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ferdam, which allowed the shotcrete nozzleman rial. Approximately 350 to 2205 lb (1000 kg) bulk to maintain the proper distance 3 to 5 ft (0.9 to bags were used on the project (Fig. 7). 1.5 m) from the end of the nozzle to the receiving A line wire was used by the Béton projeté surface. Once placement and finishing was com- MAH Inc. crews to maintain the same thickness plete, the portable cofferdam would be moved to and surface profile as the existing concrete. Once the next section while skipping the section an area was shot, the crew cut off any excess directly beside to be able to be anchored into shotcrete, ensuring the area was plumb and level existing concrete and not the fresh shotcrete. with the existing concrete. A mechanical spin- The flexibility of the dry-mix shotcrete process ning trowel was used for the rough finish and allowed Béton projeté MAH Inc. to set up the then a magnesium trowel for the final finish. machine on solid ground in areas that gave them Once the shotcrete reached its initial set, the access to a forklift and enough room to man- dewatering pumps were shut off to re-submerge euver the 2205 lb (1000kg) bulk bags. On the repair and maintain ideal curing conditions average, they required approximately 250 to (Fig. 8). 300 ft (76 to 91.5 m) of hose to access the work The cooperation between the general con- area. With the repair areas in most cases sub- tractor (BBMarine), the shotcrete contractor merged, the receiving area was always saturated, (Béton projeté MAH Inc.), and the material and which helped to ensure a strong and durable bond equipment supplier (King Shotcrete Solutions) between the parent concrete and the repair mate- resulted in an extremely successful project with the end result being a satisfied owner (Société en Commandite Hydroélectrique Manicouagan). The success of this project will no doubt result in more opportunities in which shotcrete will play a vital role in the marine infrastructure rehabili- tation market in la Côte-Nord (Fig. 9 and 10). Roger Côté, Eng., is the Director of Engineering for BBMarine. His area of expertise includes ap- plication and design equipment for concrete rehabilitation. Harold Ferland is the co-owner of Béton projeté MAH Inc., a Fig. 5: Mobile cofferdam set up company that has been doing only shotcrete work for 14 years throughout Canada. Ferland is an ACI Certified Nozzleman for dry- and wet-mix shotcrete (overhead and vertical). He has been in the shotcrete industry for 29 years. Kevin Robertson is a Techni- cal Sales Representative for King Shotcrete Solutions, Bois- briand, QC, Canada. His areas ofexpertiseincludeshotcrete materials,application,and equipment, focused mainly on concrete rehabilitation appli- cations. Robertson is a member of ASA, the American Concrete Institute (ACI), and is on the Board of Directors of the Quebec Province Chapter of the International Concrete Repair Institute (ICRI). Fig. 6: Nozzleman shooting in mobile cofferdam system 38 Shotcrete • Winter 2015


2015WinterShotcreteEMag
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