Corrosion and puncture resistance of aluminium foil gas membranes beneath concrete slabs

Aluminium foil (AF) membranes are commonly installed below or above concrete floor slabs to reduce the migration of ground gases into buildings. The membranes typically comprise laminates of low-density polyethylene (LDPE), reinforcement and an aluminium foil layer. The key component providing gas resistance is the aluminium layer. This is typically 0.012 mm thick and is often encapsulated by very thin layers of LDPE. The foil is therefore vulnerable to damage from puncture by narrow sharp objects in the field. Aluminium corrodes in aggressive and moist environments and could therefore be affected by the fresh cement slabs and/or ground moisture. This paper summarises testing completed to assess the puncture and penetration vulnerability of AF membranes in real life scenarios and the observations from an experiment where AF membranes were exposed to various conditions, including alkaline, acidic and direct contact with cement environments. Based on the results, design considerations are provided for AF membrane applications.