17.07.2009

The advantages of TRIAX geogrids caomapared with biaxial geogrids

The unique TriAx structure incorporates several characteristics which combine to create an optimised structure that out-performs conventional biaxial geogrids in trafficking applications. When combined with a suitable aggregate TriAx produces a mechanically stabilised layer with exceptional performance.

LOAD DISTRIBUTION

Load distribution is 3-dimensional in nature and acts radially at all levels in the aggregate.
For a stabilised layer to be effective it must have the ability to distribute load through 360 degrees.
To ensure optimum performance, the geogrid reinforcement in a mechanically stabilised layer should have a high radial stiffness throughout the full 360 degrees.

Multi -directional properties
Biaxial geogrids have tensile stiffness predominantly in two directions. TriAx geogrids have three principal directions of stiffness, which is further enhanced by their rigid triangular geometry. This produces a significantly different structure than any other geogrid and provides high stiffness through 360 degrees. A truly multi-directional product with near isotropic properties.

Junction integrity
TriAx is produced from an extruded sheet of polypropylene. This is then punched with anarray of holes and stretched to create the unique TriAx structure. This Tensar  process, coupled with the design of the junctions, results in a product with high junction strength and stiffness.

Proving the importance of rib profile
TriAx geogrids have greater rib depth compared with conventional biaxial geogrids. Trafficking tests and analytical modelling were undertaken to compare performance advantages between the two forms of geogrid with various rib depths in a mechanically stabilised layer. The results were conclusive in confirming that an improved structural performance was achieved with the TriAx geogrid and its deeper rib depth and unique profile. Numerical modelling techniques confirm the importance of geogrid rib thickness on aggregate confinement and load dissipation.

TriAx rib structure directly influences the efficiency of
the stabilised layer.

Installation and handling
The final aspect of performance is handling on-site. Extensive use in projects covering a range of applications have now proved that TriAx is easy to handle, is robust and tough enough to be installed over weak sub-grades.

 

TriAx geogrid can be handled by machine or carried
by two men.

TriAx geogrid unrolled on site.
 

Aggregate placed over TriAx geogrid prior to full
compaction.

APPLICATIONS

TriAx geogrids from Tensar International offer exceptional performance in ground stabilization and sub-base reinforcement. Combined with the technical support and expertise offered by the Tensar team, TriAx represents the future of geogrid technology and, with its proven performance, will replace conventional biaxial geogrids.

Roads and trafficked areas
With TriAx geogrid and its structural performance benefits, there is an opportunity to make considerable savings on unpaved roads and permanent road construction. Less aggregate is required with TriAx geogrid, which also reduces installation time and further helps to reduce ground
stabilisation costs. The reduction in aggregate materials and transport also helps engineers meet sustainability objectives. For thin surfaced pavements, TriAx geogrids provide longer-term benefits, with an
increase in pavement life and reduction in whole life costs.

Housing
Increasingly, housing developments are being built on weak or marginal land. This means that the sub-grade conditions can be variable, which leads to differential settlement. By providing a reinforced sub-structure to a road pavement, TriAx geogrids can be used to help control differential settlement and offer cost savings of up to 75% compared to conventional solutions.

Spanning voids
TriAx geogrids can be used to help protect against sinkholes and subsidence, such as those encountered in areas of abandoned mine workings and can help to provide indications of voids developing below the surface. All geogrid applications require appropriate engineering analysis by Tensar Design Engineers or other qualified professional engineers.

A REVOLUTION IN GEOGRID TECHNOLOGY

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