Before the architects and builders could start work on the Lugano housing development project, a concrete retaining wall of substantial dimensions had to be erected. The special heavy construction company Bianchi based in Obersaxen, Switzerland requested assistance from Germany to build the retaining wall to a height of 19 metres and an overall length of 105 metres.
The shotcreting work was performed by Putzmeister customer Walter Bohr- und Injektionstechnik from Albruck in Germany, which for many years has relied on the powerful P 715 piston pump from Putzmeister for wet and dry spraying applications involving the spray manipulator. The wet spraying equipment used for the housing development project in Lugano was upgraded with a chemical control and operated wirelessly to allow automated operation of the concrete spraying equipment.
An important link in the automation chain - the Putzmeister P 715
Since the versatile, reliable piston pump is already able to convey material with a grain size of 16 mm over long distances, the 8 mm concrete mix did not pose any real challenge for a machine that boasts a maximum delivery output of 18 m3 per hour and maximum delivery pressure of 68 bar. Rarely pushed to its load limit, the oil-cooled 3-cylinder diesel engine from emission category 3A supplied a continuous flow of material to the spray manipulator attached to the swing arm on the excavator. At 80 metres long and 50 mm in diameter, the hoses posed no problems for the P 715 and resulted in an average concrete delivery rate of 12 m3 per hour. Small, compact dimensions and a low weight make the machine extremely mobile, while the roadworthy T-chassis makes it easy to transport and manoeuvre on the construction site. One particular advantage of the P 715, especially on sites with limited access, is the optional hard-wearing lifting eye, which can be used to move the hydraulic piston pump easily into position, using a crane if required.
Special requirements of the Ticino concrete retaining wall
Two concrete belts 2 metres high, 90 metres long and 50 centimetres deep first had to be created for the top section to ensure that the wall met local requirements. The second concrete belt is located in the lower third of the retaining wall and extends across a width of 75 metres. Thanks to spray technology, the steel wires for the essential strand anchors were also integrated in the concrete belts. Cased bore holes for the strand anchors usually have to be introduced into the sublayer, and the anchors must then be secured in the holes. The holes are then filled with cement mortar while the casing pipe is removed. In Lugano, it was possible to avoid these elaborate working procedures due to the concrete spraying technology used.
Good news from Switzerland: project completed ahead of schedule!
The automated wet spraying equipment used in Lugano was far superior to any conventional concreting solutions due to the interaction between different components such as the spray manipulator, chemical and radio control as well as the powerful Putzmeister P 715 piston pump. With an average concrete delivery rate of 32 m3 per day, it was possible to complete this phase of construction 16 days ahead of schedule and this technique turned out to be much more economical than conventional methods.
The shotcreting work was performed by Putzmeister customer Walter Bohr- und Injektionstechnik from Albruck in Germany, which for many years has relied on the powerful P 715 piston pump from Putzmeister for wet and dry spraying applications involving the spray manipulator. The wet spraying equipment used for the housing development project in Lugano was upgraded with a chemical control and operated wirelessly to allow automated operation of the concrete spraying equipment.
An important link in the automation chain - the Putzmeister P 715
Since the versatile, reliable piston pump is already able to convey material with a grain size of 16 mm over long distances, the 8 mm concrete mix did not pose any real challenge for a machine that boasts a maximum delivery output of 18 m3 per hour and maximum delivery pressure of 68 bar. Rarely pushed to its load limit, the oil-cooled 3-cylinder diesel engine from emission category 3A supplied a continuous flow of material to the spray manipulator attached to the swing arm on the excavator. At 80 metres long and 50 mm in diameter, the hoses posed no problems for the P 715 and resulted in an average concrete delivery rate of 12 m3 per hour. Small, compact dimensions and a low weight make the machine extremely mobile, while the roadworthy T-chassis makes it easy to transport and manoeuvre on the construction site. One particular advantage of the P 715, especially on sites with limited access, is the optional hard-wearing lifting eye, which can be used to move the hydraulic piston pump easily into position, using a crane if required.
Special requirements of the Ticino concrete retaining wall
Two concrete belts 2 metres high, 90 metres long and 50 centimetres deep first had to be created for the top section to ensure that the wall met local requirements. The second concrete belt is located in the lower third of the retaining wall and extends across a width of 75 metres. Thanks to spray technology, the steel wires for the essential strand anchors were also integrated in the concrete belts. Cased bore holes for the strand anchors usually have to be introduced into the sublayer, and the anchors must then be secured in the holes. The holes are then filled with cement mortar while the casing pipe is removed. In Lugano, it was possible to avoid these elaborate working procedures due to the concrete spraying technology used.
Good news from Switzerland: project completed ahead of schedule!
The automated wet spraying equipment used in Lugano was far superior to any conventional concreting solutions due to the interaction between different components such as the spray manipulator, chemical and radio control as well as the powerful Putzmeister P 715 piston pump. With an average concrete delivery rate of 32 m3 per day, it was possible to complete this phase of construction 16 days ahead of schedule and this technique turned out to be much more economical than conventional methods.
