Precast Slab Structures Made of Carbon Reinforced Concrete

Carbon reinforced concrete allows a new way to think of and design structural load bearing elements. Two different lightweight load bearing structures were developed, produced and tested at the Technische Universitat (TU) Dresden. The first main structure is a 4.5 m long semi-precast ceiling element, which consists of a 45 mm thick shell in longitudinal direction and two 40 mm thin webs below the shell at the longitudinal edges of the element. A reduction of the dead load up to 70%, compared to a usual rectangular cross section made of common steel reinforcement and the same concrete, could be achieved. The second precast element type is 5.0 m long and has a maximum height of 200 mm. Two versions of this element type - one unstressed and one externally post-tensioned with carbon strips - were produced. Both structures are reinforced with carbon textile and carbon rebars. The required load capacity and deflection stiffness for both precast slab structures with a conventional construction height could be verified and proved by experimental large-scale tests which will be focus of the paper.