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Ján Ondruška, Anton Trník, Libor Vozár The influence of heating rate on thermal field in cylindric ceramic samples 114 Zbyšek Pavlík, Lukáš Fiala, Milena Pavlíková, Robert Černý Experimental analysis of water and nitrate transport in porous building materials 122 Stanislav Šťastník, Jiří Vala, Jaroslav Nováček Thermomechanical modelling of maturing concrete mixture 131 Zbigniew Suchorab, Henryk Sobczuk Dielectric properties of building materials 138 Eva Vejmelková, Martin Keppert, Milena Pavlíková, Robert Černý Thermal, hygric and salt-related properties of high performance concrete 147 Pavel Tesárek, Robert Černý Properties of innovative materials on gypsum basis 157 Jan Toman, Tomáš Korecký Thermal conductivity in dependence on temperature 167 Anton Trník, Igor Štubňa, Ján Ondruška The thermodilatometric analysis of kaolin-quartz samples 174 Eva Vejmelková, Martin Keppert, Petr Konvalinka and Robert Černý Effect of porosity on moisture transport properties of composite materials 178 Viliam Vretenár, Ľudovít Kubičár, Vlastimil Boháč and Miloš Predmerský Thermal conductivity measurement of dynamo sheets 185 Eva Vejmelková, Petr Konvalinka, Stefania Grzeszczyk, Robert Černý Water and heat transport properties of slag concrete 193 Oldřich Zmeškal, Lenka Hřebenová, Pavla Štefková Use of step wise and pulse transient methods for the photovoltaic cells laminating films thermal properties study 200 Eva Vejmelková, Michal Ondráček, Martin Sedlmajer, Zbyšek Pavlík, Robert Černý High-performance materials containing alternative silicate binders: analysis of properties and recommendations for application in building practice 208 Janusz Terpiłowski, Grzegorz Woroniak Investigation of the thermal diffusivity of Fe52Ni48 and Fe40Ni60 iron-nickel alloys by means of modified flash method 216 Eva Vejmelková,Jan Toman, Petr Konvalinka, Robert Černý Mechanical, thermal and hygric properties of cracked self compacting concrete 228 Janusz Zmywaczyk, Monika Wielgosz, Piotr Koniorczyk, Marcin Gapski Identification of Some Thermophysical and Boundry Parameters of Black Foamglas by an Inverse Method 235 Andrzej J. Panas, Mirosław Nowakowski Numerical Validation of the Scanning Mod e Procedure of Thermal Diffusivity Investigation Applying Temperature Oscillation 252 List of Participants 260 4
Measurement of the thermo‐physical parameters of materials with the use of the generalized non‐stationary regime Ivan. Baník, Jozefa. Lukovičová Physics Department of Faculty of Civil Engineering of Slovak University of Technology in Bratislava, 813 68 Bratislava, Radlinského 11, e‐mail: ivan.banik@stuba.sk Abstract: In this paper the specific measurement method for the determination of thermo‐physical parameters of materials is described. All kinds of non‐stationary thermal processes in a specimen can be used in this method. In practice, some advantageous thermal processes (concerning the dimension, etc.) are chosen. The repeated measurement does not require the application of the self‐same non‐stationary thermal process. In the measurement of the thermal conductivity coefficient of thermal insulating materials, it is very advantageous to use an accumulated core. The time‐dependence of the temperature in chosen points of the specimen is recorded continuously. The analysis of these records yields thermal parameters. In some cases, the variable thermal power of the laboratory oven is also continuously recorded. The method can be applied to the measurement of the temperature dependences of the thermo‐ physical parameters in a wide temperature interval. Keywords: thermal measurement, thermo‐physical parameters, thermal conductivity, accumulative core 1 Introduction Considering the measurement of thermo‐physical parameters, there is a large number of measuring methods and set‐ups. Many of them are described in papers [1 – 8]. The methods used for measuring of thermo‐physical parameters of materials can be divided into steady state and dynamic ones. J. Krempaský [2] estimated that there are approximately 500 measuring methods. 1.1 Measurement of thermal conductivity coefficient by the Accumulation Core Method (ACM) This paper is a follow up to an earlier one [5]: “Method of Accumulation Core and its use by measuring thermal parameters of porous materials”. This paper includes a proposal and theoretical analysis of a measuring method for thermo‐physical parameters of materials using so called accumulation core. The accumulation core AC is a body of very good thermal conductivity (Fig. 1). Heat penetrates into the accumulation core from an outer metal block MB through the measured specimen (sample) S. Thermal differences in the volume of the metal block are to be ignored. The work deduces some general relations applicable for the accumulation core method in case of permanent temperature increase. The accumulation core method is an integral method. It is suitable for measuring parameters of heat insulants within a wide temperature range from low up to high temperatures. Essentials of the accumulation core AC method are fully displayed in Fig. 1. 5
Page 1 and 2: Thermophysics 2009 29 th and 30 th
Page 3: Content Ivan Baník, Jozefa Lukovi
Page 7 and 8: As the right side of the previous r
Page 9 and 10: The initial vector k r in the k1, k
Page 11 and 12: 2.4 The computer programs testing T
Page 13 and 14: Investigation of moisture influence
Page 15 and 16: ⎛ t t ⎞ −1 ⋅ ln⎜ ⎝ tm t
Page 17 and 18: Density [kg.m -3 ] 620 600 580 560
Page 19 and 20: for a new building have to be great
Page 21 and 22: Fig.1. Photo of the hot ball sensor
Page 23 and 24: Fig.6.Left: formation of blocks. Ri
Page 25 and 26: 4. Conclusions With this experiment
Page 27 and 28: 1a. Three‐dimensional temperature
Page 29 and 30: n+ ∞ ( ) 4 ( ) ∑ π n= 1 ( 2 1)
Page 31 and 32: a 2 2 ( Fo) ⎛ l ⎞ r = ⎜ ⎟
Page 33 and 34: Substitution of ordinates of the in
Page 35 and 36: Moisture transport through porous m
Page 37 and 38: Data acquired through the hot ball
Page 39 and 40: In this way, the water spreading wa
Page 41 and 42: Thermal conductivity [W m -1 K -1 ]
Page 43 and 44: Relationship between relative permi
Page 45 and 46: ( ) i n Φ − Φ K i = ki i i, cri
Page 47 and 48: Figure 4: Comparison of measured an
Page 49 and 50: Computational modelling of coupled
Page 51 and 52: a ξ = d 2 ( lnκ − lnκ ) lnξ +
Page 53 and 54: on the results of experiments and c
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Figures 8a, b: Moisture content (a)
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Conclusions The computer simulation
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properties as are the bulk density,
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elation determined from the measure
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In the evaluation of the difference
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Heat source I RT-Lab II Specimen Ch
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Thermal conductivity [W m -1 K -1 ]
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silicon glue epoxy probe hole Figur
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Computational modelling of temperat
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1 2 3 EXT. INT. 5-15 50-60 375 5 Nu
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Fig. 4 shows a comparison of the re
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Envelope D Figs. 14, 15 present the
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Application of computational modell
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Table 2: Basic material characteris
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Temperature [K] 320 300 280 260 240
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Mineral wool has the same effect as
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Nowadays, most of concrete building
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Figure 2: Ceramic dessicator plate
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dessicators are decreased by the pe
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The surface water vapour diffusion
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where h is the Planck constant and
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(a) (b) Figure 2: Schematic picture
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[7] BLUM, V.; HART, G. L. W.; WALOR
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Analysis of moisture hysteresis of
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The water content during scanning b
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All analysed cellulose based materi
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Thermodilatometry of ceramics using
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of the dilatometric cell with the s
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thermal expansion / % 2 1,5 1 0,5 0
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[8] KAMSEU, E. ; LEONELLI, C. ; BOC
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heating, the temperatures were meas
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temperature difference [°C] 140 12
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temperature difference [°C] 180 16
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[4] ČÍČEL, B. - NOVÁK, I. - HOR
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space and the crystallization press
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20 mm face to the penetrating KNO3
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Cb [kg/m 3 (sample)] 1800 1600 1400
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D [m 2 /s] 1.0E-03 1.0E-04 1.0E-05
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Thermomechanical modelling of matur
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ε ε (velocity rates) a x , t . By
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ε ε w v The process of redistribu
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Conclusion In this paper we have br
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most popular among direct technique
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• Closed pores (not available for
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espective volume of inclusions frac
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Summary Among the indirect methods
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Thermal, hygric and salt‐related
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The water vapor diffusion coefficie
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Thermal properties Thermal conducti
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On the other hand, apparent moistur
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Thermal conductivity.. [Wm -1 K -1
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Properties of innovative materials
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or hygrothermal analysis of buildin
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where Da is the diffusion coefficie
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The bending and compressive strengt
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moisture diffusivity which was caus
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Abstract: Thermal conductivity in d
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, (5) where λ is thermal conductiv
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4.Measured values and calculation I
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Acknowledgements This research has
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3 Results During heating, the struc
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Acknowledgment This work was suppor
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mixture by short mixing, the mixtur
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detected by MIP and thus the intrus
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diffusion. The general Arrhenius eq
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Thermal conductivity measurement of
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S s o 2 4 4 λ ∇ T = wεσ ( T
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steel (20 W m ‐1 K ‐1 ) is arou
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significant larger cross‐section.
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Water and heat transport properties
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The open porosity ψ0 [%], bulk den
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Table 3: Basic material parameters
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Acknowledgements This research has
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comparison of results we can determ
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specimen and heat source R at infin
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6.E-04 4.E-04 ΔU (V) 2.E-04 0.E+00
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[3] KUBIČÁR Ľ. Pulse method of m
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silicate binders as partial replace
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Table 2. Mechanical properties HPC
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HPC Table 5. Water transport proper
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The results obtained for using high
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aerospace engineering, cryogenic en
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4 ⎡ ′ ⎤ Δθ( t) = ⎢ l ∫
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Alloy Components Weight Percent, [%
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Figure 8: Final results of the ther
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Figure 11: Preliminary results of t
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In case of the FeNi35, FeNi39 and F
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Experimental Methods Compressive st
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Type of mixture Water transport pro
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Thermal properties The thermal para
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Identification of Some Thermophysic
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Physical model of the direct proble
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2 ( λ − Bi) sin( λ) − 2λ Bic
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To calculate the sensitivity coeffi
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symmetry of the specimen when the t
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Figure 5: View of experimental setu
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During the inverse calculations the
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temperature dependence for the blac
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4. Conclusions The results of the t
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cross‐planar direction applying s
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3. Thermal diffusivity identificati
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Table 2: Effect of the convective h
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[2] BODZENTA, J.; BURAKA, B.; NOWAK
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doc. Ing. Jiří Vala, CSc. Brno Un
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