Sydney Harbour Tunnel

Commencing in September of 1991, repair systems using Xypex Concentrate and Patch’n Plug were used as part of an ongoing program of repair and maintenance of the North and South land driven tunnels and transition tunnels of this renown structure.

Xypex products were selected ahead of some 52 others to repair the extensive cracking that has occurred.

Xypex technology was chosen primarily because of it’s unique ability to be applied from the negative pressure side of water affected structures.

Extensive crack repair was undertaken using Xypex after other products failed to stop water seepage. Xypex products are applied firstly to shut down the water flow.  Repair systems are then installed, giving rise to Xypex crystal growth through the entire depth of the structure, strengthening and waterproofing the concrete as well as protecting the rebar in the repair area. Two work crews spent three months in the tunnel using both Xypex Patch’n Plug and Concentrate to stop leaks.