The woven geotextile is placed in a trench (or similar) which is then filled with aggregate and/or pipe. By virtue of its specified aperture size, the geotextile encapsulates the drainage medium while at the same time preventing the ingress of the unwanted surrounding soil. The permeability of the geotextile allows water to enter the drain and flow away without the possibility of the drain clogging at some point in the future i.e. the geotextile acts as a natural and durable filter.

Applications: Trenches, ditches, road cuttings, road bases, ground slopes, embankments, findrains behind walls and under floors and gardens.

A woven geotextile fabric combined with a gabion basket structure is used in a number of civil engineering applications to restrict the flow of soil particles through or under the structure. This containment combination is generally used for the stabilisation and support of embankments, to minimize other modes of soil erosion, and to either direct water flow (permanently or intermittently) or contain static bodies of water (dams or weirs).

Applications: Walls, culverts, river diversions, bridge abutments, soil erosion and rock slide prevention, dam, river and canal linings, flood control, and groynes.

The physical properties of polypropylene woven geotextiles make them ideal for separating aggregate and soil sub-grade to stabilise the foundation and thus prolong the surface life of the road (or similar). The separation geotextile prevents the mixing of the sub-grade soil fines with the aggregate in the transition zone thus preserving the original structural integrity of the aggregate whilst still allowing water to pass through the layers. Use of a geotextile also allows the laying of more open, easier-draining aggregates. Geotextiles are also cost-efficient for temporary roads as almost all the aggregate can be reclaimed and re-used once the road has fulfilled its original purpose due to minimal intermixing with the sub-grade.

Applications: Roads, railways, pavements, parking lots, other paved or tarred areas.

Silt fences are used as barriers along the contours of soil slopes that are not stabilised by natural vegetation and yet are impacted by heavy rains or water runoff. They consist of a continuous length of permeable geotextile stretched between anchoring posts that are spaced at regular intervals along the contour of the slope. When water flow does occur, the fence prevents the sediment from being carried away by sheet flow and entering the natural drainage ways.

Applications: Mountainsides, slopes, and construction sites with exposed topsoil.

In the world of deep-level mining, the backfill concept plays a pivotal role in allowing mining to continue safely and efficiently at world-record depths. Mine tailings (extracted earlier from the mine for their mineral content) are pumped back underground into long woven fabric geosynthetic tubes specifically designed for the solids and fines contained in that mine’s tailings. The main function of the tubular backfill bag is to replace traditional wood packs in propping up the hanging wall (roof) thereby preventing catastrophic fall of rock during any subsequent mining or seismic activities. This system has the added advantages of greatly reducing the need for large above-ground tailings dams as well as minimising the air volume that needs to be cooled and de-humidified at these depths.

The backfill system has come to replace the age-old use of wood packs and steel as the primary mine support system in deep-level mines because it is more cost-efficient and less time-consuming to transport and install at the frontline mining areas. Also, when filled, it is essentially non-combustible as opposed to wood packs which become tinder-dry over time and are prone to spontaneous combustion. The designed-in longitudinal strength of the fabric ensures that it does not rupture on filling and the specific permeability allows dewatering of the tailings to occur in a controlled manner. The solids of the tailings remain in the bag, dry out and harden, creating a firm foundation for ongoing support of the hanging wall.

Applications: Deep-level mining (depths > 2000m)

Spilo now exports geotextiles to the USA where there is a growing market for geosynthetic tubes. Using our experience gained in mine backfilling and with the aid of specialized software, Spilo can assist in designing a fit-for-purpose solution for any of the above (or similar) applications. In the case of immovable dewatered tubes containing silt or sewerage, they are often covered with a layer of topsoil and then compatible vegetation to minimize their aesthetic impact on the surrounding area.

Applications: Coastal and river protection or reclamation, silt containment (inert or toxic), sewerage dewatering.

Spilo produces, Agri Weave, four synthetic woven fabrics for weed growth prevention avoiding the use of harmful or noxious chemicals. The built-in strength and other properties of the woven fabrics also give them a high resistance to extreme weather conditions. The primary difference between the two is that the longer term product is manufactured using high density polyethylene (HDPE) and as such has a much greater UV resistance. The shorter term product, made from polypropylene (PP), is also UV stabilized but will not last as long as the high density polyethylene (HDPE) in direct sunlight.

Until recently, the only two ways to control weed growth has been with plastic sheeting or chemicals that were often harmful to the environment or the crops themselves. The disadvantage of plastic sheeting is that it does not withstand windy or rainy conditions for very long and requires constant maintenance and replacement. Also, it is not permeable, causing water build-up (ponding) on top of the plastic, and encouraging mould and root rot underneath. While the woven fabric allows free passage of water and air, it’s tight weave and total cover largely prevents evaporation and thus large-scale water loss after irrigation or rains in hot climates.

Applications: Soil moisture retention, Soil temperature control, Soil erosion prevention

Spilo manufactures UV-stabilised HDPE shadecloth in a range of colours to suit the end-use applications or customer requirements. Due to its tightly woven construction, it is effectively a sun and wind blockout and is already employed extensively as curtaining in the game capture industry. The selective use of similar colouring to the local environment (light green and sand) and the total inability of the animals to perceive even shadows beyond the curtains ensures that they are herded with minimal stress into the desired bomas or trucks.

As the need grows for 100% blockout fencing on construction sites (as opposed to current ‘ready-fence’ or see-through knitted shadecloth), so the civil engineering industry should consider switching to this more appropriate product, especially as it very competitively priced compared to the alternatives.

For large orders (e.g. a large commercial building site), Spilo is willing to manufacture a unique run in the corporate colours of the project client or the main contractor.

Applications: Construction site blockout, bomas, animal and game channeling, shading, windbreaks, carports.