Seam concreting: the cause of occurrence, location, rules of

The cold seam of concreting is the weakest point of the concrete structure. And if you do not take care of it properly, then such negligence in the end can lead to sad consequences, the scope of which will depend on the size and purpose of the building. We will devote this article to this problem and its solutions.

Creating seams

What could lead to the emergence of such vulnerable zones in a seemingly flawless and so strong monolith?

Cause

For a general and deeper understanding, you can spend a miniature experience at home:

1. We take any stationery glue and put two drops on a smooth surface so that they spread together to spread out.
2. After solidification, they form a single and inseparable lump of silicone.
3. Now let's drop one more drop on it and wait for it to dry, after which after doing some manipulations, without much difficulty we can detach it from the main mass.

Also exactly happening in the process of concreting. Small objects most often manage to fill in with one pass and then, as in our experience, a solid monolith is formed. But if the volumes are too large, and the previously laid concrete has time to grab, which is sometimes enough for five hours, then the fresh solution simply has nothing to catch and an unreliable joint line is formed.

Working seam during concreting gets a decrease in the set of technical characteristics, which include:

• strength;
• frost resistance;
• moisture resistance

As a result, a negative impact on the durability of the building. But all this is fully true, if you leave this process without control. In the case of the proper arrangement of the docking site, you can be confident in the reliability of the entire structure.

Locations

Advice: do not allow spontaneous formation of cold seams. If you are confident in their inevitability, then create your own hands in a pre-selected safe zone. So it will minimize the risks associated with them.

Safe places for the formation of seams in different designs:

Tip: also be sure to consider that the joints must be horizontal or at least vertical. Avoid the formation of diagonals, otherwise even diamond drilling of holes in concrete somewhere nearby due to the propagation of vibration can provoke a fracture or cracking.

Rules of arrangement

Instructions for creating cold concreting seams are as follows:

1. Choose the most appropriate place according to the above recommendations and fill the first portion of the concrete to that level..

Tip: Do not start pouring a new solution until the former has gained 1.5 MPa. This is necessary in order not to violate its structure.

1. Clearing the gripped surface one of the mechanical methods presented in the table:

1. The remains of garbage we wash away water or an air stream from the compressor.

1. Strengthen the adhesion of the surface of frozen concrete. Here you can apply several methods, both individually and in combination with each other:

• Create notches with a chisel and a hammer or perforator. This is especially worth doing if the cement coating is smooth and has a solid age.

• Treat with deep penetration primer. This will create a thin polymer layer that has perfect adhesion with any materials and solutions.

• Reinforce the fine-meshed metal mesh. It provides many evenly distributed points of high-quality grip, plus enhances the strength of the seam itself.

• Installation of a double-sided galvanized spline. It forms a fairly strong and reliable connection of two monoliths.

1. Next, we first pour a thin layer of concrete a few centimeters wide., giving him the opportunity to make contact with the stone strictly cover.
2. After a couple of hours, pour the entire required volume of cement mixture..

Tip: for large amounts of concreting, use special modifiers that slow down the process of solidification of the mixture. So you can at least reduce the number of stitches.

Other seams

There is also such a thing as thermohaws in concrete, which is designed to compensate for thermal expansion. The fact is that the mortar mixed in the concrete during the temperature change can increase its volume, which can lead to damage to other elements of the building and the appearance of small cracks throughout the entire casting area.

To create it, cutting of reinforced concrete with diamond circles is used. More precisely, we carry out even cuts in certain places and fill them with silicone or other filler with similar characteristics. Thus, the increasing cement plate will only compress the artificially created gap, instead of breaking the walls and columns.

There are three types of expansion joints:

It is important not to confuse cold seams with temperature joints and their purpose.

Conclusion

Concrete construction is not always possible to pour in one go. This leads to the occurrence of working seams. Such a process must be controlled in order to be able to locate such vulnerable elements in safe places and provide them with a sufficiently high strength.

This includes cleaning the docking surface and increasing its adhesive properties. Neglecting the rules and recommendations for arranging concrete defects of this kind can lead to disastrous consequences.

The video in this article will provide you with additional information directly related to the above materials.

Successful you concreting!