Due to repeated enquiries regarding conditions of SIRCONTEC
foam-concrete application in the winter season our company provides the following information:
1. In order to choose the
foam-concrete modification in the winter season it is important to know the assumed surrounding temperature (atmosphere) and the temperature of the structure – to be measured in contact with the structure in the area of the foam-concrete application.
2. The temperatures mentioned in the paragraph 1. should be maintained in the permissible range during the whole setting period – from pouring till acquiring the walkable strength – the time when it is possible to walk upon the foam-concrete surface without damaging it.
From achieving the walkable strength until the 28th day the surrounding temperature and the temperature of the structure should not drop below +5°C.
It should be noted that the temperatures must be maintained also during the night and on holidays.
3. Allowed temperature range for SIRCONTEC foam-concrete application is +5 to + 30 °C.
4. Temperature and its influence:
Temperature range: +15 to +8°C
Recommended SIRCONTEC foam-concrete modification:
min
PBG 45, optimal
PBG 50, using
PBG 40 brings about extended time of achieving the walkable strength above 72 hours.
Impacts:
- Time of achieving the walkable strength in comparison with 20°C temp. extended by up to 30%.
- There is no risk of interrupting the hydrating process.
- No danger of decrease of the final strength below the declared value.
Temperature range: +8 to +5°C
Recommended SIRCONTEC foam-concrete modification:
PBG 50, at the worst PBG 50 / CEM I 42,5R
5. The values, information and data given here come from practical experience of SIRCONTEC company’s employees with subsequent verification in the lab.
6. For achieving the above given values it is assumed that components described in SIRCONTEC manufacturing processes, relevant to respective
SIRCONTEC foam-concrete modifications, are used:
7. Interruption of the hydrating process during acquiring the walkable strength usually leads to degradation of the cellular structure of the foam concrete with subsequent loss in volume, damage to the surface and significant decrease of the compression strength.
8. Recommendations for SIRCONTEC foam-concrete application in the winter season:
- In any case, suspending a geotextile can compensate for closed windows, doors.
- Hot-air blower heating the air must not blow on the surface of the applied foam concrete.
- It is convenient that the bearing structure of the floor is heated from below - be careful about the thermal lag.
- Impact of the low temperature can be partially compensated for by using the batch water with max 23°C temperature.
General conditions for SIRCONTEC foam-concrete manufacture and application can be found in DS_110 - Conditions and rules for manufacture of SIRCONTEC light-weight concretes in the section
Dowload.
