Geotextile capping system provides low permeability
The landfill capping operation has been completed at the Wapsey's Wood Landfill in Buckinghamshire using Naue Geosynthetics' low permeability barrier Bentofix ® NSP 4300-1.The benefits provided by this capping system included the self-sealing properties of the longitudinal overlap joints which ensured fast installation speeds and less time lost to bad weather, states Naue Geosynthetics. In addition, low permeability characteristics also played a major decisions to specify Bentofix®. It was installed directly on to the prepared subgrade using a 360° excavator with spreader bar at an average of 10,000m2 each week of a 12-week period.
Bentofix® Geosynthetic Clay Liner NSP 4300-1 is a composite of two geotextiles sandwiching a mass of sodium bentonite clay. The upper geotextile is non-woven and the lower is of the woven polypropylene variety. A special manufacturing process of needle punching provides the composite with high strength. Needles carry fibres from the non-woven geotextile through the clay and they are embedded into the woven geotextile, providing an integral fibrous reinforcement of the membrane.
Hydration expands the original 6mm membrane by between 4-5 mm and in the process produces a low permeability barrier membrane. In addition, the hydration process seals the overlap joints making the whole 120,000m2 an entire and complete capping. Naue Geosynthetics is a specialist in landfill base lining, batter reinforcement and capping procedures.