De Realtà Mapei n.° 34 - 9/28/2021
MAPEI helps deliver mass transit for all seasons
VivaNext is a major bus transit expansion project stretching across the north of Canada’s largest metropolitan area, and into Toronto’s downtown core at the shore of Lake Ontario. With dedicated bus lanes and large attractive passenger terminals, it is meant to entice more use of public transit, thus reducing reliance on automobiles.
Building external infrastructure in this geographical area always poses a unique challenge, as the region experiences one of the larger seasonal temperature differentials to be found anywhere – from its lowest winter temperature of -27°F (-33°C) to its highest summertime high of 105°F (40.6°C). The contractor, Belluz Group, was tasked with finding a proven solution that would withstand installation through the freeze/thaw cycles of the different seasons, while providing durability and waterproofing assurance.
Further, covering the Highway 7 line and Yonge Street, the area to be constructed totaled approximately 75,000 sq. ft. (6 968 m²).
Ultimately, it was delivered three months ahead of schedule. The story of that accomplishment is one of close cooperation between contractor and manufacturer. It is a story of Belluz and MAPEI.
Belluz Group’s Paul Belluz was seeking high-performance products that could be applied on a tight schedule, plus meet the specific needs for installation during the winter months. Product choices had to be as flexible as the weather. “We knew we’d need to tarp the site in winter,” Paul Belluz noted. “We knew MAPEI quality, and we knew we could rely on MAPEI Technical Services.”
MAPEI products on site
The roadside platforms’ mortar bed foundations were laid using Topcem Premix (accelerated-cure screed) with Planicrete AC (acrylic latex admixture for mortar) where site conditions allowed. For specialized conditions, they instead chose Mapecem 202, a shrinkage-compensated, polymer-modified, fast-setting cementitious mortar with a corrosion inhibitor. This portion of the work was completed using Mapecem Quickpatch, primarily as gap filler, to provide continuous sloping for run-off.
Once surface preparation of the on-ground concrete was done, the exterior specifications called for a good waterproofing barrier and tile shell. Along with MAPEI’s Fiberglass Mesh, the Belluz Group crew installed Mapelastic 315 trowel-applied, flexible, fiber-mesh-reinforced waterproofing and crack-isolation membrane, which exceeds ANSI A118.10 requirements, for waterproofing.
Flexibility needs informed the choice of mortar as well. To facilitate installation that wouldn’t be hampered by extreme weather conditions, tiling was completed using MAPEI Ultralite S2 premium, highly deformable, lightweight, gauged-tile mortar with polymer, formulated with Easy Glide Technology™ for ease of application. MAPEI Ultralite S2 features a long open time and superior transfer properties to enhance back-buttering – all of which made it possible for installation crews to maximize their efficiency despite working in challenging weather conditions.
The need for a quick turnaround influenced the choice for grouting. MAPEI’s Ultracolor Plus FA was selected, where appropriate, for its rapid-setting properties and for its DropEffect™ technology, which reduces surface absorption and helps repel water, dirt and grime from penetrating grout joints.
For portions calling for cast-iron tiles, they used Planigrout 712 non-shrinking, non-metallic grout with corrosion inhibitor and silica fume, which provides superior resistance to water penetration, freeze/thaw cycles and de-icing salts. It also provides exceptional placing and performance characteristics, and here was coupled with Planibond EBA as its nonshrink, moisture-tolerant epoxy bonding agent.
The completed work on this site is just one piece of a major infrastructure build for VivaNext. With over 40 platforms, it is designed to tie into the Metrolinx Light Rail Transit (LRT) network, with 25 terminals planned across Eglington Avenue. This will all help move traffic seamlessly throughout Toronto. Aided by the scope of reliable MAPEI products, all formulated to meet the specific needs of any construction job in any season, the future of Toronto’s mass transit should be on track and on time.