A neighbor's blind area is destroyed. He is at a loss: why did the concrete begin to crumble? And can I fix this?

One of the neighbors at the dacha shared with me his indignation at the expense of the fact that the blind area of ​​the house after the winter began to collapse. The house is quite new - a few years in total, and already such troubles. For him, a mystery - why could this happen?

Let's discuss why concrete can begin to crumble in principle, and how to fix it.

The main reason for the destruction of concrete is the accumulation of moisture in it and its further freezing.

Concrete is classified into grades for frost resistance (F) and water resistance (W). The stamp consists of a Latin letter and a number. The number after the F shows how many freeze and thaw cycles the concrete will withstand when saturated with moisture. The number after the W - speaks about the waterproofness of concrete - how much water it can absorb into itself.

These two indicators are related to each other, because frost-resistant characteristics depend on the amount of water that concrete takes. Therefore, concrete with good frost resistance (F100 and higher) cannot be a grade with a water resistance grade less than W6.

Often, builders, or customers, are chasing savings and do not consider it necessary to build a blind area or garden path from frost-resistant concrete. They use low strength concrete, such as M100 - M150. And while mixing concrete on their own, they allegedly strive for the M300, while not “bothering” too much with respect to the proportions. And the output is a low-grade solution that does not meet any standards.

What concrete is better to use?

I think one of the most suitable concrete М300 В22,5 F150 W6. Where:

B - strength factor

F - coefficient of frost resistance

W - coefficient of water resistance

This is when it comes to the ready-made concrete made to order. This option will have sufficient strength, frost resistance and water resistance. But it is important not to start adding water to the solution for further easier laying))

You can make durable concrete yourself. But this is a rather subtle and difficult process. It is necessary to mix the solution in a concrete mixer. Manually it will not be possible to knead it properly.

Waterproof concrete is usually concrete with a low water-to-cement ratio (no more than 0.4-0.6, provided that the sand and gravel are dry). If there is more water, then the strength and frost resistance of concrete will be lower than required.

How will excess water harm?

Water in a concrete solution is just a mixing agent. And excess water is a “harmful element”. It only adds unnecessary mobility to the concrete. When concrete hardens, excess moisture is released, forming "cavities" in which moisture then accumulates, freezing at low temperatures and destroying the concrete.

How to fix the situation with the collapsing blind area?

There is only one option - to make the concrete surface waterproof. For such cases, they release water repellent for concrete.

There are many funds. But all of them can be divided into 2 groups - some create a waterproofing film, which, unfortunately, will wear out over time, the second impregnate the concrete, filling the cavities in it. Which one to choose - decide for yourself! They work perfectly, but each has its own period of operation.

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