Carbon prestressed concrete slabs developed at the ZHAW reveal the high-performance capacity of the material based on the example of a curved bench.

In July 2022, a curved bench made of carbon prestressed concrete (CPC) slabs was set up at the Lagerplatz campus in the centre of Winterthur. Its components were cut out of a flat one-inch thick slab and then assembled by using basic braced plug-in connectors. CPC slabs are reinforced with carbon instead of steel, and they can be bent by pretensioning them. A slow bending process makes fine cracks appear on the material’s surface in a deliberate and controlled procedure. The slabs become softer, and the bending radius can be gradually reduced without impacting their load-bearing capacity and durability. Last but not least, the curved bench is held in shape and stabilised by two CPC wedges.

Rust-proof and recyclable, strong yet lightweight

In addition to being rust-proof, CPC slabs are strong yet lightweight. They are industrially manufactured and can be formed into any shape. The production of CPC slabs requires less material compared to regular concrete slabs. Construction of CPC slabs is as cost effective as producing steel-concrete, since it requires 80% less carbon than regular carbon concrete slabs. The materials can be easily dismantled and reused thanks to the mechanical plug-in connectors. CPC slabs were developed by the Fiber-Reinforced Plastics section at the ZHAW School of Architecture, Design and Civil Engineering in collaboration with Silidur AG. For several years, CPC slabs have been successfully used as construction material for bridges, balconies and other structures.