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Carbon Fibre Ultra-High Performance Concrete (C-UHPFRC) – Workability and Structural Behaviour of a Novel Fibre Reinforced Concrete

Unewisse, Leon / Strotmann, Andre / Jungwirth, Jörg

Abstract

Carbon Fibre Reinforced Ultra-High Performance Concrete (C-UHPFRC) is an innovative composite material, notable for its strength properties and the formation of fine multi-cracks. Non-metallic fibres in combination with UHPC offer advantages such as better surface properties and the absence of corrosion. Furthermore, they enable a more sustainable replacement for steel fibres.

In cooperation with the industrial partners Implenia, KIBAG and newcycle, the University of Applied Sciences Munich (MUAS) conducted comprehensive laboratory tests regarding both rheological and mechanical properties. The study delves into a wide range of parameters, offering a thorough understanding of C-UHPFRC. The main emphasis was on the bending behaviour, with complementary investigations on compressive strength and Young’s modulus.

The data analysis allows a comparison of various mix designs and highlights what the authors have identified as the limiting values for workability and critical fibre quantities for mechanical properties. These findings are based on interpretation of the data, framed within the context of this study’s objectives. Specimens that are over-critically reinforced with fibres show evidence of multi-cracking. An inspection for strain hardening behaviour was conducted based on the stress distribution approach of Swiss standard SIA2052. This property could initially not be proven, hence it is recommended to verify the applicability of the assumed stress distribution to carbon fibre-reinforced UHPC without further adjustments. Finally, the data obtained is classified according to SIA2052.

The data from the systematic investigation is used to identify potential application scenarios, aiming to utilise the novel concrete technology to develop new and improved applications in civil engineering.