We designed a modular stair system made of ultra-high-performance fiber-reinforced concrete. One module is composed by one step. The assembly between the modules is realised by four post-tensioned cables through the stringers.
To deal with the fabrication constraints and the material performances, we worked on a sheet-based-shape, the thinner as possible, that we bend and fold to draw the steps the two stringers and the risers. The stair geometry is composed of developable surfaces to make the formwork base easily replaceable.