine the moisture diffusivity of calcium silicate and ceramic brick. Results show that the ruler method and multi-step method produce acceptable diffusivities and λ-profiles compared with the common X-ray method, meaning that both methods can determine moisture diffusivity reliably to some extent without the expensive X-ray setup and complicated data processing.

Validation of Genetic Programming Tool for the Inverse Analysis of Moisture Transport in Building Materials

2015 ◽  
Vol 1126 ◽  
pp. 75-80
Author(s):  
Jan Kočí ◽  
Robert Černý
Keyword(s):  
Genetic Programming ◽  
Moisture Transport ◽  
Inverse Analysis ◽  
Building Materials ◽  
Stochastic Approach ◽  
Moisture Diffusivity ◽  
Deterministic Approach ◽  
Programming Tool ◽  
Traditional Approaches ◽  
Good Agreement

This paper offers a comparison of two different approaches aimed at the identification of moisture diffusivity of porous building materials as a function of moisture content. The approaches are represented by a traditional deterministic approach using the Boltzmann-Matano method and novel stochastic approach by genetic programming. The results of the comparative analysis show that genetic programming may be used as an alternative to the traditional approaches. On the basis of the very good agreement between experimental data and optimized output of genetic programming, the validation of the genetic programming method may be considered as successful.

Evaluation of Functional Approaches to Describe the Moisture Diffusivity of Building Materials

2007 ◽  
Vol 4 (2) ◽  
pp. 100498 ◽  
Author(s):  
Gregor Scheffler ◽  
John Grunewald ◽  
Rudolf Plagge ◽  
P. Mukhopadhyaya ◽  
M. Kumaran ◽  
...  
Keyword(s):  
Building Materials ◽  
Moisture Diffusivity

Comparison of Two Different Modes of Inverse Analysis Used for Determination of Moisture Diffusivity of Building Materials

2014 ◽  
Vol 982 ◽  
pp. 49-53 ◽  
Author(s):  
Jan Kočí ◽  
Zbyšek Pavlík ◽  
Robert Černý
Keyword(s):  
Genetic Algorithms ◽  
Laboratory Experiment ◽  
Inverse Analysis ◽  
Building Materials ◽  
Moisture Diffusivity ◽  
Inverse Methods ◽  
Short Discussion ◽  
Porous Building Materials

This paper gives a brief overview of two different approaches within the inverse analysis used for determination of moisture diffusivity of porous building materials. The inverse methods are represented by Boltzman-Matano approach and genetic algorithms. Both methods are described in this paper and its application is demonstrated on a simple laboratory experiment. Finally, the results of both treatments are compared together and short discussion is given.

Application of different transient sorption methods to evaluate moisture diffusion coefficients of building materials on the hygroscopic range

2011 ◽  
Vol 35 (3) ◽  
pp. 251-266 ◽  
Author(s):  
JMPQ Delgado ◽  
NMM Ramos ◽  
VP de Freitas
Keyword(s):  
Building Materials ◽  
Transport Coefficients ◽  
Moisture Diffusion ◽  
Moisture Diffusivity ◽  
Time Saving ◽  
Adsorption Processes ◽  
Different Temperatures ◽  
Set Up ◽  
The Moment ◽  
End Stage

Typically, moisture transport coefficients are determined either by stationary measurements, as standard cup set-up and modified cup method, or by dynamic measurements, as the means of the type [Formula: see text] rule in the initial phase of adsorption processes, logarithmic procedure in the end stage of adsorption processes, the half-time method, the moment method, and the hybrid 1-term method. The aim of this work was to test the usability of the five dynamic calculation methods to define the moisture diffusivity in the hygroscopic range of different building materials. The results obtained were compared in order to evaluate the discrepancies between the different calculation techniques. Advantages in time saving using each experimental technique were compared with the feasibility of each process. Two commonly used building materials are considered in the study, gypsum board and gypsum plaster, for adsorptive measurement of the moisture diffusivity at three different temperatures in three different relative humidity ranges.

Scanning electron microscopy of asbestos-containing material where the asbestos fibers are considered locked in a binder

1993 ◽  
Vol 51 ◽  
pp. 472-473
Author(s):  
J. R. Millette ◽  
R. S. Brown
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Environmental Protection Agency ◽  
Building Materials ◽  
The United States ◽  
Protection Agency ◽  
Asbestos Fibers ◽  
Different Types ◽  
Binder Material ◽  
Scanning Electron

The United States Environmental Protection Agency (EPA) has labeled as “friable” those building materials that are likely to readily release fibers. Friable materials when dry, can easily be crumbled, pulverized, or reduced to powder using hand pressure. Other asbestos containing building materials (ACBM) where the asbestos fibers are in a matrix of cement or bituminous or resinous binders are considered non-friable. However, when subjected to sanding, grinding, cutting or other forms of abrasion, these non-friable materials are to be treated as friable asbestos material. There has been a hypothesis that all raw asbestos fibers are encapsulated in solvents and binders and are not released as individual fibers if the material is cut or abraded. Examination of a number of different types of non-friable materials under the SEM show that after cutting or abrasion, tuffs or bundles of fibers are evident on the surfaces of the materials. When these tuffs or bundles are examined, they are shown to contain asbestos fibers which are free from binder material. These free fibers may be released into the air upon further cutting or abrasion.

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