The University of British Columbia initiated the upgrade of this structure to meet current building design code, and Southwest Contracting Ltd. was selected to prepare existing concrete and to apply shotcrete.

Structural Shotcrete Applications

• Permanent foundation walls
• Seismic retrofitting
• Tunnel support

Factors Influencing the Choice of Shotcrete

1. Access: Less restrictive access of equipment than cast-in-place methods
2. Preparation: Less forming, if any
3. Secondary Reinforcement: Mesh-reinforced, steel fiber-reinforced and/or synthetic fiber-reinforced
4. Placement to surfaces on any angle
5. Longer stand up time compared to wet mix concrete
6. Increasing formwork costs

First, the interior was demolished back to the original 20MPa concrete walls, holding the exterior cracked face granite stone. SWC then prepared the walls, beams and column surfaces by water blasting to >5000 psi.

Wet shotcrete was applied up to 90 ft above the ground. Unique formwork creativity saved significant time and costs.