STRUCTURAL STRENGTHENING FOR FLOORS
When horizontal structures need to be strengthened, it is often necessary to use thin layers of light, pourable mortar that work actively with the screed. This was the precise rationale behind Mapei’s R&D labs developing Planitop HPC Floor, a fiber-reinforced, free-flowing cementitious mortar that is highly ductile and extremely strong. The secret to the formula lies in the carefully chosen, highly resistant cement, selected aggregates, special admixtures and stiff steel fibers. Compared to traditional concrete solutions, Planitop HPC Floor is lighter and thinner, applied in layers of 1.5 to 3 cm, meaning the overall weight is reduced. The structural steel fibers provide a sort of widespread reinforcement, so a traditional metal grid is not required, which cuts building time and costs. Where floors already have a layer of structural screed, Planitop HPC Floor’s excellent adhesion on concrete means metallic joints are not necessary. The Gregorianum Complex at Milan’s Catholic University was recently given an earthquake upgrade, with the concrete partition walls reinforced using FRP fabrics and the upper surfaces of the floors strengthened. After testing the floors, it was decided the best approach was to clean and then roughen the structure before applying a layer of Primer 3296. After shoring up the structure using metal rods fixed with Mapefix EP 385, a 2.5 cm cast of Planitop HPC Floor was used. The real benefits of this mortar are ease of use and speed of application. It is also light, thin and versatile as it can be used on floors made of masonry and brickwork, wood or mixed brickwork and H-beams.