WALO has played a pioneering role in the field of bituminous asphalt seals for over 75 years with its various services in Switzerland and worldwide. Apart from sealing reservoirs, canals, landfills and dams, mastic asphalt seals are also part of our specialist department’s range of services.
For over 60 years, dams have been made impermeable to water with asphalt core walls. There are more than 200 core walls of this kind worldwide in dams up to 150 metres in height. An asphalt liner wall is built inside the dam at the same time as the support body is filled. Using core pavers specially developed by WALO, the seal is installed step by step in layers up to 250 mm thick as the construction of the dam progresses. Bituminous core walls are particularly recommended in regions that are vulnerable to earthquakes since the viscoelastic and ductile properties of the asphalt liner mean that it can compensate for these settlements without becoming damaged or permeable.