For existing containment areas in VT, these may include either concrete or asphalt areas. In the case of concrete, a variety of paint systems have been applied over the years. Well with the natural movement of concrete, these paints will crack, thus providing a leakage point through the concrete into the ground area.
Full aware of impending environmental regulations, the US Military has success utilized the polyurea technology for lining of various fuel storage containment areas. In fact, engineering contract firms working with the US Air Force and US Navy technology are currently specifying polyurea technology.
Work includes applications at Patrick Air Force Base, Cape Canaveral Air Force Station, AUTEC US Navy Base and a variety of fuel storage areas for Municipal airports. Most of these areas have an existing epoxy paint system applied to the concrete. The concrete's natural tendency to shift has caused the epoxy to crack, thus allowing for a breach in the containment area and providing for environmental issues. Polyurea technology, being an elastomeric system, fills those cracks and yields a superior containment lining material.
Some containment may be existing asphalt, earthen berms or gravel. For these configurations, a geotextile membrane is laid on the substrate, to which a polyurea system is then applied. The polyurea system application bonds to the geotextile membrane, as well as the existing tanks, pipe penetrations and sump areas. This bond provides for a truly seamless installation without the use of mechanical fastening found in installations of sheet material membranes.
Applications here form major chemical facilities for fuel, oil and chemical storage. The polyurea systems used in these instances are specifically formulated to provide for low cure shrinkage when applied over the unsupported geotextile membrane. Recent work in North America includes projects that range in area between 300,000-450,000 ft2 (28,000-42,000 m2). Trained installation crews typically complete these large projects within one month.
With the resurgence of oil and gas exploration in the US, the requirement for containment areas for the fractionation fluid is required at each drilling site. For this work, a designed containment area is prepared, metal support walls are constructed and a designed polyurea spray system is applied over a geotextile fabric. The polyurea system bonds to the wall area and geotextile fabric to provide for a seamless, leak-free area. The storage tanks are then set within the area and piped in that same day of liner system installation.