If you are saying you have a 10cm (4-inch) concrete slab on grade which is being used for heavy fork lift traffic, my first reaction would be that the slab is probably going to cracked and failing in numerous places. As a structural engineer, I would never specify a slab being used in a warehouse with fork lift traffic less than 15cm or about 6-inches thick.

Concrete repair can be made on cracked slabs and it usually consists of either cutting out a section if it is badly damaged and replacing or by using injected epoxy joint grouts. There are numerous products available but I do not know what is stocked in Qatar.

It sounds like that even if you repair the cracks you have now though, with the type of traffic to which you are subjecting the slab, it will continue to deterioate. I could help more if I were there but we are not schedule to arrive until July.

Send me some pictures of the problem at [email protected] and I may be able to advise more accurately.