Many companies producing paving slabs make it in the form of two layers. But many at the same time neglect the requirements of GOST 17608-91, which states that the upper layer of tiles should be at least 2 cm thick.
In reality, we get tiles with the thickness of the upper layer of not more than 5 mm, in vibration tiles and about 10 mm in producers of vibrolyte. This production technology is certainly much cheaper, since expensive material is used for the manufacture of only the upper layer, and not the whole product.
But after a year of operation, you can notice traces of savings:
? Due to the presence of the boundary layer, the upper layer begins to gradually exfoliate, because of this, the lower layer begins to collapse, while the tile loses color and eventually becomes gray;
? Due to moisture getting between layers, temperature and mechanical exposure, the tile loses color, and becomes gray.
To avoid such defects, it is recommended to make a single -layer product in accordance with the requirements of GOSTs:
? In accordance with GOST 13087-81, the abrasion must correspond to 0.38 g/cm;
? Frost resistance F200-F300;
? B35 concrete class in accordance with GOST 10180-90.