Polyurea at the San Siro stadium

Italchimica, an Italian company specialising in synthetic coatings, has waterproofed 13,000 square metres of concrete at the San Siro stadium in Milan using a spray-on MDI-polyurea solution created by Huntsman.
Italchimica's aim was to protect the network of concrete corridors at the stadium prone to extreme wear due to the large influx of football fans and concert-goers. Having to prioritise durability, and to complete the project within a relatively tight deadline, Italchimica had to use a coating system that could be applied quickly but could also have an aesthetically pleasing effect and be sufficiently resistant to thermal and mechanical stress.
The company therefore opted for a spray-on polyurea solution based on the Suprasec 2054 prepolymer, which provides very good tear strength. Before application, Italchimica tested the polyurea in an area of concrete in the stalls. The test proved to be successful. The Company then prepared the corridors for spraying, using an epoxy resin mortar to repair damage in the concrete.  After filling all cracks and holes, the company sprayed on the polyurea solution and applied aliphatic paint to increase the level of durability (which is expected to be between eight and ten years).
"After meeting with the directors of the stadium a number of times, we decided that polyurea was the best choice of coating. There were two deciding factors: aesthetic appearance, and quick drying, so that the surfaces could be treadable relatively soon after application," said Emilio Bargigia, the owner of Italchimica.