The load-deformation characteristics and the capacity of prestressed concrete T and double T elements were analysed with the finite element method using DIANA’s total strain based constitutive model. The numerical simulations accompanied two experimental programs. The first program concerned old bridge beam elements strengthened with carbon fiber reinforced polymer plates. The second program concerned beam elements without shear reinforcement. The non-linear behaviour of concrete was considered in both tension and compression including the influence of lateral cracking on the compressive strength. The elastoplastic material behaviour of the prestressing steel was also taken into account. Predicted and measured load-deformation responses showed good agreement.