There are various reasons for the Cement floor to chip. Some of them are listed here below:
The base floor was laid without proper civil concrete specifications and hence the top floor never got attached to the Bottom layer.
Solution: Grinding the floor will give a clear picture. If the composition has more sand in it the bottom layer will start throwing a lot of sand and the floor will get rough. In extreme cases of bad concrete it is often seen that the bottom layer shatters. It is time for new concrete as per specifications (M25 or M 35).
The bottom layer dried sooner and the top layer was put later. The cement layer will never sit on a dry concrete unless some special chemicals are used.
Solution: The chipped layer must be removed first. Then the floor needs to be ground with Metal Segments for surface preparation. The new layer of cement should be mixed with either a latex based adhesive or by using a special Beton Hardener. This will allow the cement to sit on top and the hardener will also penetrate into the bottom, thereby holding this together.
Both the CC layer and the cement layer were not cured properly. Sometimes it is seen that the Concrete was not given adequate time to cure or curing was not properly done and hence it started getting damaged within 6 months of use.
Solution: This has weakened the Concrete and most probably cracks have started appearing the entire concrete especially the joints where the four corners meet. In case there are no joints left, this is the problem. The concrete essentially needs these joints as they are known as controlled cracks, deliberately left for expansion and contraction of concrete.
The usage of the Concrete floor is heavier than the Concrete itself.
Solution: Needs expert help to check whether new concrete can be laid on current layer or should it be removed to get a new top. Some times 12-16mm overlay can help resolve this problem. But it needs to be studied well before commenting.
There could be a lot more to this than only the above. But if I can have more inputs on this with some photographs, I will be in a better position to answer.
Deepak Baluja
Director-Final Technologies