‘You’re only supposed to blow the tunnel up’: ‘Green’ explosive cuts CO2 emissions

Implenia’s Hypex Bio leaves no harmful residues in the rock which makes it easier to comply with environmental regulations and reduces the need for costly water treatment plants, Implenia said.

The new explosive is a biodegradable emulsion that uses hydrogen peroxide as an oxidising agent and eliminates the need for harmful ammonium nitrate, Implenia said.

Implenia Sweden has already tested Hypex Bio on the CHF87.4 million (US$101.4 million) Farstagrenen project to connect tracks in Stockholm. It involves the construction of a double-track tunnel around 2,000 metres long, including a 450m-long stabling area for trains, beneath the streets of the Swedish capital. Implenia is building the connecting tunnel to the extended Högdalen subway depot in Stockholm.

Construction is being carried out using drill and blast method and the first findings of the pilot project, which saw Hypex Bio being used alongside conventional explosives, found that it improved air and wastewater quality, as well as reducing CO2 emissions.

Implenia added that the effectiveness of the biodegradable explosive was “in no way inferior” to that of conventional nitrate-based explosives.