Paving technology
Pre-paving
Base layers shall be designed in accordance with the Construction Norms and Regulations SNiP 2.0502-85; such layers shall be of equally distributed load-bearing capability, frost- and water-resistant, compliant with the set profile, and flat.
Particular attention shall be directed on the reliable drainage of the «paving stone-base-soil» system. If the system’s throughput of precipitation and melt water is below 0.02 l/s per 1 m2, then the issue of waste water removal over the surface, or using a drainage system, shall be finally settled at the design stage.
The base layer can be made of any frost-resistant material ensuring due drainage, e.g. gravel, or gravel chippings of fractions 5-20 mm, or 20-40 mm. The thickness of base layer shall be defined in the project, and may range within 14 - 70 cm, depending in the class of area, road, etc. The bedding course can be made up of sand, gravel, or gravel chippings of fractions 0-5 mm.
The thickness of compacted bedding course shall range within 3 - 5 cm. The upper limit cannot be exceeded, as this may result in deformation of road surfacing through traffic load. In specific case, e.g. paving of bus stops, driveways, etc., the bedding course material may include a binding material – cement or caustic lime (at the ratio of 1:7 or 1:8). When you need to fill mortar in the joints between paving stones, the bedding course shall include a binding material.
In case with surfaces protected against weather conditions (intended for use indoors, or under a tent), the bedding course shall be made of cement-sand mortar (to be wetted prior to placement).
Placement of paving stones
PSEs are placed on bedding course prepared beforehand, starting from the surface already laid, in even rows and according to the selected profile (as per template, or rail, or rubber-cord). All paving stones are placed at the same height. The spacing between joints shall be 3-5 mm (when to be further filed with sand), and 8 mm (when filling is done with mortar of mastic compound.
Jointless placement of paving stones is not acceptable, as in this case ribs of stones may spall off in the course of use (resulting from temperature and force deformations). Remember that the 1.5 to 2 mm fixing lugs provided in paving stones are no replacement for the joints!
It is noteworthy that the joints along with the filling material function as elastic support between separate stones in the course of use, therefore ensuring even horizontal and vertical distribution of load between such stones. If you plan to fill in the joints with mortar, contraction joints are required. Following placement, the surfacing shall be evenly tamped starting from the edges towards the middle.
Take notice!
When in the course of placement, use paving stones from various packages. This concerns all colors, especially color shades. Avoid soiling face surfaces of stones, e.g. by covering with plastic film.
Tamping of paving stones
Following placement the paving stones must be tamped. Tamping results in the expansion of joints between PSEs and the material of the bedding course. Tamping can only be done on the dry surface, in an even fashion, starting from the edges towards the middle! Be sure to thoroughly clean the surface. Tamping is usually performed using vibrating plates (colored PSEs require plates with polymeric coating).
We also recommend that you use areal vibrators of working weight up to 170-200 kg and sealing centrifugal sealing force up to 20 kN.
The use of asphalt spreaders or vibratory rollers is not allowed.
Remember that vibration results in the subsidence of paving stones face surface by app. 1 cm!
Filling of joints
Filling of joints must be performed immediately following tamping, in pace with the overall progress of placement. Joints are typically filled by pouring sand until the joints are completely stuffed.
A greater degree of joint integrity can be attained by watering the joints after each filling. This means that joint filling procedure may include several stages. The materials most appropriate for joint filling are sand, gravel, and gravel chippings of fractions 0-2 and 0-4 mm.
In cases of increased external action, e.g. in areas of gasoline stations, joints may be filled with cement mortar or any other substance resistant to petroleum products, with the joint spacing no less than 8 mm.
As soon as you have filled the joints, just remove the remnants of sand – and your paved area is ready to use!
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