REQUIREMENT:
High early strength, for early stripping of formwork, early use of concrete structures, etc. Also for large pours of concrete floors to allow finishing to closely follow placing.PRODUCT TO USE:
RAPIDARDHOW TO SPECIFY:
All concrete (specify sections) shall contain Rapidard high-early-strength admixture at the rate of 3/4 to 2 litres per bag of cement.
EFFECTS:
Produces normal concrete strength in reduced times as follows: (Approx. results only – brand cements vary somewhat)
| Qty. used per bag | Normal 7 days strength at: | Normal 28 days strength at: |
|---|---|---|
| 3/4 litres 1 litre 1.5 litre 2 litre |
4 days 3-4 days 3 days 2 days |
12-14 days 8-10 days 7-8 days 6-7 days |
Rapidard contains special high-early-strength components, plus Calcium chloride, plus anti-corrosion factors. Rapidard increases workability considerably, and the mix may be adjusted to take advantage of this, by reducing water content about 1.5 litres for each litre of Rapidard used.
SETTING TIME:
Rapidard has only a limited effect on initial setting time, being designed for adequate time for working and placing, and yet accelerate strength gain after setting. At 1 litre/bag, setting time will be reduced by about 30% at 2 litres, by about 50%. If required, this can be corrected by use of PLASTET No. 2 for set retardation. When used in place of water, Rapidard causes fresh neat cement to harden in minutes.
WHERE RECOMMENDED:
Concrete that will be exposed very quickly after placement.- Cold weather concreting.
- Non-reinforced pre-cast elements.
- Quick-setting repair putty/mortars.
- Large pours of concrete floors to allow finishing to closely follow placing.
NOTE:
Not recommended for pre-stressed concrete or reinforced concrete exposed to moisture.
For marine or other reinforced concrete exposed to moisture, see SUPERPLASTET F for high early strength.
