One of the most exciting aspects of the Mullet Hall project is one that will never be seen once it is covered with insulation and finished. About 6/7 of the fine aggregate (sand) in the wall concrete was replaced with Poraver recycled glass beads. This accomplished a few goals:
- Increased recycled content, reducing sand use.
- Insulative quality of foundation wall (about R0.4 per inch, making the 8 inch walls R-3.2 and the 10 inch walls R-4.) Normally concrete has an R value of about 0.08, which would give and 8 inch wall an R value of 0.64 and a 10 inch wall an R value of 0.8. This is a marked improvement which shows up in the THERM models.
- Reducing the weight of the Mobile Mix truck, which reduces fuel use.
The Poraver was added at about a 2:1 ratio between the 1-2 mm beads and the 0-0.5 beads as a replacement for about 6/7 of the fine aggregate (sand). In addition to the entrained Poraver in the walls, we will be using 10 inches of the 2-4 mm beads subslab instead of foam. After participating in Riverkeeper’s River cleanup today, I can attest that the world would be a better place with less plastic and less foam.