PREFABRICATED BITUMINOUS GEOMEMBRANE: A CANDIDATE FOR EXPOSED GEOMEMBRANE CAPS FOR LANDFILL CLOSURES

Landfill caps prevent incident precipitation from becoming leachate that has to be treated, contain landfill gas that can be used to generate electricity, and prevent odors that annoy neighbors. Typically they are covered with soil and vegetation for appearance and for the construction of parkland and recreational facilities. However, exposed geomembrane caps (EGC) are increasingly being used as interim and even permanent covers for their cost savings and to eliminate potential problems with sliding cover soil layers. However, a new set of concerns such as exposure to UV radiation, the potential for wind uplift, and drainage of incident precipitation need to be considered. To date reinforced polypropylene (RPP) and high density polyethylene (HDPE) have been used for EGCs and ethylene interpolymer alloy (EIA) has been proposed. Another candidate geomembrane is prefabricated bituminous geomembrane (PBGM). The properties and performance characteristics of these materials are reviewed