ABG GEOSYNTHETICS has successfully completed trials of its Finesse Pozidrain geocomposite drainage layer for a waste management company in east Yorkshire. The aim was to determine whether Pozidrain could be used instead of filter stone as a drainage layer for leachate and contaminated groundwater from landfill sites.
Pozidrain is supplied in 6mm thick, 4.4m wide rolls and consists of a thin HDPE cuspated core bonded to a heat treated needle punched geotextile filter fabric. The company says that although it has been used on previous contracts to replace up to 300mm of traditional crushed stone, this was the first time that this client had used it in such thin layers.
For the trial, a 150mm layer of fill was placed on two types of the geocomposite. The Pozidrain 6S500D was then compacted in 20 passes while the 6S240D received 10 passes. when it excavated, no crushing of Pozidrain was evident. As a result, the original design was modified to include the Pozidrain instead of filter stone, saving around £11,000.
The firm has also supplied and installed 140,000m2 of Finesse Pozidrain 6S240 for Reading Football Club's new £22M Madjeski stadium. The stadium is being built on the site of a former landfill and the geocomposite was laid under the HDPE liner to provide gas venting and membrane protection against contamination leaks. ABG claims that as well as being faster and more cost effective to install, smaller amounts of contaminated material had to be excavated as a result of using the system.