Figure 1.
Graphic diagram of the various stages in the manufacture of PCM composites, molecular sieves, carbon recyclate and cement and epoxy matrices.
Figure 1.
Graphic diagram of the various stages in the manufacture of PCM composites, molecular sieves, carbon recyclate and cement and epoxy matrices.
Figure 2.
Gibbs triangle showing the range of variability of the input quantities of the full symplectic–centroid plan.
Figure 2.
Gibbs triangle showing the range of variability of the input quantities of the full symplectic–centroid plan.
Figure 3.
Diagram for the determination of the heating and cooling efficiencies of composite heat accumulators.
Figure 3.
Diagram for the determination of the heating and cooling efficiencies of composite heat accumulators.
Figure 4.
Graphic diagram of research and analysis.
Figure 4.
Graphic diagram of research and analysis.
Figure 5.
(a)—molecular silica sieves before PCM saturation; (b)—molecular silica sieves after PCM saturation in vacuum; (c)—laboratory bench during the vacuum saturation of molecular sieves with liquid organic PCM.
Figure 5.
(a)—molecular silica sieves before PCM saturation; (b)—molecular silica sieves after PCM saturation in vacuum; (c)—laboratory bench during the vacuum saturation of molecular sieves with liquid organic PCM.
Figure 6.
(a)—coal recyclate; (b)—concrete mix power mixer; (c)—cement matrix heat accumulator samples; (d)—epoxy matrix heat accumulator samples.
Figure 6.
(a)—coal recyclate; (b)—concrete mix power mixer; (c)—cement matrix heat accumulator samples; (d)—epoxy matrix heat accumulator samples.
Figure 7.
(a)—heat accumulator test sample with sensors connected; (b)—Espec climate chamber and Comet recorders, shown while testing; (c)—photograph of the heat accumulator samples produced.
Figure 7.
(a)—heat accumulator test sample with sensors connected; (b)—Espec climate chamber and Comet recorders, shown while testing; (c)—photograph of the heat accumulator samples produced.
Figure 8.
(a)—FLIR 7i thermal imaging camera; (b)—thermal imaging test benches; (c)—heated heat accumulator samples.
Figure 8.
(a)—FLIR 7i thermal imaging camera; (b)—thermal imaging test benches; (c)—heated heat accumulator samples.
Figure 9.
(a)—connected composite heat accumulators prepared for frost resistance testing; (b)—climate chamber with test samples of heat accumulators.
Figure 9.
(a)—connected composite heat accumulators prepared for frost resistance testing; (b)—climate chamber with test samples of heat accumulators.
Figure 10.
(a)—soaking of heat accumulator samples; (b)—temperature stabilisation of samples in the climate chamber; (c)—cracks in molecular silica sieves found in some samples.
Figure 10.
(a)—soaking of heat accumulator samples; (b)—temperature stabilisation of samples in the climate chamber; (c)—cracks in molecular silica sieves found in some samples.
Figure 11.
(a)—destructive testing of a cement matrix heat accumulator; (b)—destructive testing of an epoxy matrix heat accumulator.
Figure 11.
(a)—destructive testing of a cement matrix heat accumulator; (b)—destructive testing of an epoxy matrix heat accumulator.
Figure 12.
Found examples of anomalous molecular sieves saturated with PCM; (a)—cracking of molecular sieves; (b)—leakage of PCM from non-matrix encased molecular sieves.
Figure 12.
Found examples of anomalous molecular sieves saturated with PCM; (a)—cracking of molecular sieves; (b)—leakage of PCM from non-matrix encased molecular sieves.
Figure 13.
Temperature variation plot for PCM heat accumulator samples with cement matrix during matrix setting.
Figure 13.
Temperature variation plot for PCM heat accumulator samples with cement matrix during matrix setting.
Figure 14.
Temperature change plot for PCM heat accumulator samples with epoxy matrix during matrix setting.
Figure 14.
Temperature change plot for PCM heat accumulator samples with epoxy matrix during matrix setting.
Figure 15.
Temperature changes in the heat accumulators with cement matrix PCM molecular sieves.
Figure 15.
Temperature changes in the heat accumulators with cement matrix PCM molecular sieves.
Figure 16.
Temperature changes in the heat accumulators with epoxy matrix PCM molecular sieves.
Figure 16.
Temperature changes in the heat accumulators with epoxy matrix PCM molecular sieves.
Figure 17.
(a)—Compilation of thermal images of the epoxy matrix specimens during the cooling process of fully heated specimens; (b)—Compilation of thermal images of the cement matrix specimens during the cooling process of fully heated specimens.
Figure 17.
(a)—Compilation of thermal images of the epoxy matrix specimens during the cooling process of fully heated specimens; (b)—Compilation of thermal images of the cement matrix specimens during the cooling process of fully heated specimens.
Figure 18.
(a,b)—Charts of the obtained approximating function as a response plane.
Figure 18.
(a,b)—Charts of the obtained approximating function as a response plane.
Figure 19.
(a,b)—Charts of the obtained approximating function as a response plane.
Figure 19.
(a,b)—Charts of the obtained approximating function as a response plane.
Figure 20.
(a,b)—Charts of the obtained approximating function as a response plane.
Figure 20.
(a,b)—Charts of the obtained approximating function as a response plane.
Figure 21.
(a,b)—Charts of the obtained approximating function as a response plane.
Figure 21.
(a,b)—Charts of the obtained approximating function as a response plane.
Figure 22.
(a,b)—Charts of the obtained approximating function as a response plane.
Figure 22.
(a,b)—Charts of the obtained approximating function as a response plane.
Figure 23.
(a,b)—Charts of the obtained approximating function as a response plane.
Figure 23.
(a,b)—Charts of the obtained approximating function as a response plane.
Figure 24.
(a,b)—Charts of the obtained approximating function as a response plane.
Figure 24.
(a,b)—Charts of the obtained approximating function as a response plane.
Figure 25.
(a,b)—Charts of the obtained approximating function as a response plane.
Figure 25.
(a,b)—Charts of the obtained approximating function as a response plane.
Figure 26.
Summary scatter graphs for the empirical input quantities and those calculated from the produced response functions, (a)-graph for cement samples, not frozen, for flexural strength values; (b)-graph for cement samples, not frozen, for Heat load values; (c)-graph for cement samples after freezing for flexural strength values; (d)-graph for cement samples after freezing for Heat load values; (e)-graph for epoxy samples, not frozen, for flexural strength values; (f)-graph for epoxy samples, not frozen, for Heat load values; (g)-graph for epoxy samples after freezing for flexural strength values; (h)-graph for epoxy samples after freezing for Heat load values.
Figure 26.
Summary scatter graphs for the empirical input quantities and those calculated from the produced response functions, (a)-graph for cement samples, not frozen, for flexural strength values; (b)-graph for cement samples, not frozen, for Heat load values; (c)-graph for cement samples after freezing for flexural strength values; (d)-graph for cement samples after freezing for Heat load values; (e)-graph for epoxy samples, not frozen, for flexural strength values; (f)-graph for epoxy samples, not frozen, for Heat load values; (g)-graph for epoxy samples after freezing for flexural strength values; (h)-graph for epoxy samples after freezing for Heat load values.
Figure 27.
Summary of the heat capacity of all heat accumulators and their components tested. ΔH.C—heat capacity of the carbon recyclate; ΔH.ME—heat capacity of the epoxy matrix; ΔH.MC—heat capacity of the cement matrix; ΔH.SM.PCM—heat capacity of the PCM-saturated molecular sieves.
Figure 27.
Summary of the heat capacity of all heat accumulators and their components tested. ΔH.C—heat capacity of the carbon recyclate; ΔH.ME—heat capacity of the epoxy matrix; ΔH.MC—heat capacity of the cement matrix; ΔH.SM.PCM—heat capacity of the PCM-saturated molecular sieves.
Figure 28.
Summary of the masses of the heat accumulator tested and their components. M.C—mass of the carbon recyclate; M.ME—mass of the epoxy matrix; M.MC—mass of the cement matrix; M.SM.PCM—mass of the PCM-saturated molecular sieves.
Figure 28.
Summary of the masses of the heat accumulator tested and their components. M.C—mass of the carbon recyclate; M.ME—mass of the epoxy matrix; M.MC—mass of the cement matrix; M.SM.PCM—mass of the PCM-saturated molecular sieves.
Table 1.
Summary of the ranges of variation for the input quantities of the experimental plan.
Table 1.
Summary of the ranges of variation for the input quantities of the experimental plan.
No | Input Value | Minimum Value | Maximum Value |
---|
1 | Molecular sieves with PCM | 0.1 | 0.8 |
2 | Carbon recyclate | 0.1 | 0.8 |
3 | Concrete matrix/epoxy matrix | 0.1 | 0.8 |
Table 2.
Summary of input and output quantities for the experiments carried out.
Table 2.
Summary of input and output quantities for the experiments carried out.
No | Input Values |
---|
Volume Fraction of Molecular Sieves from PCM | Volume Fraction of Cement or Epoxy Matrix | Volume Fraction of Carbon Recyclate |
---|
symbol | VSM.PCM | VMC.ME | VC |
unit | [−] | [−] | [−] |
1 | 0.800 | 0.100 | 0.100 |
2 | 0.100 | 0.800 | 0.100 |
3 | 0.100 | 0.100 | 0.800 |
4 | 0.333 | 0.567 | 0.100 |
5 | 0.333 | 0.100 | 0.567 |
6 | 0.100 | 0.333 | 0.567 |
7 | 0.567 | 0.333 | 0.100 |
8 | 0.567 | 0.100 | 0.333 |
9 | 0.100 | 0.567 | 0.333 |
10 | 0.333 | 0.333 | 0.333 |
11 | 0.567 | 0.217 | 0.217 |
12 | 0.217 | 0.567 | 0.217 |
13 | 0.217 | 0.217 | 0.567 |
14 | 0.333 | 0.333 | 0.333 |
Table 3.
Summary of input and output quantities for the completed experiments.
Table 3.
Summary of input and output quantities for the completed experiments.
No | Input Values | Output Values |
---|
Volume Fraction of Molecular Sieves from PCM | Volume Fraction of Matrix | Volume Fraction of Carbon Recyclate | Thermal Efficiency Index of Cement Matrix Samples | Thermal Efficiency Index of Epoxy Matrix Samples |
---|
symbol | VSM.PCM | VMC.ME | VC | IT.MC | IT.ME |
unit | [−] | [−] | [−] | [−] | [−] |
1 | 0.800 | 0.100 | 0.100 | 0.544 | 0.620 |
2 | 0.100 | 0.800 | 0.100 | 0.496 | 0.596 |
3 | 0.100 | 0.100 | 0.800 | 0.386 | 0.519 |
4 | 0.333 | 0.567 | 0.100 | 0.504 | 0.599 |
5 | 0.333 | 0.100 | 0.567 | 0.380 | 0.537 |
6 | 0.100 | 0.333 | 0.567 | 0.271 | 0.625 |
7 | 0.567 | 0.333 | 0.100 | 0.426 | 0.656 |
8 | 0.567 | 0.100 | 0.333 | 0.508 | 0.629 |
9 | 0.100 | 0.567 | 0.333 | 0.436 | 0.586 |
10 | 0.333 | 0.333 | 0.333 | 0.311 | 0.606 |
11 | 0.567 | 0.217 | 0.217 | 0.446 | 0.500 |
12 | 0.217 | 0.567 | 0.217 | 0.380 | 0.568 |
13 | 0.217 | 0.217 | 0.567 | 0.319 | 0.512 |
14 | 0.333 | 0.333 | 0.333 | 0.500 | 0.588 |
Table 4.
Summary of statistical results produced for the epoxy matrix heat accumulator samples.
Table 4.
Summary of statistical results produced for the epoxy matrix heat accumulator samples.
Input Quantities | Simplex–Centroid Design of the Experiment. R2 = 0.8806; Plan for Three-Constrained Mixtures |
---|
Factor | Standard Error | t(10) | p | −95% Gran. | +95% Gran. |
---|
(A) V molecular sieves with PCM | 0.503768 | 0.042141 | 11.95430 | 0.000000 | 0.409872 | 0.409872 |
(B) V matrix | 0.484694 | 0.050237 | 9.64817 | 0.000002 | 0.372759 | 0.372759 |
(C) carbon recyclate | 0.353824 | 0.050237 | 7.04312 | 0.000035 | 0.241889 | 0.241889 |
BC | −0.389456 | 0.252705 | −1.54115 | 0.154306 | −0.952519 | −0.952519 |
Table 5.
Summary of statistical results produced for the cement matrix heat accumulator samples.
Table 5.
Summary of statistical results produced for the cement matrix heat accumulator samples.
Input Quantities | Simplex–Centroid Design of the Experiment. R2 = 0.9056; Plan for Three-Constrained Mixtures |
---|
Factor | Standard Error | t(10) | p | −95% Gran. | +95% Gran. |
---|
(A) V molecular sieves with PCM | 0.630949 | 0.071899 | 8.77545 | 0.000005 | 0.470747 | 0.791151 |
(B) V matrix | 0.624738 | 0.071899 | 8.68906 | 0.000006 | 0.464536 | 0.784940 |
(C) carbon recyclate | 0.505985 | 0.044748 | 11.30741 | 0.000001 | 0.406280 | 0.605690 |
AB | −0.064498 | 0.379402 | −0.17000 | 0.868401 | −0.909857 | 0.780862 |
Table 6.
Summary of input and output quantities for the experiments carried out after the frost resistance tests.
Table 6.
Summary of input and output quantities for the experiments carried out after the frost resistance tests.
No | Input Values | Output Values |
---|
Volume Fraction of Molecular Sieves from PCM | Volume Fraction of Matrix | Volume Fraction of Carbon Recyclate | Thermal Efficiency Index of Cement Matrix Samples | Thermal Efficiency Index of Epoxy Matrix Samples |
---|
symbol | VSM.PCM | VMC.ME | VC | IT.MC | IT.ME |
unit | [−] | [−] | [−] | [−] | [−] |
1 | 0.800 | 0.100 | 0.100 | 0.404 | 0.457 |
2 | 0.100 | 0.800 | 0.100 | 0.404 | 0.462 |
3 | 0.100 | 0.100 | 0.800 | 0.235 | 0.394 |
4 | 0.333 | 0.567 | 0.100 | 0.398 | 0.508 |
5 | 0.333 | 0.100 | 0.567 | 0.319 | 0.323 |
6 | 0.100 | 0.333 | 0.567 | 0.287 | 0.457 |
7 | 0.567 | 0.333 | 0.100 | 0.374 | 0.479 |
8 | 0.567 | 0.100 | 0.333 | 0.398 | 0.417 |
9 | 0.100 | 0.567 | 0.333 | 0.374 | 0.462 |
10 | 0.333 | 0.333 | 0.333 | 0.319 | 0.438 |
11 | 0.567 | 0.217 | 0.217 | 0.404 | 0.512 |
12 | 0.217 | 0.567 | 0.217 | 0.326 | 0.370 |
13 | 0.217 | 0.217 | 0.567 | 0.354 | 0.488 |
14 | 0.333 | 0.333 | 0.333 | 0.410 | 0.484 |
Table 7.
Summary of statistical results produced for the epoxy matrix heat accumulator samples after frost resistance testing.
Table 7.
Summary of statistical results produced for the epoxy matrix heat accumulator samples after frost resistance testing.
Input Quantities | Simplex–Centroid Design of the Experiment, R2 = 0.9237; Plan for Three-Constrained Mixtures |
---|
Factor | Standard Error | t(10) | p | −95% Gran. | +95% Gran. |
---|
(A) V molecular sieves with PCM | 0.393833 | 0.024949 | 15.78535 | 0.000000 | 0.338243 | 0.449423 |
(B) V matrix | 0.392878 | 0.020929 | 18.77221 | 0.000000 | 0.346246 | 0.439510 |
(C) carbon recyclate | 0.244442 | 0.024949 | 9.79755 | 0.000002 | 0.188851 | 0.300032 |
AC | −0.211588 | 0.125502 | 1.68594 | 0.122706 | −0.068048 | 0.491223 |
Table 8.
Summary of statistical results produced for the cement matrix heat accumulator samples after frost resistance testing.
Table 8.
Summary of statistical results produced for the cement matrix heat accumulator samples after frost resistance testing.
Input Quantities | Simplex–Centroid Design of the Experiment. R2 = 0.9337; Plan for Three-Constrained Mixtures |
---|
Factor | Standard Error | t(10) | p | −95% Gran. | +95% Gran. |
---|
(A) V molecular sieves with PCM | 0.467022 | 0.030853 | 15.13697 | 0.000000 | 0.39828 | 0.535767 |
(B) V matrix | 0.496569 | 0.032728 | 15.17267 | 0.000000 | 0.42365 | 0.569491 |
(C) carbon recyclate | 0.375909 | 0.032728 | 11.48590 | 0.000000 | 0.30299 | 0.448831 |
BC (B-C) | −0.729940 | 0.398828 | −1.83021 | 0.097142 | −1.61858 | 0.158704 |
Table 9.
Summary of input and output quantities for the experiments carried out before the frost resistance tests.
Table 9.
Summary of input and output quantities for the experiments carried out before the frost resistance tests.
No | Input Values | Output Values |
---|
Volume Fraction of Molecular Sieves from PCM | Volume Fraction of Matrix | Volume Fraction of Carbon Recyclate | Flexural Strength of Cement Matrix Samples | Flexural Strength of Epoxy Matrix Samples |
---|
symbol | VSM.PCM | VMC.ME | VC | FMC | FME |
unit | [-] | [-] | [-] | [MPa] | [MPa] |
1 | 0.800 | 0.100 | 0.100 | 0.41 | 3.86 |
2 | 0.100 | 0.800 | 0.100 | 2.25 | 9.53 |
3 | 0.100 | 0.100 | 0.800 | 0.20 | 2.49 |
4 | 0.333 | 0.567 | 0.100 | 0.53 | 8.32 |
5 | 0.333 | 0.100 | 0.567 | 0.19 | 1.54 |
6 | 0.100 | 0.333 | 0.567 | 0.31 | 8.78 |
7 | 0.567 | 0.333 | 0.100 | 0.26 | 10.89 |
8 | 0.567 | 0.100 | 0.333 | 0.31 | 7.40 |
9 | 0.100 | 0.567 | 0.333 | 0.62 | 9.57 |
10 | 0.333 | 0.333 | 0.333 | 0.30 | 4.22 |
11 | 0.567 | 0.217 | 0.217 | 0.48 | 5.37 |
12 | 0.217 | 0.567 | 0.217 | 1.15 | 11.02 |
13 | 0.217 | 0.217 | 0.567 | 0.22 | 4.25 |
14 | 0.333 | 0.333 | 0.333 | 0.16 | 10.48 |
15 | 0 | 100 | 0 | 6.34 | 30.45 |
Table 10.
Summary of bending strength statistical results produced for the epoxy matrix heat accumulator samples.
Table 10.
Summary of bending strength statistical results produced for the epoxy matrix heat accumulator samples.
Input Quantities | Simplex–Centroid Design of the Experiment. R2 = 0.9106; Plan for Three-Constrained Mixtures |
---|
Factor | Standard Error | t(10) | p | −95% Gran. | +95% Gran. |
---|
(A) V molecular sieves with PCM | 0.46507 | 0.153871 | 3.02246 | 0.014422 | 0.11699 | 0.81315 |
(B) V matrix | 2.15395 | 0.178889 | 12.04073 | 0.000001 | 1.74928 | 2.55862 |
(C) V carbon recyclate | 0.19459 | 0.153871 | 1.26460 | 0.237778 | −0.15349 | 0.54267 |
AB | −3.51328 | 0.772809 | −4.54611 | 0.001394 | −5.26149 | −1.76506 |
BC | −2.74871 | 0.772809 | −3.55678 | 0.006150 | −4.49693 | −1.00050 |
Table 11.
Summary of bending strength statistical results produced for the cement matrix heat accumulator samples.
Table 11.
Summary of bending strength statistical results produced for the cement matrix heat accumulator samples.
Input Quantities | Simplex–Centroid Design of the Experiment, R2 = 0.9061; Plan for Three-Constrained Mixtures |
---|
Factor | Standard Error | t(10) | p | −95% Gran. | +95% Gran. |
---|
(A) V molecular sieves with PCM | 6.17547 | 1.529429 | 4.037760 | 0.002370 | 2.76769 | 9.58324 |
(B) V matrix | 10.35547 | 1.823245 | 5.679695 | 0.000204 | 6.29303 | 14.41792 |
(C) carbon recyclate | 1.81374 | 1.823245 | 0.994784 | 0.343302 | −2.2471 | 5.87618 |
BC | 13.21256 | 9.171430 | 1.440622 | 0.180258 | −7.22266 | 33.64778 |
Table 12.
Summary of input and output quantities for the experiments carried out after the frost resistance tests.
Table 12.
Summary of input and output quantities for the experiments carried out after the frost resistance tests.
No | Input Values | Output Values |
---|
Volume Fraction of Molecular Sieves from PCM | Volume Fraction of Molecular Sieves from PCM | Volume Fraction of Molecular Sieves from PCM | Flexural Strength of Cement Matrix Samples | Flexural Strength of Epoxy Matrix Samples |
---|
symbol | VSM.PCM | VMC.ME | VC | FMC | FME |
unit | [−] | [−] | [−] | [MPa] | [MPa] |
1 | 0.800 | 0.100 | 0.100 | 0.60 | 3.75 |
2 | 0.100 | 0.800 | 0.100 | 1.15 | 12.41 |
3 | 0.100 | 0.100 | 0.800 | 0.07 | 3.13 |
4 | 0.333 | 0.567 | 0.100 | 0.52 | 12.75 |
5 | 0.333 | 0.100 | 0.567 | 0.16 | 1.21 |
6 | 0.100 | 0.333 | 0.567 | 0.20 | 7.91 |
7 | 0.567 | 0.333 | 0.100 | 0.15 | 10.49 |
8 | 0.567 | 0.100 | 0.333 | 0.37 | 7.29 |
9 | 0.100 | 0.567 | 0.333 | 0.62 | 11.03 |
10 | 0.333 | 0.333 | 0.333 | 0.22 | 7.07 |
11 | 0.567 | 0.217 | 0.217 | 0.48 | 4.11 |
12 | 0.217 | 0.567 | 0.217 | 1.23 | 11.34 |
13 | 0.217 | 0.217 | 0.567 | 0.23 | 2.22 |
14 | 0.333 | 0.333 | 0.333 | 0.15 | 12.43 |
15 | 0 | 100 | 0 | 6.04 | 25.91 |
Table 13.
Summary of bending strength statistical results produced for the epoxy matrix heat accumulator samples after frost resistance testing.
Table 13.
Summary of bending strength statistical results produced for the epoxy matrix heat accumulator samples after frost resistance testing.
Input Quantities | Simplex–Centroid Design of the Experiment, R2 = 0.9271; Plan for Three-Constrained Mixtures |
---|
Factor | Standard Error | t(10) | p | −95% Gran. | +95% Gran. |
---|
(A) V molecular sieves with PCM | 0.56932 | 0.175140 | 3.25066 | 0.008711 | 0.17909 | 0.959560 |
(B) V matrix | 1.21019 | 0.175140 | 6.90984 | 0.000041 | 0.81995 | 1.600429 |
(C) carbon recyclate | −0.05746 | 0.146917 | −0.39113 | 0.703903 | −0.38481 | 0.269886 |
AB | −2.05771 | 0.881005 | −2.33564 | 0.041648 | −4.02071 | −0.094710 |
Table 14.
Summary of bending strength statistical results produced for the cement matrix heat accumulator samples after frost resistance testing.
Table 14.
Summary of bending strength statistical results produced for the cement matrix heat accumulator samples after frost resistance testing.
Input Quantities | Simplex–Centroid Design of the Experiment. R2 = 0.8932; Plan for Three-Constrained Mixtures |
---|
Factor | Standard Error | t(10) | p | −95% Gran. | +95% Gran. |
---|
(A) V molecular sieves with PCM | 4.83237 | 1.61602 | 2.990301 | 0.013567 | 1.2317 | 8.43308 |
(B) V matrix | 14.85199 | 1.52344 | 9.748968 | 0.000002 | 11.4575 | 18.24643 |
(C) carbon recyclate | 3.27421 | 1.61602 | 2.026101 | 0.070261 | −0.3265 | 6.87492 |
AC(A-C) | 27.62123 | 19.69305 | 1.402587 | 0.191014 | −16.2576 | 71.50008 |
Table 15.
Summary of the response functions produced for all completed experiments.
Table 15.
Summary of the response functions produced for all completed experiments.
Function | Formula |
---|
Cement samples | Before freezing | Flexural strength | FMC = 0.465·VSM.PCM + 2.154·VMC.ME + 0.195·VC − 3.513 VSM.PCM·VMC.ME − 2.749·VMC.ME·VC |
Thermal efficiency index | IT.MC = 0.504·VSM.PCM + 0.485·VMC.ME + 0.354·VC − 0.389 VMC.ME·VC |
After freezing | Flexural strength | FMC = 0.569·VSM.PCM + 1.210·VMC.ME − 0.057·VC − 2.05·VSM.PCM·VMC.ME |
Thermal efficiency index | IT.MC = 0.394·VSM.PCM + 0.393·VMC.ME + 0.244·VC − 0.216 VSM.PCM·VC |
Epoxy samples | Before freezing | Flexural strength | FME = 6.175·VSM.PCM + 10.355·VMC.ME + 1.814·VC + 13.213·VMC.ME·VC |
Thermal efficiency index | IT.ME = 0.613·VSM.PCM + 0.608·VMC.ME + 0.530·VC − 0.316 VMC.ME·VSM.PCM |
After freezing | Flexural strength | FME = 4.832·VSM.PCM + 14.852·VMC.ME + 3.274·VC + 27.621 VSM.PCM·VC·(VSM.PCM − VC) |
Thermal efficiency index | IT.ME = 0.467·VSM.PCM + 0.497·VMC.ME + 0.376·VC − 0.730 VMC.ME·VC·(VMC.ME − VC) |
Table 16.
Summary of calculated values and critical Snedecor–Fischer statistics.
Table 16.
Summary of calculated values and critical Snedecor–Fischer statistics.
Research Case | Quotient of Variances FPCM(α.f1.f2) | Critical Value Fkr |
---|
Cement samples | Before freezing | Flexural strength | 2.4321 | 2.4800 |
Heat load | 2.4730 | 2.4800 |
After freezing | Flexural strength | 2.4605 | 2.4800 |
Heat load | 2.4737 | 2.4800 |
Epoxy samples | Before freezing | Flexural strength | 2.4538 | 2.4800 |
Heat load | 2.4612 | 2.4800 |
After freezing | Flexural strength | 2.4775 | 2.4800 |
Heat load | 2.4297 | 2.4800 |