Experimental
work has been undertaken to assess the nature of water, salt water and concrete
pore solution uptake,
and corresponding
swelling effects, in Carbon Fibre
Reinforced Polymer tendons. A method is presented to predict the long-term
diffusion
behaviour of aqueous solutions in CFRP tendons using short-term tests
and Fickian models. Year long uptake tests have shown Fickian diffusive
behaviour that is insensitive to the solution types considered. After one year,
tendon mass and volume increases in the order of 0.3 % and 0.5 % respectively
have been observed and the two phenomena appear to increase proportionally with
respect to each other. Compared to thermal expansion effects, such swelling may
be significant: potentially affecting the integrity of prestressed concrete
structures.