TENAX T-Block - Retaining wall system for geogrid reinforced block walls

The components of T-Block System
The T-BLOCK Retaining Wall System features a modular precast concrete block facing unit, a polymeric T-CLIP connector and layers of TENAX TT geogrid reinforcement material.



TENAX TT mono-oriented geogrids

The TENAX TT mono-oriented geogrids are two-dimensional polymer structures manufactured from HDPE (High Density Polyethylene) by a process of extrusion and mono-directional drawing. The geogrids are certified for the reinforcement of the soil mass behind the wall by major international organisations. Soil and aggregate interlock within the geogrid openings, which confine the soil, limit its relative displacements and increase the soil’s shear stress resistance. The soil/geogrid structure integrates the fill soil’s high compressive strength with the geogrid’s tensile strength, thus creating a material having greater rigidity and stability and improving the structure’s resistance to static and dynamic loads.

The T-block wall units

The T-BLOCK units are high strength precast concrete modular facing units with a compressive strength of 35 kN. Each T-Block unit has a face area of 0,06 m2 (150 x 400 mm x 240 mm thickness) and consists of a groove formed in the bottom of the block and a locating rib (or tongue) formed in the top of the unit.

This “tongue and groove” connection allows many T-BLOCK units to be securely interconnected, thereby forming a locked vertical face.

The concrete units have a minimum compressive strength of 35kN. Moisture absorption is less then 5%. Pigments used in the concrete are pure iron oxides or, if green or blue, chrome oxides.
Plasticizers and water proofer may be used, but sodium accelerants are not recommended.

Aimed at satisfying the most demanding markets worldwide aesthetically and technically, it’s possible to deliver a range of existing blocks or custom-design blocks for specific market needs.

The T-clip connectors

One of the most critical areas for retaining wall structures is the connection strength between the geogrid reinforcement and the block wall facing units.
The TENAX patented T-CLIP connectors deliver a 100% effective mechanical connection with the geogrids and the T-BLOCK units to form a totally integrated system.




The fill material

Typically constructed using compacted granular backfill, selected site-won or imported material. There is also the opportunity to use carefully selected recycled or stabilized backfills within the reinforced soil mass, thereby dealing with environmental pressures concerning the use of natural resources.

Connection strength
The design of the T-BLOCK connection system is the result of seventeen years experience of making mechanical connections between HDPE geogrids and segmental concrete blocks.

This experience with loose connectors, grids and blocks led to increasing the simplicity by making smaller connectors which clip onto the geogrids thus making two parts into one. This enables the grid with the connectors to be laid on the blocks and secured in position with the next layer of blocks very easily.

The mechanical connection is important as it allows the system to be used in seismic areas and optimises the design by allowing the full long term strength of the geogrids to be used in the geotechnical design of the structure. By using a straight through path for the geogrids the blocks sit level on the geogrids and so eliminates rotation of the wall units common with some other systems.