For a long time it was believed that the foundation should be filled only when it gets warmer - in the spring, summer or autumn. However, modern materials and fixtures in construction have radically changed this approach. Now pouring the foundation in the fall has become the same familiar activity as in the summer. Just a little changed approaches to this matter.
I must say that if concrete pouring can be postponed until the summer, then it is better to do so. Indeed, in the autumn period more resources are spent on additional equipment, fillers and materials that will not allow concrete to freeze, creating the conditions for its full solidification.
How does hydration of concrete
People are often interested in when it is possible to fill the foundation in the fall, and whether it is worth doing it at such an unpredictable time of the year. Now we will consider how concrete hardens in order to better understand all the processes and plan the construction accordingly:
- at the initial stage, a crust appears on the surface of the mixture, it is sodium hydrosilicate;
- after that, harder particles of the foundation surface solidify;
- the next stage of solidification is the contraction of the shell due to evaporation of the liquid;
- this process begins to go to the center until the mixture acquires its stated strength.
Based on this scheme and answering the question whether it is possible to fill the foundation in October, experienced builders confidently say: “It is possible!” And we will describe why, comparing this process in summer and autumn-winter time.
Comparison of concrete poured in heat and autumn
It is logical that in the summer heat the foundation dries many times faster. But will its structure become dense, as necessary? After all, the whole house depends on it - how long it will stand, whether cracks will appear in its walls. Quick freezing occurs due to the fact that water rapidly evaporates. However, this is not very good, because instead of it voids form, which make concrete brittle.
In autumn, the pouring of the foundation - in October, for example - can be hindered by the fact that freezing begins. As a result, water crystallizes, and voids are formed due to the fact that ice forms in the mixture, which also expands, creating microcracks. That is why the foundation is poured in the cold season using special technologies.
Properties of concrete, which are on hand builders
When the mixture solidifies, a chemical reaction occurs in it that causes heat. Thanks to this, the concrete dries better, but due to the fact that the ambient temperature is low, voids do not form in it and it does not dry out. Therefore, the answer to the question of whether it is possible to fill the foundation in the fall is unequivocal: yes. The most important thing in this matter is to carefully calculate everything. In addition, pouring concrete must be included in the construction plan, this will allow you to prepare in advance all the necessary materials, devices and devices.
It is better not to fill the poles in the cold, unless they are sufficiently insulated. Indeed, under such conditions, internal heat will last for a very short period of time, during which it will not have time to freeze completely. It is better to limit yourself only to a low base, in which case the chemical reaction is able to continue and dry the solution much longer.
Concrete hardening factors
Often, in order to have time to build a house in spring and summer, the owners are always interested in whether it is possible to fill the foundation in October, so that in the spring, as it gets warmer, immediately start building the house. After all, when the foundation is ready, the construction will be much faster. And this is especially important when the building is planned to be large, and there is a risk of not having time to rebuild it before the next cold weather.
The following factors affect the quality of concrete :
- volumes and dimensions of the structure;
- proportions of fill elements;
- cement quality and grinding;
- climate;
- the possibility of heating and warming concrete.
In order for the cement to react faster, it must be grinded as finely as possible, then pouring the foundation in October will be much better, because voids do not form in it. Only aggregates and water should be heated. In no case can this be done with cement, because it will lose the properties that are necessary for a quality foundation. But this is very undesirable.
When warm water is added to cement, its temperature should not exceed +30 ° . If it is added first to the placeholder, then it can be hotter. If the solution is well mixed, then it withstands the temperature longer. In addition, it more densely fills the form, penetrating into all corners and crevices.
Difficulties associated with autumn weather
First of all, the question of whether it is possible to fill the foundation in October, arises due to the fact that the earth is frozen, and it is impossible to dig it manually. Of course, this is true, but you can use a technique that can dig a foundation pit of any length and depth. Just calling an excavator will require financial investment.
Solving Concrete Freezing
The next unsolvable task of the builders of the past years was that in frost the concrete loses its qualities, becoming brittle. This is because its components do not mix under such conditions due to the crystallization of water due to exposure to frost. Therefore, pouring the foundation in the fall, and even more so in the winter, was something unrealistic.
Now everything is solved with the help of chemical additives that prevent water from freezing. In addition, special concrete is sold, in which substances are already included that contribute to its normal solidification at sub-zero temperatures. Its properties are no different from the summer counterpart.
However, there is an opinion that it is undesirable to use chemical additives in concrete in a residential building, because many of them are poisonous. Therefore, when building a building, this nuance must be taken into account.
Still, to fill the foundation, in October or February - it does not matter, salt is added to the solution. Its content should not exceed 2%, it does not allow water to freeze. Accordingly, all the ingredients are fully mixed and solidified. Without heating, this method can be used up to -5 ° C, and if the temperature drops even lower, then it is worth using heating, which will be discussed later.
You can also make the solution not susceptible to freezing with acid additives. They are added, after which a chemical reaction occurs in the mixture, which raises the temperature. Under this influence, the concrete dries. Well, of course, in severe frosts, the foundation should be additionally covered so that the heat generated does not immediately evaporate.
Concrete heating
In practice, answering the question of whether it is possible to fill the foundation in October, many builders prefer not to add chemistry to the solution, but simply to heat it. For this, special machines that are equipped with heating can be used. However, when pouring, it is worth doing everything very quickly so that the cement does not have time to freeze. But even if this happened, do not pour boiling water into it. This will lead to the formation of voids inside the structure, which will make its quality much worse.
Foundation insulation
When the foundation is being built in the fall, another method can be used to protect against low temperatures. They do not add anything to concrete, its consistency remains, as in the summer, only the base is insulated. This can be done with different materials. Mostly used:
- only;
- polyethylene;
- tarpaulin.
In general, you can use any material at hand. In severe frosts, the foundation is even covered with sawdust, which perfectly protects from subzero temperatures. The main thing is that the top layer is waterproof and can protect from rain. In addition, it is necessary to make a slope so that water does not remain on the material, but leaves sideways from the foundation. In general, it is worth doing everything in the form of an awning, it will be more convenient.
Often the question arises as to whether it is possible to fill the foundation in the fall, also because there is a lot of dampness in addition to frost. This is also solved very easily: a heat gun is sent under an awning created from polyethylene, roofing paper or tarpaulin. It drives warm air inside, heating the solution and promoting the evaporation of moisture. Thus, you can easily dry the foundation even in January frosts.
Quite often, greenhouses made of polyethylene are placed in places filled with concrete, inside of which a heater or heat gun is placed.
Electric drying of the foundation
There is another great way to dry the foundation. When pouring it into the solution, the wire is laid. It can be copper, steel or aluminum. On the one hand, all ends are divided into two beams, they will be connected to the welding machine. Light bulbs are connected from the other side, two ends to each. The lamps should be 36 V, the most important thing is that everything needs to be connected correctly. If there is a mistake somewhere, then nothing will work. Next, the wires are connected to the lamps in pairs and connected to the device. The first should light up, first a dim light, but when the concrete begins to dry out, they will burn brighter. Thus, you can perfectly monitor the progress of the entire operation and know when the foundation is ready. This method is also suitable to heat the foundation in October or another cold month.
Many builders generally prefer autumn concrete pouring, because it does not dry out, as happens in the summer heat. The pouring method, or rather, the method of retaining heat in the mixture, must be selected based on weather conditions, available equipment and materials.