80 year old Concrete Augmented with Modern Technology

Client: Go Transit, City of Toronto

Where: Toronto, ON M5J 1E6

The Task: Expand Canada’s largest, multi-modal hub to accommodate 90 million passengers (70 million currently). Create a destination, commercial retail hub. Preserve the character of National Historic Site. Maintain passenger access at all times.

The Solution: Add the equivalent of 1 million sq ft by Digging Down

What We Did: Duron’s skilled waterproofers installed CoreFlex 60 over the graded and compacted clear stone. The seams of the Coreflex 60 were all heat welded and thousands of penetrations were booted and clamped using various details. Once waterproofing was complete, a layer of Voltex was laid on top for protection. CoreFlex 60 was terminated at all column extensions and over 100 rebar penetrations per column were also welded, booted, clamped and sealed creating a watertight termination. A shotcrete smoothing layer was used on the rock face walls. Waterproofing was then installed directly to the shotcrete. Coreflex 60 was then fastened to the wall and welded in an offset seam to create a fully welded membrane. The walls had thousands of penetrations including form ties, rebar anchors, and tie backs. All details were meticulously detailed to ensure no weak locations for water ingress.

Challenges: Access and egress of waterproofing material & equipment down to the work area required pre-planning and co-ordination due to the site location. There were numerous water issues throughout construction, poor lighting and inadequate electricity. There were daily mobilizations and other contractors running equipment on the waterproofing daily.

This work received the SWA’s Inaugural Trillium Award