Giv­ing Con­crete a New Life in Oulu

Kier­tokaari is explor­ing var­i­ous ways to uti­lize side streams and waste mate­ri­als. One such activ­i­ty is the pro­duc­tion of con­crete ele­ments that has been ongo­ing for three years. These con­grete ele­ments that resem­ble giant Lego blocks, is not a new inven­tion, but it can replace oth­er con­crete struc­tures, reduc­ing the over­all need for con­crete and oth­er vir­gin mate­ri­als.

Ini­tial­ly, the need for these blocks came from with­in the orga­ni­za­tion. They are used in the Rusko waste man­age­ment cen­ter, for exam­ple as retain­ing walls and to sep­a­rate waste recep­tion areas. Due to increas­ing demand, part of the pro­duc­tion has been sold to com­pa­nies. Cur­rent­ly, cast­ing the blocks employs one per­son full-time.

About 500 blocks are pro­duced each year, and the goal is to increase pro­duc­tion to 1,000–1,500 units, which still requires con­sid­er­able effort. In addi­tion to the blocks, Kier­tokaari is also inves­ti­gat­ing what oth­er prod­ucts could be made from sur­plus con­crete.

Kier­tokaari also par­tic­i­pat­ed in the recent­ly com­plet­ed Ash­Cy­cle project, which involved a total of 27 research orga­ni­za­tions and indus­try part­ners. The project explored ways to uti­lize ash from the incin­er­a­tion of under­used bio­mass, munic­i­pal waste, and sewage sludge. At the same time, valu­able mate­ri­als were recov­ered and new prod­ucts devel­oped. In Fin­land, the focus was on pre­cast con­crete ele­ments and aggre­gates for road base lay­ers. Bot­tom ash was used as one of the com­po­nents in con­crete cast­ing.

Con­crete can also be seen in var­i­ous forms in the cen­ter of Oulu, for exam­ple as ping-pong tables and park bench­es. The Sopuk­ka project, locat­ed in Pik­isaari, aims to trans­form under­uti­lized urban spaces into invit­ing meet­ing places. For exam­ple, Sopuk­ka has used chem­i­cal bar­rels, bricks, ply­wood, and OSB boards at the Top­pi­la Silo to cre­ate dif­fer­ent struc­tures, all sourced through Kier­tokaari. Mate­ri­als can also be pur­chased or rent­ed from Kier­tokaari for use in events. Per­haps we will also see ele­ments made from recy­cled con­crete at events in the future.

One poten­tial indus­tri­al appli­ca­tion for con­crete ele­ments “Lego blocks” could be in wind pow­er and hydro­gen projects.

For more infor­ma­tion con­tact: Jari Kan­gas­nie­mi, jari.kangasniemi@kiertokaari.fi, tel 044 7033 972

Text: Han­nele Ter­vo