Determination of the water retention curve from drying experiments using infrared thermography: A preliminary study

Janetti, Michele Bianchi; Colombo, Luigi Pietro Maria; Ochs, Fabian; Feist, Wolfgang

doi:10.1016/j.ijthermalsci.2016.12.018

Cited by 15 publications

(10 citation statements)

References 13 publications

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“…This non-contact and non-destructive technique was used to assess buildings for a couple of decades [1][2][3][4][5][6]. Particularly, when used to evaluate moisture problems [7][8][9][10][11][12], thermal patterns can result from (a) evaporative cooling at the moist area as evaporation decreases surface temperature [13][14][15][16][17][18][19], (b) reduced thermal resistance of the wet materials [20,21], and (c) increased heat storage capacity of the moist material [22,23].…”

Section: Introductionmentioning

confidence: 99%

Quantitative Infrared Thermography to Evaluate the Humidification of Lightweight Concrete

Barreira

Almeida

Simões

et al. 2020

Sensors

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Moisture is one of the major causes of problems in buildings, and it can compromise their performance. Infrared thermography (IRT) is a non-destructive testing technology that can be used to assess the humidification phenomenon and, thus, prevent some of the problems caused by moisture. The images obtained by IRT reflect the thermal patterns of the surface under study and can be evaluated using a quantitative approach, which allows not only the traditional visualization of the thermal patterns but also quantification of surface temperatures and/or their differences. The relevance of this work is related to the discussion of the strengths and weaknesses of several methods to quantitatively assess the humidification phenomenon using IRT. For that purpose, the partial humidification by the bottom surface of a lightweight concrete specimen was considered as a case study. To evaluate the thermal gradients, the evolution of the thermal imaging throughout the measurement period and the definition of the areas particularly affected by moisture, a methodology that included a pre-processing phase for data reduction, followed by a data processing phase, were implemented. In the data processing, different statistical and numerical methods were tested. The results of the statistical descriptive analysis highlighted the time variation of the surface temperature, both when considering the entire specimen and when considering only specific areas. The variability of the temperatures at certain moments of the experiment could be observed in the box-plot representation. The image subtraction proved to be an interesting technique to quantify the temperature differences if the first image was used as reference. A thermal index, TI, was proposed to assess the cooling rate. The index highlighted the initial instant when the effect of moisture on the surface temperature was detectable.

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Section: Introductionmentioning

confidence: 99%

Quantitative Infrared Thermography to Evaluate the Humidification of Lightweight Concrete

Barreira

Almeida

Simões

et al. 2020

Sensors

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“…Regarding the second, their greatest advantage is that they do not physically penetrate the material, which makes them ideal for rehabilitation work [24]. In historical buildings where interventions are difficult, infrared thermography has been used to detect humidity with a high degree of precision [25].…”

Section: Introductionmentioning

confidence: 99%

Low-Cost Sensors for Determining the Variation in Interior Moisture Content in Gypsum Composite Materials

et al. 2020

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Non-destructive testing can be used to determine some of the most relevant physical properties of building materials. In this work, two low-cost measuring devices were developed capable of determining the variation in real-time of the percentage of humidity that is produced in the construction of gypsum and plaster during the hardening process. For this, an Arduino resistive sensor and a capacitive sensor of our design were used. The results show how it is possible to determine the variations in mixing water content during the seven days of curing established by the UNE-EN 13279-2 standard as well relate to the mechanical resistance of the test specimens with the same percentage of humidity. Additionally, the study was completed with the determination of the formation of the dihydrate compound linked to this setting process in the test specimens by conducting X-ray diffraction and thermogravimetric analysis tests at different ages of the samples.

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“…For this reason, the range of these air flow parameters influences the experimental stand development. For example, the experiment may be conducted in free convection conditions or with low velocity forced convection in a climatic chamber [1,10]. For high speed forced convection, special wind tunnels are built.…”

Section: Introductionmentioning

confidence: 99%

Development of The Experimental Stand With Centrally Located Specimen For The Investigation of Heat and Moisture Phenomena in Porous Building Materials

Cieślikiewicz

Wąsik

Kubiś

et al. 2019

Civil and Environmental Engineering Reports

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The paper presents development of an experimental stand with centrally located specimen for the investigation of heating and drying processes in porous building materials. Additionally, the paper contains preliminary results of measurements which test and verify the assumed operation conditions of the stand. In order to control parameters of air which was used to heat and dry the specimen, the stand was operating in a closed loop and was equipped with several elements, i.e., the cooler (humidity condenser), fan with variable rotation speed, humidifier and heater. Moreover, the stand consisted of two square and parallel ducts with air streams which had identical parameters. This allowed for two measurements at the same time.

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Determination of the water retention curve from drying experiments using infrared thermography: A preliminary study

Cited by 15 publications

References 13 publications

Quantitative Infrared Thermography to Evaluate the Humidification of Lightweight Concrete

Quantitative Infrared Thermography to Evaluate the Humidification of Lightweight Concrete

Low-Cost Sensors for Determining the Variation in Interior Moisture Content in Gypsum Composite Materials

Development of The Experimental Stand With Centrally Located Specimen For The Investigation of Heat and Moisture Phenomena in Porous Building Materials

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