In the construction of heavily trafficked areas such as parking lots, a stable subgrade with sufficient bearing capacity is required. When installed between the subsoil and the base course, Secugrid^® geogrids, made from high strength, extruded monolithic flat bars, with welded junctions, are particularly well suited for this application. The coarse grained cover soil interlocks with the Secugrid^® geogrid creating a bond.

This immediate interlock provides a horizontal force transfer which increases the bearing capacity of the soil due to the high force absorption of Secugrid^® - even under low elongation. The required bearing capacity can be achieved without additional expensive soil exchange, and in some cases, the base course thickness can be reduced. Secutex^® separation and filter nonwoven geotextiles are used to prevent the migration of fine particles into the base course. To facilitate the installation and create shear strength transfer, Secugrid^® and Secutex^® components are premanufactured into a bonded composite product - Combigrid^®. On extremely soft subgrade, the bearing capacity can be markedly improved by using multiple layers of Secugrid^® geogrids.

Reduction of Rutting

When building unpaved roads (e. g. forest paths and temporary construction roads) on soft subsoil, rutting and intermixing of the cover material into the subsoil should be avoided. Combigrid^® or Secugrid^® geogrids can significantly improve load distribution, minimizing rutting and soil intermixing. The selection of the Secugrid^® geogrids is on a project-specific basis according to standard guidelines and site specific requirements.

Strength/Elongation Behavior

Unlike the separation function of geotextiles, reinforcement requires a product with low elongation characteristics. Secugrid^® geogrids have no product manufacturing elongation. With the stiff junctions of the welded reinforcement bars, Secugrid^® has less than 8 % elongation at break. For product comparisons and design issues, the strength absorption at 2 % and 5 % elongation are often used.

Installation Robustness

When installing and compacting coarse-grained cover soils and base course materials the reinforcement can be subjected to high dynamic stresses. Due to the thick, robust, monolithic reinforcement bars, Secugrid^® geogrids and Combigrid^® have a high resistance to installation loads. Compared to conventional construction methods, the use of Secugrid^® and Combigrid^® geosynthetics is an economical and effective alternative.