Paving of terrazzo tiles during improvement of adjacent territories and pavements.

First of all the surface soil or old wearing coat must be removed up to the required depth.

Two variants of surface paving with terrazzo tiles are proposed: by means of pavement border stone (border) and using a decorative ballast stone.

While paving with decorative ballast stone it is necessary to take into account ground excavation depth, so that as a result of paving the tiles are at grade with ground level. The ground is excavated with the tolerance of 20 cm per side for back filling with decorative ballast stone. This compacted base must be leveled and in full conformity with final paving profile – be plain for plain paving, and slanting or figured – for intricate profile.

It is one of the most important stages in the process of abaculus paving. Service life of the whole paved surface depends on foundation quality.

Upon conditioning of foundation materials are laid layer-by-layer:

• The first layer – ballast stone 5-20 mm grade, layer thickness 15-20 cm. Upon paving the ballast stone shall be carefully leveled and compacted.
• The second layer is sand with grain diameter not more than 7 mm. Layer thickness 5-7 mm. Before paving the sand must be separated and without large inclusions. The second layer shall also be carefully leveled and compacted (applying sand by means of it being poured with water).

Instead of sand it is recommended to use ballast stone graded 1-4 mm with layer thickness 5-7 mm.

During conditioning of sites used by cargo transport foundation the height increases up to 30-40 cm (ballast stone layer 30-35 cm, sand layer 5-10 cm), with layers compacted by paving compactor.

It should be accounted for that the upper layer is to be about 1 cm higher than desired height of coating before ramming.

If there is a ready-fitted foundation represented by concrete blinding coat, it is necessary to lay and to level a sand layer on the top (5-7 cm), according to requirements abovementioned.

In case of using pavement border stone, it is installed upon conditioning of foundation. Border stone shall be installed exactly along the line of markings and on level, the trench shall be filled with foundation material, which is then rammed. To avoid toppling over of border stone in soft formation, good ramming of border stone must be ensured.

Paving of terrazzo tiles must be done from the area, where they have been already laid, so that not to step on compacted surface. A clearance of 3 mm is to be held between tiles, as while contact their corners may chip.

If decorative ballast stone (instead of border) is used, it is to be filled into the opening between soil and tiles upon paving, and then carefully compacted.

The tiles are paved; the surface must be compacted with compacting device. After the first vibrocompaction of finished coating, some separated river sand must be spilled over the surface, so that the sand might fill in gaps between the elements easily and tightly. The sand filled into joints must be clean and without salts and organic substances, which may cause appearance of plants in it. The spilled sand shall be evenly scattered over the whole surface and rammed into seams by simple sweeping, “connecting” the whole coating firmly and reliably. Then dry and clean surface shall be again rammed with vibroplate, and a layer of dry separated sand shall be applied. It is recommended to leave this sand layer for it to remain still for some time. After that the site may be swept once more.

Then the whole area, both tiles and decorative ballast stone, will be carefully rammed by means of rubber based compacting device.