Concrete Pumping: A New World Record

New world record of altitude transportation of concrete (532 m) was reached on the 2nd of June 1994 in Riva del Garda Hydroelectric Power Plant. The requirement involved the construction of a new piezometric well and intake conduit and the replacing of the existing surface penstock with a new one built underground to reduce environmental impact. Two parallel tunnels were excavated: one for Ledro - Garda lakes location, the other for transporting penstock's metal elements. The self supporting metal pipe has been blocked for all its length (790 m) by filling of the ring space between the excavation wall and the piping with 5,000 m2 of concrete. In order to reduce environmental impact it was decided to pump concrete from the lower end from and excavated chamber near the Powerhouse. The record level: 532 m (vertical) and 790 m (total length) widely exceeded the former one (432 m) obtained in 1985 in Spanish "ESTANGENTO SALLENTE" Power Plant.