Caring for concrete - factors affecting the strength of

As is known, concrete is one of the most durable and durable materials, and this is due to its wide popularity, both in the field of industrial construction and among individual developers. And if professional experts know all the features of the technology, then in the construction of private houses mistakes are often made. People do not know that caring for concrete after pouring in late autumn is different from similar activities in the summer and even more so in the winter, and in this review we will look at how to properly care for the material.

After the end of the concrete work, a whole range of special events is to be held to ensure high strength of the material.

What you need to know about concrete

To understand how important it is to take care of freshly filled concrete structures, let us familiarize with the main features of the hardening of this material:

  • The strength of the material is due to a rather complex chemical process called hydration. The bottom line is that water molecules gradually penetrate into the cement particles, as a result of which new ultrastrong compounds are formed.
In the photo - cement, which in combination with water forms a very strong and durable compound.
  • The process of hydration is quite long, which causes a long period of recruiting concrete strength characteristics. Water penetrates the cement gradually and reaches the center of the cement particles in only a few months.
  • Despite the fact that it takes a long time to build up strength, structures can be used after 28 days, when the material becomes sufficiently reliable and resistant to deformation.
  • In the process of hardening the volume of the composition decreases, that is, it shrinks. This is normal, moreover, controlling the shrinkage rates, you can roughly calculate the strength of concrete, although this method is most often used by professionals, since special equipment is unlikely to be available to a simple developer - its price is quite high.
  • It is known that structures made of concrete, which dry in a wet environment, are gaining much higher strength than outdoors.. This property is very important to always remember, because there is nothing worse than drying the surface.

Factors affecting the strength of concrete

In fact, the speed of strength and the final characteristics depend on several important nuances:

  • Cement, which is used for the preparation of concrete. Its different types have a different period of the set of primary strength, it is worth using Portland cement. It is best suited for use due to its excellent characteristics and the shortest freezing period.
  • Humidity, reliability of a design directly depends on this indicator. Her ideal rate for a set of high properties - 90 percent. It is necessary to maintain it constantly, it is easiest to do this with a sprayer.
Care for fresh concrete in the first place is to constantly moisten the surface and prevent it from drying out.
  • Air temperature: the best conditions for a set of optimal properties of the solution are created at a rate of +20 degrees. At zero temperature, the freezing process stops, and at negative values, water in the structure freezes and, expanding, damages the material, reducing its strength.

Features of care, depending on external conditions

Как отмечалось выше, мероприятия, проводимые в рамках ухода за бетоном, в первую очередь зависят от температуры и влажности. Если эти показатели оптимальны, то это значительно упрощает работы, но на практике идеальные условия практически не встречаются и, тем не менее, можно создать их и самостоятельно. Рассмотрим основные варианты работ в зависимости от условий внешней среды (читайте также статью «Балясины из бетона – простой способ облагородить лестницу»).

Summer period

Everybody can do a reliable foundation with his own hands, but any violations of technology can reduce strength

Most often, the work is carried out in the summer, as this is the most favorable period in the sense that the temperature drops are insignificant, and the working conditions are comfortable enough.

But the high temperature creates a lot of difficulties, because drying the surface is contraindicated for a number of reasons:

  • Termination in the surface layer of the process of hydration, because of which its strength is significantly reduced.
  • Also, due to too rapid evaporation of moisture, surface cracks are formed, which over time can cause more significant damage.
This is what happens with a rapid loss of moisture from a concrete base.
  • Drying can cause a decrease in strength, and this figure can be even 40%, that is, the final indicator of concrete reliability will be only 60% of the planned.
  • The structure of the surface with premature drying is more porous, which reduces its moisture resistance and frost resistance. In addition, reduced deformation resistance.

How to protect concrete and create the most favorable conditions for its maturation? All activities are fairly simple, but they should be followed carefully.

A simplified instruction looks like this:

  • In sunny weather, it is very important to protect the freshly filled design from exposure to the sun and wind. For this, any shields or canopies of awnings can be used. At temperatures above 25 degrees, it is better to use a reflective film, although this is not necessary for small objects.

Tip! Among private developers, when pouring strip foundations and small screeds, the simplest option will be plastic film, which will protect the surface from moisture evaporation and weathering.

Plain transparent film - ideal when working indoors
  • The first moistening is carried out after a few hours. It is very easy to find out that this is necessary: ​​the surface will become much drier, but it is important that it does not dry out, this may have irreversible consequences for the final result.
  • Moistening frequency is 2-3 hours in the daytime, one-time processing can be carried out at night - the temperature in this period is lower, and this is usually sufficient.
  • Humidification is carried out in such a way for the first few days, then this process is carried out as necessary, but the state of the concrete must be monitored constantly.

Note! If the surfaces are open and there is no possibility to protect them, then they should be covered with either bitumen emulsion or Etinol varnish, this will prevent moisture loss.

Emulsion protects the surface from moisture loss
  • After the end of moistening, the covering materials should not be removed for another 3-4 days, so that the humidity will return to normal and no cracks form on the surface due to abrupt drying.

It should be noted that when pouring large planes, in order to avoid cracks, it will be necessary to cut the reinforced concrete with diamond circles - the grooves will perform a compensating function.

Winter period

There is a SNiP for the care of concrete in the winter, it is called 3.03.01-87 "Bearing and enclosing structures."

According to him, and the following features of the care of concrete:

  • At temperatures below + 5 degrees moistening is not required.
  • When pouring the foundation, additional warming of the formwork with foam or mineral wool is necessary.
  • If the temperatures are negative, then special additives are needed to protect the composition from freezing. You can use electric heating, but it will require more financial investments, in addition, the cost of this option is much higher.
Additives help improve concrete properties

As for the work in the autumn and spring, it all depends on the temperature conditions, in accordance with them you choose one of the two options listed above. As you can see, the process of maintenance is required even for such a durable material as concrete, this will ensure durability and reliability.

If you have to pass pipes or other communications through the concrete surface, consider this before starting work - diamond drilling of holes in concrete is a difficult and expensive process.

Conclusion

Уход за бетоном в процессе твердения не отличается сложностью, важна периодичность и постоянный контроль состояния поверхности. Только так можно добиться отличного результата (см.также статью «Компоненты бетона: характеристики, пропорции, расчет»).

If you have any questions, watch the video in this article, it will tell some points in more detail.

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