Good afternoon, dear guests and subscribers of the "Build for myself" channel!
Sometimes you have to deal with situations in which it is necessary to carry out concrete work on a wet base or being completely in water. This can be work related to the construction of wells, structures in areas with a high GWL level, or supports for bridges on the banks of reservoirs and I'm sure there are still a lot of cases where such a need exist.
To begin with, I would like to briefly touch on what concrete is. Concrete is an artificial building material that hardens with a binder. In 99% of cases, the binder is cement, and the filler is sand and crushed stone.
And, if you have already tried, then you know that concrete based on ordinary Portland cement when trying concreting in too humid conditions - does not live up to the expectations placed on it and becomes limp in water.
In our case, in order for the chemical reaction of cement crystallization to occur naturally in water conditions, special cement is required. And this miracle substance is alumina cement (for convenience I will use "GC").
I have an article on restoring and strengthening the old foundations of private houses, where this type of cement is used, since it is self-expanding and, with the correct organization of work, it "picks up" the old building from below, which allows to ensure high efficiency of the cold seam! (Link to article)
This type of cement did not receive wide distribution in private housing construction due to 4 times the price of the usual Portland cement, but even despite this, such a product actually simplifies work at times and saves time and nerves, because after 15 hours. the strength of the concrete is already sufficient to put the structure into operation.
In practice, a mortar created on the basis of such a cement begins to harden within half an hour after adding water. And for the normal provision of hardening of the mixture under water, its temperature should be + 15-20 ° C. The resulting building compounds at GC are waterproof, fireproof and chemically resistant.
It finds its main application in the industrial field, where it is required to achieve increased strength in a very short time: offshore structures, cold wells, emergency restoration of bridges and dams, well sealing and construction of structures with heating up to 1700 ° C.
In addition, the hardening process takes place with sufficient heat release (exothermic reaction), which makes it possible to successfully work at low temperatures.
The optimal ratio of water to cement is 0.4, i.e. for 1 kg. HZ requires 0.4 liters. plain water. And one cubic meter of concrete requires 350 kg. HZ
GC is marked for ultimate compressive strength: GC-40, GC-50, GC-60, where the figure expresses the pressure in MPa.
Thus, I think that the presented article has revealed for you the unique properties of GC, which can be used not only in industry, but also for a number of tasks in private housing construction!
I would be glad if the article was useful to you!
There is no waterproofing between the plinth and the wall! Photo of the consequences and how to eliminate the cause?
Why is it profitable to make a footing for the foundation?
What is the service life of copper wiring after installation?