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Geotechnics for Utilities

In this section you will find:

Woven Geotextiles 

Keyline Utilities offers a complete range of woven geotextiles. From the Fastrack 609 for use as a basic separation and filtration material to high strength woven reinforcing grades for use in basal reinforcement, highway and applications with larger stone sizes. Also available are high flow geotextiles that can be used where water infiltration properties are the most important requirement. Our Woven geotextiles are manufactured from polypropylene tapes & yarns, and exhibit an excellent chemical resistance to commonly encountered acids and alkalis at ambient temperatures. 

Geosynthetic Clay Liners

Geosynthetic Clay Liners (GCL) are high performance environmental liners comprised of a layer of low-permeability sodium bentonite encapsulated between geosynthetic carrier layers. They provide hydraulic performance equivalent to one metre of compacted clay, with a total GCL thickness of less than 10mm. GCLs are self-sealing if punctured, and are manufactured in large rolls that require just a simple overlapped seam. Fast and easy to install, as well as being highly cost effective, GCLs provide a superior choice for both designers and contractors.

Tensar® TriAx® Geogrids

Over the last 10 years there has been an increase in the development of brownfield rather than greenfield sites where ground conditions are normally poor. With the rise of flooding, erosion of embankments has become an increasing problem. Additionally the growth of renewable energy generation which by its nature often involves the building of Windfarms, or Hydro schemes some distance from the main highway infrastructure has resulted in contractors looking for innovative solutions to reduce construction speed, enviromental inpact and overall material costs. 


Over the last 10 years there has been an increase in the development of brownfield rather than greenfield sites where ground conditions are normally poor. With the rise of flooding, erosion of embankments has become an increasing problem. Additionally the growth of renewable energy generation which by its nature often involves the building of Windfarms, or Hydro schemes some distance from the main highway infrastructure has resulted in contractors looking for innovative solutions to reduce construction speed, enviromental inpact and overall material costs. Whatever your requirements Keyline Utilities can provide a complete solution.

Tensar® Basetex High Strength Geotextiles

Tensar® Basetex products are a range of ultra high strength geotextiles manufactured using a weft insertion knitted process. Products produced from this process differ from conventional woven fabrics in that the load bearing yarns remain essentially linear. When subjected to load the yarns are able to reach full tensile strength without undergoing the elongation associated with straightening of the yarns. For the Standard Product Range, the load bearing yarns are 100% high tenacity polyester, providing excellent creep performance and high tensile modulus. The high molecular weight of the polyester yarn selected for Basetex ensures that the product is highly resistant to environmental damage within the normal range of pH and temperatures encountered in soils. Tensar® Basetex can be manufactured with longitudinal strengths up to 1200kN/m and transverse strengths up to 500kN/m.

Gabions and Mattresses 

Gabions are manufactured from dimensionally stable panels of mesh that are formed by welding transverse and longitudinal wires at each and every intersection to form a grid. The gabion box is then part assembled by hinging the face, back, sides and internal diaphragms to the base panel and the lid to the rear panel with ‘C’ rings or clips. The units are transported to site flat packed with lacing wire as standard for on site erection. Once assembled, the gabions are filled with stone or rock and the lid secured to form a monolithic structure in accordance with the recommended installation procedures.

Welded Mesh Gabion 39 System: Standard Gabions
Welded mesh Gabion 39 System is available in mesh aperture 76.2mm x 76.2mm and in the following specifications to the nominal dimensions stated below. Other non-standard mesh apertures are available on request.

Welded Mesh Gabion 27 System: Modular Welded Mesh Gabions
The Gabion 27 System comprises of modular welded mesh units that are sub-divided into 685mm cells along the length of the cage. The base of the gabion forms the lid of the unit below. The base is extended by fixed dimensions on one face to allow for a predetermined stepping arrangement at each course. The base on the other face is flush, allowing for a flush faced wall to be constructed if required or coursing with a combination of flush and stepped faces.

Woven Mesh Gabions and Mattresses
The mesh fabric for all these products is formed by weaving adjacent strands of wire by twisting them through one and a half turns at intervals, forming a hexagonal shaped mesh. The ends of the mesh wires are wrapped around a heavier transverse edge wire to form the panels. The tensile strength of the mesh in the direction of the weave is greater than across the weave. The gabion box is manufactured from a main panel that forms the face, base, rear and lid of the unit. The side panels and diaphragms are then jointed to the base section of the main panel. The unit is then folded flat for transportation. On site, the unit can be opened out into the required position and the sides, diaphragm and end panels are rotated vertically. The vertical joints are formed by a continuous lacing operation with the wire supplied or with ‘C’ rings to form the box shape.

Once assembled the gabions are filled with stone or rock and the lid secured to form a monolithic structure. The gabion mattress is a box unit where the plan area is large compared to its height. Each unit is subdivided into compartments normally to give cells 2m x 1m in plan. The units are laid on the bed of rivers. Once filled with stone or rock and the lid closed, they form a blanket erosion control system. Mattresses are also used to provide under scour protection to retaining structures.

Concrete Canvas

Concrete Canvas (CC), is a flexible, concrete impregnated fabric that hardens when hydrated to form a thin, durable, waterproof concrete layer. CC allows concrete construction without the need for plant or mixing equipment. Simply position the Canvas and just add water. CC consists of a 3-dimensional fibre matrix containing a specially formulated dry concrete mix. A PVC backing on one surface of the canvas ensures the material is waterproof. The material can be hydrated either by spraying or by being fully immersed in water. Once set, the fibres reinforce the concrete, preventing crack propagation and providing a safe plastic failure mode. CC is available in 3 thicknesses: CC5, CC8 and CC13, which are 5, 8 and 13mm thick respectively.

FloodSax® Commercial - The Sandless Sandbag

FloodSax® are an innovative self-inflating flood defence system set to revolutionise the way we control damage due to flooding. The semi-porous inner liner contains hundreds of absorbent crystals which absorb water to 90% capacity in just 3 to 5 minutes. FloodSax® are so easy to carry, store and deploy that anyone can use them from national government and local councils through to local tradesmen.
Features and benefits:

  • Super absorbent – Each bag will absorb 20 litres of water
  • Compact – Store anywhere as five vacuum packed bags weigh just over 2 kilograms and are only centimetres thin
  • Ease of Use – You can build walls up to a metre high, you can soak up water and divert water flow.

Download a PDF of the Geotechnics section of our Utilities Guide here