Ground floor slab was just poured. Air temperature was frigid, hovering around 30F with a forecast for low 20′s by nightfall , but that’s OK. The guys took precautions:
- 2% accelerator was added to the mix, to help it “kick” (set) sooner. The sooner it kicks to sooner it can be troweled and then blanketed for curing;
- Concrete was heated at the Boston Sand & Gravel plant to ~80F so it would arrive on site at ~70F and could be placed while still steaming hot (~60F);
- The site fence was draped with tarps and two “torpedo” heaters were positioned to jet hot air over the slab as it was being poured. This effectively transformed the worksite into a little heat island.
- A concrete boom pump truck, with a far reaching remote-controlled articulating hose, sped up the process of spreading ~40 cubic yards of heavy concrete over an area of ~2,000 square feet.
- Scrap slabs of board insulation and insulating blankets filled with bubble-wrap were at the ready, to cover the slab once everything was said and done.