Author Contributions
Conceptualization, R.H.; methodology, R.H.; software, R.H.; validation, R.H.; formal analysis, R.H.; investigation, R.H.; resources, R.H. and B.S.; data curation, R.H.; writing—original draft preparation, R.H.; writing—review and editing, B.S.; visualization, R.H.; supervision, B.S.; project administration, B.S.; funding acquisition, B.S. All authors have read and agreed to the published version of the manuscript.
Figure 1.
Particle gradation.
Figure 1.
Particle gradation.
Figure 2.
Example temperature and relative humidity data for 7-day samples.
Figure 2.
Example temperature and relative humidity data for 7-day samples.
Figure 3.
Sample creation and storage.
Figure 3.
Sample creation and storage.
Figure 4.
Compression testing setup.
Figure 4.
Compression testing setup.
Figure 5.
The 7-day compressive strength results.
Figure 5.
The 7-day compressive strength results.
Figure 6.
The 28-day compressive strength results.
Figure 6.
The 28-day compressive strength results.
Figure 7.
Coefficient of variation vs. water content by cure time.
Figure 7.
Coefficient of variation vs. water content by cure time.
Figure 8.
The 95% statistical significance level for compressive strength for changes in cement content separated by initial compression for both 7-day and 28-day samples.
Figure 8.
The 95% statistical significance level for compressive strength for changes in cement content separated by initial compression for both 7-day and 28-day samples.
Figure 9.
The 95% statistical significance level for compressive strength for changes in water content separated by initial compression for both 7-day and 28-day samples.
Figure 9.
The 95% statistical significance level for compressive strength for changes in water content separated by initial compression for both 7-day and 28-day samples.
Figure 10.
Compressive strength vs. water-to-cement ratio color-coded by (a) individual mix, (b) water content, (c) cement content for 7-day samples of all initial compression levels.
Figure 10.
Compressive strength vs. water-to-cement ratio color-coded by (a) individual mix, (b) water content, (c) cement content for 7-day samples of all initial compression levels.
Figure 11.
Compressive strength vs. water-to-cement ratio color-coded by (a) individual mix, (b) water content, (c) cement content for 28-day samples of all initial compression levels.
Figure 11.
Compressive strength vs. water-to-cement ratio color-coded by (a) individual mix, (b) water content, (c) cement content for 28-day samples of all initial compression levels.
Figure 12.
The 95% statistical significance level results for compressive strength for changes in mix composition separated by initial compression for both 7-day and 28-day samples.
Figure 12.
The 95% statistical significance level results for compressive strength for changes in mix composition separated by initial compression for both 7-day and 28-day samples.
Figure 13.
The 95% statistical significance level results for compressive strength for changes in initial compression separated by mix composition for both 7-day and 28-day samples.
Figure 13.
The 95% statistical significance level results for compressive strength for changes in initial compression separated by mix composition for both 7-day and 28-day samples.
Figure 14.
The 7-day density results separated by mix composition.
Figure 14.
The 7-day density results separated by mix composition.
Figure 15.
The 28-day density results separated by mix composition.
Figure 15.
The 28-day density results separated by mix composition.
Figure 16.
Density result coefficient of variation vs. water content.
Figure 16.
Density result coefficient of variation vs. water content.
Figure 17.
The 95% statistical significance level for density for changes in cement content separated by initial compression for both 7-day and 28-day samples.
Figure 17.
The 95% statistical significance level for density for changes in cement content separated by initial compression for both 7-day and 28-day samples.
Figure 18.
The 95% statistical significance level for density for changes in water content separated by initial compression for both 7-day and 28-day samples.
Figure 18.
The 95% statistical significance level for density for changes in water content separated by initial compression for both 7-day and 28-day samples.
Figure 19.
Statistical significance as mix composition changes.
Figure 19.
Statistical significance as mix composition changes.
Figure 20.
The 95% statistical significance level results for density for changes in initial compression separated by mix composition for both 7-day and 28-day samples.
Figure 20.
The 95% statistical significance level results for density for changes in initial compression separated by mix composition for both 7-day and 28-day samples.
Figure 21.
Flowchart for developing linear regression.
Figure 21.
Flowchart for developing linear regression.
Figure 22.
Density prediction equation adjusted and MAPE performance vs. included variables.
Figure 22.
Density prediction equation adjusted and MAPE performance vs. included variables.
Figure 23.
Predicted density vs. experimental density.
Figure 23.
Predicted density vs. experimental density.
Figure 24.
Compressive strength prediction equation adjusted and MAPE performance vs. included variables.
Figure 24.
Compressive strength prediction equation adjusted and MAPE performance vs. included variables.
Figure 25.
Predicted compressive strength vs. experimental compressive strength for (a) 7-day samples and (b) 28-day samples.
Figure 25.
Predicted compressive strength vs. experimental compressive strength for (a) 7-day samples and (b) 28-day samples.
Figure 26.
Combined graph of density and 28-day compressive strength variation predictions within the range of mix composition tested.
Figure 26.
Combined graph of density and 28-day compressive strength variation predictions within the range of mix composition tested.
Table 1.
CSEB code requirement summary.
Table 1.
CSEB code requirement summary.
| International Building Code 2021 | New Zealand Standards 4298:2024 | Indian Standards 1725:2020 |
---|
Code Reference | IBC 2021 | NZS 4298:2024 | IS 1725:2020 |
Jurisdiction | North America | New Zealand | India |
Compressive Strength | 2 MPa min. | 1.4 MPa min. | 3.5 MPa min. |
Density | N/A | min. | min. |
Variability | N/A | Used to adjust characteristic strength | No sample more than 15% below average |
Durability | N/A | Thickness to not decrease by more than 5% or 30 mm during building lifespan | Lose no more than 3% mass within testing period |
Table 2.
Particle gradation.
Table 2.
Particle gradation.
Sieve no. | Diameter (mm) | Total wt. (g) | % Passing |
---|
3/8” | 9.525 | 0 | 100.00 |
4 | 4.750 | 0 | 100.00 |
8 | 2.360 | 75.5 | 91.94 |
16 | 1.180 | 162.5 | 82.65 |
30 | 0.600 | 182 | 80.57 |
40 | 0.425 | 308 | 67.11 |
50 | 0.300 | 505.5 | 46.02 |
80 | 0.180 | 751 | 19.81 |
100 | 0.150 | 789 | 15.75 |
200 | 0.075 | 885.5 | 5.45 |
pan | N/A | 936.5 | 0.00 |
Table 3.
Soil classifications used in other studies.
Table 3.
Soil classifications used in other studies.
Sample Source | Fines% | USCS | AASHTO |
---|
Present Study | 5% | SP | A3 |
Sitton et al., 2018 [2] | 9% | SC | A-2-7 |
Cid-Falceto et al., 2012 [3] | 11% | SP | A-1-b |
R.K. Preethi and Reddy 2020 [6] | 50% | CL | A6 |
Mansour et al., 2016 [15] | 60% | CL+ML | A4 |
Gonzalez-Lopez et al., 2018 [14] | 30% | SC | A-2-6 |
Ruiz et al., 2018 [30] | 12% | SM | A-1-b |
Narayanaswamy et al., 2020 [31] | 43% | SC | A-2-6 |
Table 4.
Mix compositions by percent mass.
Table 4.
Mix compositions by percent mass.
Mix | Portland Cement | Water | Soil |
---|
1 | 3% | 6% | 91% |
2 | 6% | 6% | 88% |
3 | 9% | 6% | 85% |
4 | 3% | 8% | 89% |
5 | 6% | 8% | 86% |
6 | 9% | 8% | 83% |
7 | 3% | 10% | 87% |
8 | 6% | 10% | 84% |
9 | 9% | 10% | 81% |
Table 5.
The 7-day compressive strength results.
Table 5.
The 7-day compressive strength results.
7-Day Compressive Strength (Mpa) |
---|
| Initial Compression |
---|
2.2 MPa | 4.4 MPa | 8.8 MPa | 13.2 MPa |
---|
MIX | | | | | | | | |
---|
1 | 0.11 | 0.04 | 0.18 | 0.04 | 0.29 | 0.12 | 0.33 | 0.11 |
2 | 0.42 | 0.11 | 0.63 | 0.07 | 0.62 | 0.06 | 0.72 | 0.15 |
3 | 0.40 | 0.07 | 0.41 | 0.13 | 0.60 | 0.18 | 0.66 | 0.27 |
4 | 0.51 | 0.06 | 0.45 | 0.05 | 0.66 | 0.08 | 0.71 | 0.04 |
5 | 0.51 | 0.05 | 0.73 | 0.11 | 1.00 | 0.14 | 1.33 | 0.14 |
6 | 0.98 | 0.07 | 1.33 | 0.15 | 1.56 | 0.13 | 1.86 | 0.29 |
7 | 0.54 | 0.08 | 0.25 | 0.09 | 0.92 | 0.12 | 0.96 | 0.04 |
8 | 1.29 | 0.11 | 1.52 | 0.10 | 2.03 | 0.07 | 2.05 | 0.08 |
9 | 2.08 | 0.17 | 2.62 | 0.13 | 2.68 | 0.11 | 3.40 | 0.52 |
Table 6.
The 28-day compressive strength results.
Table 6.
The 28-day compressive strength results.
28-Day Compressive Strength (Mpa) |
---|
| Initial Compression |
---|
2.2 MPa | 4.4 MPa | 8.8 MPa | 13.2 MPa |
---|
MIX | | | | | | | | |
---|
1 | 0.22 | 0.07 | 0.18 | 0.04 | 0.29 | 0.06 | 0.43 | 0.07 |
2 | 0.47 | 0.06 | 0.62 | 0.07 | 0.49 | 0.16 | 0.85 | 0.23 |
3 | 0.53 | 0.16 | 0.55 | 0.07 | 0.73 | 0.10 | 0.94 | 0.16 |
4 | 0.37 | 0.03 | 0.53 | 0.03 | 0.87 | 0.10 | 0.97 | 0.09 |
5 | 1.14 | 0.08 | 0.97 | 0.08 | 1.59 | 0.31 | 1.54 | 0.14 |
6 | 1.48 | 0.19 | 1.61 | 0.14 | 1.99 | 0.17 | 2.83 | 0.39 |
7 | 0.42 | 0.03 | 0.67 | 0.02 | 0.95 | 0.07 | 0.98 | 0.08 |
8 | 1.86 | 0.10 | 1.66 | 0.12 | 2.17 | 0.23 | 2.30 | 0.26 |
9 | 2.21 | 0.34 | 2.55 | 0.22 | 4.05 | 0.56 | 3.87 | 0.12 |
Table 7.
Compressive strength coefficient of variation.
Table 7.
Compressive strength coefficient of variation.
Compressive Strength CV |
---|
| Initial Compression |
---|
2.2 MPa | 4.4 MPa | 8.8 MPa | 13.2 MPa |
---|
MIX | 7-Day | 28-Day | 7-Day | 28-Day | 7-Day | 28-Day | 7-Day | 28-Day |
---|
1 | 0.34 | 0.34 | 0.23 | 0.22 | 0.40 | 0.21 | 0.33 | 0.17 |
2 | 0.25 | 0.13 | 0.12 | 0.13 | 0.10 | 0.34 | 0.20 | 0.27 |
3 | 0.18 | 0.30 | 0.32 | 0.13 | 0.31 | 0.14 | 0.40 | 0.17 |
4 | 0.13 | 0.08 | 0.11 | 0.05 | 0.12 | 0.12 | 0.05 | 0.10 |
5 | 0.09 | 0.07 | 0.16 | 0.10 | 0.14 | 0.19 | 0.11 | 0.09 |
6 | 0.07 | 0.13 | 0.11 | 0.09 | 0.08 | 0.09 | 0.15 | 0.14 |
7 | 0.14 | 0.08 | 0.38 | 0.03 | 0.13 | 0.07 | 0.04 | 0.08 |
8 | 0.09 | 0.06 | 0.07 | 0.07 | 0.04 | 0.11 | 0.04 | 0.11 |
9 | 0.08 | 0.15 | 0.05 | 0.09 | 0.04 | 0.14 | 0.15 | 0.03 |
Table 8.
The 7-day density results.
Table 8.
The 7-day density results.
7-Day Density |
---|
| Initial Compression |
---|
2.2 MPa | 4.4 MPa | 8.8 MPa | 13.2 MPa |
---|
MIX | | | | | | | | |
---|
1 | 1628 | 44 | 1704 | 18 | 1791 | 56 | 1799 | 10 |
2 | 1694 | 43 | 1770 | 39 | 1785 | 13 | 1824 | 28 |
3 | 1692 | 23 | 1718 | 41 | 1795 | 7 | 1845 | 12 |
4 | 1761 | 4 | 1766 | 19 | 1865 | 13 | 1859 | 3 |
5 | 1728 | 10 | 1783 | 17 | 1854 | 5 | 1903 | 12 |
6 | 1740 | 7 | 1794 | 5 | 1870 | 11 | 1909 | 13 |
7 | 1788 | 8 | 1799 | 32 | 1880 | 12 | 1927 | 14 |
8 | 1838 | 20 | 1879 | 9 | 1951 | 5 | 1972 | 7 |
9 | 1857 | 4 | 1924 | 15 | 1965 | 20 | 1995 | 9 |
Table 9.
The 28-day density results.
Table 9.
The 28-day density results.
28-Day Density |
---|
| Initial Compression |
---|
2.2 MPa | 4.4 MPa | 8.8 MPa | 13.2 MPa |
---|
MIX | | | | | | | | |
---|
1 | 1669 | 34 | 1700 | 28 | 1778 | 30 | 1805 | 18 |
2 | 1715 | 16 | 1775 | 8 | 1778 | 22 | 1841 | 14 |
3 | 1730 | 27 | 1764 | 12 | 1830 | 13 | 1865 | 7 |
4 | 1698 | 19 | 1751 | 8 | 1818 | 11 | 1860 | 7 |
5 | 1747 | 9 | 1769 | 11 | 1857 | 18 | 1879 | 11 |
6 | 1784 | 19 | 1812 | 10 | 1873 | 11 | 1918 | 16 |
7 | 1724 | 12 | 1803 | 13 | 1875 | 12 | 1914 | 7 |
8 | 1857 | 13 | 1870 | 23 | 1934 | 13 | 1966 | 14 |
9 | 1838 | 20 | 1883 | 13 | 1958 | 13 | 1973 | 9 |
Table 10.
Coefficient of variation for density.
Table 10.
Coefficient of variation for density.
Density CV |
---|
| Initial Compression |
---|
2.2 MPa | 4.4 MPa | 8.8 MPa | 13.2 MPa |
---|
MIX | 7D | 28D | 7D | 28D | 7D | 28D | 7D | 28D |
---|
1 | 0.03 | 0.02 | 0.01 | 0.02 | 0.03 | 0.02 | 0.01 | 0.01 |
2 | 0.03 | 0.01 | 0.02 | 0.00 | 0.01 | 0.01 | 0.02 | 0.01 |
3 | 0.01 | 0.02 | 0.02 | 0.01 | 0.00 | 0.01 | 0.01 | 0.00 |
4 | 0.00 | 0.01 | 0.01 | 0.00 | 0.01 | 0.01 | 0.00 | 0.00 |
5 | 0.01 | 0.01 | 0.01 | 0.01 | 0.00 | 0.01 | 0.01 | 0.01 |
6 | 0.00 | 0.01 | 0.00 | 0.01 | 0.01 | 0.01 | 0.01 | 0.01 |
7 | 0.00 | 0.01 | 0.02 | 0.01 | 0.01 | 0.01 | 0.01 | 0.00 |
8 | 0.01 | 0.01 | 0.00 | 0.01 | 0.00 | 0.01 | 0.00 | 0.01 |
9 | 0.00 | 0.01 | 0.01 | 0.01 | 0.01 | 0.01 | 0.00 | 0.00 |
Table 11.
Prospective variables for density prediction equation.
Table 11.
Prospective variables for density prediction equation.
Variable | Type | Symbol | Range |
---|
Portland Cement Content | Independent | C | 3–9% of mass |
Water Content | Independent | W | 6% –10% of mass |
Initial Compression | Independent | IC | 2.2 MPa–13.2 MPa |
Water to Portland Cement Ratio | Composite | WC | 0.67–3.3% |
Water to Soil Ratio | Composite | WS | 6.5–12.3% |
Table 12.
Prospective variables for compressive strength prediction equation.
Table 12.
Prospective variables for compressive strength prediction equation.
Variable | Type | Symbol | Range |
---|
Portland Cement Content | Independent | C | 3–9% of mass |
Water Content | Independent | W | 6–10% of mass |
Initial Compression | Independent | IC | 2.2 MPa–13.2 MPa |
Water-To-Portland Cement Ratio | Composite | WC | 0.67–3.3% |
Water-To-Soil Ratio | Composite | WS | 6.5–12.3% |
Predicted Density | Composite | | 1650 –2000 |