Concrete hardening: features of the hardening process.

In the construction of such a parameter as the timing is not the last value, therefore, when organizing the construction of reinforced concrete structures must take into account the hardening time of concrete. In addition, the construction of subsequent structures is not allowed before the set of design strength of the previous design, which is the basis.

The topic of our article is how the process of hardening takes place, how long it takes and whether it is possible to influence the speed of curing.

Phased solidification process

Before you understand how the process of interest to us proceeds, you need to start from the simplest - understand what the concrete mix consists of:

1. Cement.
2. Water.
3. Sand.
4. Filler required fraction:

• Rubble
• Gravel

The process of hardening of concrete begins almost from the moment of mixing loose components with water. As the water flows to the cement, the process of complex interaction between them begins.

Water gradually penetrates the cement grains, while the minerals contained in them, enter into a chemical reaction with water, and a completely new compound is formed, with characteristics different from the original sources. During this reaction, the minerals are converted to potassium hydrosilicates - we tried in the most understandable language to describe how the concrete hardens.

Note! Of course, to describe this process can be more extensive with the use of the most accurate formulations, but not every ordinary builder will be able to realize their meaning.

The next question is how much time does the concrete harden? Hardening of the concrete mix does not end in one day. Even if visually it seems to you that the newly formed structure looks ready and firm to the touch, do not rush to exploit it.

What properties should a concrete mix acquire in order to meet design requirements:

• Loss of plasticity (hardening).
• Set of design strength.
• Complete drying (loss of moisture).

How many days solidifies concrete definitely can not be answered. In general, it can freeze for a very long time, and in this case, construction can continue for years.

Of course, builders and customers are not satisfied. Therefore, the control terms of concrete setting were calculated, after which the base is considered ready to withstand the design loads.

Deadline for setting

The target date for setting concrete is the time period, after which the concrete reaches its brand compressive strength.

How quickly concrete hardens depends on its composition and environmental conditions:

• Temperatures
• Humidity of air.

The optimal parameters for the strength of concrete mix are:

• Temperatures between 20 and 30 degrees Celsius are above zero.
• Air humidity not less than 90%.

Of course, such conditions can be created only in laboratory conditions and it is during them that the most active phase of hardening occurs already in the first week after casting with a set of strength up to 70% of the calculated one.

In real life, the air temperature and humidity change not only with the arrival of the next day, but even during the day. Therefore, construction is planned, as a rule, for a favorable time of year.

But if it is necessary to build in bad weather, measures are taken to protect and speed up the solidification process:

• Covering with plastic wrap, as a measure of insulation and moisture retention.
• If necessary (low temperatures or sudden changes in temperature) - electric heating.

There is an opportunity to create fast-hardening concrete, it can be obtained by entering into the composition, as a percentage, established by laboratory method, special additives:

• Salt of nitric acid - 4%.
• Sodium sulfate - 2%.
• Calcium chloride - 3%.

There are also other additives that improve the quality and affect how much the concrete foundation, walls and floors solidify.

These include the following components:

• Fiberglass.
• Accelerators curing concrete.
• Plasticizers.
• Anti-frost components.

The price of the ready mix directly depends on their presence and quantity.

Note! The quality of the material itself influences how long the concrete hardens, because if the same sand is unpurified, or the particles of rubble will be larger - the dates should be corrected.

Do it yourself

As a rule, the construction of any scale with their own hands zealous owners schedule for a warm spring - the beginning of summer. It all starts with the foundation, so let's talk about it. As a rule, in private construction give preference to the tape base.

Instructions for compliance with the rules of concrete strength in the strip foundation contains the following items:

1. The fresh mixture will certainly be compacted in a manner suitable for this case:
2. Splicing shovel.
3. With the help of immersion vibrator.
4. Removable formwork is removed only after the control set time (28 days or more, if necessary).

1. In very hot weather, concrete is covered to slow the loss of moisture.

Also, after the expiration of the full hardening period, if necessary, manipulations are performed such as:

• cutting of reinforced concrete with diamond circles - is used in cases when it is necessary to make a hole in the finished concrete product.
• Diamond drilling holes in concrete is a quick way to make a smooth through hole.

Conclusion

Теперь вы имеете представление о том, что собой представляет затвердевание бетонной смеси, какие факторы могут влиять на срок данного процесса. Эта полезная информация поможет вам избежать неприятных моментов, обойти все подводные камни, которые часто встречаются новичкам, затеявшим строительство или ремонт (см.также статью «Минимальная температура застывания бетона – особенности бетонирования в зимнее время»).

In the presented video in this article you will find additional information on this topic.