Geomesh and geotextile membranes to prevent pavement cracking.
The term “Heavy vehicle traffic” refers to any type of large vehicle intended for transporting goods or people. Thousands of heavy vehicles drive through our roads day after day.
In some areas nearby trading estates, there are an even larger number of heavy vehicles causing several negative effects on the road surface, such as cracking and potholes. Although there are several reasons that can cause these issues, they can be grouped in the following categories:
- Surface settlement issues
- Lack of draining in the pavement’s subgrade
- Asphalt mix shrinking
- Flexibility between adjacent asphalt material layer seams
- Movements in the asphalt layer due to expansion or shrinking of road surface caused by changes in humidity and temperature.
- Changes in the volume of base layer fines.
- Lack of bonding between the asphalt mix and the sub bases that may be due by different causes such as the appearance of contaminants, lack of a bonding layer, using a very sandy mix, mix not properly settled.
All the above circumstances may cause different types of cracking. That’s why it is so crucial to use different materials to prevent it for as long as possible. Currently, no significant investments are destined to rebuilding damaged roads, but the focus is on allocating funds for their maintenance. Therefore, a good solution would be to choose maintenance materials that are specific for heavy traffic roads.
One of the products that will help prevent the occurrence of cracks and fissures is the geomesh that we have been speaking about in several posts, which can be made of different materials such as fibre glass, polyester, polyvinyl alcohol, etc. However, the most recommended products for these resurfacing processes and to prevent cracking are the geocomposite fabrics, comprising a geomesh and geotextile membranes. By combining these non woven fabrics we can improve the bonding between the base and upper layers. Both components are supplied with a bituminous coating.
At Tex Delta we have developed the DLT-GRID HL PET50-50 and the DLT GRID HL PVA 50-50 geomesh. Both are manufactured from a strengthening geocomposite comprising a geomesh and a geotextile membrane. While the geotextile membrane is made from polypropylene fibres, the geomesh in this geocomposite is highly resistant to traction with low deformation.
Following is a description of the different phases or stages for a correct installation of the strengthening mesh in asphalt areas:
1. Surface preparation
Ensuce the surface is clean, dry and free of ant loose material.
2 Tack-coat spraying
An unstable cationic emulsion of 70% bitumen content (U70K) shoud be evenly applied at a rate of 0.6 kg/m2 – 1.2 kg/m2 (to be adjusted on site); adequate enough to hold down th Hatelit.
3 Tack- coat “break”
Allow the bitumen emulsion to break before placing the grid (colour chabge from brown to black).
4 Laying the grid
The grid shoud be pulled out over the surface by using a pulling system. The Hatelit roll has to lay on the sublayer, while being unrolled, and not being in the air. After unrolling it is recommended that the Hatelit is rolled using a light tnadem roller. Laying of the asphalt ( minimum 40 mm in compacted condition) shoud follow the installation of the Hatelit without delay. If it rains after installation special treatement must be undertaken.
5. Joints/overlaps
In the cross direction 150 mm and in the length direction 250 mm. The end of a roll always being plasced over the beginning of the next, ensuring the overlap is not lifted during the covering operation. The overlaps should be treated with a minimum of 0.15 Kg/m2 of bituminous emulsion.
6. Bends and curves
On curves, Hatelit is curt to shorter lenghts and laid with overlaps. The lenghts of the pieces depends on the radius of the curve.
7. Trafficking the grid
The grid covered surface should not carry normal road traffic until the covering asphalt course has been placed. When moving vehicles on the hatelit sharp turns, rapid changes in the speed and hard braking must be avoided.
Important hint
When air temperatures are either very hot (> 30º C) or cold (< 5ºC) special measures may be necessary. In the event of one of these situations, please contact us.
For further information or prices for our strengthening geomesh do not hesitate to contact us at info@texdelta.com
