HOW TO CORRECTLY INSTALL FORTGRID ASPHALT GEOGRIDS FOR REINFORCEMENT OF ASPHALT LAYERS?
In road rehabilitation projects, the implementation of geogrids FORTGRID ASPHALT for asphalt layers plays a crucial role. Polyester woven geogrids FORTGRID ASPHALT not only reinforce the asphalt concrete layer, but also control and reduce reflective cracking. To ensure their optimum performance, it is essential to follow proper handling and installation practices, which in simplified form are detailed below: FORTGRID ASPHALT geogrids for reinforcement of asphalt layers
FORTGRID ASPHALT geogrids for reinforcement of asphalt layers
Surface Preparation:
It is essential that the surface area intended for geogrid installation FORTGRID ASPHALT The pavement should be as homogeneous as possible, free of imperfections, serious cracks or unevenness. In case such irregularities exist, it is suggested to correct them by applying a layer of asphalt mix of at least 19 mm (3/4"). Cracks and fissures larger than 3.0 mm should be treated and sealed.
In cases where the geogrid is required to be placed directly on a milled surface, micro-milling is recommended to avoid deep grooves in the surface. Dust particles present on the surface should be removed completely, as they can The effect on pavement adhesion and performance.
FORTGRID ASPHALT geogrids for reinforcement of asphalt layers
2. Asphaltic watering of league:
Once the surface is clean and dry, the application of the asphaltic tack coat is carried out as uniformly as possible and with the appropriate dosage of tack coat. It is suggested to use fast breaking cationic asphaltic emulsion as a bonding agent.
To determine the correct amount of tack coat, in situ adhesion tests shall be performed with three (3) 1.0 m x 1.0 m geogrid samples, varying the asphalt dosage in each one. In no case should the dosage be less than 0.5 kg/m2 of asphalt. This test consists of measuring the resistance to detachment of the geogrid using a pocket dynamometer, which must show a resistance equal to or greater than 5 kg.
For existing asphalt surfaces, the minimum amount of asphalt to be applied is 0.6 kg/m². However, if the surface is rough, it is necessary to increase this ratio. For example, in the case of surfaces obtained by milling, it is recommended to apply between 0.8 and 1.0 kg/m² of asphalt. In addition, the adhesion test should also determine the time required for emulsion breakage.
3. Extending and fixing the Geogrid:
Geogrid rolls FORTGRID ASPHALT should be unpacked and unrolled directly on the surface to be installed once the asphalt emulsion breaks, in order to prevent the binder from losing its adhesion potential.
Installation can be done manually or by using equipment that keeps the roll elevated while it is being moved. When unrolling, proceed gradually, avoiding wrinkles and ensuring correct alignment. It is crucial that no voids or hollow areas are left under the geogrid, as this will prevent proper adhesion to the surface below.
At the edges of the road, as well as near sardinels, wells and structures, a margin of 10 cm should be left to prevent water absorption by capillarity.
Longitudinal joints should have an overlap of at least 10 cm, while transverse joints require a minimum overlap of 25 cm. All sides of the geogrid strips converging at the joint should be impregnated with asphalt and mechanically anchored to prevent displacement. The overlaps should be aligned with the direction of travel of the asphalt placing equipment. In sharp curves, the geogrid should be cut in short lengths to accommodate the radius of curvature and the width of the overlap, ensuring that the overlapping sections are securely anchored to the surface.
4. Geogrid compaction
The geogrid FORTGRID ASPHALT should be compacted using a tire compactor, adding a little water to prevent the bonding agent from adhering to the tires and causing their detachment. This process must be homogeneous, ensuring that the entire surface of the geogrid is adhered and compacted and preventing the geogrid from lifting during the passage of the equipment placing the asphalt mix.
If necessary, additional mechanical fasteners such as metal staples or steel nails with metal washers, with a penetration of approximately 40 mm, can be added to supplement the bond achieved with compaction.
5. Installation of asphalt concrete
If the geogrid has been exposed to traffic or if the initial bond coat does not adequately cover the exposed areas in the geogrid openings, it will be necessary to apply an additional bond coat, ensuring that the entire surface is uniformly covered and, before equipment enters, a thin layer of asphalt mix should be spread over the footprints or traffic areas to avoid direct contact with their tires.
Subsequently, the asphalt concrete layer should be applied with a minimum compacted thickness of between 5.0 and 8.0 cm, depending on the geogrid reference. The layer thickness should be at least three times the maximum aggregate size of the asphalt mix.
The placement joints of the asphalt layer should not coincide with the joints of the geogrid, both in the longitudinal and transverse directions. Care should also be taken to ensure that the tires of the spreading equipment do not run in line with the longitudinal overlap zone between the geogrid rolls.
Compaction should begin with a few passes using light, non-vibrating, smooth cylinder compaction equipment. Then, it should be continued with a pneumatic tire compaction equipment, to achieve the optimum degree of compaction of the layer. Final finishing is done with a vibratory cylinder compactor.
The correct installation of a geogrid reinforcement for asphalt layers is crucial to ensure its effectiveness on the project. By following these steps and considering the specific recommendations from GEOMATRIXIf the geogrid is not installed, you can achieve a proper and durable installation. It is always recommended to follow the recommendations presented in the geogrid installation guide. FORTGRID ASPHALT.
