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Application of Planitop HDM Maxi high-ductility pozzolan-reaction, fibre-reinforced mortar. Application of MapeWrap C Fiocco carbon fibre cord. Application depth-check for Heatlok Soya HFO. M A R C H 2 0 2 3 | 17 Restoration Products & Services P H OTO G R A P H Y CO U RT E S Y M A P EI I N C .; H U N T S M A N B U I L D I N G S O LU T I O N S The wide range of innovative restoration products facilitate the move from old to new by ROBIN BRUNET T he steady deterioration of all man-made things, and how to restore them, takes up a huge portion of construction activity in Canada, and this focus continues to drive the development of a vast array of products, as well as the skill needed to restore buildings and infrastructure. A recent prime example was Mapei's involvement in restoring the top floors of McGill University's Strathcona Music Building, constructed in 1896 and whose upper levels had suffered internally over the generations from winds and seismic forces. Hamza Ouziame, Mapei engineering and architectural sales representative, says when he and Mapei S.p.A. (Italy) consultant Luca Albertario inspected Strathcona's interior walls in the spring of 2022, they found they were composed of terracotta bricks dating from the 19th century – and badly needed extra strengthening. "The engineers were looking for a fibre-reinforced polymer [FRP] solution, but FRP would not allow for the breathability of the masonry," he recalls. "So, we used a fibre-reinforced cementitious matrix [FRCM] option designed for masonry." The restoration was undertaken with Mapegrid G 220, an alkali-resistant, glass fibre mesh, set with Planitop HDM Maxi high-ductility pozzolan-reaction, fibre-reinforced mortar. When applied on masonry structures, Mapegrid G 220 makes up for their lack of tensile strength and increases their overall ductility so that stresses are distributed more evenly. The system adheres perfectly to the substrate and its mechanical properties are such that localized stresses always provoke a failure in the substrate rather than at the substrate/strengthening system interface. "Mapegrid G 220 was the main product, but it required a matrix," Ouziame says. "The Planitop HDM Maxi mortar is compatible with masonry, allowing breathability. It has a low modulus of elasticity, and together with its moderate compressive strength the products combine to work better with masonry than an FRP system." MapeWrap C Fiocco carbon fibre cord was added to assist the long-term bond of the system for the interior. "After preparing the substrate, FRCM adhered strongly to the masonry substrate with no need for transfer connectors," Ouziame says. "We used mechanical connectors MapeWrap C Fiocco, because we were strengthening the wall from one side of the building." Ouziame adds: "Heritage buildings in Montreal, Ottawa, Toronto, Quebec City, and elsewhere that need structural strengthening will benefit greatly from this FRCM system solution." Huntsman Building Solutions' Heatlok Soya HFO has been used on a host of building envelope retrofits in 2022, including the low-income project Habitations Jeanne-Mance in Montreal. As for trends, Maxime Duzyk, Huntsman's global director, building science and engineering, says, "We are seeing more projects changing the insulation systems for under slab applica- tions to spray foam. Also, the D-Max wall assembly is getting a lot of traction both with architects and general contractors because it's the perfect solution to meet energy efficiency requirements, while increasing productivity on site." Revive, Refresh, Renew Duzyk goes on to note, "Retrofit projects are often complicated and the sur- face upon which products are to be applied is often uneven. Heatlok Soya HFO is an ideal solution for retrofits because the product provides air/vapour barrier properties as well as insulation. The fact that the insulation value per inch is one of the highest also solves a lot of issues with retrofits where the space to insulate is not always enough to meet new requirements with other insulation products. "Also, foundations are more commonly retrofitted by the exterior, because you can insulate and waterproof them at the same time. Heatlok Soya HFO is the perfect solution to retrofit old foundations from the exterior, and in cases when the water table is high a Polyurea membrane is the best solution for waterproof- ing and can be applied directly to the spray foam. This provides a high quality assembly that can resist both heat transfer and water infiltration."

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