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Hybrid composite rods, comprised of unidirectional reinforcing carbon/glass-fiber and adhesive epoxy matrix, are viewed as promising candidates to be used in high-voltage overhead conductors. However, before widespread application, their long-term durability needs to be clarified. In this study, accelerated creep testing for hybrid composite rods, is presented by taking dynamic mechanical analysis tests at different temperatures. Using the time-temperature superposition principle and thermal activation energy theory, the short-term creep data are combined to generate creep long-term compliance master curves. Through the master curve, predictions can be made concerning the creep levels that will occur during the design lifetime of hybrid composite rods (i.e., 30 years). It is found that after 30-year service at 120 °C, fully-cured hybrid composite rods only exhibit a slight increase in compliance (about 5%), indicating a satisfactory creep resistance at this temperature.

Five carbon-carbon composites were prepared with different fibre orientations in the preform and were densified by different methods. Their ablation behaviour was examined by an oxy-acetylene test and scanning electron microscopy. The densities of the composites were in the range of 1.77 to 1.85 g/cm 3 . Fibres having an angle of 30° with the oxy-acetylene flame turned into a sharp wedge shape, whereas fibres parallel to the flame had a needle-like shape with diameter up to 3.5–4.5 μm after ablation. The needled fibres were easily attacked and ultimately became blunt. Partially filled macropores with sizes of 1.0–1.26 mm, needle pores, interfacial cracks and gaps in non-woven cloth were easily attacked by the flame, resulting in macroscopic ablation pits that decreased with increasing density of the composites. The needled fibres around pitch carbon layers were severely denuded due to their discontinuity with the pyrolytic carbon matrix. A high density (1.85 g/cm 3 ) composite had an excellent ablation resistance.