Bitumen is used as anticorrosion material to protect armor wires in subsea cables and umbilicals. Establishing bitumen’s viscoelastic properties is essential for developing analytical models of how bitumen influences the cable’s mechanical properties, in particular the bending stiffness. A new laboratory instrument has been developed for establishing the viscoelastic properties of bitumen subject to equally large strains as in real-life cables. This paper presents the basic principle of the new instrument and derives how to calculate bitumen’s viscoelastic properties from the measurements logged by the instrument. The paper also models bitumen’s viscoelastic properties as function of strain amplitude, strain frequency, and bitumen temperature, using multi-variable data analysis. These models show that the viscoelastic properties are highly temperature dependent. Bitumen’s shear stress / shear strain amplitude ratio grows with increasing rate as the temperature decreases.

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