Research Article
Waste Foundry Sand Usage for Building Material Production: A First Geopolymer Record in Material Reuse
Table 3
The results of the WFS-based geopolymer materials produced by using NaOH.
| Curing temperature (°C) | NaOH amount (with respect to WFS amount, w/w) (%) | UW (g/cm3) | CS (MPa) | WAP (%) | Porosity (%) | 7 days | 28 days |
| 50 | 10 | — | — | — | BIW | BIW | 20 | — | — | — | BIW | BIW | 30 | — | — | — | BIW | BIW |
| 75 | 10 | 1.42 | 1 | 1 | BIW | BIW | 20 | 1.44 | 1 | 1 | BIW | BIW | 30 | 1.50 | 1 | 1 | BIW | BIW |
| 100 | 10 | 1.41 | 2.4 | 2.5 | 29 | 35 | 20 | 1.44 | 1.8 | 1.9 | 29 | 33 | 30 | 1.51 | 1.1 | 1.2 | 28 | 33 |
| 150 | 10 | 1.40 | 1.7 | 1.8 | 28 | 34 | 20 | 1.45 | 1.6 | 1.6 | 27 | 32 | 30 | 1.52 | 1.5 | 1.6 | 26 | 31 |
| 200 | 10 | 1.42 | 1.8 | 1.8 | 26 | 33 | 20 | 1.45 | 1.6 | 1.6 | 24 | 31 | 30 | 1.57 | 1.6 | 1.6 | 24 | 31 |
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