Set of strength of concrete depending on temperature: graph

One of the significant indicators of the quality of concrete is its strength. If you look at state standards, then you can find the conditions for compression. According to them, strength can be equal to the limit of M50-800. As one of the most frequently used are cement grades up to M-500. Many professional builders and private developers take into account the schedule of strength strength of the material. About him and will be discussed below.

For you, this information can also be useful, because from it you can find out after what period of time after mixing the solution you can start further work. This is due to the fact that manipulation of the construction may involve loading of structures from concrete. Most often in conjunction with this we are talking about the foundations, which must necessarily be sustained for 28 days before the beginning of the erection of the walls.

Set strength on schedule

The strength of concrete as a function of temperature is determined by the graph, which is the time interval. In the process, the solution acquires operational properties, after which it is possible to carry out the formation of the finishing layer. The durability schedule is the time that concrete needs to reach the required strength value. If normal conditions are maintained, the composition will mature within 28 days.

Within 5 days, the fastest hardening can be observed. After this time, the material will reach 70 percent strength. Subsequent work should be continued only after 28 days, because only then the material will reach a 100-percent strength level.

Hardening and strength strength of concrete occur in different ways for each specific case. In order to determine the time, samples are tested. In warm times, in monolithic housing construction, some operations are performed to obtain the optimal properties. For example, the material is aged in the formwork, it is left to ripen and after the fences are removed. The strength of concrete depending on the temperature will occur over a different period of time. This is also due to the fact that the events can be held in the cold season. In this case, to achieve brand strength, it is necessary to ensure the heating of the material and the waterproofing of the concrete. This is due to the fact that a decrease in temperature slows down the polymerization process.

Recommendations for speeding up the process

In order to speed up the collection of strength and reduce the time of aging of the material, it is necessary to use sand concrete, in which a low ratio of water and cement. If this ratio looks like 1 to 4, then the terms will be compressed twice. In order to achieve this result, the formulation should be supplemented with plasticizers. Reduce the maturity of the material can be artificial, by increasing the temperature.

Dependence of the strength level on the material temperature

The strength of concrete depending on the temperature of the material will occur in different ways. As an example, we can consider concrete grades ranging from M-200 to M-300, which were closed on Portland cement with the marking ranging from M-400 to M-500. Within a day, the material will achieve a 3% compression strength, if its temperature is -3 ° C. Under the conditions that the mixture will have a temperature of +30 ° C, the strength per day will be 35%.

For three days the strength will reach 8% if the temperature of the material is -3 ° C. 60% strength can be achieved at + 30 ° C temperature over the same period of time. If the temperature of the material is +5 ° C for 28 days, the strength of the material will be 77%. 100% strength can be achieved in 14 days, if the material temperature is +30 ° C.

Monitoring the process

The strength of concrete as a function of temperature was highlighted above. However, it is important to monitor the process during the first week. Activities aimed at providing conditions for aging are expressed in:

• Electric heating;
• Humidification;
• Covering with waterproof and heat-insulating materials;
• Heating with heat guns.

It will be necessary to pay attention to the wetting of the surface. A week after the development of the composition, the structure can be loaded, this is true if the air temperature is 25-30 ° C.

In addition, the steps of recruitment

The grasping of the poured concrete occurs within the first 24 hours after its preparation. A private builder must know what the dependence of the strength of concrete on air temperature. For example, in warm weather, when the temperature outside the window is within 20 ° C, the setting will occur within an hour. The process will begin in a couple of hours, the count must be conducted after the components are connected, and completed after 3.

Cool time

At cooling, the beginning and the completion of the grasping shift. It will take more than a day to grasp. If the temperature is at zero, the process will begin at least 6 hours after mixing. Under these conditions, it lasts up to 20 hours, the countdown begins after the solution is in the formwork. On a hot day, time decreases. This indicates that sometimes it takes only 10 minutes to grasp.

Decrease in viscosity of a solution

You should definitely learn the process of recasting concrete depending on the temperature. It is also important to know about the decrease in viscosity. In the first stage, the mixture will retain mobility. During this time, the material can be mechanically affected, and the structure can still be shaped to the desired shape. To extend the setting step, it is possible to thixotropy, which will help reduce the viscosity when applying mechanical stress.

An excellent example may be a solution mixed in a concrete mixer. During this period, the solution will remain in the first stage longer. But it is necessary to take into account that many processes cause irreversible changes in the solution, which can adversely affect the quality of the hardened concrete. For example, "welding" occurs quite quickly in the summer.

The hardening stage

The concrete strength set, the time schedule of which is described in the article, begins after grasping. This process is still not over in a few years. But after 4 weeks you can determine the brand of concrete. Strength of the material will be typed at different speeds. This process will be most intensive in the first 7 days. In the first three days, under normal conditions, strength will reach 30% of the brand value. During the first two weeks, the solution will reach 70% strength from the specified value. After 3 months, this parameter will increase by 20%, after the process will slow down, but it will not stop. In 3 years the indicator can increase by 2 times.

In addition, the effect of ambient temperature on the hardening of the material

The strength set of concrete, the features, the graph of which is described in the article, depends on the temperature. The colder, the slower the strength will increase. At negative temperatures, the process stops altogether, as water freezes, and in fact it provides hydration of cement. With increasing temperature, the set will continue. But with a decrease, this process will stop again. If modifiers exist in the composition, the hardening time decreases, while the temperature at which the process stops is reduced.

On the market you can find high-speed compounds that have the ability to give concrete vintage strength in 2 weeks. Since warming will help to reduce the maturing process of the material, it can be argued that at 40 ° C the brand value will be reached after 7 days. Therefore, the pouring of concrete should be carried out in hot weather. In winter, to ensure normal conditions, the material will need to be heated, and it will be problematic to perform such work on your own, because special equipment will be required. In addition, it is not permissible to heat the solution to 90 ° C or higher.

Conclusion

The graph of the strength of concrete, the conditions of solidification, you must be studied before starting work. Thus, according to the schedule, you will be able to determine, after what amount of time can be performed the decking of monolithic structures. The formwork can only be dismantled after the strength of the material exceeds 50% of the brand value.

In this case, it must be taken into account that if the column falls below +10 ° C, this value will not be reached even 2 weeks after pouring. Under such conditions it is necessary to think about heating the solution. The normatively safe period is set at 50 percent strength. Then how to proceed to further work is possible only after the brand value of the solution reaches 80%.