scholarly journals Thermal and Hygric Expansion of High Performance Concrete

10.14311/170 ◽  
2001 ◽  
Vol 41 (1) ◽  
Author(s):  
J. Toman ◽  
R. Černý
Keyword(s):  
Thermal Expansion ◽  
Expansion Coefficient ◽  
High Performance ◽  
Linear Thermal Expansion Coefficient ◽  
High Performance Concrete ◽  
Linear Thermal Expansion ◽  
Effect Of Temperature ◽  
Practical Applications ◽  
Thermal Expansion Coefficients ◽  
Expansion Coefficients

The linear thermal expansion coefficient of two types of high performance concrete was measured in the temperature range from 20 °C to 1000 °C, and the linear hygric expansion coefficient was determined in the moisture range from dry material to saturation water content. Comparative methods were applied for measurements of both coefficients. The experimental results show that both the effect of temperature on the values of linear thermal expansion coefficients and the effect of moisture on the values of linear hygric expansion coefficients are very significant and cannot be neglected in practical applications.

Measurement of thermal expansion coefficient of substrate GGG and its epitaxial layer YIG

1999 ◽  
Vol 14 (1) ◽  
pp. 2-4 ◽  
Author(s):  
Rui-sheng Liang ◽  
Feng-chao Liu
Keyword(s):  
Thin Film ◽  
Thermal Expansion ◽  
Single Crystal ◽  
Thermal Expansion Coefficient ◽  
Epitaxial Layer ◽  
Expansion Coefficient ◽  
Linear Thermal Expansion ◽  
New Method ◽  
Thermal Expansion Coefficients ◽  
Expansion Coefficients

A new method is used in measuring the linear thermal expansion coefficients in composite consisting of a substrate Gd3Ga2Ga3O12 (GGG) and its epitaxial layer Y3Fe2Fe3O12 (YIG) within the temperature range 13.88 °C–32.50 °C. The results show that the thermal expansion coefficient of GGG in composite is larger than that of the GGG in single crystal; the thermal expansion coefficient of thick film YIG is also larger than that of thin film. The results also show that the thermal expansion coefficient of a composite consisting of film and its substrate can be measured by using a new method.

Shrinkage of Cured Fluoroelastomers. I. Basic Parameters

1976 ◽  
Vol 49 (1) ◽  
pp. 34-42 ◽  
Author(s):  
A. W. Fogiel ◽  
H. K. Frensdorff ◽  
J. D. MacLachlan
Keyword(s):  
Thermal Expansion ◽  
Expansion Coefficient ◽  
Linear Thermal Expansion ◽  
Three Dimensions ◽  
Volumetric Expansion ◽  
Thermal Expansion Coefficients ◽  
Basic Parameters ◽  
Expansion Coefficients ◽  
Isotropic Expansion

Abstract The thermomechanical analyzer (TMA) is eminently suitable for the measurement of the thermal expansion coefficient of rubbers, provided the equipment is calibrated with materials of similar expansion coefficient. FKM or other thermally stable and amorphous polymers (of independently determined thermal expansion characteristics) can be used as calibration standards. The relative simplicity and precision of the TMA method for the determination of the coefficient of isotropic linear expansion, and hence, of volumetric expansion of rubbers, makes this important thermodynamic parameter easily accessible experimentally. Because of the frequently observed anisotropy of molded elastomeric compounds, measurements in all three dimensions are required to define linear, isotropic expansion and shrinkage which, to an excellent approximation, are represented by arithmetic averages of the three unidirectional values. Good agreement has been found between the average (isotropic) shrinkage determined experimentally and that calculated from the average (isotropic) coefficient of linear thermal expansion, α. The effect of fillers, such as carbon black, on α is additive. This makes it possible to predict α and shrinkage of all filled compounds from a single value of α of the unfilled rubber. The linear thermal expansion coefficients of the tested rubbers (FKM, NBR, EPDM) increase linearly with temperature, the increase being generally stronger for FKM than for the other elastomers. The appreciably higher mold shrinkage of FKM relative to NBR is directly due to the higher α of FKM for comparable levels of fillers. This must be kept in mind when expedience dictates the use of the same molds for FKM and NBR compounds.

scholarly journals Temperature-dependent structural behaviour of samarium cobalt oxide

2017 ◽  
Vol 32 (S2) ◽  
pp. S38-S42
Author(s):  
Matthew R. Rowles ◽  
Cheng-Cheng Wang ◽  
Kongfa Chen ◽  
Na Li ◽  
Shuai He ◽  
...  
Keyword(s):  
Thermal Expansion ◽  
Cobalt Oxide ◽  
Sol Gel ◽  
Linear Thermal Expansion ◽  
Rietveld Analysis ◽  
Structural Behaviour ◽  
Temperature Dependent ◽  
Thermal Expansion Coefficients ◽  
Expansion Coefficients ◽  
Sol Gel Synthesis

The crystal structure and thermal expansion of the perovskite samarium cobalt oxide (SmCoO3) have been determined over the temperature range 295–1245 K by Rietveld analysis of X-ray powder diffraction data. Polycrystalline samples were prepared by a sol–gel synthesis route followed by high-temperature calcination in air. SmCoO3 is orthorhombic (Pnma) at all temperatures and is isostructural with GdFeO3. The structure was refined as a distortion mode of a parent $ Pm{\bar 3}m $ structure. The thermal expansion was found to be non-linear and anisotropic, with maximum average linear thermal expansion coefficients of 34.0(3) × 10−6, 24.05(17) × 10−6, and 24.10(18) × 10−6 K−1 along the a-, b-, and c-axes, respectively, between 814 and 875 K.

scholarly journals Thermal Properties of Stabilized Zirconia at Low Temperatures

1985 ◽  
Vol 38 (4) ◽  
pp. 617 ◽  
Author(s):  
JG Collins ◽  
SJ Collocott ◽  
GK White
Keyword(s):  
Heat Capacity ◽  
Thermal Expansion ◽  
Thermal Properties ◽  
Thermal Expansion Coefficient ◽  
Expansion Coefficient ◽  
Low Temperatures ◽  
Linear Thermal Expansion Coefficient ◽  
Linear Thermal Expansion ◽  
Stabilized Zirconia ◽  
Elastic Data

The linear thermal expansion coefficient a from 2 to 100 K and heat capacity per gram cp from 0�3 to 30 K are reported for fully-stabilized zirconia containing a nominal 16 wt.% (9 mol.%) of yttria. The heat capacity below 7 K has been analysed into a linear (tunnelling?) term, a Schottky term centred at 1�2 K, a Debye term (e~ = 540 K), and a small T5 contribution. The expansion coefficient is roughly proportional to T from 5 to 20 K and gives a limiting lattice Griineisen parameter 'Yo ::::: 5, which agrees with that calculated from elastic data.

Effect of the Isotopic Composition of Fe on Its Linear Thermal Expansion Coefficient

2021 ◽  
Vol 57 (11) ◽  
pp. 1135-1139
Author(s):  
Yu. S. Belozerov ◽  
A. V. Knyazev ◽  
B. N. Kodess ◽  
A. S. Shipilova ◽  
M. O. Steshin ◽  
...  
Keyword(s):  
Thermal Expansion ◽  
Isotopic Composition ◽  
Thermal Expansion Coefficient ◽  
Expansion Coefficient ◽  
Linear Thermal Expansion Coefficient ◽  
Linear Thermal Expansion

Low-Melting Glass-Ceramic Composites with Low Linear Thermal Expansion Coefficient for Radio-Electronics

2015 ◽  
Vol 756 ◽  
pp. 313-318 ◽  
Author(s):  
Valeriy M. Pogrebenkov ◽  
Kirill S. Kostikov ◽  
E.A. Sudarev ◽  
A.V. Elistratova ◽  
Ksenia S. Kamyshnaya ◽  
...  
Keyword(s):  
Thermal Expansion ◽  
Thermal Expansion Coefficient ◽  
Expansion Coefficient ◽  
Glass Ceramic ◽  
Ceramic Composite ◽  
Linear Thermal Expansion Coefficient ◽  
Linear Thermal Expansion ◽  
Ceramic Composites ◽  
Radio Electronics ◽  
Glass Ceramic Composite

Glass-ceramic composite materials based on lead-borate glass and eucryptite – a compound with a negative coefficient of linear thermal expansion (CTE), along with the conditions for their production are studied in this paper. Effects of the amount and granulometric composition of the eucryptite as well as time/temperature processing conditions on the change of the linear thermal expansion coefficient of the sintered samples are also examined.

Anomaly in Thermal Expansion of YB2Cu307-y Around 250K

1989 ◽  
Vol 169 ◽  
Author(s):  
G.A. Ramadass ◽  
V. Ramcahdnran ◽  
R. Srinivasan
Keyword(s):  
Thermal Expansion ◽  
Thermal Expansion Coefficient ◽  
Expansion Coefficient ◽  
Linear Thermal Expansion Coefficient ◽  
Oxygen Deficiency ◽  
Linear Thermal Expansion

AbstractThe linear thermal expansion coefficient of YBa2Cu307 as a function of temperature has been studied. An anomaly is observed at 250K. This temperature is found to be dependent on oxygen deficiency.

Combustion Synthesis of ZrW2O8 and Preparation of its Composite with Near Zero Thermal Expansion

2007 ◽  
Vol 353-358 ◽  
pp. 1235-1238 ◽  
Author(s):  
Xue Yan ◽  
Xiao Nong Cheng ◽  
Xin Bo Yang ◽  
Cheng Hua Zhang
Keyword(s):  
Thermal Expansion ◽  
Combustion Synthesis ◽  
Thermal Expansion Coefficient ◽  
Expansion Coefficient ◽  
Linear Thermal Expansion Coefficient ◽  
Linear Thermal Expansion ◽  
Weight Ratio ◽  
Combustion Method ◽  
Temperature Range ◽  
Thermal Expansion Property

ZrW2O8 was successfully synthesized via combustion method with (NH4)5H5[H2(WO4)6] ·H2O, ZrOCl2·8H2O, H3BO3, (NH2)2CO and HNO3. The best prescription of combustion synthesizing of ZrW2O8 was obtained. The linear thermal expansion coefficient of synthesized ZrW2O8 is -5.08×10-6oC-1 in the temperature range of 50-600oC. Different weight ratios of ZrW2O8 and ZrO2 were taken into account. Al2O3 was added into the composite during sintering to increase the density of the composites. When the weight ratio of ZrO2 to ZrW2O8 is 2, the composite with near zero thermal expansion can be obtained. 0.25 wt% Al2O3 can effectively increase the density of ZrO2/ZrW2O8 composites with slight influence on the thermal expansion property.

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