With the onset of winter concreting of conduct is much more difficult, and most importantly, such activities require careful preparation and full compliance with all building regulations.For example, fill the basement in mёrzluyu soil can lead to the fact that the spring thaw and the land gives way, and the foundation will crack, which would entail an expensive repair.
But sometimes life is different.Estimated time of work breaks, and the foundation, which had planned to fill the summer, we have to build, when the temperature falls below zero.
How to be in this case?To postpone the work until spring?Or is it to take a chance and try to create a solid foundation for your dream house under adverse weather conditions?User Experience forumhouse.ru says that in such important construction - equipped with knowledge and not to allow anything to chance!
user forum with the nickname AlecScrab builders offered to pour a foundation in December to the spring he grabbed, and in March - to begin to raise the wa
Needless to say, the proposal - tempting, but not forumchanin nadaёt left wondering: how to pour concrete in freezing temperatures, and whether it will affect in the future on the strength of the foundation?
- Concrete is gaining strength 28 days, but it is at zero temperature, while negative concrete may not gain strength.
forumchanin verdict is: winter fill only benefit the builders, becausethey want to earn.And for himself he would never pour a foundation in the winter, even if a serious advantage.
If the air temperature drops to the day + 5 ° C, and at night the thermometer drops below 0 ° C, the conditions of construction are considered winter.
When winter building the foundation necessary to fill using antifreeze additives and special concrete technology warming.This leads to a significant increase in the cost estimates for the construction.And often completely eliminates the appreciation of the benefits of seasonal decline in prices for the work of builders.
According 44alex, when pouring concrete in the winter in compliance with all the technology, it will be cheaper, if only the workers will work for free.
According forumchanin with the nickname Grinpik, construction of a monolithic foundation in the winter it is not necessary to perform because:
- require additional costs for concrete;
- need special requirements for installing and maintaining the concrete;
- needs elektroprogrev concrete (or other heating) at a constant temperature control;
- short winter day leads to additional costs to cover the area, warming huts for the workers, who are not eager to work in the cold;
- can run on low-quality materials.
- I too would first like to pour the floor slab in the winter, but looking at the ordeal neighbors who filled his plate in the last year in December at -5 C, changed his mind.Now they have already been set up with the edge of the plate and fall off pieces of concrete.The top layer seems to grab the frost, but it crumbles under foot.
So what is the technology of winter pouring the foundation and how increasing complexity of these works?To answer this question it is necessary to understand what processes occur in the concrete when pouring at low temperatures.
During hardening of the concrete hydration reactions take place in which minerals cement interact with water to form a new compound.Dehydration of the concrete in the early stages may slow or stop the curing process and lead to a shortfall of strength and cause it to shrink and crack.
sub-zero temperatures the water, unable to react with the cement, freezes.Therefore, the hydration reaction does not occur, and hence the concrete is significantly reduced zatverdevaet.Takzhe foundation strength and durability.The water, frozen in concrete, often expands in volume, reduced friction coefficient with the reinforcement of concrete, which leads to further degradation of the foundation.Therefore, the construction of the basement in the winter requires careful observance of technology of casting.
Taking into account all of the above, no wonder why most developers wary of winter concreting.However, if the matter is approached with intelligence and armed with the necessary knowledge, you can pour the foundation and quality at low temperatures.And sometimes - this is the only way out.
For example, the foundation in forumchanin Svetoch - melkozaglublennaya tape under house 10x10.He only had time to dig a trench and began to knit reinforcement.Pour concrete like in the middle of the week (with antifreeze additives, as night - has long been a minus).And it turned out that the weather forecasters promise rain and snow.Validating I worried: whether to leave the dug trench partially flooded foundation and reinforcement in the winter?
- If you leave everything as is, the reinforcement rust, and the base tape burst!It is necessary to fill completely the foundation, and the rain and the snow is not a hindrance, most importantly - care after pouring concrete.
user forum with the nickname Georgespb asked a single question: how to make a shelter for the pouring of the foundation?
- Shelter done as follows: on the perimeter of the foundation erected a big tent, set it in the heat gun, and the temperature inside rises to plus.
should be remembered that such a scheme gun 10 kW on an area of 100 square meters.m + gives about 8-10 degrees to the outside temperature.
fuel consumption at the same time is about 16-20 liters of gas per day.
If you want to operate from -15 ° C, it is necessary to increase the power of the gun up to 30 kW.Gas consumption will make up 60-70 liters.It is about 1,000 rubles.in a day.
Just warm concrete and using electricity - welding transformer connected to the valve.
There are special transformers for heating concrete products: the current is fed through electrodes placed at a distance of 40-50 cm from each other in the basement.
But this method of warming requires special attention!
- Need an experienced master, who correctly mount electric heating and shall aim at maintaining the required temperature.
With this method of heating the concrete increases the probability of hitting the workers of electric shock.It is therefore necessary to use a transformer with a voltage of 36 volts.Overheating is also fraught with cracked concrete and subcooling - freezing.
for concrete with antifreeze additives strength by the time it cooled to a temperature at which the calculated additive should be at least 30% of the project with the mark of 200, 25% - for concrete grade 300 and 20% - for concrete stamps 400.
For concrete without antifreeze additives monolithic structures and monolithic part prefabricated monolithic structures strength at the time of the freeze should be at least 50% of the project when the concrete mark 150, 40% - for concrete grade 200-300, 30% - for concrete marks of 400-500,70% - regardless of the brand of concrete for structures exposed to freezing and thawing.
antifreeze provide hydration of the cement and concrete hardening, but at low temperatures, these processes are slow and the concrete is gaining a critical strength in about a month hardening in the cold.
Concrete, reached at the time of freezing the critical strength, design strength gains only after thawing and storage at positive temperature of not less than 28 days!This means that to maintain a positive temperature nestled foundation is necessary, not only during the concreting, but also after.
To summarize, we can say that fill the basement at low temperatures leads to a rise in the cost estimates and requires careful control at all stages of work.Instead, developers have the opportunity to boost the construction work ahead of time and prepare the foundation for the house before the start of the spring construction season.
What temperature withstanding by pouring concrete in the winter, it is told here.About the construction of the well in the winter can be found in this thread.
most complete and detailed information on winter concreting collected here.How to pour concrete in the winter?Hot Thread "cold" matter is conducted in this subject.
In this video explains the nuances melkozaglublennogo reinforcement strip foundation.